xnu-6153.81.5.tar.gz

[apple/xnu.git] / osfmk / kern / task_policy.c

/*
 * Copyright (c) 2000-2016 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 *
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */

#include <kern/policy_internal.h>
#include <mach/task_policy.h>

#include <mach/mach_types.h>
#include <mach/task_server.h>

#include <kern/host.h>                  /* host_priv_self()        */
#include <mach/host_priv.h>             /* host_get_special_port() */
#include <mach/host_special_ports.h>    /* RESOURCE_NOTIFY_PORT    */
#include <kern/sched.h>
#include <kern/task.h>
#include <mach/thread_policy.h>
#include <sys/errno.h>
#include <sys/resource.h>
#include <machine/limits.h>
#include <kern/ledger.h>
#include <kern/thread_call.h>
#include <kern/sfi.h>
#include <kern/coalition.h>
#if CONFIG_TELEMETRY
#include <kern/telemetry.h>
#endif
#if CONFIG_EMBEDDED
#include <kern/kalloc.h>
#include <sys/errno.h>
#endif /* CONFIG_EMBEDDED */

#if IMPORTANCE_INHERITANCE
#include <ipc/ipc_importance.h>
#if IMPORTANCE_TRACE
#include <mach/machine/sdt.h>
#endif /* IMPORTANCE_TRACE */
#endif /* IMPORTANCE_INHERITACE */

#include <sys/kdebug.h>

/*
 *  Task Policy
 *
 *  This subsystem manages task and thread IO priority and backgrounding,
 *  as well as importance inheritance, process suppression, task QoS, and apptype.
 *  These properties have a suprising number of complex interactions, so they are
 *  centralized here in one state machine to simplify the implementation of those interactions.
 *
 *  Architecture:
 *  Threads and tasks have two policy fields: requested, effective.
 *  Requested represents the wishes of each interface that influences task policy.
 *  Effective represents the distillation of that policy into a set of behaviors.
 *
 *  Each thread making a modification in the policy system passes a 'pending' struct,
 *  which tracks updates that will be applied after dropping the policy engine lock.
 *
 *  Each interface that has an input into the task policy state machine controls a field in requested.
 *  If the interface has a getter, it returns what is in the field in requested, but that is
 *  not necessarily what is actually in effect.
 *
 *  All kernel subsystems that behave differently based on task policy call into
 *  the proc_get_effective_(task|thread)_policy functions, which return the decision of the task policy state machine
 *  for that subsystem by querying only the 'effective' field.
 *
 *  Policy change operations:
 *  Here are the steps to change a policy on a task or thread:
 *  1) Lock task
 *  2) Change requested field for the relevant policy
 *  3) Run a task policy update, which recalculates effective based on requested,
 *     then takes a diff between the old and new versions of requested and calls the relevant
 *     other subsystems to apply these changes, and updates the pending field.
 *  4) Unlock task
 *  5) Run task policy update complete, which looks at the pending field to update
 *     subsystems which cannot be touched while holding the task lock.
 *
 *  To add a new requested policy, add the field in the requested struct, the flavor in task.h,
 *  the setter and getter in proc_(set|get)_task_policy*,
 *  then set up the effects of that behavior in task_policy_update*. If the policy manifests
 *  itself as a distinct effective policy, add it to the effective struct and add it to the
 *  proc_get_effective_task_policy accessor.
 *
 *  Most policies are set via proc_set_task_policy, but policies that don't fit that interface
 *  roll their own lock/set/update/unlock/complete code inside this file.
 *
 *
 *  Suppression policy
 *
 *  These are a set of behaviors that can be requested for a task.  They currently have specific
 *  implied actions when they're enabled, but they may be made customizable in the future.
 *
 *  When the affected task is boosted, we temporarily disable the suppression behaviors
 *  so that the affected process has a chance to run so it can call the API to permanently
 *  disable the suppression behaviors.
 *
 *  Locking
 *
 *  Changing task policy on a task takes the task lock.
 *  Changing task policy on a thread takes the thread mutex.
 *  Task policy changes that affect threads will take each thread's mutex to update it if necessary.
 *
 *  Querying the effective policy does not take a lock, because callers
 *  may run in interrupt context or other place where locks are not OK.
 *
 *  This means that any notification of state change needs to be externally synchronized.
 *  We do this by idempotent callouts after the state has changed to ask
 *  other subsystems to update their view of the world.
 *
 * TODO: Move all cpu/wakes/io monitor code into a separate file
 * TODO: Move all importance code over to importance subsystem
 * TODO: Move all taskwatch code into a separate file
 * TODO: Move all VM importance code into a separate file
 */

/* Task policy related helper functions */
static void proc_set_task_policy_locked(task_t task, int category, int flavor, int value, int value2);

static void task_policy_update_locked(task_t task, task_pend_token_t pend_token);
static void task_policy_update_internal_locked(task_t task, boolean_t in_create, task_pend_token_t pend_token);

/* For attributes that have two scalars as input/output */
static void proc_set_task_policy2(task_t task, int category, int flavor, int value1, int value2);
static void proc_get_task_policy2(task_t task, int category, int flavor, int *value1, int *value2);

static boolean_t task_policy_update_coalition_focal_tasks(task_t task, int prev_role, int next_role, task_pend_token_t pend_token);

static uint64_t task_requested_bitfield(task_t task);
static uint64_t task_effective_bitfield(task_t task);

/* Convenience functions for munging a policy bitfield into a tracepoint */
static uintptr_t trequested_0(task_t task);
static uintptr_t trequested_1(task_t task);
static uintptr_t teffective_0(task_t task);
static uintptr_t teffective_1(task_t task);

/* CPU limits helper functions */
static int task_set_cpuusage(task_t task, uint8_t percentage, uint64_t interval, uint64_t deadline, int scope, int entitled);
static int task_get_cpuusage(task_t task, uint8_t *percentagep, uint64_t *intervalp, uint64_t *deadlinep, int *scope);
static int task_enable_cpumon_locked(task_t task);
static int task_disable_cpumon(task_t task);
static int task_clear_cpuusage_locked(task_t task, int cpumon_entitled);
static int task_apply_resource_actions(task_t task, int type);
static void task_action_cpuusage(thread_call_param_t param0, thread_call_param_t param1);

#ifdef MACH_BSD
typedef struct proc *   proc_t;
int                     proc_pid(void *proc);
extern int              proc_selfpid(void);
extern char *           proc_name_address(void *p);
extern char *           proc_best_name(proc_t proc);

extern int proc_pidpathinfo_internal(proc_t p, uint64_t arg,
    char *buffer, uint32_t buffersize,
    int32_t *retval);
#endif /* MACH_BSD */


#if CONFIG_EMBEDDED
/* TODO: make CONFIG_TASKWATCH */
/* Taskwatch related helper functions */
static void set_thread_appbg(thread_t thread, int setbg, int importance);
static void add_taskwatch_locked(task_t task, task_watch_t * twp);
static void remove_taskwatch_locked(task_t task, task_watch_t * twp);
static void task_watch_lock(void);
static void task_watch_unlock(void);
static void apply_appstate_watchers(task_t task);

typedef struct task_watcher {
        queue_chain_t   tw_links;       /* queueing of threads */
        task_t          tw_task;        /* task that is being watched */
        thread_t        tw_thread;      /* thread that is watching the watch_task */
        int             tw_state;       /* the current app state of the thread */
        int             tw_importance;  /* importance prior to backgrounding */
} task_watch_t;

typedef struct thread_watchlist {
        thread_t        thread;         /* thread being worked on for taskwatch action */
        int             importance;     /* importance to be restored if thread is being made active */
} thread_watchlist_t;

#endif /* CONFIG_EMBEDDED */

extern int memorystatus_update_priority_for_appnap(proc_t p, boolean_t is_appnap);

/* Importance Inheritance related helper functions */

#if IMPORTANCE_INHERITANCE

static void task_importance_mark_live_donor(task_t task, boolean_t donating);
static void task_importance_mark_receiver(task_t task, boolean_t receiving);
static void task_importance_mark_denap_receiver(task_t task, boolean_t denap);

static boolean_t task_is_marked_live_importance_donor(task_t task);
static boolean_t task_is_importance_receiver(task_t task);
static boolean_t task_is_importance_denap_receiver(task_t task);

static int task_importance_hold_internal_assertion(task_t target_task, uint32_t count);

static void task_add_importance_watchport(task_t task, mach_port_t port, int *boostp);
static void task_importance_update_live_donor(task_t target_task);

static void task_set_boost_locked(task_t task, boolean_t boost_active);

#endif /* IMPORTANCE_INHERITANCE */

#if IMPORTANCE_TRACE
#define __imptrace_only
#else /* IMPORTANCE_TRACE */
#define __imptrace_only __unused
#endif /* !IMPORTANCE_TRACE */

#if IMPORTANCE_INHERITANCE
#define __imp_only
#else
#define __imp_only __unused
#endif

/*
 * Default parameters for certain policies
 */

int proc_standard_daemon_tier = THROTTLE_LEVEL_TIER1;
int proc_suppressed_disk_tier = THROTTLE_LEVEL_TIER1;
int proc_tal_disk_tier        = THROTTLE_LEVEL_TIER1;

int proc_graphics_timer_qos   = (LATENCY_QOS_TIER_0 & 0xFF);

const int proc_default_bg_iotier  = THROTTLE_LEVEL_TIER2;

/* Latency/throughput QoS fields remain zeroed, i.e. TIER_UNSPECIFIED at creation */
const struct task_requested_policy default_task_requested_policy = {
        .trp_bg_iotier = proc_default_bg_iotier
};
const struct task_effective_policy default_task_effective_policy = {};

/*
 * Default parameters for CPU usage monitor.
 *
 * Default setting is 50% over 3 minutes.
 */
#define         DEFAULT_CPUMON_PERCENTAGE 50
#define         DEFAULT_CPUMON_INTERVAL   (3 * 60)

uint8_t         proc_max_cpumon_percentage;
uint64_t        proc_max_cpumon_interval;


kern_return_t
qos_latency_policy_validate(task_latency_qos_t ltier)
{
        if ((ltier != LATENCY_QOS_TIER_UNSPECIFIED) &&
            ((ltier > LATENCY_QOS_TIER_5) || (ltier < LATENCY_QOS_TIER_0))) {
                return KERN_INVALID_ARGUMENT;
        }

        return KERN_SUCCESS;
}

kern_return_t
qos_throughput_policy_validate(task_throughput_qos_t ttier)
{
        if ((ttier != THROUGHPUT_QOS_TIER_UNSPECIFIED) &&
            ((ttier > THROUGHPUT_QOS_TIER_5) || (ttier < THROUGHPUT_QOS_TIER_0))) {
                return KERN_INVALID_ARGUMENT;
        }

        return KERN_SUCCESS;
}

static kern_return_t
task_qos_policy_validate(task_qos_policy_t qosinfo, mach_msg_type_number_t count)
{
        if (count < TASK_QOS_POLICY_COUNT) {
                return KERN_INVALID_ARGUMENT;
        }

        task_latency_qos_t ltier = qosinfo->task_latency_qos_tier;
        task_throughput_qos_t ttier = qosinfo->task_throughput_qos_tier;

        kern_return_t kr = qos_latency_policy_validate(ltier);

        if (kr != KERN_SUCCESS) {
                return kr;
        }

        kr = qos_throughput_policy_validate(ttier);

        return kr;
}

uint32_t
qos_extract(uint32_t qv)
{
        return qv & 0xFF;
}

uint32_t
qos_latency_policy_package(uint32_t qv)
{
        return (qv == LATENCY_QOS_TIER_UNSPECIFIED) ? LATENCY_QOS_TIER_UNSPECIFIED : ((0xFF << 16) | qv);
}

uint32_t
qos_throughput_policy_package(uint32_t qv)
{
        return (qv == THROUGHPUT_QOS_TIER_UNSPECIFIED) ? THROUGHPUT_QOS_TIER_UNSPECIFIED : ((0xFE << 16) | qv);
}

#define TASK_POLICY_SUPPRESSION_DISABLE  0x1
#define TASK_POLICY_SUPPRESSION_IOTIER2  0x2
#define TASK_POLICY_SUPPRESSION_NONDONOR 0x4
/* TEMPORARY boot-arg controlling task_policy suppression (App Nap) */
static boolean_t task_policy_suppression_flags = TASK_POLICY_SUPPRESSION_IOTIER2 |
    TASK_POLICY_SUPPRESSION_NONDONOR;

kern_return_t
task_policy_set(
        task_t                                  task,
        task_policy_flavor_t    flavor,
        task_policy_t                   policy_info,
        mach_msg_type_number_t  count)
{
        kern_return_t           result = KERN_SUCCESS;

        if (task == TASK_NULL || task == kernel_task) {
                return KERN_INVALID_ARGUMENT;
        }

        switch (flavor) {
        case TASK_CATEGORY_POLICY: {
                task_category_policy_t info = (task_category_policy_t)policy_info;

                if (count < TASK_CATEGORY_POLICY_COUNT) {
                        return KERN_INVALID_ARGUMENT;
                }

#if CONFIG_EMBEDDED
                /* On embedded, you can't modify your own role. */
                if (current_task() == task) {
                        return KERN_INVALID_ARGUMENT;
                }
#endif

                switch (info->role) {
                case TASK_FOREGROUND_APPLICATION:
                case TASK_BACKGROUND_APPLICATION:
                case TASK_DEFAULT_APPLICATION:
                        proc_set_task_policy(task,
                            TASK_POLICY_ATTRIBUTE, TASK_POLICY_ROLE,
                            info->role);
                        break;

                case TASK_CONTROL_APPLICATION:
                        if (task != current_task() || task->sec_token.val[0] != 0) {
                                result = KERN_INVALID_ARGUMENT;
                        } else {
                                proc_set_task_policy(task,
                                    TASK_POLICY_ATTRIBUTE, TASK_POLICY_ROLE,
                                    info->role);
                        }
                        break;

                case TASK_GRAPHICS_SERVER:
                        /* TODO: Restrict this role to FCFS <rdar://problem/12552788> */
                        if (task != current_task() || task->sec_token.val[0] != 0) {
                                result = KERN_INVALID_ARGUMENT;
                        } else {
                                proc_set_task_policy(task,
                                    TASK_POLICY_ATTRIBUTE, TASK_POLICY_ROLE,
                                    info->role);
                        }
                        break;
                default:
                        result = KERN_INVALID_ARGUMENT;
                        break;
                } /* switch (info->role) */

                break;
        }

/* Desired energy-efficiency/performance "quality-of-service" */
        case TASK_BASE_QOS_POLICY:
        case TASK_OVERRIDE_QOS_POLICY:
        {
                task_qos_policy_t qosinfo = (task_qos_policy_t)policy_info;
                kern_return_t kr = task_qos_policy_validate(qosinfo, count);

                if (kr != KERN_SUCCESS) {
                        return kr;
                }


                uint32_t lqos = qos_extract(qosinfo->task_latency_qos_tier);
                uint32_t tqos = qos_extract(qosinfo->task_throughput_qos_tier);

                proc_set_task_policy2(task, TASK_POLICY_ATTRIBUTE,
                    flavor == TASK_BASE_QOS_POLICY ? TASK_POLICY_BASE_LATENCY_AND_THROUGHPUT_QOS : TASK_POLICY_OVERRIDE_LATENCY_AND_THROUGHPUT_QOS,
                    lqos, tqos);
        }
        break;

        case TASK_BASE_LATENCY_QOS_POLICY:
        {
                task_qos_policy_t qosinfo = (task_qos_policy_t)policy_info;
                kern_return_t kr = task_qos_policy_validate(qosinfo, count);

                if (kr != KERN_SUCCESS) {
                        return kr;
                }

                uint32_t lqos = qos_extract(qosinfo->task_latency_qos_tier);

                proc_set_task_policy(task, TASK_POLICY_ATTRIBUTE, TASK_BASE_LATENCY_QOS_POLICY, lqos);
        }
        break;

        case TASK_BASE_THROUGHPUT_QOS_POLICY:
        {
                task_qos_policy_t qosinfo = (task_qos_policy_t)policy_info;
                kern_return_t kr = task_qos_policy_validate(qosinfo, count);

                if (kr != KERN_SUCCESS) {
                        return kr;
                }

                uint32_t tqos = qos_extract(qosinfo->task_throughput_qos_tier);

                proc_set_task_policy(task, TASK_POLICY_ATTRIBUTE, TASK_BASE_THROUGHPUT_QOS_POLICY, tqos);
        }
        break;

        case TASK_SUPPRESSION_POLICY:
        {
#if CONFIG_EMBEDDED
                /*
                 * Suppression policy is not enabled for embedded
                 * because apps aren't marked as denap receivers
                 */
                result = KERN_INVALID_ARGUMENT;
                break;
#else /* CONFIG_EMBEDDED */

                task_suppression_policy_t info = (task_suppression_policy_t)policy_info;

                if (count < TASK_SUPPRESSION_POLICY_COUNT) {
                        return KERN_INVALID_ARGUMENT;
                }

                struct task_qos_policy qosinfo;

                qosinfo.task_latency_qos_tier = info->timer_throttle;
                qosinfo.task_throughput_qos_tier = info->throughput_qos;

                kern_return_t kr = task_qos_policy_validate(&qosinfo, TASK_QOS_POLICY_COUNT);

                if (kr != KERN_SUCCESS) {
                        return kr;
                }

                /* TEMPORARY disablement of task suppression */
                if (info->active &&
                    (task_policy_suppression_flags & TASK_POLICY_SUPPRESSION_DISABLE)) {
                        return KERN_SUCCESS;
                }

                struct task_pend_token pend_token = {};

                task_lock(task);

                KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
                    (IMPORTANCE_CODE(IMP_TASK_SUPPRESSION, info->active)) | DBG_FUNC_START,
                    proc_selfpid(), task_pid(task), trequested_0(task),
                    trequested_1(task), 0);

                task->requested_policy.trp_sup_active      = (info->active)         ? 1 : 0;
                task->requested_policy.trp_sup_lowpri_cpu  = (info->lowpri_cpu)     ? 1 : 0;
                task->requested_policy.trp_sup_timer       = qos_extract(info->timer_throttle);
                task->requested_policy.trp_sup_disk        = (info->disk_throttle)  ? 1 : 0;
                task->requested_policy.trp_sup_throughput  = qos_extract(info->throughput_qos);
                task->requested_policy.trp_sup_cpu         = (info->suppressed_cpu) ? 1 : 0;
                task->requested_policy.trp_sup_bg_sockets  = (info->background_sockets) ? 1 : 0;

                task_policy_update_locked(task, &pend_token);

                KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
                    (IMPORTANCE_CODE(IMP_TASK_SUPPRESSION, info->active)) | DBG_FUNC_END,
                    proc_selfpid(), task_pid(task), trequested_0(task),
                    trequested_1(task), 0);

                task_unlock(task);

                task_policy_update_complete_unlocked(task, &pend_token);

                break;

#endif /* CONFIG_EMBEDDED */
        }

        default:
                result = KERN_INVALID_ARGUMENT;
                break;
        }

        return result;
}

/* Sets BSD 'nice' value on the task */
kern_return_t
task_importance(
        task_t                          task,
        integer_t                       importance)
{
        if (task == TASK_NULL || task == kernel_task) {
                return KERN_INVALID_ARGUMENT;
        }

        task_lock(task);

        if (!task->active) {
                task_unlock(task);

                return KERN_TERMINATED;
        }

        if (proc_get_effective_task_policy(task, TASK_POLICY_ROLE) >= TASK_CONTROL_APPLICATION) {
                task_unlock(task);

                return KERN_INVALID_ARGUMENT;
        }

        task->importance = importance;

        struct task_pend_token pend_token = {};

        task_policy_update_locked(task, &pend_token);

        task_unlock(task);

        task_policy_update_complete_unlocked(task, &pend_token);

        return KERN_SUCCESS;
}

kern_return_t
task_policy_get(
        task_t                                  task,
        task_policy_flavor_t    flavor,
        task_policy_t                   policy_info,
        mach_msg_type_number_t  *count,
        boolean_t                               *get_default)
{
        if (task == TASK_NULL || task == kernel_task) {
                return KERN_INVALID_ARGUMENT;
        }

        switch (flavor) {
        case TASK_CATEGORY_POLICY:
        {
                task_category_policy_t          info = (task_category_policy_t)policy_info;

                if (*count < TASK_CATEGORY_POLICY_COUNT) {
                        return KERN_INVALID_ARGUMENT;
                }

                if (*get_default) {
                        info->role = TASK_UNSPECIFIED;
                } else {
                        info->role = proc_get_task_policy(task, TASK_POLICY_ATTRIBUTE, TASK_POLICY_ROLE);
                }
                break;
        }

        case TASK_BASE_QOS_POLICY: /* FALLTHRU */
        case TASK_OVERRIDE_QOS_POLICY:
        {
                task_qos_policy_t info = (task_qos_policy_t)policy_info;

                if (*count < TASK_QOS_POLICY_COUNT) {
                        return KERN_INVALID_ARGUMENT;
                }

                if (*get_default) {
                        info->task_latency_qos_tier = LATENCY_QOS_TIER_UNSPECIFIED;
                        info->task_throughput_qos_tier = THROUGHPUT_QOS_TIER_UNSPECIFIED;
                } else if (flavor == TASK_BASE_QOS_POLICY) {
                        int value1, value2;

                        proc_get_task_policy2(task, TASK_POLICY_ATTRIBUTE, TASK_POLICY_BASE_LATENCY_AND_THROUGHPUT_QOS, &value1, &value2);

                        info->task_latency_qos_tier = qos_latency_policy_package(value1);
                        info->task_throughput_qos_tier = qos_throughput_policy_package(value2);
                } else if (flavor == TASK_OVERRIDE_QOS_POLICY) {
                        int value1, value2;

                        proc_get_task_policy2(task, TASK_POLICY_ATTRIBUTE, TASK_POLICY_OVERRIDE_LATENCY_AND_THROUGHPUT_QOS, &value1, &value2);

                        info->task_latency_qos_tier = qos_latency_policy_package(value1);
                        info->task_throughput_qos_tier = qos_throughput_policy_package(value2);
                }

                break;
        }

        case TASK_POLICY_STATE:
        {
                task_policy_state_t info = (task_policy_state_t)policy_info;

                if (*count < TASK_POLICY_STATE_COUNT) {
                        return KERN_INVALID_ARGUMENT;
                }

                /* Only root can get this info */
                if (current_task()->sec_token.val[0] != 0) {
                        return KERN_PROTECTION_FAILURE;
                }

                if (*get_default) {
                        info->requested = 0;
                        info->effective = 0;
                        info->pending = 0;
                        info->imp_assertcnt = 0;
                        info->imp_externcnt = 0;
                        info->flags = 0;
                        info->imp_transitions = 0;
                } else {
                        task_lock(task);

                        info->requested = task_requested_bitfield(task);
                        info->effective = task_effective_bitfield(task);
                        info->pending   = 0;

                        info->tps_requested_policy = *(uint64_t*)(&task->requested_policy);
                        info->tps_effective_policy = *(uint64_t*)(&task->effective_policy);

                        info->flags = 0;
                        if (task->task_imp_base != NULL) {
                                info->imp_assertcnt = task->task_imp_base->iit_assertcnt;
                                info->imp_externcnt = IIT_EXTERN(task->task_imp_base);
                                info->flags |= (task_is_marked_importance_receiver(task) ? TASK_IMP_RECEIVER : 0);
                                info->flags |= (task_is_marked_importance_denap_receiver(task) ? TASK_DENAP_RECEIVER : 0);
                                info->flags |= (task_is_marked_importance_donor(task) ? TASK_IMP_DONOR : 0);
                                info->flags |= (task_is_marked_live_importance_donor(task) ? TASK_IMP_LIVE_DONOR : 0);
                                info->imp_transitions = task->task_imp_base->iit_transitions;
                        } else {
                                info->imp_assertcnt = 0;
                                info->imp_externcnt = 0;
                                info->imp_transitions = 0;
                        }
                        task_unlock(task);
                }

                break;
        }

        case TASK_SUPPRESSION_POLICY:
        {
                task_suppression_policy_t info = (task_suppression_policy_t)policy_info;

                if (*count < TASK_SUPPRESSION_POLICY_COUNT) {
                        return KERN_INVALID_ARGUMENT;
                }

                task_lock(task);

                if (*get_default) {
                        info->active            = 0;
                        info->lowpri_cpu        = 0;
                        info->timer_throttle    = LATENCY_QOS_TIER_UNSPECIFIED;
                        info->disk_throttle     = 0;
                        info->cpu_limit         = 0;
                        info->suspend           = 0;
                        info->throughput_qos    = 0;
                        info->suppressed_cpu    = 0;
                } else {
                        info->active            = task->requested_policy.trp_sup_active;
                        info->lowpri_cpu        = task->requested_policy.trp_sup_lowpri_cpu;
                        info->timer_throttle    = qos_latency_policy_package(task->requested_policy.trp_sup_timer);
                        info->disk_throttle     = task->requested_policy.trp_sup_disk;
                        info->cpu_limit         = 0;
                        info->suspend           = 0;
                        info->throughput_qos    = qos_throughput_policy_package(task->requested_policy.trp_sup_throughput);
                        info->suppressed_cpu    = task->requested_policy.trp_sup_cpu;
                        info->background_sockets = task->requested_policy.trp_sup_bg_sockets;
                }

                task_unlock(task);
                break;
        }

        default:
                return KERN_INVALID_ARGUMENT;
        }

        return KERN_SUCCESS;
}

/*
 * Called at task creation
 * We calculate the correct effective but don't apply it to anything yet.
 * The threads, etc will inherit from the task as they get created.
 */
void
task_policy_create(task_t task, task_t parent_task)
{
        task->requested_policy.trp_apptype          = parent_task->requested_policy.trp_apptype;

        task->requested_policy.trp_int_darwinbg     = parent_task->requested_policy.trp_int_darwinbg;
        task->requested_policy.trp_ext_darwinbg     = parent_task->requested_policy.trp_ext_darwinbg;
        task->requested_policy.trp_int_iotier       = parent_task->requested_policy.trp_int_iotier;
        task->requested_policy.trp_ext_iotier       = parent_task->requested_policy.trp_ext_iotier;
        task->requested_policy.trp_int_iopassive    = parent_task->requested_policy.trp_int_iopassive;
        task->requested_policy.trp_ext_iopassive    = parent_task->requested_policy.trp_ext_iopassive;
        task->requested_policy.trp_bg_iotier        = parent_task->requested_policy.trp_bg_iotier;
        task->requested_policy.trp_terminated       = parent_task->requested_policy.trp_terminated;
        task->requested_policy.trp_qos_clamp        = parent_task->requested_policy.trp_qos_clamp;

        if (task->requested_policy.trp_apptype == TASK_APPTYPE_DAEMON_ADAPTIVE && !task_is_exec_copy(task)) {
                /* Do not update the apptype for exec copy task */
                if (parent_task->requested_policy.trp_boosted) {
                        task->requested_policy.trp_apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
                        task_importance_mark_donor(task, TRUE);
                } else {
                        task->requested_policy.trp_apptype = TASK_APPTYPE_DAEMON_BACKGROUND;
                        task_importance_mark_receiver(task, FALSE);
                }
        }

        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            (IMPORTANCE_CODE(IMP_UPDATE, (IMP_UPDATE_TASK_CREATE | TASK_POLICY_TASK))) | DBG_FUNC_START,
            task_pid(task), teffective_0(task),
            teffective_1(task), task->priority, 0);

        task_policy_update_internal_locked(task, TRUE, NULL);

        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            (IMPORTANCE_CODE(IMP_UPDATE, (IMP_UPDATE_TASK_CREATE | TASK_POLICY_TASK))) | DBG_FUNC_END,
            task_pid(task), teffective_0(task),
            teffective_1(task), task->priority, 0);

        task_importance_update_live_donor(task);
}


static void
task_policy_update_locked(task_t task, task_pend_token_t pend_token)
{
        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            (IMPORTANCE_CODE(IMP_UPDATE, TASK_POLICY_TASK) | DBG_FUNC_START),
            task_pid(task), teffective_0(task),
            teffective_1(task), task->priority, 0);

        task_policy_update_internal_locked(task, FALSE, pend_token);

        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            (IMPORTANCE_CODE(IMP_UPDATE, TASK_POLICY_TASK)) | DBG_FUNC_END,
            task_pid(task), teffective_0(task),
            teffective_1(task), task->priority, 0);
}

/*
 * One state update function TO RULE THEM ALL
 *
 * This function updates the task or thread effective policy fields
 * and pushes the results to the relevant subsystems.
 *
 * Must call update_complete after unlocking the task,
 * as some subsystems cannot be updated while holding the task lock.
 *
 * Called with task locked, not thread
 */

static void
task_policy_update_internal_locked(task_t task, boolean_t in_create, task_pend_token_t pend_token)
{
        /*
         * Step 1:
         *  Gather requested policy
         */

        struct task_requested_policy requested = task->requested_policy;

        /*
         * Step 2:
         *  Calculate new effective policies from requested policy and task state
         *  Rules:
         *      Don't change requested, it won't take effect
         */

        struct task_effective_policy next = {};

        /* Update task role */
        next.tep_role = requested.trp_role;

        /* Set task qos clamp and ceiling */
        next.tep_qos_clamp = requested.trp_qos_clamp;

        if (requested.trp_apptype == TASK_APPTYPE_APP_DEFAULT ||
            requested.trp_apptype == TASK_APPTYPE_APP_TAL) {
                switch (next.tep_role) {
                case TASK_FOREGROUND_APPLICATION:
                        /* Foreground apps get urgent scheduler priority */
                        next.tep_qos_ui_is_urgent = 1;
                        next.tep_qos_ceiling = THREAD_QOS_UNSPECIFIED;
                        break;

                case TASK_BACKGROUND_APPLICATION:
                        /* This is really 'non-focal but on-screen' */
                        next.tep_qos_ceiling = THREAD_QOS_UNSPECIFIED;
                        break;

                case TASK_DEFAULT_APPLICATION:
                        /* This is 'may render UI but we don't know if it's focal/nonfocal' */
                        next.tep_qos_ceiling = THREAD_QOS_UNSPECIFIED;
                        break;

                case TASK_NONUI_APPLICATION:
                        /* i.e. 'off-screen' */
                        next.tep_qos_ceiling = THREAD_QOS_LEGACY;
                        break;

                case TASK_CONTROL_APPLICATION:
                case TASK_GRAPHICS_SERVER:
                        next.tep_qos_ui_is_urgent = 1;
                        next.tep_qos_ceiling = THREAD_QOS_UNSPECIFIED;
                        break;

                case TASK_THROTTLE_APPLICATION:
                        /* i.e. 'TAL launch' */
                        next.tep_qos_ceiling = THREAD_QOS_UTILITY;
                        break;

                case TASK_DARWINBG_APPLICATION:
                        /* i.e. 'DARWIN_BG throttled background application' */
                        next.tep_qos_ceiling = THREAD_QOS_BACKGROUND;
                        break;

                case TASK_UNSPECIFIED:
                default:
                        /* Apps that don't have an application role get
                         * USER_INTERACTIVE and USER_INITIATED squashed to LEGACY */
                        next.tep_qos_ceiling = THREAD_QOS_LEGACY;
                        break;
                }
        } else {
                /* Daemons and dext get USER_INTERACTIVE squashed to USER_INITIATED */
                next.tep_qos_ceiling = THREAD_QOS_USER_INITIATED;
        }

        /* Calculate DARWIN_BG */
        boolean_t wants_darwinbg        = FALSE;
        boolean_t wants_all_sockets_bg  = FALSE; /* Do I want my existing sockets to be bg */
        boolean_t wants_watchersbg      = FALSE; /* Do I want my pidbound threads to be bg */

        /*
         * If DARWIN_BG has been requested at either level, it's engaged.
         * Only true DARWIN_BG changes cause watchers to transition.
         *
         * Backgrounding due to apptype does.
         */
        if (requested.trp_int_darwinbg || requested.trp_ext_darwinbg ||
            next.tep_role == TASK_DARWINBG_APPLICATION) {
                wants_watchersbg = wants_all_sockets_bg = wants_darwinbg = TRUE;
        }

        /*
         * Deprecated TAL implementation for TAL apptype
         * Background TAL apps are throttled when TAL is enabled
         */
        if (requested.trp_apptype == TASK_APPTYPE_APP_TAL &&
            requested.trp_role == TASK_BACKGROUND_APPLICATION &&
            requested.trp_tal_enabled == 1) {
                next.tep_tal_engaged = 1;
        }

        /* New TAL implementation based on TAL role alone, works for all apps */
        if ((requested.trp_apptype == TASK_APPTYPE_APP_DEFAULT ||
            requested.trp_apptype == TASK_APPTYPE_APP_TAL) &&
            requested.trp_role == TASK_THROTTLE_APPLICATION) {
                next.tep_tal_engaged = 1;
        }

        /* Adaptive daemons are DARWIN_BG unless boosted, and don't get network throttled. */
        if (requested.trp_apptype == TASK_APPTYPE_DAEMON_ADAPTIVE &&
            requested.trp_boosted == 0) {
                wants_darwinbg = TRUE;
        }

        /* Background daemons are always DARWIN_BG, no exceptions, and don't get network throttled. */
        if (requested.trp_apptype == TASK_APPTYPE_DAEMON_BACKGROUND) {
                wants_darwinbg = TRUE;
        }

        if (next.tep_qos_clamp == THREAD_QOS_BACKGROUND || next.tep_qos_clamp == THREAD_QOS_MAINTENANCE) {
                wants_darwinbg = TRUE;
        }

