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 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * 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.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * 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 OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * 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_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
+
+#include <mach/mach_types.h>
+#include <mach/task_server.h>
+
+#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>
+#if CONFIG_TELEMETRY
+#include <kern/telemetry.h>
+#endif
+
+#if IMPORTANCE_DEBUG
+#include <mach/machine/sdt.h>
+#endif /* IMPORTANCE_DEBUG */
+
+#include <sys/kdebug.h>
+
 /*
- * Copyright (c) 2000 Apple Computer, Inc.  All rights reserved.
+ *  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 three policy fields: requested, effective, and pending.
+ *  Requested represents the wishes of each interface that influences task policy.
+ *  Effective represents the distillation of that policy into a set of behaviors.
+ *  Pending represents updates that haven't been applied yet.
+ *
+ *  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 get_effective_policy function, which returns 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*, and dump the state in task_requested_bitfield,
+ *  then set up the effects of that behavior in task_policy_update*.
+ *
+ *  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
  *
- * HISTORY
+ *  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 or thread takes the task lock, and not the thread lock.
+ *  TODO: Should changing policy on a thread take the thread lock instead?
+ *
+ *  Querying the effective policy does not take the task lock, to prevent deadlocks or slowdown in sensitive code.
+ *  This means that any notification of state change needs to be externally synchronized.
  *
- * 15 October 2000 (debo)
- *  Created.
  */
 
-#include <mach/mach_types.h>
+/* for task holds without dropping the lock */
+extern void task_hold_locked(task_t task);
+extern void task_release_locked(task_t task);
+extern void task_wait_locked(task_t task, boolean_t until_not_runnable);
+
+/* Task policy related helper functions */
+static void proc_set_task_policy_locked(task_t task, thread_t thread, int category, int flavor, int value);
+
+static void task_policy_update_locked(task_t task, thread_t thread);
+static void task_policy_update_internal_locked(task_t task, thread_t thread, boolean_t in_create);
+static void task_policy_update_task_locked(task_t task, boolean_t update_throttle, boolean_t update_bg_throttle);
+static void task_policy_update_thread_locked(thread_t thread, int update_cpu, boolean_t update_throttle);
+
+static void task_policy_update_complete_unlocked(task_t task, thread_t thread);
+
+static int proc_get_effective_policy(task_t task, thread_t thread, int policy);
+
+static void proc_iopol_to_tier(int iopolicy, int *tier, int *passive);
+static int proc_tier_to_iopol(int tier, int passive);
+
+static uintptr_t trequested(task_t task, thread_t thread);
+static uintptr_t teffective(task_t task, thread_t thread);
+static uintptr_t tpending(task_t task, thread_t thread);
+static uint64_t task_requested_bitfield(task_t task, thread_t thread);
+static uint64_t task_effective_bitfield(task_t task, thread_t thread);
+static uint64_t task_pending_bitfield(task_t task, thread_t thread);
+
+void proc_get_thread_policy(thread_t thread, thread_policy_state_t info);
+
+/* CPU Limits related helper functions */
+static int task_get_cpuusage(task_t task, uint8_t *percentagep, uint64_t *intervalp, uint64_t *deadlinep, int *scope);
+int task_set_cpuusage(task_t task, uint8_t percentage, uint64_t interval, uint64_t deadline, int scope, int entitled);
+static int task_clear_cpuusage_locked(task_t task, int cpumon_entitled);
+int task_disable_cpumon(task_t task);
+static int task_apply_resource_actions(task_t task, int type);
+void task_action_cpuusage(thread_call_param_t param0, thread_call_param_t param1);
+void proc_init_cpumon_params(void);
+
+#ifdef MACH_BSD
+int             proc_pid(void *proc);
+extern int      proc_selfpid(void);
+extern char *   proc_name_address(void *p);
+extern void     rethrottle_thread(void * uthread);
+extern void     proc_apply_task_networkbg(void * bsd_info, thread_t thread, int bg);
+#endif /* MACH_BSD */
+
+
+/* Importance Inheritance related helper functions */
+
+void task_importance_mark_receiver(task_t task, boolean_t receiving);
+
+#if IMPORTANCE_INHERITANCE
+static void task_update_boost_locked(task_t task, boolean_t boost_active);
+
+static int task_importance_hold_assertion_locked(task_t target_task, int external, uint32_t count);
+static int task_importance_drop_assertion_locked(task_t target_task, int external, uint32_t count);
+#endif /* IMPORTANCE_INHERITANCE */
+
+#if IMPORTANCE_DEBUG
+#define __impdebug_only
+#else
+#define __impdebug_only __unused
+#endif
+
+#if IMPORTANCE_INHERITANCE
+#define __imp_only
+#else
+#define __imp_only __unused
+#endif
+
+#define TASK_LOCKED   1
+#define TASK_UNLOCKED 0
+
+#define DO_LOWPRI_CPU   1
+#define UNDO_LOWPRI_CPU 2
+
+/* Macros for making tracing simpler */
+
+#define tpriority(task, thread)  ((uintptr_t)(thread == THREAD_NULL ? (task->priority)  : (thread->priority)))
+#define tisthread(thread) (thread == THREAD_NULL ? TASK_POLICY_TASK  : TASK_POLICY_THREAD)
+#define targetid(task, thread)   ((uintptr_t)(thread == THREAD_NULL ? (audit_token_pid_from_task(task)) : (thread->thread_id)))
+
+/*
+ * 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;
+
+
+const struct task_requested_policy default_task_requested_policy = {
+       .bg_iotier = proc_default_bg_iotier
+};
+const struct task_effective_policy default_task_effective_policy = {};
+const struct task_pended_policy default_task_pended_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;
+
+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;
+
+       if ((ltier != LATENCY_QOS_TIER_UNSPECIFIED) &&
+           ((ltier > LATENCY_QOS_TIER_5) || (ltier < LATENCY_QOS_TIER_0)))
+               return KERN_INVALID_ARGUMENT;
+
+       if ((ttier != THROUGHPUT_QOS_TIER_UNSPECIFIED) &&
+           ((ttier > THROUGHPUT_QOS_TIER_5) || (ttier < THROUGHPUT_QOS_TIER_0)))
+               return KERN_INVALID_ARGUMENT;
+
+       return KERN_SUCCESS;
+}
+
+static uint32_t
+task_qos_extract(uint32_t qv) {
+       return (qv & 0xFF);
+}
+
+static uint32_t
+task_qos_latency_package(uint32_t qv) {
+       return (qv == LATENCY_QOS_TIER_UNSPECIFIED) ? LATENCY_QOS_TIER_UNSPECIFIED : ((0xFF << 16) | qv);
+}
+
+static uint32_t
+task_qos_throughput_package(uint32_t qv) {
+       return (qv == THROUGHPUT_QOS_TIER_UNSPECIFIED) ? THROUGHPUT_QOS_TIER_UNSPECIFIED : ((0xFE << 16) | qv);
+}
 
 kern_return_t
 task_policy_set(
@@ -37,38 +260,205 @@ task_policy_set(
        task_policy_t                   policy_info,
        mach_msg_type_number_t  count)
 {
-       if (task == TASK_NULL)
+       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;
+       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);
 
-               switch (info->role) {
 
-               case TASK_UNSPECIFIED:
-               case TASK_FOREGROUND_APPLICATION:
-               case TASK_BACKGROUND_APPLICATION:
-               case TASK_CONTROL_APPLICATION:
-               case TASK_GRAPHICS_SERVER:
-                       return (KERN_SUCCESS);
+               switch(info->role) {
+                       case TASK_FOREGROUND_APPLICATION:
+                       case TASK_BACKGROUND_APPLICATION:
+                       case TASK_DEFAULT_APPLICATION:
+                               proc_set_task_policy(task, THREAD_NULL,
+                                                    TASK_POLICY_ATTRIBUTE, TASK_POLICY_ROLE,
+                                                    info->role);
+                               break;
 
-               default:
+                       case TASK_CONTROL_APPLICATION:
+                               if (task != current_task() || task->sec_token.val[0] != 0)
+                                       result = KERN_INVALID_ARGUMENT;
+                               else
+                                       proc_set_task_policy(task, THREAD_NULL,
+                                                            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, THREAD_NULL,
+                                                            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:
+       {
+               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;
+
+               task_lock(task);
+
+               /* This uses the latency QoS tracepoint, even though we might be changing both */
+               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                         (IMPORTANCE_CODE(TASK_POLICY_LATENCY_QOS, (TASK_POLICY_ATTRIBUTE | TASK_POLICY_TASK))) | DBG_FUNC_START,
+                                         proc_selfpid(), targetid(task, THREAD_NULL), trequested(task, THREAD_NULL), 0, 0);
+
+               task->requested_policy.t_base_latency_qos = task_qos_extract(qosinfo->task_latency_qos_tier);
+               task->requested_policy.t_base_through_qos = task_qos_extract(qosinfo->task_throughput_qos_tier);
+
+               task_policy_update_locked(task, THREAD_NULL);
+
+               task_unlock(task);
+
+               task_policy_update_complete_unlocked(task, THREAD_NULL);
+
+               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                         (IMPORTANCE_CODE(TASK_POLICY_LATENCY_QOS, (TASK_POLICY_ATTRIBUTE | TASK_POLICY_TASK))) | DBG_FUNC_END,
+                                         proc_selfpid(), targetid(task, THREAD_NULL), trequested(task, THREAD_NULL), 0, 0);
+       }
+               break;
+