        /* Calculate side effects of DARWIN_BG */

        if (wants_darwinbg) {
                next.tep_darwinbg = 1;
                /* darwinbg tasks always create bg sockets, but we don't always loop over all sockets */
                next.tep_new_sockets_bg = 1;
                next.tep_lowpri_cpu = 1;
        }

        if (wants_all_sockets_bg) {
                next.tep_all_sockets_bg = 1;
        }

        if (wants_watchersbg) {
                next.tep_watchers_bg = 1;
        }

        /* Calculate low CPU priority */

        boolean_t wants_lowpri_cpu = FALSE;

        if (wants_darwinbg) {
                wants_lowpri_cpu = TRUE;
        }

        if (next.tep_tal_engaged) {
                wants_lowpri_cpu = TRUE;
        }

        if (requested.trp_sup_lowpri_cpu && requested.trp_boosted == 0) {
                wants_lowpri_cpu = TRUE;
        }

        if (wants_lowpri_cpu) {
                next.tep_lowpri_cpu = 1;
        }

        /* Calculate IO policy */

        /* Update BG IO policy (so we can see if it has changed) */
        next.tep_bg_iotier = requested.trp_bg_iotier;

        int iopol = THROTTLE_LEVEL_TIER0;

        if (wants_darwinbg) {
                iopol = MAX(iopol, requested.trp_bg_iotier);
        }

        if (requested.trp_apptype == TASK_APPTYPE_DAEMON_STANDARD) {
                iopol = MAX(iopol, proc_standard_daemon_tier);
        }

        if (requested.trp_sup_disk && requested.trp_boosted == 0) {
                iopol = MAX(iopol, proc_suppressed_disk_tier);
        }

        if (next.tep_tal_engaged) {
                iopol = MAX(iopol, proc_tal_disk_tier);
        }

        if (next.tep_qos_clamp != THREAD_QOS_UNSPECIFIED) {
                iopol = MAX(iopol, thread_qos_policy_params.qos_iotier[next.tep_qos_clamp]);
        }

        iopol = MAX(iopol, requested.trp_int_iotier);
        iopol = MAX(iopol, requested.trp_ext_iotier);

        next.tep_io_tier = iopol;

        /* Calculate Passive IO policy */

        if (requested.trp_ext_iopassive || requested.trp_int_iopassive) {
                next.tep_io_passive = 1;
        }

        /* Calculate suppression-active flag */
        boolean_t appnap_transition = FALSE;

        if (requested.trp_sup_active && requested.trp_boosted == 0) {
                next.tep_sup_active = 1;
        }

        if (task->effective_policy.tep_sup_active != next.tep_sup_active) {
                appnap_transition = TRUE;
        }

        /* Calculate timer QOS */
        int latency_qos = requested.trp_base_latency_qos;

        if (requested.trp_sup_timer && requested.trp_boosted == 0) {
                latency_qos = requested.trp_sup_timer;
        }

        if (next.tep_qos_clamp != THREAD_QOS_UNSPECIFIED) {
                latency_qos = MAX(latency_qos, (int)thread_qos_policy_params.qos_latency_qos[next.tep_qos_clamp]);
        }

        if (requested.trp_over_latency_qos != 0) {
                latency_qos = requested.trp_over_latency_qos;
        }

        /* Treat the windowserver special */
        if (requested.trp_role == TASK_GRAPHICS_SERVER) {
                latency_qos = proc_graphics_timer_qos;
        }

        next.tep_latency_qos = latency_qos;

        /* Calculate throughput QOS */
        int through_qos = requested.trp_base_through_qos;

        if (requested.trp_sup_throughput && requested.trp_boosted == 0) {
                through_qos = requested.trp_sup_throughput;
        }

        if (next.tep_qos_clamp != THREAD_QOS_UNSPECIFIED) {
                through_qos = MAX(through_qos, (int)thread_qos_policy_params.qos_through_qos[next.tep_qos_clamp]);
        }

        if (requested.trp_over_through_qos != 0) {
                through_qos = requested.trp_over_through_qos;
        }

        next.tep_through_qos = through_qos;

        /* Calculate suppressed CPU priority */
        if (requested.trp_sup_cpu && requested.trp_boosted == 0) {
                next.tep_suppressed_cpu = 1;
        }

        /*
         * Calculate background sockets
         * Don't take into account boosting to limit transition frequency.
         */
        if (requested.trp_sup_bg_sockets) {
                next.tep_all_sockets_bg = 1;
                next.tep_new_sockets_bg = 1;
        }

        /* Apply SFI Managed class bit */
        next.tep_sfi_managed = requested.trp_sfi_managed;

        /* Calculate 'live donor' status for live importance */
        switch (requested.trp_apptype) {
        case TASK_APPTYPE_APP_TAL:
        case TASK_APPTYPE_APP_DEFAULT:
                if (requested.trp_ext_darwinbg == 1 ||
                    (next.tep_sup_active == 1 &&
                    (task_policy_suppression_flags & TASK_POLICY_SUPPRESSION_NONDONOR)) ||
                    next.tep_role == TASK_DARWINBG_APPLICATION) {
                        next.tep_live_donor = 0;
                } else {
                        next.tep_live_donor = 1;
                }
                break;

        case TASK_APPTYPE_DAEMON_INTERACTIVE:
        case TASK_APPTYPE_DAEMON_STANDARD:
        case TASK_APPTYPE_DAEMON_ADAPTIVE:
        case TASK_APPTYPE_DAEMON_BACKGROUND:
        case TASK_APPTYPE_DRIVER:
        default:
                next.tep_live_donor = 0;
                break;
        }

        if (requested.trp_terminated) {
                /*
                 * Shoot down the throttles that slow down exit or response to SIGTERM
                 * We don't need to shoot down:
                 * passive        (don't want to cause others to throttle)
                 * all_sockets_bg (don't need to iterate FDs on every exit)
                 * new_sockets_bg (doesn't matter for exiting process)
                 * pidsuspend     (jetsam-ed BG process shouldn't run again)
                 * watchers_bg    (watcher threads don't need to be unthrottled)
                 * latency_qos    (affects userspace timers only)
                 */

                next.tep_terminated     = 1;
                next.tep_darwinbg       = 0;
                next.tep_lowpri_cpu     = 0;
                next.tep_io_tier        = THROTTLE_LEVEL_TIER0;
                next.tep_tal_engaged    = 0;
                next.tep_role           = TASK_UNSPECIFIED;
                next.tep_suppressed_cpu = 0;
        }

        /*
         * Step 3:
         *  Swap out old policy for new policy
         */

        struct task_effective_policy prev = task->effective_policy;

        /* This is the point where the new values become visible to other threads */
        task->effective_policy = next;

        /* Don't do anything further to a half-formed task */
        if (in_create) {
                return;
        }

        if (task == kernel_task) {
                panic("Attempting to set task policy on kernel_task");
        }

        /*
         * Step 4:
         *  Pend updates that can't be done while holding the task lock
         */

        if (prev.tep_all_sockets_bg != next.tep_all_sockets_bg) {
                pend_token->tpt_update_sockets = 1;
        }

        /* Only re-scan the timer list if the qos level is getting less strong */
        if (prev.tep_latency_qos > next.tep_latency_qos) {
                pend_token->tpt_update_timers = 1;
        }

#if CONFIG_EMBEDDED
        if (prev.tep_watchers_bg != next.tep_watchers_bg) {
                pend_token->tpt_update_watchers = 1;
        }
#endif /* CONFIG_EMBEDDED */

        if (prev.tep_live_donor != next.tep_live_donor) {
                pend_token->tpt_update_live_donor = 1;
        }

        /*
         * Step 5:
         *  Update other subsystems as necessary if something has changed
         */

        boolean_t update_threads = FALSE, update_sfi = FALSE;

        /*
         * Check for the attributes that thread_policy_update_internal_locked() consults,
         *  and trigger thread policy re-evaluation.
         */
        if (prev.tep_io_tier != next.tep_io_tier ||
            prev.tep_bg_iotier != next.tep_bg_iotier ||
            prev.tep_io_passive != next.tep_io_passive ||
            prev.tep_darwinbg != next.tep_darwinbg ||
            prev.tep_qos_clamp != next.tep_qos_clamp ||
            prev.tep_qos_ceiling != next.tep_qos_ceiling ||
            prev.tep_qos_ui_is_urgent != next.tep_qos_ui_is_urgent ||
            prev.tep_latency_qos != next.tep_latency_qos ||
            prev.tep_through_qos != next.tep_through_qos ||
            prev.tep_lowpri_cpu != next.tep_lowpri_cpu ||
            prev.tep_new_sockets_bg != next.tep_new_sockets_bg ||
            prev.tep_terminated != next.tep_terminated) {
                update_threads = TRUE;
        }

        /*
         * Check for the attributes that sfi_thread_classify() consults,
         *  and trigger SFI re-evaluation.
         */
        if (prev.tep_latency_qos != next.tep_latency_qos ||
            prev.tep_role != next.tep_role ||
            prev.tep_sfi_managed != next.tep_sfi_managed) {
                update_sfi = TRUE;
        }

        /* Reflect task role transitions into the coalition role counters */
        if (prev.tep_role != next.tep_role) {
                if (task_policy_update_coalition_focal_tasks(task, prev.tep_role, next.tep_role, pend_token)) {
                        update_sfi = TRUE;
                }
        }

        boolean_t update_priority = FALSE;

        int priority     = BASEPRI_DEFAULT;
        int max_priority = MAXPRI_USER;

        if (next.tep_lowpri_cpu) {
                priority = MAXPRI_THROTTLE;
                max_priority = MAXPRI_THROTTLE;
        } else if (next.tep_suppressed_cpu) {
                priority = MAXPRI_SUPPRESSED;
                max_priority = MAXPRI_SUPPRESSED;
        } else {
                switch (next.tep_role) {
                case TASK_CONTROL_APPLICATION:
                        priority = BASEPRI_CONTROL;
                        break;
                case TASK_GRAPHICS_SERVER:
                        priority = BASEPRI_GRAPHICS;
                        max_priority = MAXPRI_RESERVED;
                        break;
                default:
                        break;
                }

                /* factor in 'nice' value */
                priority += task->importance;

                if (task->effective_policy.tep_qos_clamp != THREAD_QOS_UNSPECIFIED) {
                        int qos_clamp_priority = thread_qos_policy_params.qos_pri[task->effective_policy.tep_qos_clamp];

                        priority        = MIN(priority, qos_clamp_priority);
                        max_priority    = MIN(max_priority, qos_clamp_priority);
                }

                if (priority > max_priority) {
                        priority = max_priority;
                } else if (priority < MINPRI) {
                        priority = MINPRI;
                }
        }

        assert(priority <= max_priority);

        /* avoid extra work if priority isn't changing */
        if (priority != task->priority ||
            max_priority != task->max_priority) {
                /* update the scheduling priority for the task */
                task->max_priority  = max_priority;
                task->priority      = priority;
                update_priority     = TRUE;
        }

        /* Loop over the threads in the task:
         * only once
         * only if necessary
         * with one thread mutex hold per thread
         */
        if (update_threads || update_priority || update_sfi) {
                thread_t thread;

                queue_iterate(&task->threads, thread, thread_t, task_threads) {
                        struct task_pend_token thread_pend_token = {};

                        if (update_sfi) {
                                thread_pend_token.tpt_update_thread_sfi = 1;
                        }

                        if (update_priority || update_threads) {
                                thread_policy_update_tasklocked(thread,
                                    task->priority, task->max_priority,
                                    &thread_pend_token);
                        }

                        assert(!thread_pend_token.tpt_update_sockets);

                        // Slightly risky, as we still hold the task lock...
                        thread_policy_update_complete_unlocked(thread, &thread_pend_token);
                }
        }

        /*
         * Use the app-nap transitions to influence the
         * transition of the process within the jetsam band
         * [and optionally its live-donor status]
         * On macOS only.
         */
        if (appnap_transition == TRUE) {
                if (task->effective_policy.tep_sup_active == 1) {
                        memorystatus_update_priority_for_appnap(((proc_t) task->bsd_info), TRUE);
                } else {
                        memorystatus_update_priority_for_appnap(((proc_t) task->bsd_info), FALSE);
                }
        }
}


/*
 * Yet another layering violation. We reach out and bang on the coalition directly.
 */
static boolean_t
task_policy_update_coalition_focal_tasks(task_t            task,
    int               prev_role,
    int               next_role,
    task_pend_token_t pend_token)
{
        boolean_t sfi_transition = FALSE;
        uint32_t new_count = 0;

        /* task moving into/out-of the foreground */
        if (prev_role != TASK_FOREGROUND_APPLICATION && next_role == TASK_FOREGROUND_APPLICATION) {
                if (task_coalition_adjust_focal_count(task, 1, &new_count) && (new_count == 1)) {
                        sfi_transition = TRUE;
                        pend_token->tpt_update_tg_ui_flag = TRUE;
                }
        } else if (prev_role == TASK_FOREGROUND_APPLICATION && next_role != TASK_FOREGROUND_APPLICATION) {
                if (task_coalition_adjust_focal_count(task, -1, &new_count) && (new_count == 0)) {
                        sfi_transition = TRUE;
                        pend_token->tpt_update_tg_ui_flag = TRUE;
                }
        }

        /* task moving into/out-of background */
        if (prev_role != TASK_BACKGROUND_APPLICATION && next_role == TASK_BACKGROUND_APPLICATION) {
                if (task_coalition_adjust_nonfocal_count(task, 1, &new_count) && (new_count == 1)) {
                        sfi_transition = TRUE;
                }
        } else if (prev_role == TASK_BACKGROUND_APPLICATION && next_role != TASK_BACKGROUND_APPLICATION) {
                if (task_coalition_adjust_nonfocal_count(task, -1, &new_count) && (new_count == 0)) {
                        sfi_transition = TRUE;
                }
        }

        if (sfi_transition) {
                pend_token->tpt_update_coal_sfi = 1;
        }
        return sfi_transition;
}

#if CONFIG_SCHED_SFI

/* coalition object is locked */
static void
task_sfi_reevaluate_cb(coalition_t coal, void *ctx, task_t task)
{
        thread_t thread;

        /* unused for now */
        (void)coal;

        /* skip the task we're re-evaluating on behalf of: it's already updated */
        if (task == (task_t)ctx) {
                return;
        }

        task_lock(task);

        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                sfi_reevaluate(thread);
        }

        task_unlock(task);
}
#endif /* CONFIG_SCHED_SFI */

/*
 * Called with task unlocked to do things that can't be done while holding the task lock
 */
void
task_policy_update_complete_unlocked(task_t task, task_pend_token_t pend_token)
{
#ifdef MACH_BSD
        if (pend_token->tpt_update_sockets) {
                proc_apply_task_networkbg(task->bsd_info, THREAD_NULL);
        }
#endif /* MACH_BSD */

        /* The timer throttle has been removed or reduced, we need to look for expired timers and fire them */
        if (pend_token->tpt_update_timers) {
                ml_timer_evaluate();
        }

#if CONFIG_EMBEDDED
        if (pend_token->tpt_update_watchers) {
                apply_appstate_watchers(task);
        }
#endif /* CONFIG_EMBEDDED */

        if (pend_token->tpt_update_live_donor) {
                task_importance_update_live_donor(task);
        }

#if CONFIG_SCHED_SFI
        /* use the resource coalition for SFI re-evaluation */
        if (pend_token->tpt_update_coal_sfi) {
                coalition_for_each_task(task->coalition[COALITION_TYPE_RESOURCE],
                    (void *)task, task_sfi_reevaluate_cb);
        }
#endif /* CONFIG_SCHED_SFI */

}

/*
 * Initiate a task policy state transition
 *
 * Everything that modifies requested except functions that need to hold the task lock
 * should use this function
 *
 * Argument validation should be performed before reaching this point.
 *
 * TODO: Do we need to check task->active?
 */
void
proc_set_task_policy(task_t     task,
    int        category,
    int        flavor,
    int        value)
{
        struct task_pend_token pend_token = {};

        task_lock(task);

        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            (IMPORTANCE_CODE(flavor, (category | TASK_POLICY_TASK))) | DBG_FUNC_START,
            task_pid(task), trequested_0(task),
            trequested_1(task), value, 0);

        proc_set_task_policy_locked(task, category, flavor, value, 0);

        task_policy_update_locked(task, &pend_token);


        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            (IMPORTANCE_CODE(flavor, (category | TASK_POLICY_TASK))) | DBG_FUNC_END,
            task_pid(task), trequested_0(task),
            trequested_1(task), tpending(&pend_token), 0);

        task_unlock(task);

        task_policy_update_complete_unlocked(task, &pend_token);
}

/*
 * Variant of proc_set_task_policy() that sets two scalars in the requested policy structure.
 * Same locking rules apply.
 */
void
proc_set_task_policy2(task_t    task,
    int       category,
    int       flavor,
    int       value,
    int       value2)
{
        struct task_pend_token pend_token = {};

        task_lock(task);

        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            (IMPORTANCE_CODE(flavor, (category | TASK_POLICY_TASK))) | DBG_FUNC_START,
            task_pid(task), trequested_0(task),
            trequested_1(task), value, 0);

        proc_set_task_policy_locked(task, category, flavor, value, value2);

        task_policy_update_locked(task, &pend_token);

        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            (IMPORTANCE_CODE(flavor, (category | TASK_POLICY_TASK))) | DBG_FUNC_END,
            task_pid(task), trequested_0(task),
            trequested_1(task), tpending(&pend_token), 0);

        task_unlock(task);

        task_policy_update_complete_unlocked(task, &pend_token);
}

/*
 * Set the requested state for a specific flavor to a specific value.
 *
 *  TODO:
 *  Verify that arguments to non iopol things are 1 or 0
 */
static void
proc_set_task_policy_locked(task_t      task,
    int         category,
    int         flavor,
    int         value,
    int         value2)
{
        int tier, passive;

        struct task_requested_policy requested = task->requested_policy;

        switch (flavor) {
        /* Category: EXTERNAL and INTERNAL */

        case TASK_POLICY_DARWIN_BG:
                if (category == TASK_POLICY_EXTERNAL) {
                        requested.trp_ext_darwinbg = value;
                } else {
                        requested.trp_int_darwinbg = value;
                }
                break;

        case TASK_POLICY_IOPOL:
                proc_iopol_to_tier(value, &tier, &passive);
                if (category == TASK_POLICY_EXTERNAL) {
                        requested.trp_ext_iotier  = tier;
                        requested.trp_ext_iopassive = passive;
                } else {
                        requested.trp_int_iotier  = tier;
                        requested.trp_int_iopassive = passive;
                }
                break;

        case TASK_POLICY_IO:
                if (category == TASK_POLICY_EXTERNAL) {
                        requested.trp_ext_iotier = value;
                } else {
                        requested.trp_int_iotier = value;
                }
                break;

        case TASK_POLICY_PASSIVE_IO:
                if (category == TASK_POLICY_EXTERNAL) {
                        requested.trp_ext_iopassive = value;
                } else {
                        requested.trp_int_iopassive = value;
                }
                break;

        /* Category: INTERNAL */

        case TASK_POLICY_DARWIN_BG_IOPOL:
                assert(category == TASK_POLICY_INTERNAL);
                proc_iopol_to_tier(value, &tier, &passive);
                requested.trp_bg_iotier = tier;
                break;

        /* Category: ATTRIBUTE */

        case TASK_POLICY_TAL:
                assert(category == TASK_POLICY_ATTRIBUTE);
                requested.trp_tal_enabled = value;
                break;

        case TASK_POLICY_BOOST:
                assert(category == TASK_POLICY_ATTRIBUTE);
                requested.trp_boosted = value;
                break;

        case TASK_POLICY_ROLE:
                assert(category == TASK_POLICY_ATTRIBUTE);
                requested.trp_role = value;
                break;

        case TASK_POLICY_TERMINATED:
                assert(category == TASK_POLICY_ATTRIBUTE);
                requested.trp_terminated = value;
                break;

        case TASK_BASE_LATENCY_QOS_POLICY:
                assert(category == TASK_POLICY_ATTRIBUTE);
                requested.trp_base_latency_qos = value;
                break;

        case TASK_BASE_THROUGHPUT_QOS_POLICY:
                assert(category == TASK_POLICY_ATTRIBUTE);
                requested.trp_base_through_qos = value;
                break;

        case TASK_POLICY_SFI_MANAGED:
                assert(category == TASK_POLICY_ATTRIBUTE);
                requested.trp_sfi_managed = value;
                break;

        case TASK_POLICY_BASE_LATENCY_AND_THROUGHPUT_QOS:
                assert(category == TASK_POLICY_ATTRIBUTE);
                requested.trp_base_latency_qos = value;
                requested.trp_base_through_qos = value2;
                break;

        case TASK_POLICY_OVERRIDE_LATENCY_AND_THROUGHPUT_QOS:
                assert(category == TASK_POLICY_ATTRIBUTE);
                requested.trp_over_latency_qos = value;
                requested.trp_over_through_qos = value2;
                break;

        default:
                panic("unknown task policy: %d %d %d %d", category, flavor, value, value2);
                break;
        }

        task->requested_policy = requested;
}

/*
 * Gets what you set. Effective values may be different.
 */
int
proc_get_task_policy(task_t     task,
    int        category,
    int        flavor)
{
        int value = 0;

        task_lock(task);

        struct task_requested_policy requested = task->requested_policy;

        switch (flavor) {
        case TASK_POLICY_DARWIN_BG:
                if (category == TASK_POLICY_EXTERNAL) {
                        value = requested.trp_ext_darwinbg;
                } else {
                        value = requested.trp_int_darwinbg;
                }
                break;
        case TASK_POLICY_IOPOL:
                if (category == TASK_POLICY_EXTERNAL) {
                        value = proc_tier_to_iopol(requested.trp_ext_iotier,
                            requested.trp_ext_iopassive);
                } else {
                        value = proc_tier_to_iopol(requested.trp_int_iotier,
                            requested.trp_int_iopassive);
                }
                break;
        case TASK_POLICY_IO:
                if (category == TASK_POLICY_EXTERNAL) {
                        value = requested.trp_ext_iotier;
                } else {
                        value = requested.trp_int_iotier;
                }
                break;
        case TASK_POLICY_PASSIVE_IO:
                if (category == TASK_POLICY_EXTERNAL) {
                        value = requested.trp_ext_iopassive;
                } else {
                        value = requested.trp_int_iopassive;
                }
                break;
        case TASK_POLICY_DARWIN_BG_IOPOL:
                assert(category == TASK_POLICY_ATTRIBUTE);
                value = proc_tier_to_iopol(requested.trp_bg_iotier, 0);
                break;
        case TASK_POLICY_ROLE:
                assert(category == TASK_POLICY_ATTRIBUTE);
                value = requested.trp_role;
                break;
        case TASK_POLICY_SFI_MANAGED:
                assert(category == TASK_POLICY_ATTRIBUTE);
                value = requested.trp_sfi_managed;
                break;
        default:
                panic("unknown policy_flavor %d", flavor);
                break;
        }

        task_unlock(task);

        return value;
}

/*
 * Variant of proc_get_task_policy() that returns two scalar outputs.
 */
void
proc_get_task_policy2(task_t task,
    __assert_only int category,
    int flavor,
    int *value1,
    int *value2)
{
        task_lock(task);

        struct task_requested_policy requested = task->requested_policy;

        switch (flavor) {
        case TASK_POLICY_BASE_LATENCY_AND_THROUGHPUT_QOS:
                assert(category == TASK_POLICY_ATTRIBUTE);
                *value1 = requested.trp_base_latency_qos;
                *value2 = requested.trp_base_through_qos;
                break;

        case TASK_POLICY_OVERRIDE_LATENCY_AND_THROUGHPUT_QOS:
                assert(category == TASK_POLICY_ATTRIBUTE);
                *value1 = requested.trp_over_latency_qos;
                *value2 = requested.trp_over_through_qos;
                break;

        default:
                panic("unknown policy_flavor %d", flavor);
                break;
        }

        task_unlock(task);
}

/*
 * Function for querying effective state for relevant subsystems
 * Gets what is actually in effect, for subsystems which pull policy instead of receive updates.
 *
 * ONLY the relevant subsystem should query this.
 * NEVER take a value from the 'effective' function and stuff it into a setter.
 *
 * NOTE: This accessor does not take the task lock.
 * Notifications of state updates need to be externally synchronized with state queries.
 * This routine *MUST* remain interrupt safe, as it is potentially invoked
 * within the context of a timer interrupt.  It is also called in KDP context for stackshot.
 */
int
proc_get_effective_task_policy(task_t   task,
    int      flavor)
{
        int value = 0;

        switch (flavor) {
        case TASK_POLICY_DARWIN_BG:
                /*
                 * This backs the KPI call proc_pidbackgrounded to find
                 * out if a pid is backgrounded.
                 * It is used to communicate state to the VM system, as well as
                 * prioritizing requests to the graphics system.
                 * Returns 1 for background mode, 0 for normal mode
                 */
                value = task->effective_policy.tep_darwinbg;
                break;
        case TASK_POLICY_ALL_SOCKETS_BG:
                /*
                 * do_background_socket() calls this to determine what it should do to the proc's sockets
                 * Returns 1 for background mode, 0 for normal mode
                 *
                 * This consults both thread and task so un-DBGing a thread while the task is BG
                 * doesn't get you out of the network throttle.
                 */
                value = task->effective_policy.tep_all_sockets_bg;
                break;
        case TASK_POLICY_SUP_ACTIVE:
                /*
                 * Is the task in AppNap? This is used to determine the urgency
                 * that's passed to the performance management subsystem for threads
                 * that are running at a priority <= MAXPRI_THROTTLE.
                 */
                value = task->effective_policy.tep_sup_active;
                break;
        case TASK_POLICY_LATENCY_QOS:
                /*
                 * timer arming calls into here to find out the timer coalescing level
                 * Returns a QoS tier (0-6)
                 */
                value = task->effective_policy.tep_latency_qos;
                break;
        case TASK_POLICY_THROUGH_QOS:
                /*
                 * This value is passed into the urgency callout from the scheduler
                 * to the performance management subsystem.
                 * Returns a QoS tier (0-6)
                 */
                value = task->effective_policy.tep_through_qos;
                break;
        case TASK_POLICY_ROLE:
                /*
                 * This controls various things that ask whether a process is foreground,
                 * like SFI, VM, access to GPU, etc
                 */
                value = task->effective_policy.tep_role;
                break;
        case TASK_POLICY_WATCHERS_BG:
                /*
                 * This controls whether or not a thread watching this process should be BG.
                 */
                value = task->effective_policy.tep_watchers_bg;
                break;
        case TASK_POLICY_SFI_MANAGED:
                /*
                 * This controls whether or not a process is targeted for specific control by thermald.
                 */
                value = task->effective_policy.tep_sfi_managed;
                break;
        default:
                panic("unknown policy_flavor %d", flavor);
                break;
        }

        return value;
}

/*
 * Convert from IOPOL_* values to throttle tiers.
 *
 * TODO: Can this be made more compact, like an array lookup
 * Note that it is possible to support e.g. IOPOL_PASSIVE_STANDARD in the future
 */

void
proc_iopol_to_tier(int iopolicy, int *tier, int *passive)
{
        *passive = 0;
        *tier = 0;
        switch (iopolicy) {
        case IOPOL_IMPORTANT:
                *tier = THROTTLE_LEVEL_TIER0;
                break;
        case IOPOL_PASSIVE:
                *tier = THROTTLE_LEVEL_TIER0;
                *passive = 1;
                break;
        case IOPOL_STANDARD:
                *tier = THROTTLE_LEVEL_TIER1;
                break;
        case IOPOL_UTILITY:
                *tier = THROTTLE_LEVEL_TIER2;
                break;
        case IOPOL_THROTTLE:
                *tier = THROTTLE_LEVEL_TIER3;
                break;
        default:
                panic("unknown I/O policy %d", iopolicy);
                break;
        }
}

int
proc_tier_to_iopol(int tier, int passive)
{
        if (passive == 1) {
                switch (tier) {
                case THROTTLE_LEVEL_TIER0:
                        return IOPOL_PASSIVE;
                default:
                        panic("unknown passive tier %d", tier);
                        return IOPOL_DEFAULT;
                }
        } else {
                switch (tier) {
                case THROTTLE_LEVEL_NONE:
                case THROTTLE_LEVEL_TIER0:
                        return IOPOL_DEFAULT;
                case THROTTLE_LEVEL_TIER1:
                        return IOPOL_STANDARD;
                case THROTTLE_LEVEL_TIER2:
                        return IOPOL_UTILITY;
                case THROTTLE_LEVEL_TIER3:
                        return IOPOL_THROTTLE;
                default:
                        panic("unknown tier %d", tier);
                        return IOPOL_DEFAULT;
                }
        }
}

int
proc_darwin_role_to_task_role(int darwin_role, int* task_role)
{
        integer_t role = TASK_UNSPECIFIED;

        switch (darwin_role) {
        case PRIO_DARWIN_ROLE_DEFAULT:
                role = TASK_UNSPECIFIED;
                break;
        case PRIO_DARWIN_ROLE_UI_FOCAL:
                role = TASK_FOREGROUND_APPLICATION;
                break;
        case PRIO_DARWIN_ROLE_UI:
                role = TASK_DEFAULT_APPLICATION;
                break;
        case PRIO_DARWIN_ROLE_NON_UI:
                role = TASK_NONUI_APPLICATION;
                break;
        case PRIO_DARWIN_ROLE_UI_NON_FOCAL:
                role = TASK_BACKGROUND_APPLICATION;
                break;
        case PRIO_DARWIN_ROLE_TAL_LAUNCH:
                role = TASK_THROTTLE_APPLICATION;
                break;
        case PRIO_DARWIN_ROLE_DARWIN_BG:
                role = TASK_DARWINBG_APPLICATION;
                break;
        default:
                return EINVAL;
        }

        *task_role = role;

        return 0;
}

int
proc_task_role_to_darwin_role(int task_role)
{
        switch (task_role) {
        case TASK_FOREGROUND_APPLICATION:
                return PRIO_DARWIN_ROLE_UI_FOCAL;
        case TASK_BACKGROUND_APPLICATION:
                return PRIO_DARWIN_ROLE_UI_NON_FOCAL;
        case TASK_NONUI_APPLICATION:
                return PRIO_DARWIN_ROLE_NON_UI;
        case TASK_DEFAULT_APPLICATION:
                return PRIO_DARWIN_ROLE_UI;
        case TASK_THROTTLE_APPLICATION:
                return PRIO_DARWIN_ROLE_TAL_LAUNCH;
        case TASK_DARWINBG_APPLICATION:
                return PRIO_DARWIN_ROLE_DARWIN_BG;
        case TASK_UNSPECIFIED:
        default:
                return PRIO_DARWIN_ROLE_DEFAULT;
        }
}


/* TODO: remove this variable when interactive daemon audit period is over */
extern boolean_t ipc_importance_interactive_receiver;

/*
 * Called at process exec to initialize the apptype, qos clamp, and qos seed of a process
 *
 * TODO: Make this function more table-driven instead of ad-hoc
 */
void
proc_set_task_spawnpolicy(task_t task, thread_t thread, int apptype, int qos_clamp, int role,
    ipc_port_t * portwatch_ports, uint32_t portwatch_count)
{
        struct task_pend_token pend_token = {};

        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            (IMPORTANCE_CODE(IMP_TASK_APPTYPE, apptype)) | DBG_FUNC_START,
            task_pid(task), trequested_0(task), trequested_1(task),
            apptype, 0);

        switch (apptype) {
        case TASK_APPTYPE_APP_TAL:
        case TASK_APPTYPE_APP_DEFAULT:
                /* Apps become donors via the 'live-donor' flag instead of the static donor flag */
                task_importance_mark_donor(task, FALSE);
                task_importance_mark_live_donor(task, TRUE);
                task_importance_mark_receiver(task, FALSE);
#if CONFIG_EMBEDDED
                task_importance_mark_denap_receiver(task, FALSE);
#else
                /* Apps are de-nap recievers on desktop for suppression behaviors */
                task_importance_mark_denap_receiver(task, TRUE);
#endif /* CONFIG_EMBEDDED */
                break;

        case TASK_APPTYPE_DAEMON_INTERACTIVE:
                task_importance_mark_donor(task, TRUE);
                task_importance_mark_live_donor(task, FALSE);

                /*
                 * A boot arg controls whether interactive daemons are importance receivers.
                 * Normally, they are not.  But for testing their behavior as an adaptive
                 * daemon, the boot-arg can be set.
                 *
                 * TODO: remove this when the interactive daemon audit period is over.
                 */
                task_importance_mark_receiver(task, /* FALSE */ ipc_importance_interactive_receiver);
                task_importance_mark_denap_receiver(task, FALSE);
                break;

        case TASK_APPTYPE_DAEMON_STANDARD:
                task_importance_mark_donor(task, TRUE);
                task_importance_mark_live_donor(task, FALSE);
                task_importance_mark_receiver(task, FALSE);
                task_importance_mark_denap_receiver(task, FALSE);
                break;

        case TASK_APPTYPE_DAEMON_ADAPTIVE:
                task_importance_mark_donor(task, FALSE);
                task_importance_mark_live_donor(task, FALSE);
                task_importance_mark_receiver(task, TRUE);
                task_importance_mark_denap_receiver(task, FALSE);
                break;

        case TASK_APPTYPE_DAEMON_BACKGROUND:
                task_importance_mark_donor(task, FALSE);
                task_importance_mark_live_donor(task, FALSE);
                task_importance_mark_receiver(task, FALSE);
                task_importance_mark_denap_receiver(task, FALSE);
                break;

        case TASK_APPTYPE_DRIVER:
                task_importance_mark_donor(task, FALSE);
                task_importance_mark_live_donor(task, FALSE);
                task_importance_mark_receiver(task, FALSE);
                task_importance_mark_denap_receiver(task, FALSE);
                break;

        case TASK_APPTYPE_NONE:
                break;
        }

        if (portwatch_ports != NULL && apptype == TASK_APPTYPE_DAEMON_ADAPTIVE) {
                int portwatch_boosts = 0;

                for (uint32_t i = 0; i < portwatch_count; i++) {
                        ipc_port_t port = NULL;