+       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;
+
+               task_lock(task);
+
+               /* This uses the latency QoS tracepoint, even though we might be changing both */
+               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                         (IMPORTANCE_CODE(TASK_POLICY_LATENCY_QOS, (TASK_POLICY_ATTRIBUTE | TASK_POLICY_TASK))) | DBG_FUNC_START,
+                                         proc_selfpid(), targetid(task, THREAD_NULL), trequested(task, THREAD_NULL), 0, 0);
+
+               task->requested_policy.t_over_latency_qos = task_qos_extract(qosinfo->task_latency_qos_tier);
+               task->requested_policy.t_over_through_qos = task_qos_extract(qosinfo->task_throughput_qos_tier);
+
+               task_policy_update_locked(task, THREAD_NULL);
+
+               task_unlock(task);
+
+               task_policy_update_complete_unlocked(task, THREAD_NULL);
+
+               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                         (IMPORTANCE_CODE(TASK_POLICY_LATENCY_QOS, (TASK_POLICY_ATTRIBUTE | TASK_POLICY_TASK))) | DBG_FUNC_END,
+                                         proc_selfpid(), targetid(task, THREAD_NULL), trequested(task, THREAD_NULL), 0, 0);            
+       }
+               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);
-               }
+
+               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;
+
+               task_lock(task);
+
+               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                         (IMPORTANCE_CODE(IMP_TASK_SUPPRESSION, info->active)) | DBG_FUNC_START,
+                                         proc_selfpid(), audit_token_pid_from_task(task), trequested(task, THREAD_NULL),
+                                         0, 0);
+
+               task->requested_policy.t_sup_active      = (info->active)         ? 1 : 0;
+               task->requested_policy.t_sup_lowpri_cpu  = (info->lowpri_cpu)     ? 1 : 0;
+               task->requested_policy.t_sup_timer       = task_qos_extract(info->timer_throttle);
+               task->requested_policy.t_sup_disk        = (info->disk_throttle)  ? 1 : 0;
+               task->requested_policy.t_sup_cpu_limit   = (info->cpu_limit)      ? 1 : 0;
+               task->requested_policy.t_sup_suspend     = (info->suspend)        ? 1 : 0;
+               task->requested_policy.t_sup_throughput  = task_qos_extract(info->throughput_qos);
+               task->requested_policy.t_sup_cpu         = (info->suppressed_cpu) ? 1 : 0;
+
+               task_policy_update_locked(task, THREAD_NULL);
+
+               task_unlock(task);
+
+               task_policy_update_complete_unlocked(task, THREAD_NULL);
+
+               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                         (IMPORTANCE_CODE(IMP_TASK_SUPPRESSION, info->active)) | DBG_FUNC_END,
+                                         proc_selfpid(), audit_token_pid_from_task(task), trequested(task, THREAD_NULL),
+                                         0, 0);
 
                break;
+
        }
 
        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;
+
+       /* TODO: tracepoint? */
+
+       /* Redrive only the task priority calculation */
+       task_policy_update_task_locked(task, FALSE, FALSE);
+
+       task_unlock(task);
+
        return (KERN_SUCCESS);
 }
 
@@ -80,7 +470,7 @@ task_policy_get(
        mach_msg_type_number_t  *count,
        boolean_t                               *get_default)
 {
-       if (task == TASK_NULL)
+       if (task == TASK_NULL || task == kernel_task)
                return (KERN_INVALID_ARGUMENT);
 
        switch (flavor) {
@@ -92,7 +482,110 @@ task_policy_get(
                if (*count < TASK_CATEGORY_POLICY_COUNT)
                        return (KERN_INVALID_ARGUMENT);
 
-               info->role = TASK_UNSPECIFIED;
+               if (*get_default)
+                       info->role = TASK_UNSPECIFIED;
+               else
+                       info->role = proc_get_task_policy(task, THREAD_NULL, 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) {
+                       task_lock(task);
+
+                       info->task_latency_qos_tier    = task_qos_latency_package(task->requested_policy.t_base_latency_qos);
+                       info->task_throughput_qos_tier = task_qos_throughput_package(task->requested_policy.t_base_through_qos);
+
+                       task_unlock(task);
+               } else if (flavor == TASK_OVERRIDE_QOS_POLICY) {
+                       task_lock(task);
+
+                       info->task_latency_qos_tier    = task_qos_latency_package(task->requested_policy.t_over_latency_qos);
+                       info->task_throughput_qos_tier = task_qos_throughput_package(task->requested_policy.t_over_through_qos);
+
+                       task_unlock(task);
+               }
+
+               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;
+
+               task_lock(task);
+
+               if (*get_default) {
+                       info->requested = 0;
+                       info->effective = 0;
+                       info->pending = 0;
+                       info->imp_assertcnt = 0;
+                       info->imp_externcnt = 0;
+                       info->flags = 0;
+               } else {
+                       info->requested = task_requested_bitfield(task, THREAD_NULL);
+                       info->effective = task_effective_bitfield(task, THREAD_NULL);
+                       info->pending   = task_pending_bitfield(task, THREAD_NULL);
+                       info->imp_assertcnt = task->task_imp_assertcnt;
+                       info->imp_externcnt = task->task_imp_externcnt;
+                       
+                       info->flags = 0;
+                       info->flags |= (task->imp_receiver      ? TASK_IMP_RECEIVER : 0);
+                       info->flags |= (task->imp_donor         ? TASK_IMP_DONOR    : 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.t_sup_active;
+                       info->lowpri_cpu        = task->requested_policy.t_sup_lowpri_cpu;
+                       info->timer_throttle    = task_qos_latency_package(task->requested_policy.t_sup_timer);
+                       info->disk_throttle     = task->requested_policy.t_sup_disk;
+                       info->cpu_limit         = task->requested_policy.t_sup_cpu_limit;
+                       info->suspend           = task->requested_policy.t_sup_suspend;
+                       info->throughput_qos    = task_qos_throughput_package(task->requested_policy.t_sup_throughput);
+                       info->suppressed_cpu    = task->requested_policy.t_sup_cpu;
+               }
+
+               task_unlock(task);
                break;
        }
 
@@ -102,3 +595,2344 @@ task_policy_get(
 
        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, int parent_boosted)
+{
+       if (task->requested_policy.t_apptype == TASK_APPTYPE_DAEMON_ADAPTIVE) {
+               if (parent_boosted) {
+                       task->requested_policy.t_apptype = TASK_APPTYPE_DAEMON_INTERACTIVE;
+                       task_importance_mark_donor(task, TRUE);
+               } else {
+                       task->requested_policy.t_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,
+                                 proc_selfpid(), audit_token_pid_from_task(task),
+                                 teffective(task, THREAD_NULL), tpriority(task, THREAD_NULL), 0);
+
+       task_policy_update_internal_locked(task, THREAD_NULL, TRUE);
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                 (IMPORTANCE_CODE(IMP_UPDATE, (IMP_UPDATE_TASK_CREATE | TASK_POLICY_TASK))) | DBG_FUNC_END,
+                                 proc_selfpid(), audit_token_pid_from_task(task),
+                                 teffective(task, THREAD_NULL), tpriority(task, THREAD_NULL), 0);
+}
+
+static void
+task_policy_update_locked(task_t task, thread_t thread)
+{
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                 (IMPORTANCE_CODE(IMP_UPDATE, tisthread(thread)) | DBG_FUNC_START),
+                                 proc_selfpid(), targetid(task, thread),
+                                 teffective(task, thread), tpriority(task, thread), 0);
+
+       task_policy_update_internal_locked(task, thread, FALSE);
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                 (IMPORTANCE_CODE(IMP_UPDATE, tisthread(thread))) | DBG_FUNC_END,
+                                 proc_selfpid(), targetid(task, thread),
+                                 teffective(task, thread), tpriority(task, thread), 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, thread_t thread, boolean_t in_create)
+{
+       boolean_t on_task = (thread == THREAD_NULL) ? TRUE : FALSE;
+
+       /*
+        * Step 1:
+        *  Gather requested policy
+        */
+
+       struct task_requested_policy requested =
+               (on_task) ? task->requested_policy : thread->requested_policy;
+
+       /*
+        * Step 2:
+        *  Calculate new effective policies from requested policy and task state
+        *  Rules:
+        *      If in an 'on_task' block, must only look at and set fields starting with t_
+        *      If operating on a task, don't touch anything starting with th_
+        *      If operating on a thread, don't touch anything starting with t_
+        *      Don't change requested, it won't take effect
+        */
+
+       struct task_effective_policy next = {};
+
+       /* 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 */
+       boolean_t wants_tal             = FALSE; /* Do I want the effects of TAL mode */
+       /*
+        * If DARWIN_BG has been requested at either level, it's engaged.
+        * Only true DARWIN_BG changes cause watchers to transition.