                        if (IP_VALID(port = portwatch_ports[i])) {
                                int boost = 0;
                                task_add_importance_watchport(task, port, &boost);
                                portwatch_boosts += boost;
                        }
                }

                if (portwatch_boosts > 0) {
                        task_importance_hold_internal_assertion(task, portwatch_boosts);
                }
        }

        /* Redirect the turnstile push of watchports to task */
        if (portwatch_count && portwatch_ports != NULL) {
                task_add_turnstile_watchports(task, thread, portwatch_ports, portwatch_count);
        }

        task_lock(task);

        if (apptype == TASK_APPTYPE_APP_TAL) {
                /* TAL starts off enabled by default */
                task->requested_policy.trp_tal_enabled = 1;
        }

        if (apptype != TASK_APPTYPE_NONE) {
                task->requested_policy.trp_apptype = apptype;
        }

#if CONFIG_EMBEDDED
        /* Remove this after launchd starts setting it properly */
        if (apptype == TASK_APPTYPE_APP_DEFAULT && role == TASK_UNSPECIFIED) {
                task->requested_policy.trp_role = TASK_FOREGROUND_APPLICATION;
        } else
#endif
        if (role != TASK_UNSPECIFIED) {
                task->requested_policy.trp_role = role;
        }

        if (qos_clamp != THREAD_QOS_UNSPECIFIED) {
                task->requested_policy.trp_qos_clamp = qos_clamp;
        }

        task_policy_update_locked(task, &pend_token);

        task_unlock(task);

        /* Ensure the donor bit is updated to be in sync with the new live donor status */
        pend_token.tpt_update_live_donor = 1;

        task_policy_update_complete_unlocked(task, &pend_token);

        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
            (IMPORTANCE_CODE(IMP_TASK_APPTYPE, apptype)) | DBG_FUNC_END,
            task_pid(task), trequested_0(task), trequested_1(task),
            task_is_importance_receiver(task), 0);
}

/*
 * Inherit task role across exec
 */
void
proc_inherit_task_role(task_t new_task,
    task_t old_task)
{
        int role;

        /* inherit the role from old task to new task */
        role = proc_get_task_policy(old_task, TASK_POLICY_ATTRIBUTE, TASK_POLICY_ROLE);
        proc_set_task_policy(new_task, TASK_POLICY_ATTRIBUTE, TASK_POLICY_ROLE, role);
}

extern void *initproc;

/*
 * Compute the default main thread qos for a task
 */
int
task_compute_main_thread_qos(task_t task)
{
        int primordial_qos = THREAD_QOS_UNSPECIFIED;

        int qos_clamp = task->requested_policy.trp_qos_clamp;

        switch (task->requested_policy.trp_apptype) {
        case TASK_APPTYPE_APP_TAL:
        case TASK_APPTYPE_APP_DEFAULT:
                primordial_qos = THREAD_QOS_USER_INTERACTIVE;
                break;

        case TASK_APPTYPE_DAEMON_INTERACTIVE:
        case TASK_APPTYPE_DAEMON_STANDARD:
        case TASK_APPTYPE_DAEMON_ADAPTIVE:
        case TASK_APPTYPE_DRIVER:
                primordial_qos = THREAD_QOS_LEGACY;
                break;

        case TASK_APPTYPE_DAEMON_BACKGROUND:
                primordial_qos = THREAD_QOS_BACKGROUND;
                break;
        }

        if (task->bsd_info == initproc) {
                /* PID 1 gets a special case */
                primordial_qos = MAX(primordial_qos, THREAD_QOS_USER_INITIATED);
        }

        if (qos_clamp != THREAD_QOS_UNSPECIFIED) {
                if (primordial_qos != THREAD_QOS_UNSPECIFIED) {
                        primordial_qos = MIN(qos_clamp, primordial_qos);
                } else {
                        primordial_qos = qos_clamp;
                }
        }

        return primordial_qos;
}


/* for process_policy to check before attempting to set */
boolean_t
proc_task_is_tal(task_t task)
{
        return (task->requested_policy.trp_apptype == TASK_APPTYPE_APP_TAL) ? TRUE : FALSE;
}

int
task_get_apptype(task_t task)
{
        return task->requested_policy.trp_apptype;
}

boolean_t
task_is_daemon(task_t task)
{
        switch (task->requested_policy.trp_apptype) {
        case TASK_APPTYPE_DAEMON_INTERACTIVE:
        case TASK_APPTYPE_DAEMON_STANDARD:
        case TASK_APPTYPE_DAEMON_ADAPTIVE:
        case TASK_APPTYPE_DAEMON_BACKGROUND:
                return TRUE;
        default:
                return FALSE;
        }
}

bool
task_is_driver(task_t task)
{
        if (!task) {
                return FALSE;
        }
        return task->requested_policy.trp_apptype == TASK_APPTYPE_DRIVER;
}

boolean_t
task_is_app(task_t task)
{
        switch (task->requested_policy.trp_apptype) {
        case TASK_APPTYPE_APP_DEFAULT:
        case TASK_APPTYPE_APP_TAL:
                return TRUE;
        default:
                return FALSE;
        }
}

/* for telemetry */
integer_t
task_grab_latency_qos(task_t task)
{
        return qos_latency_policy_package(proc_get_effective_task_policy(task, TASK_POLICY_LATENCY_QOS));
}

/* update the darwin background action state in the flags field for libproc */
int
proc_get_darwinbgstate(task_t task, uint32_t * flagsp)
{
        if (task->requested_policy.trp_ext_darwinbg) {
                *flagsp |= PROC_FLAG_EXT_DARWINBG;
        }

        if (task->requested_policy.trp_int_darwinbg) {
                *flagsp |= PROC_FLAG_DARWINBG;
        }

#if CONFIG_EMBEDDED
        if (task->requested_policy.trp_apptype == TASK_APPTYPE_DAEMON_BACKGROUND) {
                *flagsp |= PROC_FLAG_IOS_APPLEDAEMON;
        }

        if (task->requested_policy.trp_apptype == TASK_APPTYPE_DAEMON_ADAPTIVE) {
                *flagsp |= PROC_FLAG_IOS_IMPPROMOTION;
        }
#endif /* CONFIG_EMBEDDED */

        if (task->requested_policy.trp_apptype == TASK_APPTYPE_APP_DEFAULT ||
            task->requested_policy.trp_apptype == TASK_APPTYPE_APP_TAL) {
                *flagsp |= PROC_FLAG_APPLICATION;
        }

        if (task->requested_policy.trp_apptype == TASK_APPTYPE_DAEMON_ADAPTIVE) {
                *flagsp |= PROC_FLAG_ADAPTIVE;
        }

        if (task->requested_policy.trp_apptype == TASK_APPTYPE_DAEMON_ADAPTIVE &&
            task->requested_policy.trp_boosted == 1) {
                *flagsp |= PROC_FLAG_ADAPTIVE_IMPORTANT;
        }

        if (task_is_importance_donor(task)) {
                *flagsp |= PROC_FLAG_IMPORTANCE_DONOR;
        }

        if (task->effective_policy.tep_sup_active) {
                *flagsp |= PROC_FLAG_SUPPRESSED;
        }

        return 0;
}

/*
 * Tracepoint data... Reading the tracepoint data can be somewhat complicated.
 * The current scheme packs as much data into a single tracepoint as it can.
 *
 * Each task/thread requested/effective structure is 64 bits in size. Any
 * given tracepoint will emit either requested or effective data, but not both.
 *
 * A tracepoint may emit any of task, thread, or task & thread data.
 *
 * The type of data emitted varies with pointer size. Where possible, both
 * task and thread data are emitted. In LP32 systems, the first and second
 * halves of either the task or thread data is emitted.
 *
 * The code uses uintptr_t array indexes instead of high/low to avoid
 * confusion WRT big vs little endian.
 *
 * The truth table for the tracepoint data functions is below, and has the
 * following invariants:
 *
 * 1) task and thread are uintptr_t*
 * 2) task may never be NULL
 *
 *
 *                                     LP32            LP64
 * trequested_0(task, NULL)            task[0]         task[0]
 * trequested_1(task, NULL)            task[1]         NULL
 * trequested_0(task, thread)          thread[0]       task[0]
 * trequested_1(task, thread)          thread[1]       thread[0]
 *
 * Basically, you get a full task or thread on LP32, and both on LP64.
 *
 * The uintptr_t munging here is squicky enough to deserve a comment.
 *
 * The variables we are accessing are laid out in memory like this:
 *
 * [            LP64 uintptr_t  0          ]
 * [ LP32 uintptr_t 0 ] [ LP32 uintptr_t 1 ]
 *
 *      1   2   3   4     5   6   7   8
 *
 */

static uintptr_t
trequested_0(task_t task)
{
        static_assert(sizeof(struct task_requested_policy) == sizeof(uint64_t), "size invariant violated");

        uintptr_t* raw = (uintptr_t*)&task->requested_policy;

        return raw[0];
}

static uintptr_t
trequested_1(task_t task)
{
#if defined __LP64__
        (void)task;
        return 0;
#else
        uintptr_t* raw = (uintptr_t*)(&task->requested_policy);
        return raw[1];
#endif
}

static uintptr_t
teffective_0(task_t task)
{
        uintptr_t* raw = (uintptr_t*)&task->effective_policy;

        return raw[0];
}

static uintptr_t
teffective_1(task_t task)
{
#if defined __LP64__
        (void)task;
        return 0;
#else
        uintptr_t* raw = (uintptr_t*)(&task->effective_policy);
        return raw[1];
#endif
}

/* dump pending for tracepoint */
uint32_t
tpending(task_pend_token_t pend_token)
{
        return *(uint32_t*)(void*)(pend_token);
}

uint64_t
task_requested_bitfield(task_t task)
{
        uint64_t bits = 0;
        struct task_requested_policy requested = task->requested_policy;

        bits |= (requested.trp_int_darwinbg     ? POLICY_REQ_INT_DARWIN_BG  : 0);
        bits |= (requested.trp_ext_darwinbg     ? POLICY_REQ_EXT_DARWIN_BG  : 0);
        bits |= (requested.trp_int_iotier       ? (((uint64_t)requested.trp_int_iotier) << POLICY_REQ_INT_IO_TIER_SHIFT) : 0);
        bits |= (requested.trp_ext_iotier       ? (((uint64_t)requested.trp_ext_iotier) << POLICY_REQ_EXT_IO_TIER_SHIFT) : 0);
        bits |= (requested.trp_int_iopassive    ? POLICY_REQ_INT_PASSIVE_IO : 0);
        bits |= (requested.trp_ext_iopassive    ? POLICY_REQ_EXT_PASSIVE_IO : 0);
        bits |= (requested.trp_bg_iotier        ? (((uint64_t)requested.trp_bg_iotier) << POLICY_REQ_BG_IOTIER_SHIFT)   : 0);
        bits |= (requested.trp_terminated       ? POLICY_REQ_TERMINATED     : 0);

        bits |= (requested.trp_boosted          ? POLICY_REQ_BOOSTED        : 0);
        bits |= (requested.trp_tal_enabled      ? POLICY_REQ_TAL_ENABLED    : 0);
        bits |= (requested.trp_apptype          ? (((uint64_t)requested.trp_apptype) << POLICY_REQ_APPTYPE_SHIFT)  : 0);
        bits |= (requested.trp_role             ? (((uint64_t)requested.trp_role) << POLICY_REQ_ROLE_SHIFT)     : 0);

        bits |= (requested.trp_sup_active       ? POLICY_REQ_SUP_ACTIVE         : 0);
        bits |= (requested.trp_sup_lowpri_cpu   ? POLICY_REQ_SUP_LOWPRI_CPU     : 0);
        bits |= (requested.trp_sup_cpu          ? POLICY_REQ_SUP_CPU            : 0);
        bits |= (requested.trp_sup_timer        ? (((uint64_t)requested.trp_sup_timer) << POLICY_REQ_SUP_TIMER_THROTTLE_SHIFT) : 0);
        bits |= (requested.trp_sup_throughput   ? (((uint64_t)requested.trp_sup_throughput) << POLICY_REQ_SUP_THROUGHPUT_SHIFT)     : 0);
        bits |= (requested.trp_sup_disk         ? POLICY_REQ_SUP_DISK_THROTTLE  : 0);
        bits |= (requested.trp_sup_bg_sockets   ? POLICY_REQ_SUP_BG_SOCKETS     : 0);

        bits |= (requested.trp_base_latency_qos ? (((uint64_t)requested.trp_base_latency_qos) << POLICY_REQ_BASE_LATENCY_QOS_SHIFT) : 0);
        bits |= (requested.trp_over_latency_qos ? (((uint64_t)requested.trp_over_latency_qos) << POLICY_REQ_OVER_LATENCY_QOS_SHIFT) : 0);
        bits |= (requested.trp_base_through_qos ? (((uint64_t)requested.trp_base_through_qos) << POLICY_REQ_BASE_THROUGH_QOS_SHIFT) : 0);
        bits |= (requested.trp_over_through_qos ? (((uint64_t)requested.trp_over_through_qos) << POLICY_REQ_OVER_THROUGH_QOS_SHIFT) : 0);
        bits |= (requested.trp_sfi_managed      ? POLICY_REQ_SFI_MANAGED        : 0);
        bits |= (requested.trp_qos_clamp        ? (((uint64_t)requested.trp_qos_clamp) << POLICY_REQ_QOS_CLAMP_SHIFT)        : 0);

        return bits;
}

uint64_t
task_effective_bitfield(task_t task)
{
        uint64_t bits = 0;
        struct task_effective_policy effective = task->effective_policy;

        bits |= (effective.tep_io_tier          ? (((uint64_t)effective.tep_io_tier) << POLICY_EFF_IO_TIER_SHIFT) : 0);
        bits |= (effective.tep_io_passive       ? POLICY_EFF_IO_PASSIVE     : 0);
        bits |= (effective.tep_darwinbg         ? POLICY_EFF_DARWIN_BG      : 0);
        bits |= (effective.tep_lowpri_cpu       ? POLICY_EFF_LOWPRI_CPU     : 0);
        bits |= (effective.tep_terminated       ? POLICY_EFF_TERMINATED     : 0);
        bits |= (effective.tep_all_sockets_bg   ? POLICY_EFF_ALL_SOCKETS_BG : 0);
        bits |= (effective.tep_new_sockets_bg   ? POLICY_EFF_NEW_SOCKETS_BG : 0);
        bits |= (effective.tep_bg_iotier        ? (((uint64_t)effective.tep_bg_iotier) << POLICY_EFF_BG_IOTIER_SHIFT) : 0);
        bits |= (effective.tep_qos_ui_is_urgent ? POLICY_EFF_QOS_UI_IS_URGENT : 0);

        bits |= (effective.tep_tal_engaged      ? POLICY_EFF_TAL_ENGAGED    : 0);
        bits |= (effective.tep_watchers_bg      ? POLICY_EFF_WATCHERS_BG    : 0);
        bits |= (effective.tep_sup_active       ? POLICY_EFF_SUP_ACTIVE     : 0);
        bits |= (effective.tep_suppressed_cpu   ? POLICY_EFF_SUP_CPU        : 0);
        bits |= (effective.tep_role             ? (((uint64_t)effective.tep_role) << POLICY_EFF_ROLE_SHIFT)        : 0);
        bits |= (effective.tep_latency_qos      ? (((uint64_t)effective.tep_latency_qos) << POLICY_EFF_LATENCY_QOS_SHIFT) : 0);
        bits |= (effective.tep_through_qos      ? (((uint64_t)effective.tep_through_qos) << POLICY_EFF_THROUGH_QOS_SHIFT) : 0);
        bits |= (effective.tep_sfi_managed      ? POLICY_EFF_SFI_MANAGED    : 0);
        bits |= (effective.tep_qos_ceiling      ? (((uint64_t)effective.tep_qos_ceiling) << POLICY_EFF_QOS_CEILING_SHIFT) : 0);

        return bits;
}


/*
 * Resource usage and CPU related routines
 */

int
proc_get_task_ruse_cpu(task_t task, uint32_t *policyp, uint8_t *percentagep, uint64_t *intervalp, uint64_t *deadlinep)
{
        int error = 0;
        int scope;

        task_lock(task);


        error = task_get_cpuusage(task, percentagep, intervalp, deadlinep, &scope);
        task_unlock(task);

        /*
         * Reverse-map from CPU resource limit scopes back to policies (see comment below).
         */
        if (scope == TASK_RUSECPU_FLAGS_PERTHR_LIMIT) {
                *policyp = TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC;
        } else if (scope == TASK_RUSECPU_FLAGS_PROC_LIMIT) {
                *policyp = TASK_POLICY_RESOURCE_ATTRIBUTE_THROTTLE;
        } else if (scope == TASK_RUSECPU_FLAGS_DEADLINE) {
                *policyp = TASK_POLICY_RESOURCE_ATTRIBUTE_NONE;
        }

        return error;
}

/*
 * Configure the default CPU usage monitor parameters.
 *
 * For tasks which have this mechanism activated: if any thread in the
 * process consumes more CPU than this, an EXC_RESOURCE exception will be generated.
 */
void
proc_init_cpumon_params(void)
{
        /*
         * The max CPU percentage can be configured via the boot-args and
         * a key in the device tree. The boot-args are honored first, then the
         * device tree.
         */
        if (!PE_parse_boot_argn("max_cpumon_percentage", &proc_max_cpumon_percentage,
            sizeof(proc_max_cpumon_percentage))) {
                uint64_t max_percentage = 0ULL;

                if (!PE_get_default("kern.max_cpumon_percentage", &max_percentage,
                    sizeof(max_percentage))) {
                        max_percentage = DEFAULT_CPUMON_PERCENTAGE;
                }

                assert(max_percentage <= UINT8_MAX);
                proc_max_cpumon_percentage = (uint8_t) max_percentage;
        }

        if (proc_max_cpumon_percentage > 100) {
                proc_max_cpumon_percentage = 100;
        }

        /*
         * The interval should be specified in seconds.
         *
         * Like the max CPU percentage, the max CPU interval can be configured
         * via boot-args and the device tree.
         */
        if (!PE_parse_boot_argn("max_cpumon_interval", &proc_max_cpumon_interval,
            sizeof(proc_max_cpumon_interval))) {
                if (!PE_get_default("kern.max_cpumon_interval", &proc_max_cpumon_interval,
                    sizeof(proc_max_cpumon_interval))) {
                        proc_max_cpumon_interval = DEFAULT_CPUMON_INTERVAL;
                }
        }

        proc_max_cpumon_interval *= NSEC_PER_SEC;

        /* TEMPORARY boot arg to control App suppression */
        PE_parse_boot_argn("task_policy_suppression_flags",
            &task_policy_suppression_flags,
            sizeof(task_policy_suppression_flags));

        /* adjust suppression disk policy if called for in boot arg */
        if (task_policy_suppression_flags & TASK_POLICY_SUPPRESSION_IOTIER2) {
                proc_suppressed_disk_tier = THROTTLE_LEVEL_TIER2;
        }
}

/*
 * Currently supported configurations for CPU limits.
 *
 * Policy                               | Deadline-based CPU limit | Percentage-based CPU limit
 * -------------------------------------+--------------------------+------------------------------
 * PROC_POLICY_RSRCACT_THROTTLE         | ENOTSUP                  | Task-wide scope only
 * PROC_POLICY_RSRCACT_SUSPEND          | Task-wide scope only     | ENOTSUP
 * PROC_POLICY_RSRCACT_TERMINATE        | Task-wide scope only     | ENOTSUP
 * PROC_POLICY_RSRCACT_NOTIFY_KQ        | Task-wide scope only     | ENOTSUP
 * PROC_POLICY_RSRCACT_NOTIFY_EXC       | ENOTSUP                  | Per-thread scope only
 *
 * A deadline-based CPU limit is actually a simple wallclock timer - the requested action is performed
 * after the specified amount of wallclock time has elapsed.
 *
 * A percentage-based CPU limit performs the requested action after the specified amount of actual CPU time
 * has been consumed -- regardless of how much wallclock time has elapsed -- by either the task as an
 * aggregate entity (so-called "Task-wide" or "Proc-wide" scope, whereby the CPU time consumed by all threads
 * in the task are added together), or by any one thread in the task (so-called "per-thread" scope).
 *
 * We support either deadline != 0 OR percentage != 0, but not both. The original intention in having them
 * share an API was to use actual CPU time as the basis of the deadline-based limit (as in: perform an action
 * after I have used some amount of CPU time; this is different than the recurring percentage/interval model)
 * but the potential consumer of the API at the time was insisting on wallclock time instead.
 *
 * Currently, requesting notification via an exception is the only way to get per-thread scope for a
 * CPU limit. All other types of notifications force task-wide scope for the limit.
 */
int
proc_set_task_ruse_cpu(task_t task, uint32_t policy, uint8_t percentage, uint64_t interval, uint64_t deadline,
    int cpumon_entitled)
{
        int error = 0;
        int scope;

        /*
         * Enforce the matrix of supported configurations for policy, percentage, and deadline.
         */
        switch (policy) {
        // If no policy is explicitly given, the default is to throttle.
        case TASK_POLICY_RESOURCE_ATTRIBUTE_NONE:
        case TASK_POLICY_RESOURCE_ATTRIBUTE_THROTTLE:
                if (deadline != 0) {
                        return ENOTSUP;
                }
                scope = TASK_RUSECPU_FLAGS_PROC_LIMIT;
                break;
        case TASK_POLICY_RESOURCE_ATTRIBUTE_SUSPEND:
        case TASK_POLICY_RESOURCE_ATTRIBUTE_TERMINATE:
        case TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_KQ:
                if (percentage != 0) {
                        return ENOTSUP;
                }
                scope = TASK_RUSECPU_FLAGS_DEADLINE;
                break;
        case TASK_POLICY_RESOURCE_ATTRIBUTE_NOTIFY_EXC:
                if (deadline != 0) {
                        return ENOTSUP;
                }
                scope = TASK_RUSECPU_FLAGS_PERTHR_LIMIT;
#ifdef CONFIG_NOMONITORS
                return error;
#endif /* CONFIG_NOMONITORS */
                break;
        default:
                return EINVAL;
        }

        task_lock(task);
        if (task != current_task()) {
                task->policy_ru_cpu_ext = policy;
        } else {
                task->policy_ru_cpu = policy;
        }
        error = task_set_cpuusage(task, percentage, interval, deadline, scope, cpumon_entitled);
        task_unlock(task);
        return error;
}

/* TODO: get rid of these */
#define TASK_POLICY_CPU_RESOURCE_USAGE          0
#define TASK_POLICY_WIREDMEM_RESOURCE_USAGE     1
#define TASK_POLICY_VIRTUALMEM_RESOURCE_USAGE   2
#define TASK_POLICY_DISK_RESOURCE_USAGE         3
#define TASK_POLICY_NETWORK_RESOURCE_USAGE      4
#define TASK_POLICY_POWER_RESOURCE_USAGE        5

#define TASK_POLICY_RESOURCE_USAGE_COUNT        6

int
proc_clear_task_ruse_cpu(task_t task, int cpumon_entitled)
{
        int error = 0;
        int action;
        void * bsdinfo = NULL;

        task_lock(task);
        if (task != current_task()) {
                task->policy_ru_cpu_ext = TASK_POLICY_RESOURCE_ATTRIBUTE_DEFAULT;
        } else {
                task->policy_ru_cpu = TASK_POLICY_RESOURCE_ATTRIBUTE_DEFAULT;
        }

        error = task_clear_cpuusage_locked(task, cpumon_entitled);
        if (error != 0) {
                goto out;
        }

        action = task->applied_ru_cpu;
        if (task->applied_ru_cpu_ext != TASK_POLICY_RESOURCE_ATTRIBUTE_NONE) {
                /* reset action */
                task->applied_ru_cpu_ext = TASK_POLICY_RESOURCE_ATTRIBUTE_NONE;
        }
        if (action != TASK_POLICY_RESOURCE_ATTRIBUTE_NONE) {
                bsdinfo = task->bsd_info;
                task_unlock(task);
                proc_restore_resource_actions(bsdinfo, TASK_POLICY_CPU_RESOURCE_USAGE, action);
                goto out1;
        }

out:
        task_unlock(task);
out1:
        return error;
}

/* used to apply resource limit related actions */
static int
task_apply_resource_actions(task_t task, int type)
{
        int action = TASK_POLICY_RESOURCE_ATTRIBUTE_NONE;
        void * bsdinfo = NULL;

        switch (type) {
        case TASK_POLICY_CPU_RESOURCE_USAGE:
                break;
        case TASK_POLICY_WIREDMEM_RESOURCE_USAGE:
        case TASK_POLICY_VIRTUALMEM_RESOURCE_USAGE:
        case TASK_POLICY_DISK_RESOURCE_USAGE:
        case TASK_POLICY_NETWORK_RESOURCE_USAGE:
        case TASK_POLICY_POWER_RESOURCE_USAGE:
                return 0;

        default:
                return 1;
        }
        ;

        /* only cpu actions for now */
        task_lock(task);

        if (task->applied_ru_cpu_ext == TASK_POLICY_RESOURCE_ATTRIBUTE_NONE) {
                /* apply action */
                task->applied_ru_cpu_ext = task->policy_ru_cpu_ext;
                action = task->applied_ru_cpu_ext;
        } else {
                action = task->applied_ru_cpu_ext;
        }

        if (action != TASK_POLICY_RESOURCE_ATTRIBUTE_NONE) {
                bsdinfo = task->bsd_info;
                task_unlock(task);
                proc_apply_resource_actions(bsdinfo, TASK_POLICY_CPU_RESOURCE_USAGE, action);
        } else {
                task_unlock(task);
        }

        return 0;
}

/*
 * XXX This API is somewhat broken; we support multiple simultaneous CPU limits, but the get/set API
 * only allows for one at a time. This means that if there is a per-thread limit active, the other
 * "scopes" will not be accessible via this API. We could change it to pass in the scope of interest
 * to the caller, and prefer that, but there's no need for that at the moment.
 */
static int
task_get_cpuusage(task_t task, uint8_t *percentagep, uint64_t *intervalp, uint64_t *deadlinep, int *scope)
{
        *percentagep = 0;
        *intervalp = 0;
        *deadlinep = 0;

        if ((task->rusage_cpu_flags & TASK_RUSECPU_FLAGS_PERTHR_LIMIT) != 0) {
                *scope = TASK_RUSECPU_FLAGS_PERTHR_LIMIT;
                *percentagep = task->rusage_cpu_perthr_percentage;
                *intervalp = task->rusage_cpu_perthr_interval;
        } else if ((task->rusage_cpu_flags & TASK_RUSECPU_FLAGS_PROC_LIMIT) != 0) {
                *scope = TASK_RUSECPU_FLAGS_PROC_LIMIT;
                *percentagep = task->rusage_cpu_percentage;
                *intervalp = task->rusage_cpu_interval;
        } else if ((task->rusage_cpu_flags & TASK_RUSECPU_FLAGS_DEADLINE) != 0) {
                *scope = TASK_RUSECPU_FLAGS_DEADLINE;
                *deadlinep = task->rusage_cpu_deadline;
        } else {
                *scope = 0;
        }

        return 0;
}

/*
 * Suspend the CPU usage monitor for the task.  Return value indicates
 * if the mechanism was actually enabled.
 */
int
task_suspend_cpumon(task_t task)
{
        thread_t thread;

        task_lock_assert_owned(task);

        if ((task->rusage_cpu_flags & TASK_RUSECPU_FLAGS_PERTHR_LIMIT) == 0) {
                return KERN_INVALID_ARGUMENT;
        }

#if CONFIG_TELEMETRY
        /*
         * Disable task-wide telemetry if it was ever enabled by the CPU usage
         * monitor's warning zone.
         */
        telemetry_task_ctl_locked(task, TF_CPUMON_WARNING, 0);
#endif

        /*
         * Suspend monitoring for the task, and propagate that change to each thread.
         */
        task->rusage_cpu_flags &= ~(TASK_RUSECPU_FLAGS_PERTHR_LIMIT | TASK_RUSECPU_FLAGS_FATAL_CPUMON);
        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                act_set_astledger(thread);
        }

        return KERN_SUCCESS;
}

/*
 * Remove all traces of the CPU monitor.
 */
int
task_disable_cpumon(task_t task)
{
        int kret;

        task_lock_assert_owned(task);

        kret = task_suspend_cpumon(task);
        if (kret) {
                return kret;
        }

        /* Once we clear these values, the monitor can't be resumed */
        task->rusage_cpu_perthr_percentage = 0;
        task->rusage_cpu_perthr_interval = 0;

        return KERN_SUCCESS;
}


static int
task_enable_cpumon_locked(task_t task)
{
        thread_t thread;
        task_lock_assert_owned(task);

        if (task->rusage_cpu_perthr_percentage == 0 ||
            task->rusage_cpu_perthr_interval == 0) {
                return KERN_INVALID_ARGUMENT;
        }

        task->rusage_cpu_flags |= TASK_RUSECPU_FLAGS_PERTHR_LIMIT;
        queue_iterate(&task->threads, thread, thread_t, task_threads) {
                act_set_astledger(thread);
        }

        return KERN_SUCCESS;
}

int
task_resume_cpumon(task_t task)
{
        kern_return_t kret;

        if (!task) {
                return EINVAL;
        }

        task_lock(task);
        kret = task_enable_cpumon_locked(task);
        task_unlock(task);

        return kret;
}


/* duplicate values from bsd/sys/process_policy.h */
#define PROC_POLICY_CPUMON_DISABLE      0xFF
#define PROC_POLICY_CPUMON_DEFAULTS     0xFE

static int
task_set_cpuusage(task_t task, uint8_t percentage, uint64_t interval, uint64_t deadline, int scope, int cpumon_entitled)
{
        uint64_t abstime = 0;
        uint64_t limittime = 0;

        lck_mtx_assert(&task->lock, LCK_MTX_ASSERT_OWNED);

        /* By default, refill once per second */
        if (interval == 0) {
                interval = NSEC_PER_SEC;
        }

        if (percentage != 0) {
                if (scope == TASK_RUSECPU_FLAGS_PERTHR_LIMIT) {
                        boolean_t warn = FALSE;

                        /*
                         * A per-thread CPU limit on a task generates an exception
                         * (LEDGER_ACTION_EXCEPTION) if any one thread in the task
                         * exceeds the limit.
                         */

                        if (percentage == PROC_POLICY_CPUMON_DISABLE) {
                                if (cpumon_entitled) {
                                        /* 25095698 - task_disable_cpumon() should be reliable */
                                        task_disable_cpumon(task);
                                        return 0;
                                }

                                /*
                                 * This task wishes to disable the CPU usage monitor, but it's
                                 * missing the required entitlement:
                                 *     com.apple.private.kernel.override-cpumon
                                 *
                                 * Instead, treat this as a request to reset its params
                                 * back to the defaults.
                                 */
                                warn = TRUE;
                                percentage = PROC_POLICY_CPUMON_DEFAULTS;
                        }

                        if (percentage == PROC_POLICY_CPUMON_DEFAULTS) {
                                percentage = proc_max_cpumon_percentage;
                                interval   = proc_max_cpumon_interval;
                        }

                        if (percentage > 100) {
                                percentage = 100;
                        }

                        /*
                         * Passing in an interval of -1 means either:
                         * - Leave the interval as-is, if there's already a per-thread
                         *   limit configured
                         * - Use the system default.
                         */
                        if (interval == -1ULL) {
                                if (task->rusage_cpu_flags & TASK_RUSECPU_FLAGS_PERTHR_LIMIT) {
                                        interval = task->rusage_cpu_perthr_interval;
                                } else {
                                        interval = proc_max_cpumon_interval;
                                }
                        }

                        /*
                         * Enforce global caps on CPU usage monitor here if the process is not
                         * entitled to escape the global caps.
                         */
                        if ((percentage > proc_max_cpumon_percentage) && (cpumon_entitled == 0)) {
                                warn = TRUE;
                                percentage = proc_max_cpumon_percentage;
                        }

                        if ((interval > proc_max_cpumon_interval) && (cpumon_entitled == 0)) {
                                warn = TRUE;
                                interval = proc_max_cpumon_interval;
                        }

                        if (warn) {
                                int       pid = 0;
                                const char *procname = "unknown";

#ifdef MACH_BSD
                                pid = proc_selfpid();
                                if (current_task()->bsd_info != NULL) {
                                        procname = proc_name_address(current_task()->bsd_info);
                                }
#endif

                                printf("process %s[%d] denied attempt to escape CPU monitor"
                                    " (missing required entitlement).\n", procname, pid);
                        }

                        /* configure the limit values */
                        task->rusage_cpu_perthr_percentage = percentage;
                        task->rusage_cpu_perthr_interval = interval;

                        /* and enable the CPU monitor */
                        (void)task_enable_cpumon_locked(task);
                } else if (scope == TASK_RUSECPU_FLAGS_PROC_LIMIT) {
                        /*
                         * Currently, a proc-wide CPU limit always blocks if the limit is
                         * exceeded (LEDGER_ACTION_BLOCK).
                         */
                        task->rusage_cpu_flags |= TASK_RUSECPU_FLAGS_PROC_LIMIT;
                        task->rusage_cpu_percentage = percentage;
                        task->rusage_cpu_interval = interval;