+        */
+       if (requested.int_darwinbg || requested.ext_darwinbg)
+               wants_watchersbg = wants_all_sockets_bg = wants_darwinbg = TRUE;
+
+       if (on_task) {
+               /* Background TAL apps are throttled when TAL is enabled */
+               if (requested.t_apptype      == TASK_APPTYPE_APP_TAL &&
+                   requested.t_role         == TASK_BACKGROUND_APPLICATION &&
+                   requested.t_tal_enabled  == 1) {
+                       wants_tal = TRUE;
+                       next.t_tal_engaged = 1;
+               }
+
+               /* Adaptive daemons are DARWIN_BG unless boosted, and don't get network throttled. */
+               if (requested.t_apptype == TASK_APPTYPE_DAEMON_ADAPTIVE &&
+                   requested.t_boosted == 0)
+                       wants_darwinbg = TRUE;
+
+               /* Background daemons are always DARWIN_BG, no exceptions, and don't get network throttled. */
+               if (requested.t_apptype == TASK_APPTYPE_DAEMON_BACKGROUND)
+                       wants_darwinbg = TRUE;
+       } else {
+               if (requested.th_pidbind_bg)
+                       wants_all_sockets_bg = wants_darwinbg = TRUE;
+
+               if (requested.th_workq_bg)
+                       wants_darwinbg = TRUE;
+       }
+
+       /* Calculate side effects of DARWIN_BG */
+
+       if (wants_darwinbg) {
+               next.darwinbg = 1;
+               /* darwinbg threads/tasks always create bg sockets, but we don't always loop over all sockets */
+               next.new_sockets_bg = 1;
+               next.lowpri_cpu = 1;
+       }
+
+       if (wants_all_sockets_bg)
+               next.all_sockets_bg = 1;
+
+       if (on_task && wants_watchersbg)
+               next.t_watchers_bg = 1;
+
+       /* Calculate low CPU priority */
+
+       boolean_t wants_lowpri_cpu = FALSE;
+
+       if (wants_darwinbg || wants_tal)
+               wants_lowpri_cpu = TRUE;
+
+       if (on_task && requested.t_sup_lowpri_cpu && requested.t_boosted == 0)
+               wants_lowpri_cpu = TRUE;
+
+       if (wants_lowpri_cpu)
+               next.lowpri_cpu = 1;
+
+       /* Calculate IO policy */
+
+       /* Update BG IO policy (so we can see if it has changed) */
+       next.bg_iotier = requested.bg_iotier;
+
+       int iopol = THROTTLE_LEVEL_TIER0;
+
+       if (wants_darwinbg)
+               iopol = MAX(iopol, requested.bg_iotier);
+
+       if (on_task) {
+               if (requested.t_apptype == TASK_APPTYPE_DAEMON_STANDARD)
+                       iopol = MAX(iopol, proc_standard_daemon_tier);
+
+               if (requested.t_sup_disk && requested.t_boosted == 0)
+                       iopol = MAX(iopol, proc_suppressed_disk_tier);
+
+               if (wants_tal)
+                       iopol = MAX(iopol, proc_tal_disk_tier);
+       }
+
+       iopol = MAX(iopol, requested.int_iotier);
+       iopol = MAX(iopol, requested.ext_iotier);
+
+       next.io_tier = iopol;
+
+       /* Calculate Passive IO policy */
+
+       if (requested.ext_iopassive || requested.int_iopassive)
+               next.io_passive = 1;
+
+       /* Calculate miscellaneous policy */
+
+       if (on_task) {
+               /* Update role */
+               next.t_role = requested.t_role;
+
+               /* Calculate suppression-active flag */
+               if (requested.t_sup_active && requested.t_boosted == 0)
+                       next.t_sup_active = 1;
+
+               /* Calculate suspend policy */
+               if (requested.t_sup_suspend && requested.t_boosted == 0)
+                       next.t_suspended = 1;
+
+               /* Calculate GPU Access policy */
+               if (requested.t_int_gpu_deny || requested.t_ext_gpu_deny)
+                       next.t_gpu_deny = 1;
+
+
+               /* Calculate timer QOS */
+               int latency_qos = requested.t_base_latency_qos;
+
+               if (requested.t_sup_timer && requested.t_boosted == 0)
+                       latency_qos = requested.t_sup_timer;
+
+               if (requested.t_over_latency_qos != 0)
+                       latency_qos = requested.t_over_latency_qos;
+
+               /* Treat the windowserver special */
+               if (requested.t_role == TASK_GRAPHICS_SERVER)
+                       latency_qos = proc_graphics_timer_qos;
+
+               next.t_latency_qos = latency_qos;
+
+               /* Calculate throughput QOS */
+               int through_qos = requested.t_base_through_qos;
+
+               if (requested.t_sup_throughput && requested.t_boosted == 0)
+                       through_qos = requested.t_sup_throughput;
+
+               if (requested.t_over_through_qos != 0)
+                       through_qos = requested.t_over_through_qos;
+
+               next.t_through_qos = through_qos;
+
+               /* Calculate suppressed CPU priority */
+               if (requested.t_sup_cpu && requested.t_boosted == 0)
+                       next.t_suppressed_cpu = 1;
+       }
+
+       if (requested.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)
+                * gpu deny       (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)
+                * t_latency_qos  (affects userspace timers only)
+                */
+
+               next.terminated         = 1;
+               next.darwinbg           = 0;
+               next.lowpri_cpu         = 0;
+               next.io_tier            = THROTTLE_LEVEL_TIER0;
+               if (on_task) {
+                       next.t_tal_engaged = 0;
+                       next.t_role = TASK_UNSPECIFIED;
+                       next.t_suppressed_cpu = 0;
+
+                       /* TODO: This should only be shot down on SIGTERM, not exit */
+                       next.t_suspended   = 0;
+               }
+       }
+
+       /*
+        * Step 3:
+        *  Swap out old policy for new policy
+        */
+
+       struct task_effective_policy prev =
+               (on_task) ? task->effective_policy : thread->effective_policy;
+
+       /*
+        * Check for invalid transitions here for easier debugging
+        * TODO: dump the structs as hex in the panic string
+        */
+       if (task == kernel_task && prev.all_sockets_bg != next.all_sockets_bg)
+               panic("unexpected network change for kernel task");
+
+       /* This is the point where the new values become visible to other threads */
+       if (on_task)
+               task->effective_policy = next;
+       else
+               thread->effective_policy = next;
+
+       /* Don't do anything further to a half-formed task or thread */
+       if (in_create)
+               return;
+
+       /*
+        * Step 4:
+        *  Pend updates that can't be done while holding the task lock
+        *  Preserve pending updates that may still be waiting to be applied
+        */
+
+       struct task_pended_policy pended =
+               (on_task) ? task->pended_policy : thread->pended_policy;
+
+       if (prev.all_sockets_bg != next.all_sockets_bg)
+               pended.update_sockets = 1;
+
+       if (on_task) {
+               /* Only re-scan the timer list if the qos level is getting less strong */
+               if (prev.t_latency_qos > next.t_latency_qos)
+                       pended.t_update_timers = 1;
+
+       }
+
+       if (on_task)
+               task->pended_policy = pended;
+       else
+               thread->pended_policy = pended;
+
+       /*
+        * Step 5:
+        *  Update other subsystems as necessary if something has changed
+        */
+
+       boolean_t update_throttle = (prev.io_tier != next.io_tier) ? TRUE : FALSE;
+
+       if (on_task) {
+               if (prev.t_suspended == 0 && next.t_suspended == 1 && task->active) {
+                       task_hold_locked(task);
+                       task_wait_locked(task, FALSE);
+               }
+               if (prev.t_suspended == 1 && next.t_suspended == 0 && task->active) {
+                       task_release_locked(task);
+               }
+
+               boolean_t update_threads = FALSE;
+
+               if (prev.bg_iotier != next.bg_iotier)
+                       update_threads = TRUE;
+
+               if (prev.terminated != next.terminated)
+                       update_threads = TRUE;
+
+               task_policy_update_task_locked(task, update_throttle, update_threads);
+       } else {
+               int update_cpu = 0;
+
+               if (prev.lowpri_cpu != next.lowpri_cpu)
+                       update_cpu = (next.lowpri_cpu ? DO_LOWPRI_CPU : UNDO_LOWPRI_CPU);
+
+               task_policy_update_thread_locked(thread, update_cpu, update_throttle);
+       }
+}
+
+/* Despite the name, the thread's task is locked, the thread is not */
+static void
+task_policy_update_thread_locked(thread_t thread,
+                                 int update_cpu,
+                                 boolean_t update_throttle)
+{
+       thread_precedence_policy_data_t policy;
+
+       if (update_throttle) {
+               rethrottle_thread(thread->uthread);
+       }
+
+       /*
+        * TODO: pidbind needs to stuff remembered importance into saved_importance
+        * properly deal with bg'ed threads being pidbound and unbging while pidbound
+        *
+        * TODO: A BG thread's priority is 0 on desktop and 4 on embedded.  Need to reconcile this.
+        * */
+       if (update_cpu == DO_LOWPRI_CPU) {
+               thread->saved_importance = thread->importance;
+               policy.importance = INT_MIN;
+       } else if (update_cpu == UNDO_LOWPRI_CPU) {
+               policy.importance = thread->saved_importance;
+               thread->saved_importance = 0;
+       }
+
+       /* Takes thread lock and thread mtx lock */
+       if (update_cpu)
+               thread_policy_set_internal(thread, THREAD_PRECEDENCE_POLICY,
+                                           (thread_policy_t)&policy,
+                                           THREAD_PRECEDENCE_POLICY_COUNT);
+}
+
+/*
+ * Calculate priority on a task, loop through its threads, and tell them about
+ * priority changes and throttle changes.
+ */
+static void
+task_policy_update_task_locked(task_t    task,
+                               boolean_t update_throttle,
+                               boolean_t update_threads)
+{
+       boolean_t update_priority = FALSE;
+
+       if (task == kernel_task)
+               panic("Attempting to set task policy on kernel_task");
+
+       int priority     = BASEPRI_DEFAULT;
+       int max_priority = MAXPRI_USER;
+
+       if (proc_get_effective_task_policy(task, TASK_POLICY_LOWPRI_CPU)) {
+               priority = MAXPRI_THROTTLE;
+               max_priority = MAXPRI_THROTTLE;
+       } else if (proc_get_effective_task_policy(task, TASK_POLICY_SUPPRESSED_CPU)) {
+               priority = MAXPRI_SUPPRESSED;
+               max_priority = MAXPRI_SUPPRESSED;
+       } else {
+               switch (proc_get_effective_task_policy(task, TASK_POLICY_ROLE)) {
+                       case TASK_FOREGROUND_APPLICATION:
+                               priority = BASEPRI_FOREGROUND;
+                               break;
+                       case TASK_BACKGROUND_APPLICATION:
+                               priority = BASEPRI_BACKGROUND;
+                               break;
+                       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;
+       }
+
+       /* avoid extra work if priority isn't changing */
+       if (task->priority != priority || task->max_priority != max_priority) {
+               update_priority = TRUE;
+
+               /* update the scheduling priority for the task */
+               task->max_priority = max_priority;
+
+               if (priority > task->max_priority)
+                       priority = task->max_priority;
+               else if (priority < MINPRI)
+                       priority = MINPRI;
+
+               task->priority = priority;
+       }
+
+       /* Loop over the threads in the task only once, and only if necessary */
+       if (update_threads || update_throttle || update_priority ) {
+               thread_t thread;
+
+               queue_iterate(&task->threads, thread, thread_t, task_threads) {
+                       if (update_priority) {
+                               thread_mtx_lock(thread);
+
+                               if (thread->active)
+                                       thread_task_priority(thread, priority, max_priority);
+
+                               thread_mtx_unlock(thread);
+                       }
+
+                       if (update_throttle) {
+                               rethrottle_thread(thread->uthread);
+                       }
+
+                       if (update_threads) {
+                               thread->requested_policy.bg_iotier  = task->effective_policy.bg_iotier;
+                               thread->requested_policy.terminated = task->effective_policy.terminated;
+
+                               task_policy_update_internal_locked(task, thread, FALSE);
+                               /*  The thread policy must not emit any completion actions due to this change. */
+                       }
+               }
+       }
+}
+
+/*
+ * Called with task unlocked to do things that can't be done while holding the task lock
+ * To keep things consistent, only one thread can make progress through here at a time for any one task.
+ *
+ * TODO: tracepoints
+ */
+static void
+task_policy_update_complete_unlocked(task_t task, thread_t thread)
+{
+       boolean_t on_task = (thread == THREAD_NULL) ? TRUE : FALSE;
+
+       task_lock(task);
+
+       while (task->pended_policy.t_updating_policy != 0) {
+               assert_wait((event_t)&task->pended_policy, THREAD_UNINT);
+               task_unlock(task);
+               thread_block(THREAD_CONTINUE_NULL);
+               task_lock(task);
+       }
+
+       /* Take a snapshot of the current state */
+
+       struct task_pended_policy pended =
+               (on_task) ? task->pended_policy : thread->pended_policy;
+
+       struct task_effective_policy effective =
+               (on_task) ? task->effective_policy : thread->effective_policy;
+       
+       /* Mark the pended operations as being handled */
+       if (on_task)
+               task->pended_policy = default_task_pended_policy;
+       else
+               thread->pended_policy = default_task_pended_policy;
+
+       task->pended_policy.t_updating_policy = 1;
+
+       task_unlock(task);
+
+       /* Update the other subsystems with the new state */
+
+#ifdef MACH_BSD
+       if (pended.update_sockets)
+               proc_apply_task_networkbg(task->bsd_info, thread, effective.all_sockets_bg);
+#endif /* MACH_BSD */
+
+       if (on_task) {
+               /* The timer throttle has been removed, we need to look for expired timers and fire them */
+               if (pended.t_update_timers)
+                       ml_timer_evaluate();
+
+       }
+
+       /* Wake up anyone waiting to make another update */
+       task_lock(task);
+       task->pended_policy.t_updating_policy = 0;
+       thread_wakeup(&task->pended_policy);
+       task_unlock(task);
+}
+
+/*
+ * 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 or thread->active?
+ */
+void
+proc_set_task_policy(task_t     task,
+                     thread_t   thread,
+                     int        category,
+                     int        flavor,
+                     int        value)
+{
+       task_lock(task);
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                 (IMPORTANCE_CODE(flavor, (category | tisthread(thread)))) | DBG_FUNC_START,
+                                 proc_selfpid(), targetid(task, thread), trequested(task, thread), value, 0);
+
+       proc_set_task_policy_locked(task, thread, category, flavor, value);
+
+       task_policy_update_locked(task, thread);
+
+       task_unlock(task);
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                 (IMPORTANCE_CODE(flavor, (category | tisthread(thread)))) | DBG_FUNC_END,
+                                 proc_selfpid(), targetid(task, thread), trequested(task, thread), tpending(task, thread), 0);
+
+       task_policy_update_complete_unlocked(task, thread);
+}
+
+/*
+ * Initiate a task policy state transition on a thread with its TID
+ * Useful if you cannot guarantee the thread won't get terminated
+ */
+void
+proc_set_task_policy_thread(task_t     task,
+                            uint64_t   tid,
+                            int        category,
+                            int        flavor,
+                            int        value)
+{
+       thread_t thread;
+       thread_t self = current_thread();
+
+       task_lock(task);
+
+       if (tid == TID_NULL || tid == self->thread_id)
+               thread = self;
+       else
+               thread = task_findtid(task, tid);
+
+       if (thread == THREAD_NULL) {
+               task_unlock(task);
+               return;
+       }
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                 (IMPORTANCE_CODE(flavor, (category | TASK_POLICY_THREAD))) | DBG_FUNC_START,
+                                 proc_selfpid(), targetid(task, thread), trequested(task, thread), value, 0);
+
+       proc_set_task_policy_locked(task, thread, category, flavor, value);
+
+       task_policy_update_locked(task, thread);
+
+       task_unlock(task);
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                 (IMPORTANCE_CODE(flavor, (category | TASK_POLICY_THREAD))) | DBG_FUNC_END,
+                                 proc_selfpid(), targetid(task, thread), trequested(task, thread), tpending(task, thread), 0);
+
+       task_policy_update_complete_unlocked(task, thread);
+}
+
+
+/*
+ * 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,
+                            thread_t    thread,
+                            int         category,
+                            int         flavor,
+                            int         value)
+{
+       boolean_t on_task = (thread == THREAD_NULL) ? TRUE : FALSE;
+
+       int tier, passive;
+
+       struct task_requested_policy requested =
+               (on_task) ? task->requested_policy : thread->requested_policy;
+
+       switch (flavor) {
+
+       /* Category: EXTERNAL and INTERNAL, thread and task */
+
+               case TASK_POLICY_DARWIN_BG:
+                       if (category == TASK_POLICY_EXTERNAL)
+                               requested.ext_darwinbg = value;
+                       else
+                               requested.int_darwinbg = value;
+                       break;
+
+               case TASK_POLICY_IOPOL:
+                       proc_iopol_to_tier(value, &tier, &passive);
+                       if (category == TASK_POLICY_EXTERNAL) {
+                               requested.ext_iotier  = tier;
+                               requested.ext_iopassive = passive;
+                       } else {
+                               requested.int_iotier  = tier;
+                               requested.int_iopassive = passive;
+                       }
+                       break;
+
+               case TASK_POLICY_IO:
+                       if (category == TASK_POLICY_EXTERNAL)
+                               requested.ext_iotier = value;
+                       else
+                               requested.int_iotier = value;
+                       break;
+
+               case TASK_POLICY_PASSIVE_IO:
+                       if (category == TASK_POLICY_EXTERNAL)
+                               requested.ext_iopassive = value;
+                       else
+                               requested.int_iopassive = value;
+                       break;
+
+       /* Category: EXTERNAL and INTERNAL, task only */
+
+               case TASK_POLICY_GPU_DENY:
+                       assert(on_task);
+                       if (category == TASK_POLICY_EXTERNAL)
+                               requested.t_ext_gpu_deny = value;
+                       else
+                               requested.t_int_gpu_deny = value;
+                       break;
+
+               case TASK_POLICY_DARWIN_BG_AND_GPU:
+                       assert(on_task);
+                       if (category == TASK_POLICY_EXTERNAL) {
+                               requested.ext_darwinbg = value;
+                               requested.t_ext_gpu_deny = value;
+                       } else {
+                               requested.int_darwinbg = value;
+                               requested.t_int_gpu_deny = value;
+                       }
+                       break;
+
+       /* Category: INTERNAL, task only */                     
+
+               case TASK_POLICY_DARWIN_BG_IOPOL:
+                       assert(on_task && category == TASK_POLICY_INTERNAL);
+                       proc_iopol_to_tier(value, &tier, &passive);
+                       requested.bg_iotier = tier;
+                       break;
+
+       /* Category: ATTRIBUTE, task only */
+
+               case TASK_POLICY_TAL:
+                       assert(on_task && category == TASK_POLICY_ATTRIBUTE);
+                       requested.t_tal_enabled = value;
+                       break;
+
+               case TASK_POLICY_BOOST:
+                       assert(on_task && category == TASK_POLICY_ATTRIBUTE);
+                       requested.t_boosted = value;
+                       break;
+
+               case TASK_POLICY_ROLE:
+                       assert(on_task && category == TASK_POLICY_ATTRIBUTE);
+                       requested.t_role = value;
+                       break;
+
+               case TASK_POLICY_TERMINATED:
+                       assert(on_task && category == TASK_POLICY_ATTRIBUTE);
+                       requested.terminated = value;
+                       break;
+
+       /* Category: ATTRIBUTE, thread only */
+
+               case TASK_POLICY_PIDBIND_BG:
+                       assert(!on_task && category == TASK_POLICY_ATTRIBUTE);
+                       requested.th_pidbind_bg = value;
+                       break;
+
+               case TASK_POLICY_WORKQ_BG:
+                       assert(!on_task && category == TASK_POLICY_ATTRIBUTE);
+                       requested.th_workq_bg = value;
+                       break;
+
+               default:
+                       panic("unknown task policy: %d %d %d", category, flavor, value);
+                       break;
+       }
+
+       if (on_task)
+               task->requested_policy = requested;
+       else
+               thread->requested_policy = requested;
+}
+
+
+/*
+ * Gets what you set. Effective values may be different.