                        limittime = (interval * percentage) / 100;
                        nanoseconds_to_absolutetime(limittime, &abstime);

                        ledger_set_limit(task->ledger, task_ledgers.cpu_time, abstime, 0);
                        ledger_set_period(task->ledger, task_ledgers.cpu_time, interval);
                        ledger_set_action(task->ledger, task_ledgers.cpu_time, LEDGER_ACTION_BLOCK);
                }
        }

        if (deadline != 0) {
                assert(scope == TASK_RUSECPU_FLAGS_DEADLINE);

                /* if already in use, cancel and wait for it to cleanout */
                if (task->rusage_cpu_callt != NULL) {
                        task_unlock(task);
                        thread_call_cancel_wait(task->rusage_cpu_callt);
                        task_lock(task);
                }
                if (task->rusage_cpu_callt == NULL) {
                        task->rusage_cpu_callt = thread_call_allocate_with_priority(task_action_cpuusage, (thread_call_param_t)task, THREAD_CALL_PRIORITY_KERNEL);
                }
                /* setup callout */
                if (task->rusage_cpu_callt != 0) {
                        uint64_t save_abstime = 0;

                        task->rusage_cpu_flags |= TASK_RUSECPU_FLAGS_DEADLINE;
                        task->rusage_cpu_deadline = deadline;

                        nanoseconds_to_absolutetime(deadline, &abstime);
                        save_abstime = abstime;
                        clock_absolutetime_interval_to_deadline(save_abstime, &abstime);
                        thread_call_enter_delayed(task->rusage_cpu_callt, abstime);
                }
        }

        return 0;
}

int
task_clear_cpuusage(task_t task, int cpumon_entitled)
{
        int retval = 0;

        task_lock(task);
        retval = task_clear_cpuusage_locked(task, cpumon_entitled);
        task_unlock(task);

        return retval;
}

static int
task_clear_cpuusage_locked(task_t task, int cpumon_entitled)
{
        thread_call_t savecallt;

        /* cancel percentage handling if set */
        if (task->rusage_cpu_flags & TASK_RUSECPU_FLAGS_PROC_LIMIT) {
                task->rusage_cpu_flags &= ~TASK_RUSECPU_FLAGS_PROC_LIMIT;
                ledger_set_limit(task->ledger, task_ledgers.cpu_time, LEDGER_LIMIT_INFINITY, 0);
                task->rusage_cpu_percentage = 0;
                task->rusage_cpu_interval = 0;
        }

        /*
         * Disable the CPU usage monitor.
         */
        if (cpumon_entitled) {
                task_disable_cpumon(task);
        }

        /* cancel deadline handling if set */
        if (task->rusage_cpu_flags & TASK_RUSECPU_FLAGS_DEADLINE) {
                task->rusage_cpu_flags &= ~TASK_RUSECPU_FLAGS_DEADLINE;
                if (task->rusage_cpu_callt != 0) {
                        savecallt = task->rusage_cpu_callt;
                        task->rusage_cpu_callt = NULL;
                        task->rusage_cpu_deadline = 0;
                        task_unlock(task);
                        thread_call_cancel_wait(savecallt);
                        thread_call_free(savecallt);
                        task_lock(task);
                }
        }
        return 0;
}

/* called by ledger unit to enforce action due to resource usage criteria being met */
static void
task_action_cpuusage(thread_call_param_t param0, __unused thread_call_param_t param1)
{
        task_t task = (task_t)param0;
        (void)task_apply_resource_actions(task, TASK_POLICY_CPU_RESOURCE_USAGE);
        return;
}


/*
 * Routines for taskwatch and pidbind
 */

#if CONFIG_EMBEDDED

lck_mtx_t       task_watch_mtx;

void
task_watch_init(void)
{
        lck_mtx_init(&task_watch_mtx, &task_lck_grp, &task_lck_attr);
}

static void
task_watch_lock(void)
{
        lck_mtx_lock(&task_watch_mtx);
}

static void
task_watch_unlock(void)
{
        lck_mtx_unlock(&task_watch_mtx);
}

static void
add_taskwatch_locked(task_t task, task_watch_t * twp)
{
        queue_enter(&task->task_watchers, twp, task_watch_t *, tw_links);
        task->num_taskwatchers++;
}

static void
remove_taskwatch_locked(task_t task, task_watch_t * twp)
{
        queue_remove(&task->task_watchers, twp, task_watch_t *, tw_links);
        task->num_taskwatchers--;
}


int
proc_lf_pidbind(task_t curtask, uint64_t tid, task_t target_task, int bind)
{
        thread_t target_thread = NULL;
        int ret = 0, setbg = 0;
        task_watch_t *twp = NULL;
        task_t task = TASK_NULL;

        target_thread = task_findtid(curtask, tid);
        if (target_thread == NULL) {
                return ESRCH;
        }
        /* holds thread reference */

        if (bind != 0) {
                /* task is still active ? */
                task_lock(target_task);
                if (target_task->active == 0) {
                        task_unlock(target_task);
                        ret = ESRCH;
                        goto out;
                }
                task_unlock(target_task);

                twp = (task_watch_t *)kalloc(sizeof(task_watch_t));
                if (twp == NULL) {
                        task_watch_unlock();
                        ret = ENOMEM;
                        goto out;
                }

                bzero(twp, sizeof(task_watch_t));

                task_watch_lock();

                if (target_thread->taskwatch != NULL) {
                        /* already bound to another task */
                        task_watch_unlock();

                        kfree(twp, sizeof(task_watch_t));
                        ret = EBUSY;
                        goto out;
                }

                task_reference(target_task);

                setbg = proc_get_effective_task_policy(target_task, TASK_POLICY_WATCHERS_BG);

                twp->tw_task = target_task;             /* holds the task reference */
                twp->tw_thread = target_thread;         /* holds the thread reference */
                twp->tw_state = setbg;
                twp->tw_importance = target_thread->importance;

                add_taskwatch_locked(target_task, twp);

                target_thread->taskwatch = twp;

                task_watch_unlock();

                if (setbg) {
                        set_thread_appbg(target_thread, setbg, INT_MIN);
                }

                /* retain the thread reference as it is in twp */
                target_thread = NULL;
        } else {
                /* unbind */
                task_watch_lock();
                if ((twp = target_thread->taskwatch) != NULL) {
                        task = twp->tw_task;
                        target_thread->taskwatch = NULL;
                        remove_taskwatch_locked(task, twp);

                        task_watch_unlock();

                        task_deallocate(task);                  /* drop task ref in twp */
                        set_thread_appbg(target_thread, 0, twp->tw_importance);
                        thread_deallocate(target_thread);       /* drop thread ref in twp */
                        kfree(twp, sizeof(task_watch_t));
                } else {
                        task_watch_unlock();
                        ret = 0;                /* return success if it not alredy bound */
                        goto out;
                }
        }
out:
        thread_deallocate(target_thread);       /* drop thread ref acquired in this routine */
        return ret;
}

static void
set_thread_appbg(thread_t thread, int setbg, __unused int importance)
{
        int enable = (setbg ? TASK_POLICY_ENABLE : TASK_POLICY_DISABLE);

        proc_set_thread_policy(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_PIDBIND_BG, enable);
}

static void
apply_appstate_watchers(task_t task)
{
        int numwatchers = 0, i, j, setbg;
        thread_watchlist_t * threadlist;
        task_watch_t * twp;

retry:
        /* if no watchers on the list return */
        if ((numwatchers = task->num_taskwatchers) == 0) {
                return;
        }

        threadlist = (thread_watchlist_t *)kalloc(numwatchers * sizeof(thread_watchlist_t));
        if (threadlist == NULL) {
                return;
        }

        bzero(threadlist, numwatchers * sizeof(thread_watchlist_t));

        task_watch_lock();
        /*serialize application of app state changes */

        if (task->watchapplying != 0) {
                lck_mtx_sleep(&task_watch_mtx, LCK_SLEEP_DEFAULT, &task->watchapplying, THREAD_UNINT);
                task_watch_unlock();
                kfree(threadlist, numwatchers * sizeof(thread_watchlist_t));
                goto retry;
        }

        if (numwatchers != task->num_taskwatchers) {
                task_watch_unlock();
                kfree(threadlist, numwatchers * sizeof(thread_watchlist_t));
                goto retry;
        }

        setbg = proc_get_effective_task_policy(task, TASK_POLICY_WATCHERS_BG);

        task->watchapplying = 1;
        i = 0;
        queue_iterate(&task->task_watchers, twp, task_watch_t *, tw_links) {
                threadlist[i].thread = twp->tw_thread;
                thread_reference(threadlist[i].thread);
                if (setbg != 0) {
                        twp->tw_importance = twp->tw_thread->importance;
                        threadlist[i].importance = INT_MIN;
                } else {
                        threadlist[i].importance = twp->tw_importance;
                }
                i++;
                if (i > numwatchers) {
                        break;
                }
        }

        task_watch_unlock();

        for (j = 0; j < i; j++) {
                set_thread_appbg(threadlist[j].thread, setbg, threadlist[j].importance);
                thread_deallocate(threadlist[j].thread);
        }
        kfree(threadlist, numwatchers * sizeof(thread_watchlist_t));


        task_watch_lock();
        task->watchapplying = 0;
        thread_wakeup_one(&task->watchapplying);
        task_watch_unlock();
}

void
thead_remove_taskwatch(thread_t thread)
{
        task_watch_t * twp;
        int importance = 0;

        task_watch_lock();
        if ((twp = thread->taskwatch) != NULL) {
                thread->taskwatch = NULL;
                remove_taskwatch_locked(twp->tw_task, twp);
        }
        task_watch_unlock();
        if (twp != NULL) {
                thread_deallocate(twp->tw_thread);
                task_deallocate(twp->tw_task);
                importance = twp->tw_importance;
                kfree(twp, sizeof(task_watch_t));
                /* remove the thread and networkbg */
                set_thread_appbg(thread, 0, importance);
        }
}

void
task_removewatchers(task_t task)
{
        int numwatchers = 0, i, j;
        task_watch_t ** twplist = NULL;
        task_watch_t * twp = NULL;

retry:
        if ((numwatchers = task->num_taskwatchers) == 0) {
                return;
        }

        twplist = (task_watch_t **)kalloc(numwatchers * sizeof(task_watch_t *));
        if (twplist == NULL) {
                return;
        }

        bzero(twplist, numwatchers * sizeof(task_watch_t *));

        task_watch_lock();
        if (task->num_taskwatchers == 0) {
                task_watch_unlock();
                goto out;
        }

        if (numwatchers != task->num_taskwatchers) {
                task_watch_unlock();
                kfree(twplist, numwatchers * sizeof(task_watch_t *));
                numwatchers = 0;
                goto retry;
        }

        i = 0;
        while ((twp = (task_watch_t *)dequeue_head(&task->task_watchers)) != NULL) {
                twplist[i] = twp;
                task->num_taskwatchers--;

                /*
                 * Since the linkage is removed and thead state cleanup is already set up,
                 * remove the refernce from the thread.
                 */
                twp->tw_thread->taskwatch = NULL;       /* removed linkage, clear thread holding ref */
                i++;
                if ((task->num_taskwatchers == 0) || (i > numwatchers)) {
                        break;
                }
        }

        task_watch_unlock();

        for (j = 0; j < i; j++) {
                twp = twplist[j];
                /* remove thread and network bg */
                set_thread_appbg(twp->tw_thread, 0, twp->tw_importance);
                thread_deallocate(twp->tw_thread);
                task_deallocate(twp->tw_task);
                kfree(twp, sizeof(task_watch_t));
        }

out:
        kfree(twplist, numwatchers * sizeof(task_watch_t *));
}
#endif /* CONFIG_EMBEDDED */

/*
 * Routines for importance donation/inheritance/boosting
 */

static void
task_importance_update_live_donor(task_t target_task)
{
#if IMPORTANCE_INHERITANCE

        ipc_importance_task_t task_imp;

        task_imp = ipc_importance_for_task(target_task, FALSE);
        if (IIT_NULL != task_imp) {
                ipc_importance_task_update_live_donor(task_imp);
                ipc_importance_task_release(task_imp);
        }
#endif /* IMPORTANCE_INHERITANCE */
}

void
task_importance_mark_donor(task_t task, boolean_t donating)
{
#if IMPORTANCE_INHERITANCE
        ipc_importance_task_t task_imp;

        task_imp = ipc_importance_for_task(task, FALSE);
        if (IIT_NULL != task_imp) {
                ipc_importance_task_mark_donor(task_imp, donating);
                ipc_importance_task_release(task_imp);
        }
#endif /* IMPORTANCE_INHERITANCE */
}

void
task_importance_mark_live_donor(task_t task, boolean_t live_donating)
{
#if IMPORTANCE_INHERITANCE
        ipc_importance_task_t task_imp;

        task_imp = ipc_importance_for_task(task, FALSE);
        if (IIT_NULL != task_imp) {
                ipc_importance_task_mark_live_donor(task_imp, live_donating);
                ipc_importance_task_release(task_imp);
        }
#endif /* IMPORTANCE_INHERITANCE */
}

void
task_importance_mark_receiver(task_t task, boolean_t receiving)
{
#if IMPORTANCE_INHERITANCE
        ipc_importance_task_t task_imp;

        task_imp = ipc_importance_for_task(task, FALSE);
        if (IIT_NULL != task_imp) {
                ipc_importance_task_mark_receiver(task_imp, receiving);
                ipc_importance_task_release(task_imp);
        }
#endif /* IMPORTANCE_INHERITANCE */
}

void
task_importance_mark_denap_receiver(task_t task, boolean_t denap)
{
#if IMPORTANCE_INHERITANCE
        ipc_importance_task_t task_imp;

        task_imp = ipc_importance_for_task(task, FALSE);
        if (IIT_NULL != task_imp) {
                ipc_importance_task_mark_denap_receiver(task_imp, denap);
                ipc_importance_task_release(task_imp);
        }
#endif /* IMPORTANCE_INHERITANCE */
}

void
task_importance_reset(__imp_only task_t task)
{
#if IMPORTANCE_INHERITANCE
        ipc_importance_task_t task_imp;

        /* TODO: Lower importance downstream before disconnect */
        task_imp = task->task_imp_base;
        ipc_importance_reset(task_imp, FALSE);
        task_importance_update_live_donor(task);
#endif /* IMPORTANCE_INHERITANCE */
}

void
task_importance_init_from_parent(__imp_only task_t new_task, __imp_only task_t parent_task)
{
#if IMPORTANCE_INHERITANCE
        ipc_importance_task_t new_task_imp = IIT_NULL;

        new_task->task_imp_base = NULL;
        if (!parent_task) {
                return;
        }

        if (task_is_marked_importance_donor(parent_task)) {
                new_task_imp = ipc_importance_for_task(new_task, FALSE);
                assert(IIT_NULL != new_task_imp);
                ipc_importance_task_mark_donor(new_task_imp, TRUE);
        }
        if (task_is_marked_live_importance_donor(parent_task)) {
                if (IIT_NULL == new_task_imp) {
                        new_task_imp = ipc_importance_for_task(new_task, FALSE);
                }
                assert(IIT_NULL != new_task_imp);
                ipc_importance_task_mark_live_donor(new_task_imp, TRUE);
        }
        /* Do not inherit 'receiver' on fork, vfexec or true spawn */
        if (task_is_exec_copy(new_task) &&
            task_is_marked_importance_receiver(parent_task)) {
                if (IIT_NULL == new_task_imp) {
                        new_task_imp = ipc_importance_for_task(new_task, FALSE);
                }
                assert(IIT_NULL != new_task_imp);
                ipc_importance_task_mark_receiver(new_task_imp, TRUE);
        }
        if (task_is_marked_importance_denap_receiver(parent_task)) {
                if (IIT_NULL == new_task_imp) {
                        new_task_imp = ipc_importance_for_task(new_task, FALSE);
                }
                assert(IIT_NULL != new_task_imp);
                ipc_importance_task_mark_denap_receiver(new_task_imp, TRUE);
        }
        if (IIT_NULL != new_task_imp) {
                assert(new_task->task_imp_base == new_task_imp);
                ipc_importance_task_release(new_task_imp);
        }
#endif /* IMPORTANCE_INHERITANCE */
}

#if IMPORTANCE_INHERITANCE
/*
 * Sets the task boost bit to the provided value.  Does NOT run the update function.
 *
 * Task lock must be held.
 */
static void
task_set_boost_locked(task_t task, boolean_t boost_active)
{
#if IMPORTANCE_TRACE
        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_BOOST, (boost_active ? IMP_BOOSTED : IMP_UNBOOSTED)) | DBG_FUNC_START),
            proc_selfpid(), task_pid(task), trequested_0(task), trequested_1(task), 0);
#endif /* IMPORTANCE_TRACE */

        task->requested_policy.trp_boosted = boost_active;