+ */
+int
+proc_get_task_policy(task_t     task,
+                     thread_t   thread,
+                     int        category,
+                     int        flavor)
+{
+       boolean_t on_task = (thread == THREAD_NULL) ? TRUE : FALSE;
+
+       int value = 0;
+
+       task_lock(task);
+
+       struct task_requested_policy requested =
+               (on_task) ? task->requested_policy : thread->requested_policy;
+
+       switch (flavor) {
+               case TASK_POLICY_DARWIN_BG:
+                       if (category == TASK_POLICY_EXTERNAL)
+                               value = requested.ext_darwinbg;
+                       else
+                               value = requested.int_darwinbg;
+                       break;
+               case TASK_POLICY_IOPOL:
+                       if (category == TASK_POLICY_EXTERNAL)
+                               value = proc_tier_to_iopol(requested.ext_iotier,
+                                                           requested.ext_iopassive);
+                       else
+                               value = proc_tier_to_iopol(requested.int_iotier,
+                                                           requested.int_iopassive);
+                       break;
+               case TASK_POLICY_IO:
+                       if (category == TASK_POLICY_EXTERNAL)
+                               value = requested.ext_iotier;
+                       else
+                               value = requested.int_iotier;
+                       break;
+               case TASK_POLICY_PASSIVE_IO:
+                       if (category == TASK_POLICY_EXTERNAL)
+                               value = requested.ext_iopassive;
+                       else
+                               value = requested.int_iopassive;
+                       break;
+               case TASK_POLICY_GPU_DENY:
+                       assert(on_task);
+                       if (category == TASK_POLICY_EXTERNAL)
+                               value = requested.t_ext_gpu_deny;
+                       else
+                               value = requested.t_int_gpu_deny;
+                       break;
+               case TASK_POLICY_DARWIN_BG_IOPOL:
+                       assert(on_task && category == TASK_POLICY_ATTRIBUTE);
+                       value = proc_tier_to_iopol(requested.bg_iotier, 0);
+                       break;
+               case TASK_POLICY_ROLE:
+                       assert(on_task && category == TASK_POLICY_ATTRIBUTE);
+                       value = requested.t_role;
+                       break;
+               default:
+                       panic("unknown policy_flavor %d", flavor);
+                       break;
+       }
+
+       task_unlock(task);
+
+       return value;
+}
+
+
+/*
+ * Functions for querying effective state for relevant subsystems
+ * ONLY the relevant subsystem should query these.
+ * NEVER take a value from one of the 'effective' functions and stuff it into a setter.
+ */
+
+int
+proc_get_effective_task_policy(task_t task, int flavor)
+{
+       return proc_get_effective_policy(task, THREAD_NULL, flavor);
+}
+
+int
+proc_get_effective_thread_policy(thread_t thread, int flavor)
+{
+       return proc_get_effective_policy(thread->task, thread, flavor);
+}
+
+/*
+ * Gets what is actually in effect, for subsystems which pull policy instead of receive updates.
+ *
+ * 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.
+ */
+static int
+proc_get_effective_policy(task_t   task,
+                          thread_t thread,
+                          int      flavor)
+{
+       boolean_t on_task = (thread == THREAD_NULL) ? TRUE : FALSE;
+       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,
+                        * as well as proc_get_effective_thread_policy. 
+                        * Its main use is within the timer layer, as well as
+                        * prioritizing requests to the graphics system.
+                        * Returns 1 for background mode, 0 for normal mode
+                        */
+                       if (on_task)
+                               value = task->effective_policy.darwinbg;
+                       else
+                               value = (task->effective_policy.darwinbg ||
+                                         thread->effective_policy.darwinbg) ? 1 : 0;
+                       break;
+               case TASK_POLICY_IO:
+                       /*
+                        * The I/O system calls here to find out what throttling tier to apply to an operation.
+                        * Returns THROTTLE_LEVEL_* values
+                        */
+                       if (on_task)
+                               value = task->effective_policy.io_tier;
+                       else {
+                               value = MAX(task->effective_policy.io_tier,
+                                            thread->effective_policy.io_tier);
+                               if (thread->iotier_override != THROTTLE_LEVEL_NONE)
+                                       value = MIN(value, thread->iotier_override);
+                       }
+                       break;
+               case TASK_POLICY_PASSIVE_IO:
+                       /*
+                        * The I/O system calls here to find out whether an operation should be passive.
+                        * (i.e. not cause operations with lower throttle tiers to be throttled)
+                        * Returns 1 for passive mode, 0 for normal mode
+                        */
+                       if (on_task)
+                               value = task->effective_policy.io_passive;
+                       else
+                               value = (task->effective_policy.io_passive ||
+                                         thread->effective_policy.io_passive) ? 1 : 0;
+                       break;
+               case TASK_POLICY_NEW_SOCKETS_BG:
+                       /*
+                        * socreate() calls this to determine if it should mark a new socket as background
+                        * Returns 1 for background mode, 0 for normal mode
+                        */
+                       if (on_task)
+                               value = task->effective_policy.new_sockets_bg;
+                       else
+                               value = (task->effective_policy.new_sockets_bg ||
+                                         thread->effective_policy.new_sockets_bg) ? 1 : 0;
+                       break;
+               case TASK_POLICY_LOWPRI_CPU:
+                       /*
+                        * Returns 1 for low priority cpu mode, 0 for normal mode
+                        */
+                       if (on_task)
+                               value = task->effective_policy.lowpri_cpu;
+                       else
+                               value = (task->effective_policy.lowpri_cpu ||
+                                         thread->effective_policy.lowpri_cpu) ? 1 : 0;
+                       break;
+               case TASK_POLICY_SUPPRESSED_CPU:
+                       /*
+                        * Returns 1 for suppressed cpu mode, 0 for normal mode
+                        */
+                       assert(on_task);
+                       value = task->effective_policy.t_suppressed_cpu;
+                       break;
+               case TASK_POLICY_LATENCY_QOS:
+                       /*
+                        * timer arming calls into here to find out the timer coalescing level
+                        * Returns a QoS tier (0-6)
+                        */
+                       assert(on_task);
+                       value = task->effective_policy.t_latency_qos;
+                       break;
+               case TASK_POLICY_THROUGH_QOS:
+                       /*
+                        * Returns a QoS tier (0-6)
+                        */
+                       assert(on_task);
+                       value = task->effective_policy.t_through_qos;
+                       break;
+               case TASK_POLICY_GPU_DENY:
+                       /*
+                        * This is where IOKit calls into task_policy to find out whether
+                        * it should allow access to the GPU.
+                        * Returns 1 for NOT allowed, returns 0 for allowed
+                        */
+                       assert(on_task);
+                       value = task->effective_policy.t_gpu_deny;
+                       break;
+               case TASK_POLICY_ROLE:
+                       assert(on_task);
+                       value = task->effective_policy.t_role;
+                       break;
+               case TASK_POLICY_WATCHERS_BG:
+                       assert(on_task);
+                       value = task->effective_policy.t_watchers_bg;
+                       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
+ */
+
+static 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;
+       }
+}
+
+static int
+proc_tier_to_iopol(int tier, int passive)
+{
+       if (passive == 1) {
+               switch (tier) {
+                       case THROTTLE_LEVEL_TIER0:
+                               return IOPOL_PASSIVE;
+                               break;
+                       default:
+                               panic("unknown passive tier %d", tier);
+                               return IOPOL_DEFAULT;
+                               break;
+               }
+       } else {
+               switch (tier) {
+                       case THROTTLE_LEVEL_NONE:
+                               return IOPOL_DEFAULT;
+                               break;
+                       case THROTTLE_LEVEL_TIER0:
+                               return IOPOL_IMPORTANT;
+                               break;
+                       case THROTTLE_LEVEL_TIER1:
+                               return IOPOL_STANDARD;
+                               break;
+                       case THROTTLE_LEVEL_TIER2:
+                               return IOPOL_UTILITY;
+                               break;
+                       case THROTTLE_LEVEL_TIER3:
+                               return IOPOL_THROTTLE;
+                               break;
+                       default:
+                               panic("unknown tier %d", tier);
+                               return IOPOL_DEFAULT;
+                               break;
+               }
+       }
+}
+
+/* apply internal backgrounding for workqueue threads */
+int
+proc_apply_workq_bgthreadpolicy(thread_t thread)
+{
+       if (thread == THREAD_NULL)
+               return ESRCH;
+
+       proc_set_task_policy(thread->task, thread, TASK_POLICY_ATTRIBUTE,
+                            TASK_POLICY_WORKQ_BG, TASK_POLICY_ENABLE);
+
+       return(0);
+}
+
+/*
+ * remove internal backgrounding for workqueue threads
+ * does NOT go find sockets created while BG and unbackground them
+ */
+int
+proc_restore_workq_bgthreadpolicy(thread_t thread)
+{
+       if (thread == THREAD_NULL)
+               return ESRCH;
+
+       proc_set_task_policy(thread->task, thread, TASK_POLICY_ATTRIBUTE,
+                            TASK_POLICY_WORKQ_BG, TASK_POLICY_DISABLE);
+
+       return(0);
+}
+
+/* here for temporary compatibility */
+int
+proc_setthread_saved_importance(__unused thread_t thread, __unused int importance)
+{
+       return(0);
+}
+
+/*
+ * Set an override on the thread which is consulted with a
+ * higher priority than the task/thread policy. This should
+ * only be set for temporary grants until the thread
+ * returns to the userspace boundary
+ *
+ * We use atomic operations to swap in the override, with
+ * the assumption that the thread itself can
+ * read the override and clear it on return to userspace.
+ *
+ * No locking is performed, since it is acceptable to see
+ * a stale override for one loop through throttle_lowpri_io().
+ * However a thread reference must be held on the thread.
+ */
+
+void set_thread_iotier_override(thread_t thread, int policy)
+{
+       int current_override;
+
+       /* Let most aggressive I/O policy win until user boundary */
+       do {
+               current_override = thread->iotier_override;
+
+               if (current_override != THROTTLE_LEVEL_NONE)
+                       policy = MIN(current_override, policy);
+
+               if (current_override == policy) {
+                       /* no effective change */
+                       return;
+               }
+       } while (!OSCompareAndSwap(current_override, policy, &thread->iotier_override));
+
+       /*
+        * Since the thread may be currently throttled,
+        * re-evaluate tiers and potentially break out
+        * of an msleep
+        */
+       rethrottle_thread(thread->uthread);
+}
+
+/*
+ * Called at process exec to initialize the apptype of a process
+ */
+void
+proc_set_task_apptype(task_t task, int apptype)
+{
+       task_lock(task);
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                 (IMPORTANCE_CODE(IMP_TASK_APPTYPE, apptype)) | DBG_FUNC_START,
+                                 proc_selfpid(), audit_token_pid_from_task(task), trequested(task, THREAD_NULL),
+                                 apptype, 0);
+
+       switch (apptype) {
+               case TASK_APPTYPE_APP_TAL:
+                       /* TAL starts off enabled by default */
+                       task->requested_policy.t_tal_enabled = 1;
+                       /* fall through */
+
+               case TASK_APPTYPE_APP_DEFAULT:
+               case TASK_APPTYPE_DAEMON_INTERACTIVE:
+                       task->requested_policy.t_apptype = apptype;
+
+                       task_importance_mark_donor(task, TRUE);
+                       /* Apps (and interactive daemons) are boost recievers on desktop for suppression behaviors */
+                       task_importance_mark_receiver(task, TRUE);
+                       break;
+
+               case TASK_APPTYPE_DAEMON_STANDARD:
+                       task->requested_policy.t_apptype = apptype;
+
+                       task_importance_mark_donor(task, TRUE);
+                       task_importance_mark_receiver(task, FALSE);
+                       break;
+
+               case TASK_APPTYPE_DAEMON_ADAPTIVE:
+                       task->requested_policy.t_apptype = apptype;
+
+                       task_importance_mark_donor(task, FALSE);
+                       task_importance_mark_receiver(task, TRUE);
+                       break;
+
+               case TASK_APPTYPE_DAEMON_BACKGROUND:
+                       task->requested_policy.t_apptype = apptype;
+
+                       task_importance_mark_donor(task, FALSE);
+                       task_importance_mark_receiver(task, FALSE);
+                       break;
+
+               default:
+                       panic("invalid apptype %d", apptype);
+                       break;
+       }
+
+       task_policy_update_locked(task, THREAD_NULL);
+
+       task_unlock(task);
+
+       task_policy_update_complete_unlocked(task, THREAD_NULL);
+
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+                                 (IMPORTANCE_CODE(IMP_TASK_APPTYPE, apptype)) | DBG_FUNC_END,
+                                 proc_selfpid(), audit_token_pid_from_task(task), trequested(task, THREAD_NULL),
+                                 task->imp_receiver, 0);
+}
+
+/* for process_policy to check before attempting to set */
+boolean_t
+proc_task_is_tal(task_t task)
+{
+       return (task->requested_policy.t_apptype == TASK_APPTYPE_APP_TAL) ? TRUE : FALSE;
+}
+
+/* for telemetry */
+integer_t
+task_grab_latency_qos(task_t task)
+{
+       return task_qos_latency_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.ext_darwinbg)
+               *flagsp |= PROC_FLAG_EXT_DARWINBG;
+
+       if (task->requested_policy.int_darwinbg)
+               *flagsp |= PROC_FLAG_DARWINBG;
+
+
+       if (task->requested_policy.t_apptype == TASK_APPTYPE_DAEMON_ADAPTIVE)
+               *flagsp |= PROC_FLAG_ADAPTIVE;
+
+       if (task->requested_policy.t_apptype == TASK_APPTYPE_DAEMON_ADAPTIVE && task->requested_policy.t_boosted == 1)
+               *flagsp |= PROC_FLAG_ADAPTIVE_IMPORTANT;
+
+       if (task->imp_donor)
+               *flagsp |= PROC_FLAG_IMPORTANCE_DONOR;
+
+       if (task->effective_policy.t_sup_active)
+               *flagsp |= PROC_FLAG_SUPPRESSED;
+
+       return(0);
+}
+
+/* All per-thread state is in the first 32-bits of the bitfield */
+void
+proc_get_thread_policy(thread_t thread, thread_policy_state_t info)
+{
+       task_t task = thread->task;
+       task_lock(task);
+       info->requested = (integer_t)task_requested_bitfield(task, thread);
+       info->effective = (integer_t)task_effective_bitfield(task, thread);
+       info->pending   = (integer_t)task_pending_bitfield(task, thread);
+       task_unlock(task);
+}
+
+
+/* dump requested for tracepoint */
+static uintptr_t
+trequested(task_t task, thread_t thread)
+{
+       return (uintptr_t) task_requested_bitfield(task, thread);
+}
+
+/* dump effective for tracepoint */
+static uintptr_t
+teffective(task_t task, thread_t thread)
+{
+       return (uintptr_t) task_effective_bitfield(task, thread);
+}
+
+/* dump pending for tracepoint */
+static uintptr_t
+tpending(task_t task, thread_t thread)
+{
+       return (uintptr_t) task_pending_bitfield(task, thread);
+}
+
+uint64_t
+task_requested_bitfield(task_t task, thread_t thread)
+{
+       uint64_t bits = 0;
+       struct task_requested_policy requested =
+               (thread == THREAD_NULL) ? task->requested_policy : thread->requested_policy;
+
+       bits |= (requested.int_darwinbg         ? POLICY_REQ_INT_DARWIN_BG  : 0);
+       bits |= (requested.ext_darwinbg         ? POLICY_REQ_EXT_DARWIN_BG  : 0);
+       bits |= (requested.int_iotier           ? (((uint64_t)requested.int_iotier) << POLICY_REQ_INT_IO_TIER_SHIFT) : 0);
+       bits |= (requested.ext_iotier           ? (((uint64_t)requested.ext_iotier) << POLICY_REQ_EXT_IO_TIER_SHIFT) : 0);
+       bits |= (requested.int_iopassive        ? POLICY_REQ_INT_PASSIVE_IO : 0);
+       bits |= (requested.ext_iopassive        ? POLICY_REQ_EXT_PASSIVE_IO : 0);
+       bits |= (requested.bg_iotier            ? (((uint64_t)requested.bg_iotier)  << POLICY_REQ_BG_IOTIER_SHIFT)   : 0);
+       bits |= (requested.terminated           ? POLICY_REQ_TERMINATED     : 0);
+
+       bits |= (requested.th_pidbind_bg        ? POLICY_REQ_PIDBIND_BG     : 0);
+       bits |= (requested.th_workq_bg          ? POLICY_REQ_WORKQ_BG       : 0);
+
+       bits |= (requested.t_boosted            ? POLICY_REQ_BOOSTED        : 0);
+       bits |= (requested.t_tal_enabled        ? POLICY_REQ_TAL_ENABLED    : 0);
+       bits |= (requested.t_int_gpu_deny       ? POLICY_REQ_INT_GPU_DENY   : 0);
+       bits |= (requested.t_ext_gpu_deny       ? POLICY_REQ_EXT_GPU_DENY   : 0);
+       bits |= (requested.t_apptype            ? (((uint64_t)requested.t_apptype)    << POLICY_REQ_APPTYPE_SHIFT)  : 0);
+       bits |= (requested.t_role               ? (((uint64_t)requested.t_role)       << POLICY_REQ_ROLE_SHIFT)     : 0);
+
+       bits |= (requested.t_sup_active         ? POLICY_REQ_SUP_ACTIVE         : 0);
+       bits |= (requested.t_sup_lowpri_cpu     ? POLICY_REQ_SUP_LOWPRI_CPU     : 0);
+       bits |= (requested.t_sup_cpu            ? POLICY_REQ_SUP_CPU            : 0);
+       bits |= (requested.t_sup_timer          ? (((uint64_t)requested.t_sup_timer)  << POLICY_REQ_SUP_TIMER_THROTTLE_SHIFT) : 0);
+       bits |= (requested.t_sup_throughput     ? (((uint64_t)requested.t_sup_throughput)   << POLICY_REQ_SUP_THROUGHPUT_SHIFT)   : 0);
+       bits |= (requested.t_sup_disk           ? POLICY_REQ_SUP_DISK_THROTTLE  : 0);
+       bits |= (requested.t_sup_cpu_limit      ? POLICY_REQ_SUP_CPU_LIMIT      : 0);
+       bits |= (requested.t_sup_suspend        ? POLICY_REQ_SUP_SUSPEND        : 0);
+       bits |= (requested.t_base_latency_qos   ? (((uint64_t)requested.t_base_latency_qos) << POLICY_REQ_BASE_LATENCY_QOS_SHIFT) : 0);
+       bits |= (requested.t_over_latency_qos   ? (((uint64_t)requested.t_over_latency_qos) << POLICY_REQ_OVER_LATENCY_QOS_SHIFT) : 0);
+       bits |= (requested.t_base_through_qos   ? (((uint64_t)requested.t_base_through_qos) << POLICY_REQ_BASE_THROUGH_QOS_SHIFT) : 0);
+       bits |= (requested.t_over_through_qos   ? (((uint64_t)requested.t_over_through_qos) << POLICY_REQ_OVER_THROUGH_QOS_SHIFT) : 0);
+
+       return bits;
+}
+
+uint64_t
+task_effective_bitfield(task_t task, thread_t thread)
+{
+       uint64_t bits = 0;
+       struct task_effective_policy effective =