#if IMPORTANCE_TRACE
        if (boost_active == TRUE) {
                DTRACE_BOOST2(boost, task_t, task, int, task_pid(task));
        } else {
                DTRACE_BOOST2(unboost, task_t, task, int, task_pid(task));
        }
        KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_BOOST, (boost_active ? IMP_BOOSTED : IMP_UNBOOSTED)) | DBG_FUNC_END),
            proc_selfpid(), task_pid(task),
            trequested_0(task), trequested_1(task), 0);
#endif /* IMPORTANCE_TRACE */
}

/*
 * Sets the task boost bit to the provided value and applies the update.
 *
 * Task lock must be held.  Must call update complete after unlocking the task.
 */
void
task_update_boost_locked(task_t task, boolean_t boost_active, task_pend_token_t pend_token)
{
        task_set_boost_locked(task, boost_active);

        task_policy_update_locked(task, pend_token);
}

/*
 * Check if this task should donate importance.
 *
 * May be called without taking the task lock. In that case, donor status can change
 * so you must check only once for each donation event.
 */
boolean_t
task_is_importance_donor(task_t task)
{
        if (task->task_imp_base == IIT_NULL) {
                return FALSE;
        }
        return ipc_importance_task_is_donor(task->task_imp_base);
}

/*
 * Query the status of the task's donor mark.
 */
boolean_t
task_is_marked_importance_donor(task_t task)
{
        if (task->task_imp_base == IIT_NULL) {
                return FALSE;
        }
        return ipc_importance_task_is_marked_donor(task->task_imp_base);
}

/*
 * Query the status of the task's live donor and donor mark.
 */
boolean_t
task_is_marked_live_importance_donor(task_t task)
{
        if (task->task_imp_base == IIT_NULL) {
                return FALSE;
        }
        return ipc_importance_task_is_marked_live_donor(task->task_imp_base);
}


/*
 * This routine may be called without holding task lock
 * since the value of imp_receiver can never be unset.
 */
boolean_t
task_is_importance_receiver(task_t task)
{
        if (task->task_imp_base == IIT_NULL) {
                return FALSE;
        }
        return ipc_importance_task_is_marked_receiver(task->task_imp_base);
}

/*
 * Query the task's receiver mark.
 */
boolean_t
task_is_marked_importance_receiver(task_t task)
{
        if (task->task_imp_base == IIT_NULL) {
                return FALSE;
        }
        return ipc_importance_task_is_marked_receiver(task->task_imp_base);
}

/*
 * This routine may be called without holding task lock
 * since the value of de-nap receiver can never be unset.
 */
boolean_t
task_is_importance_denap_receiver(task_t task)
{
        if (task->task_imp_base == IIT_NULL) {
                return FALSE;
        }
        return ipc_importance_task_is_denap_receiver(task->task_imp_base);
}

/*
 * Query the task's de-nap receiver mark.
 */
boolean_t
task_is_marked_importance_denap_receiver(task_t task)
{
        if (task->task_imp_base == IIT_NULL) {
                return FALSE;
        }
        return ipc_importance_task_is_marked_denap_receiver(task->task_imp_base);
}

/*
 * This routine may be called without holding task lock
 * since the value of imp_receiver can never be unset.
 */
boolean_t
task_is_importance_receiver_type(task_t task)
{
        if (task->task_imp_base == IIT_NULL) {
                return FALSE;
        }
        return task_is_importance_receiver(task) ||
               task_is_importance_denap_receiver(task);
}

/*
 * External importance assertions are managed by the process in userspace
 * Internal importance assertions are the responsibility of the kernel
 * Assertions are changed from internal to external via task_importance_externalize_assertion
 */

int
task_importance_hold_internal_assertion(task_t target_task, uint32_t count)
{
        ipc_importance_task_t task_imp;
        kern_return_t ret;

        /* may be first time, so allow for possible importance setup */
        task_imp = ipc_importance_for_task(target_task, FALSE);
        if (IIT_NULL == task_imp) {
                return EOVERFLOW;
        }
        ret = ipc_importance_task_hold_internal_assertion(task_imp, count);
        ipc_importance_task_release(task_imp);

        return (KERN_SUCCESS != ret) ? ENOTSUP : 0;
}

int
task_importance_hold_file_lock_assertion(task_t target_task, uint32_t count)
{
        ipc_importance_task_t task_imp;
        kern_return_t ret;

        /* may be first time, so allow for possible importance setup */
        task_imp = ipc_importance_for_task(target_task, FALSE);
        if (IIT_NULL == task_imp) {
                return EOVERFLOW;
        }
        ret = ipc_importance_task_hold_file_lock_assertion(task_imp, count);
        ipc_importance_task_release(task_imp);

        return (KERN_SUCCESS != ret) ? ENOTSUP : 0;
}

int
task_importance_hold_legacy_external_assertion(task_t target_task, uint32_t count)
{
        ipc_importance_task_t task_imp;
        kern_return_t ret;

        /* must already have set up an importance */
        task_imp = target_task->task_imp_base;
        if (IIT_NULL == task_imp) {
                return EOVERFLOW;
        }
        ret = ipc_importance_task_hold_legacy_external_assertion(task_imp, count);
        return (KERN_SUCCESS != ret) ? ENOTSUP : 0;
}

int
task_importance_drop_file_lock_assertion(task_t target_task, uint32_t count)
{
        ipc_importance_task_t task_imp;
        kern_return_t ret;

        /* must already have set up an importance */
        task_imp = target_task->task_imp_base;
        if (IIT_NULL == task_imp) {
                return EOVERFLOW;
        }
        ret = ipc_importance_task_drop_file_lock_assertion(target_task->task_imp_base, count);
        return (KERN_SUCCESS != ret) ? EOVERFLOW : 0;
}

int
task_importance_drop_legacy_external_assertion(task_t target_task, uint32_t count)
{
        ipc_importance_task_t task_imp;
        kern_return_t ret;

        /* must already have set up an importance */
        task_imp = target_task->task_imp_base;
        if (IIT_NULL == task_imp) {
                return EOVERFLOW;
        }
        ret = ipc_importance_task_drop_legacy_external_assertion(task_imp, count);
        return (KERN_SUCCESS != ret) ? EOVERFLOW : 0;
}

static void
task_add_importance_watchport(task_t task, mach_port_t port, int *boostp)
{
        int boost = 0;

        __imptrace_only int released_pid = 0;
        __imptrace_only int pid = task_pid(task);

        ipc_importance_task_t release_imp_task = IIT_NULL;

        if (IP_VALID(port) != 0) {
                ipc_importance_task_t new_imp_task = ipc_importance_for_task(task, FALSE);

                ip_lock(port);

                /*
                 * The port must have been marked tempowner already.
                 * This also filters out ports whose receive rights
                 * are already enqueued in a message, as you can't
                 * change the right's destination once it's already
                 * on its way.
                 */
                if (port->ip_tempowner != 0) {
                        assert(port->ip_impdonation != 0);

                        boost = port->ip_impcount;
                        if (IIT_NULL != port->ip_imp_task) {
                                /*
                                 * if this port is already bound to a task,
                                 * release the task reference and drop any
                                 * watchport-forwarded boosts
                                 */
                                release_imp_task = port->ip_imp_task;
                                port->ip_imp_task = IIT_NULL;
                        }

                        /* mark the port is watching another task (reference held in port->ip_imp_task) */
                        if (ipc_importance_task_is_marked_receiver(new_imp_task)) {
                                port->ip_imp_task = new_imp_task;
                                new_imp_task = IIT_NULL;
                        }
                }
                ip_unlock(port);

                if (IIT_NULL != new_imp_task) {
                        ipc_importance_task_release(new_imp_task);
                }

                if (IIT_NULL != release_imp_task) {
                        if (boost > 0) {
                                ipc_importance_task_drop_internal_assertion(release_imp_task, boost);
                        }

                        // released_pid = task_pid(release_imp_task); /* TODO: Need ref-safe way to get pid */
                        ipc_importance_task_release(release_imp_task);
                }
#if IMPORTANCE_TRACE
                KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_WATCHPORT, 0)) | DBG_FUNC_NONE,
                    proc_selfpid(), pid, boost, released_pid, 0);
#endif /* IMPORTANCE_TRACE */
        }

        *boostp = boost;
        return;
}

#endif /* IMPORTANCE_INHERITANCE */

/*
 * Routines for VM to query task importance
 */


/*
 * Order to be considered while estimating importance
 * for low memory notification and purging purgeable memory.
 */
#define TASK_IMPORTANCE_FOREGROUND     4
#define TASK_IMPORTANCE_NOTDARWINBG    1


/*
 * (Un)Mark the task as a privileged listener for memory notifications.
 * if marked, this task will be among the first to be notified amongst
 * the bulk of all other tasks when the system enters a pressure level
 * of interest to this task.
 */
int
task_low_mem_privileged_listener(task_t task, boolean_t new_value, boolean_t *old_value)
{
        if (old_value != NULL) {
                *old_value = (boolean_t)task->low_mem_privileged_listener;
        } else {
                task_lock(task);
                task->low_mem_privileged_listener = (uint32_t)new_value;
                task_unlock(task);
        }

        return 0;
}

/*
 * Checks if the task is already notified.
 *
 * Condition: task lock should be held while calling this function.
 */
boolean_t
task_has_been_notified(task_t task, int pressurelevel)
{
        if (task == NULL) {
                return FALSE;
        }

        if (pressurelevel == kVMPressureWarning) {
                return task->low_mem_notified_warn ? TRUE : FALSE;
        } else if (pressurelevel == kVMPressureCritical) {
                return task->low_mem_notified_critical ? TRUE : FALSE;
        } else {
                return TRUE;
        }
}


/*
 * Checks if the task is used for purging.
 *
 * Condition: task lock should be held while calling this function.
 */
boolean_t
task_used_for_purging(task_t task, int pressurelevel)
{
        if (task == NULL) {
                return FALSE;
        }

        if (pressurelevel == kVMPressureWarning) {
                return task->purged_memory_warn ? TRUE : FALSE;
        } else if (pressurelevel == kVMPressureCritical) {
                return task->purged_memory_critical ? TRUE : FALSE;
        } else {
                return TRUE;
        }
}


/*
 * Mark the task as notified with memory notification.
 *
 * Condition: task lock should be held while calling this function.
 */
void
task_mark_has_been_notified(task_t task, int pressurelevel)
{
        if (task == NULL) {
                return;
        }

        if (pressurelevel == kVMPressureWarning) {
                task->low_mem_notified_warn = 1;
        } else if (pressurelevel == kVMPressureCritical) {
                task->low_mem_notified_critical = 1;
        }
}


/*
 * Mark the task as purged.
 *
 * Condition: task lock should be held while calling this function.
 */
void
task_mark_used_for_purging(task_t task, int pressurelevel)
{
        if (task == NULL) {
                return;
        }

        if (pressurelevel == kVMPressureWarning) {
                task->purged_memory_warn = 1;
        } else if (pressurelevel == kVMPressureCritical) {
                task->purged_memory_critical = 1;
        }
}


/*
 * Mark the task eligible for low memory notification.
 *
 * Condition: task lock should be held while calling this function.
 */
void
task_clear_has_been_notified(task_t task, int pressurelevel)
{
        if (task == NULL) {
                return;
        }

        if (pressurelevel == kVMPressureWarning) {
                task->low_mem_notified_warn = 0;
        } else if (pressurelevel == kVMPressureCritical) {
                task->low_mem_notified_critical = 0;
        }
}


/*
 * Mark the task eligible for purging its purgeable memory.
 *
 * Condition: task lock should be held while calling this function.
 */
void
task_clear_used_for_purging(task_t task)
{
        if (task == NULL) {
                return;
        }

        task->purged_memory_warn = 0;
        task->purged_memory_critical = 0;
}


/*
 * Estimate task importance for purging its purgeable memory
 * and low memory notification.
 *
 * Importance is calculated in the following order of criteria:
 * -Task role : Background vs Foreground
 * -Boost status: Not boosted vs Boosted
 * -Darwin BG status.
 *
 * Returns: Estimated task importance. Less important task will have lower
 *          estimated importance.
 */
int
task_importance_estimate(task_t task)
{
        int task_importance = 0;

        if (task == NULL) {
                return 0;
        }

        if (proc_get_effective_task_policy(task, TASK_POLICY_ROLE) == TASK_FOREGROUND_APPLICATION) {
                task_importance += TASK_IMPORTANCE_FOREGROUND;
        }

        if (proc_get_effective_task_policy(task, TASK_POLICY_DARWIN_BG) == 0) {
                task_importance += TASK_IMPORTANCE_NOTDARWINBG;
        }

        return task_importance;
}

boolean_t
task_has_assertions(task_t task)
{
        return task->task_imp_base->iit_assertcnt? TRUE : FALSE;
}


kern_return_t
send_resource_violation(typeof(send_cpu_usage_violation) sendfunc,
    task_t violator,
    struct ledger_entry_info *linfo,
    resource_notify_flags_t flags)
{
#ifndef MACH_BSD
        return KERN_NOT_SUPPORTED;
#else
        kern_return_t   kr = KERN_SUCCESS;
        proc_t          proc = NULL;
        posix_path_t    proc_path = "";
        proc_name_t     procname = "<unknown>";
        int             pid = -1;
        clock_sec_t     secs;
        clock_nsec_t    nsecs;
        mach_timespec_t timestamp;
        thread_t        curthread = current_thread();
        ipc_port_t      dstport = MACH_PORT_NULL;

        if (!violator) {
                kr = KERN_INVALID_ARGUMENT; goto finish;
        }

        /* extract violator information */
        task_lock(violator);
        if (!(proc = get_bsdtask_info(violator))) {
                task_unlock(violator);
                kr = KERN_INVALID_ARGUMENT; goto finish;
        }
        (void)mig_strncpy(procname, proc_best_name(proc), sizeof(procname));
        pid = task_pid(violator);
        if (flags & kRNFatalLimitFlag) {
                kr = proc_pidpathinfo_internal(proc, 0, proc_path,
                    sizeof(proc_path), NULL);
        }
        task_unlock(violator);
        if (kr) {
                goto finish;
        }

        /* violation time ~ now */
        clock_get_calendar_nanotime(&secs, &nsecs);
        timestamp.tv_sec = (int32_t)secs;
        timestamp.tv_nsec = (int32_t)nsecs;
        /* 25567702 tracks widening mach_timespec_t */

        /* send message */
        kr = host_get_special_port(host_priv_self(), HOST_LOCAL_NODE,
            HOST_RESOURCE_NOTIFY_PORT, &dstport);
        if (kr) {
                goto finish;
        }

        thread_set_honor_qlimit(curthread);
        kr = sendfunc(dstport,
            procname, pid, proc_path, timestamp,
            linfo->lei_balance, linfo->lei_last_refill,
            linfo->lei_limit, linfo->lei_refill_period,
            flags);
        thread_clear_honor_qlimit(curthread);

        ipc_port_release_send(dstport);

finish:
        return kr;
#endif      /* MACH_BSD */
}


/*
 * Resource violations trace four 64-bit integers.  For K32, two additional
 * codes are allocated, the first with the low nibble doubled.  So if the K64
 * code is 0x042, the K32 codes would be 0x044 and 0x45.
 */
#ifdef __LP64__
void
trace_resource_violation(uint16_t code,
    struct ledger_entry_info *linfo)
{
        KERNEL_DBG_IST_SANE(KDBG_CODE(DBG_MACH, DBG_MACH_RESOURCE, code),
            linfo->lei_balance, linfo->lei_last_refill,
            linfo->lei_limit, linfo->lei_refill_period);
}
#else /* K32 */
/* TODO: create/find a trace_two_LLs() for K32 systems */
#define MASK32 0xffffffff
void
trace_resource_violation(uint16_t code,
    struct ledger_entry_info *linfo)
{
        int8_t lownibble = (code & 0x3) * 2;
        int16_t codeA = (code & 0xffc) | lownibble;
        int16_t codeB = codeA + 1;

        int32_t balance_high = (linfo->lei_balance >> 32) & MASK32;
        int32_t balance_low = linfo->lei_balance & MASK32;
        int32_t last_refill_high = (linfo->lei_last_refill >> 32) & MASK32;
        int32_t last_refill_low = linfo->lei_last_refill & MASK32;

        int32_t limit_high = (linfo->lei_limit >> 32) & MASK32;
        int32_t limit_low = linfo->lei_limit & MASK32;
        int32_t refill_period_high = (linfo->lei_refill_period >> 32) & MASK32;
        int32_t refill_period_low = linfo->lei_refill_period & MASK32;

        KERNEL_DBG_IST_SANE(KDBG_CODE(DBG_MACH, DBG_MACH_RESOURCE, codeA),
            balance_high, balance_low,
            last_refill_high, last_refill_low);
        KERNEL_DBG_IST_SANE(KDBG_CODE(DBG_MACH, DBG_MACH_RESOURCE, codeB),
            limit_high, limit_low,
            refill_period_high, refill_period_low);
}
#endif /* K64/K32 */