+               (thread == THREAD_NULL) ? task->effective_policy : thread->effective_policy;
+
+       bits |= (effective.io_tier              ? (((uint64_t)effective.io_tier) << POLICY_EFF_IO_TIER_SHIFT) : 0);
+       bits |= (effective.io_passive           ? POLICY_EFF_IO_PASSIVE     : 0);
+       bits |= (effective.darwinbg             ? POLICY_EFF_DARWIN_BG      : 0);
+       bits |= (effective.lowpri_cpu           ? POLICY_EFF_LOWPRI_CPU     : 0);
+       bits |= (effective.terminated           ? POLICY_EFF_TERMINATED     : 0);
+       bits |= (effective.all_sockets_bg       ? POLICY_EFF_ALL_SOCKETS_BG : 0);
+       bits |= (effective.new_sockets_bg       ? POLICY_EFF_NEW_SOCKETS_BG : 0);
+       bits |= (effective.bg_iotier            ? (((uint64_t)effective.bg_iotier) << POLICY_EFF_BG_IOTIER_SHIFT) : 0);
+
+       bits |= (effective.t_gpu_deny           ? POLICY_EFF_GPU_DENY       : 0);
+       bits |= (effective.t_tal_engaged        ? POLICY_EFF_TAL_ENGAGED    : 0);
+       bits |= (effective.t_suspended          ? POLICY_EFF_SUSPENDED      : 0);
+       bits |= (effective.t_watchers_bg        ? POLICY_EFF_WATCHERS_BG    : 0);
+       bits |= (effective.t_sup_active         ? POLICY_EFF_SUP_ACTIVE     : 0);
+       bits |= (effective.t_suppressed_cpu     ? POLICY_EFF_SUP_CPU        : 0);
+       bits |= (effective.t_role               ? (((uint64_t)effective.t_role)        << POLICY_EFF_ROLE_SHIFT)        : 0);
+       bits |= (effective.t_latency_qos        ? (((uint64_t)effective.t_latency_qos) << POLICY_EFF_LATENCY_QOS_SHIFT) : 0);
+       bits |= (effective.t_through_qos        ? (((uint64_t)effective.t_through_qos) << POLICY_EFF_THROUGH_QOS_SHIFT) : 0);
+
+       return bits;
+}
+
+uint64_t
+task_pending_bitfield(task_t task, thread_t thread)
+{
+       uint64_t bits = 0;
+       struct task_pended_policy pended =
+               (thread == THREAD_NULL) ? task->pended_policy : thread->pended_policy;
+
+       bits |= (pended.t_updating_policy    ? POLICY_PEND_UPDATING   : 0);
+       bits |= (pended.update_sockets       ? POLICY_PEND_SOCKETS    : 0);
+
+       bits |= (pended.t_update_timers      ? POLICY_PEND_TIMERS     : 0);
+       bits |= (pended.t_update_watchers    ? POLICY_PEND_WATCHERS   : 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)
+{
+       if (!PE_parse_boot_argn("max_cpumon_percentage", &proc_max_cpumon_percentage,
+               sizeof (proc_max_cpumon_percentage))) {
+               proc_max_cpumon_percentage = DEFAULT_CPUMON_PERCENTAGE;
+       }
+
+       if (proc_max_cpumon_percentage > 100) {
+               proc_max_cpumon_percentage = 100;
+       }
+
+       /* The interval should be specified in seconds. */ 
+       if (!PE_parse_boot_argn("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;
+}
+
+/*
+ * 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);
+}
+
+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.
+ */
+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);
+}
+
+/*
+ * Disable the CPU usage monitor for the task. Return value indicates
+ * if the mechanism was actually enabled.
+ */
+int
+task_disable_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(current_task(), TF_CPUMON_WARNING, 0);
+#endif
+
+       /*
+        * Disable the monitor 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) {
+               set_astledger(thread);
+       }
+       task->rusage_cpu_perthr_percentage = 0;
+       task->rusage_cpu_perthr_interval = 0;
+
+       return (KERN_SUCCESS);
+}
+
+int
+task_set_cpuusage(task_t task, uint8_t percentage, uint64_t interval, uint64_t deadline, int scope, int cpumon_entitled)
+{
+       thread_t thread;        
+       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 == TASK_POLICY_CPUMON_DISABLE) {
+                               if (cpumon_entitled) {
+                                       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 = TASK_POLICY_CPUMON_DEFAULTS;
+                       }
+
+                       if (percentage == TASK_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;
+                               char      *procname = (char *)"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);
+                       }
+
+                       task->rusage_cpu_flags |= TASK_RUSECPU_FLAGS_PERTHR_LIMIT;
+                       task->rusage_cpu_perthr_percentage = percentage;
+                       task->rusage_cpu_perthr_interval = interval;
+                       queue_iterate(&task->threads, thread, thread_t, task_threads) {
+                               set_astledger(thread);
+                       }
+               } 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);
+}
+
+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 */
+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
+ */
+
+
+/*
+ * Routines for importance donation/inheritance/boosting
+ */
+
+void
+task_importance_mark_donor(task_t task, boolean_t donating)
+{
+#if IMPORTANCE_INHERITANCE
+       task->imp_donor = (donating ? 1 : 0);
+#endif /* IMPORTANCE_INHERITANCE */
+}
+
+void
+task_importance_mark_receiver(task_t task, boolean_t receiving)
+{
+#if IMPORTANCE_INHERITANCE
+       if (receiving) {
+               assert(task->task_imp_assertcnt == 0);
+               task->imp_receiver       = 1;  /* task can receive importance boost */
+               task->task_imp_assertcnt = 0;
+               task->task_imp_externcnt = 0;
+       } else {
+               if (task->task_imp_assertcnt != 0 || task->task_imp_externcnt != 0)
+                       panic("disabling imp_receiver on task with pending boosts!");
+
+               task->imp_receiver       = 0;
+               task->task_imp_assertcnt = 0;
+               task->task_imp_externcnt = 0;
+       }
+#endif /* IMPORTANCE_INHERITANCE */
+}
+
+
+#if IMPORTANCE_INHERITANCE
+
+static void
+task_update_boost_locked(task_t task, boolean_t boost_active)
+{
+#if IMPORTANCE_DEBUG
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_BOOST, (boost_active ? IMP_BOOSTED : IMP_UNBOOSTED)) | DBG_FUNC_START),
+                                 proc_selfpid(), audit_token_pid_from_task(task), trequested(task, THREAD_NULL), 0, 0);
+#endif
+
+       /* assert(boost_active ? task->requested_policy.t_boosted == 0 : task->requested_policy.t_boosted == 1); */
+
+       proc_set_task_policy_locked(task, THREAD_NULL, TASK_POLICY_ATTRIBUTE, TASK_POLICY_BOOST, boost_active);
+
+       task_policy_update_locked(task, THREAD_NULL);
+
+#if IMPORTANCE_DEBUG
+       if (boost_active == TRUE){
+               DTRACE_BOOST2(boost, task_t, task, int, audit_token_pid_from_task(task));
+       } else {
+               DTRACE_BOOST2(unboost, task_t, task, int, audit_token_pid_from_task(task));
+       }
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_BOOST, (boost_active ? IMP_BOOSTED : IMP_UNBOOSTED)) | DBG_FUNC_END),
+                                 proc_selfpid(), audit_token_pid_from_task(task),
+                                 trequested(task, THREAD_NULL), tpending(task, THREAD_NULL), 0);
+#endif
+}
+
+/*
+ * 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)
+{
+       return (task->imp_donor == 1 || task->task_imp_assertcnt > 0) ? TRUE : FALSE;
+}
+
+/*
+ * 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)
+{
+       return (task->imp_receiver) ? TRUE : FALSE;
+}
+
+/*
+ * 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)
+{
+       int rval = 0;
+
+       task_lock(target_task);
+       rval = task_importance_hold_assertion_locked(target_task, TASK_POLICY_INTERNAL, count);
+       task_unlock(target_task);
+
+       task_policy_update_complete_unlocked(target_task, THREAD_NULL);
+
+       return(rval);
+}
+
+int
+task_importance_hold_external_assertion(task_t target_task, uint32_t count)
+{
+       int rval = 0;
+
+       task_lock(target_task);
+       rval = task_importance_hold_assertion_locked(target_task, TASK_POLICY_EXTERNAL, count);
+       task_unlock(target_task);
+
+       task_policy_update_complete_unlocked(target_task, THREAD_NULL);
+
+       return(rval);
+}
+
+int
+task_importance_drop_internal_assertion(task_t target_task, uint32_t count)
+{
+       int rval = 0;
+
+       task_lock(target_task);
+       rval = task_importance_drop_assertion_locked(target_task, TASK_POLICY_INTERNAL, count);
+       task_unlock(target_task);
+
+       task_policy_update_complete_unlocked(target_task, THREAD_NULL);
+
+       return(rval);
+}
+
+int
+task_importance_drop_external_assertion(task_t target_task, uint32_t count)
+{
+       int rval = 0;
+
+       task_lock(target_task);
+       rval = task_importance_drop_assertion_locked(target_task, TASK_POLICY_EXTERNAL, count);
+       task_unlock(target_task);
+
+       task_policy_update_complete_unlocked(target_task, THREAD_NULL);
+
+       return(rval);
+}
+
+/*
+ * Returns EOVERFLOW if an external assertion is taken when not holding an external boost.
+ */
+static int
+task_importance_hold_assertion_locked(task_t target_task, int external, uint32_t count)
+{
+       boolean_t apply_boost = FALSE;
+       int ret = 0;
+
+       assert(target_task->imp_receiver != 0);
+
+#if IMPORTANCE_DEBUG
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_ASSERTION, (IMP_HOLD | external))) | DBG_FUNC_START,
+               proc_selfpid(), audit_token_pid_from_task(target_task), target_task->task_imp_assertcnt, target_task->task_imp_externcnt, 0);
+#endif
+
+       /* assert(target_task->task_imp_assertcnt >= target_task->task_imp_externcnt); */
+
+       if (external == TASK_POLICY_EXTERNAL) {
+               if (target_task->task_imp_externcnt == 0) {
+                       /* Only allowed to take a new boost assertion when holding an external boost */
+                       printf("BUG in process %s[%d]: it attempted to acquire a new boost assertion without holding an existing external assertion. "
+                              "(%d total, %d external)\n",
+                              proc_name_address(target_task->bsd_info), audit_token_pid_from_task(target_task),
+                              target_task->task_imp_assertcnt, target_task->task_imp_externcnt);
+                       ret = EOVERFLOW;
+                       count = 0;
+               } else {
+                       target_task->task_imp_assertcnt += count;
+                       target_task->task_imp_externcnt += count;
+               }
+       } else {
+               if (target_task->task_imp_assertcnt == 0)
+                       apply_boost = TRUE;
+               target_task->task_imp_assertcnt += count;
+       }
+
+       if (apply_boost == TRUE)
+               task_update_boost_locked(target_task, TRUE);
+
+#if IMPORTANCE_DEBUG
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_ASSERTION, (IMP_HOLD | external))) | DBG_FUNC_END,
+               proc_selfpid(), audit_token_pid_from_task(target_task), target_task->task_imp_assertcnt, target_task->task_imp_externcnt, 0);
+       DTRACE_BOOST6(receive_internal_boost, task_t, target_task, int, audit_token_pid_from_task(target_task), task_t, current_task(), int, proc_selfpid(), int, count, int, target_task->task_imp_assertcnt);
+       if (external == TASK_POLICY_EXTERNAL){
+               DTRACE_BOOST5(receive_boost, task_t, target_task, int, audit_token_pid_from_task(target_task), int, proc_selfpid(), int, count, int, target_task->task_imp_externcnt);
+       }
+#endif
+       return(ret);
+}
+
+
+/*
+ * Returns EOVERFLOW if an external assertion is over-released.
+ * Panics if an internal assertion is over-released.
+ */
+static int
+task_importance_drop_assertion_locked(task_t target_task, int external, uint32_t count)
+{
+       int ret = 0;
+
+       assert(target_task->imp_receiver != 0);
+
+#if IMPORTANCE_DEBUG
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_ASSERTION, (IMP_DROP | external))) | DBG_FUNC_START,
+               proc_selfpid(), audit_token_pid_from_task(target_task), target_task->task_imp_assertcnt, target_task->task_imp_externcnt, 0);
+#endif
+
+       /* assert(target_task->task_imp_assertcnt >= target_task->task_imp_externcnt); */
+
+       if (external == TASK_POLICY_EXTERNAL) {
+               assert(count == 1);
+               if (count <= target_task->task_imp_externcnt) {
+                       target_task->task_imp_externcnt -= count;
+                       if (count <= target_task->task_imp_assertcnt)
+                               target_task->task_imp_assertcnt -= count;
+               } else {
+                       /* Process over-released its boost count */
+                       printf("BUG in process %s[%d]: over-released external boost assertions (%d total, %d external)\n",
+                              proc_name_address(target_task->bsd_info), audit_token_pid_from_task(target_task),
+                              target_task->task_imp_assertcnt, target_task->task_imp_externcnt);
+                       
+                       /* TODO: If count > 1, we should clear out as many external assertions as there are left. */
+                       ret = EOVERFLOW;
+                       count = 0;
+               }
+       } else {
+               if (count <= target_task->task_imp_assertcnt) {
+                       target_task->task_imp_assertcnt -= count;
+               } else {
+                       /* TODO: Turn this back into a panic <rdar://problem/12592649> */
+                       printf("Over-release of kernel-internal importance assertions for task %p (%s), dropping %d assertion(s) but task only has %d remaining (%d external).\n",
+                             target_task,
+                             (target_task->bsd_info == NULL) ? "" : proc_name_address(target_task->bsd_info),
+                             count,
+                             target_task->task_imp_assertcnt,
+                             target_task->task_imp_externcnt);
+                       count = 0;
+               }
+       }
+
+       /* assert(target_task->task_imp_assertcnt >= target_task->task_imp_externcnt); */
+
+       if (target_task->task_imp_assertcnt == 0 && ret == 0)
+               task_update_boost_locked(target_task, FALSE);
+
+#if IMPORTANCE_DEBUG
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_ASSERTION, (IMP_DROP | external))) | DBG_FUNC_END,
+               proc_selfpid(), audit_token_pid_from_task(target_task), target_task->task_imp_assertcnt, target_task->task_imp_externcnt, 0);
+       if (external == TASK_POLICY_EXTERNAL) {
+               DTRACE_BOOST4(drop_boost, task_t, target_task, int, audit_token_pid_from_task(target_task), int, count, int, target_task->task_imp_externcnt);
+       }
+       DTRACE_BOOST4(drop_internal_boost, task_t, target_task, int, audit_token_pid_from_task(target_task), int, count, int, target_task->task_imp_assertcnt);
+#endif
+
+       return(ret);
+}
+
+/* Transfer an assertion to userspace responsibility */
+int
+task_importance_externalize_assertion(task_t target_task, uint32_t count, __unused int sender_pid)
+{
+       assert(target_task != TASK_NULL);
+       assert(target_task->imp_receiver != 0);
+
+       task_lock(target_task);
+
+#if IMPORTANCE_DEBUG
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_ASSERTION, IMP_EXTERN)) | DBG_FUNC_START,
+               proc_selfpid(), audit_token_pid_from_task(target_task), target_task->task_imp_assertcnt, target_task->task_imp_externcnt, 0);
+#endif
+
+       /* assert(target_task->task_imp_assertcnt >= target_task->task_imp_externcnt + count); */
+
+       target_task->task_imp_externcnt += count;
+
+#if IMPORTANCE_DEBUG
+       KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_ASSERTION, IMP_EXTERN)) | DBG_FUNC_END,
+               proc_selfpid(), audit_token_pid_from_task(target_task), target_task->task_imp_assertcnt, target_task->task_imp_externcnt, 0);
+       DTRACE_BOOST5(receive_boost, task_t, target_task, int, audit_token_pid_from_task(target_task),
+               int, sender_pid, int, count, int, target_task->task_imp_externcnt);
+#endif /* IMPORTANCE_DEBUG */
+
+       task_unlock(target_task);
+
+       return(0);
+}
+
+
+#endif /* IMPORTANCE_INHERITANCE */
+
+void
+task_hold_multiple_assertion(__imp_only task_t task, __imp_only uint32_t count)
+{
+#if IMPORTANCE_INHERITANCE
+       assert(task->imp_receiver != 0);
+
+       task_importance_hold_internal_assertion(task, count);
+#endif /* IMPORTANCE_INHERITANCE */
+}
+
+void
+task_add_importance_watchport(__imp_only task_t task, __imp_only __impdebug_only int pid, __imp_only mach_port_t port, int *boostp)
+{
+       int boost = 0;
+
+       __impdebug_only int released_pid = 0;
+
+#if IMPORTANCE_INHERITANCE
+       task_t release_imp_task = TASK_NULL;
+
+       if (task->imp_receiver == 0) {
+               *boostp = boost;
+               return;
+       }
+
+       if (IP_VALID(port) != 0) {
+               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 (port->ip_taskptr != 0) {
+                               /*
+                                * 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;
+                       }
+
+                       /* mark the port is watching another task */
+                       port->ip_taskptr = 1;
+                       port->ip_imp_task = task;
+                       task_reference(task);
+               }
+               ip_unlock(port);
+
+               if (release_imp_task != TASK_NULL) {
+                       if (boost > 0)
+                               task_importance_drop_internal_assertion(release_imp_task, boost);
+                       released_pid = audit_token_pid_from_task(release_imp_task);
+                       task_deallocate(release_imp_task);
+               }
+#if IMPORTANCE_DEBUG
+               KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, (IMPORTANCE_CODE(IMP_WATCHPORT, 0)) | DBG_FUNC_NONE,
+                       proc_selfpid(), pid, boost, released_pid, 0);
+#endif /* IMPORTANCE_DEBUG */
+       }
+#endif /* IMPORTANCE_INHERITANCE */
+
+       *boostp = boost;
+       return;
+}
+
+
+/*
+ * 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
+
+
+/*
+ * 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;
+}
+