X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/6d2010ae8f7a6078e10b361c6962983bab233e0f..2a1bd2d3eef5c7a7bb14f4bb9fdbca9a96ee4752:/osfmk/kern/thread_call.c diff --git a/osfmk/kern/thread_call.c b/osfmk/kern/thread_call.c index 93edbc489..afe86a612 100644 --- a/osfmk/kern/thread_call.c +++ b/osfmk/kern/thread_call.c @@ -1,8 +1,8 @@ /* - * Copyright (c) 1993-1995, 1999-2008 Apple Inc. All rights reserved. + * Copyright (c) 1993-1995, 1999-2020 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ - * + * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in @@ -11,10 +11,10 @@ * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. - * + * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. - * + * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, @@ -22,10 +22,10 @@ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. - * + * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ - + #include #include @@ -35,108 +35,469 @@ #include #include #include -#include +#include +#include +#include #include #include -#include - #include +#include +#include + #include +#if CONFIG_DTRACE +#include +#endif +#include + +static ZONE_DECLARE(thread_call_zone, "thread_call", + sizeof(thread_call_data_t), ZC_NOENCRYPT); + +static struct waitq daemon_waitq; + +typedef enum { + TCF_ABSOLUTE = 0, + TCF_CONTINUOUS = 1, + TCF_COUNT = 2, +} thread_call_flavor_t; + +__options_decl(thread_call_group_flags_t, uint32_t, { + TCG_NONE = 0x0, + TCG_PARALLEL = 0x1, + TCG_DEALLOC_ACTIVE = 0x2, +}); + +static struct thread_call_group { + __attribute__((aligned(128))) lck_ticket_t tcg_lock; + + const char * tcg_name; + + queue_head_t pending_queue; + uint32_t pending_count; + + queue_head_t delayed_queues[TCF_COUNT]; + struct priority_queue_deadline_min delayed_pqueues[TCF_COUNT]; + timer_call_data_t delayed_timers[TCF_COUNT]; + + timer_call_data_t dealloc_timer; + + struct waitq idle_waitq; + uint64_t idle_timestamp; + uint32_t idle_count, active_count, blocked_count; + + uint32_t tcg_thread_pri; + uint32_t target_thread_count; + + thread_call_group_flags_t tcg_flags; +} thread_call_groups[THREAD_CALL_INDEX_MAX] = { + [THREAD_CALL_INDEX_HIGH] = { + .tcg_name = "high", + .tcg_thread_pri = BASEPRI_PREEMPT_HIGH, + .target_thread_count = 4, + .tcg_flags = TCG_NONE, + }, + [THREAD_CALL_INDEX_KERNEL] = { + .tcg_name = "kernel", + .tcg_thread_pri = BASEPRI_KERNEL, + .target_thread_count = 1, + .tcg_flags = TCG_PARALLEL, + }, + [THREAD_CALL_INDEX_USER] = { + .tcg_name = "user", + .tcg_thread_pri = BASEPRI_DEFAULT, + .target_thread_count = 1, + .tcg_flags = TCG_PARALLEL, + }, + [THREAD_CALL_INDEX_LOW] = { + .tcg_name = "low", + .tcg_thread_pri = MAXPRI_THROTTLE, + .target_thread_count = 1, + .tcg_flags = TCG_PARALLEL, + }, + [THREAD_CALL_INDEX_KERNEL_HIGH] = { + .tcg_name = "kernel-high", + .tcg_thread_pri = BASEPRI_PREEMPT, + .target_thread_count = 2, + .tcg_flags = TCG_NONE, + }, + [THREAD_CALL_INDEX_QOS_UI] = { + .tcg_name = "qos-ui", + .tcg_thread_pri = BASEPRI_FOREGROUND, + .target_thread_count = 1, + .tcg_flags = TCG_NONE, + }, + [THREAD_CALL_INDEX_QOS_IN] = { + .tcg_name = "qos-in", + .tcg_thread_pri = BASEPRI_USER_INITIATED, + .target_thread_count = 1, + .tcg_flags = TCG_NONE, + }, + [THREAD_CALL_INDEX_QOS_UT] = { + .tcg_name = "qos-ut", + .tcg_thread_pri = BASEPRI_UTILITY, + .target_thread_count = 1, + .tcg_flags = TCG_NONE, + }, +}; + +typedef struct thread_call_group *thread_call_group_t; + +#define INTERNAL_CALL_COUNT 768 +#define THREAD_CALL_DEALLOC_INTERVAL_NS (5 * NSEC_PER_MSEC) /* 5 ms */ +#define THREAD_CALL_ADD_RATIO 4 +#define THREAD_CALL_MACH_FACTOR_CAP 3 +#define THREAD_CALL_GROUP_MAX_THREADS 500 + +struct thread_call_thread_state { + struct thread_call_group * thc_group; + struct thread_call * thc_call; /* debug only, may be deallocated */ + uint64_t thc_call_start; + uint64_t thc_call_soft_deadline; + uint64_t thc_call_hard_deadline; + uint64_t thc_call_pending_timestamp; + uint64_t thc_IOTES_invocation_timestamp; + thread_call_func_t thc_func; + thread_call_param_t thc_param0; + thread_call_param_t thc_param1; +}; + +static bool thread_call_daemon_awake = true; +/* + * This special waitq exists because the daemon thread + * might need to be woken while already holding a global waitq locked. + */ +static struct waitq daemon_waitq; + +static thread_call_data_t internal_call_storage[INTERNAL_CALL_COUNT]; +static queue_head_t thread_call_internal_queue; +int thread_call_internal_queue_count = 0; +static uint64_t thread_call_dealloc_interval_abs; + +static void _internal_call_init(void); + +static thread_call_t _internal_call_allocate(thread_call_func_t func, thread_call_param_t param0); +static bool _is_internal_call(thread_call_t call); +static void _internal_call_release(thread_call_t call); +static bool _pending_call_enqueue(thread_call_t call, thread_call_group_t group, uint64_t now); +static bool _delayed_call_enqueue(thread_call_t call, thread_call_group_t group, + uint64_t deadline, thread_call_flavor_t flavor); +static bool _call_dequeue(thread_call_t call, thread_call_group_t group); +static void thread_call_wake(thread_call_group_t group); +static void thread_call_daemon(void *arg); +static void thread_call_thread(thread_call_group_t group, wait_result_t wres); +static void thread_call_dealloc_timer(timer_call_param_t p0, timer_call_param_t p1); +static void thread_call_group_setup(thread_call_group_t group); +static void sched_call_thread(int type, thread_t thread); +static void thread_call_start_deallocate_timer(thread_call_group_t group); +static void thread_call_wait_locked(thread_call_t call, spl_t s); +static bool thread_call_wait_once_locked(thread_call_t call, spl_t s); + +static boolean_t thread_call_enter_delayed_internal(thread_call_t call, + thread_call_func_t alt_func, thread_call_param_t alt_param0, + thread_call_param_t param1, uint64_t deadline, + uint64_t leeway, unsigned int flags); + +/* non-static so dtrace can find it rdar://problem/31156135&31379348 */ +extern void thread_call_delayed_timer(timer_call_param_t p0, timer_call_param_t p1); + +LCK_GRP_DECLARE(thread_call_lck_grp, "thread_call"); + + +static void +thread_call_lock_spin(thread_call_group_t group) +{ + lck_ticket_lock(&group->tcg_lock, &thread_call_lck_grp); +} + +static void +thread_call_unlock(thread_call_group_t group) +{ + lck_ticket_unlock(&group->tcg_lock); +} +static void __assert_only +thread_call_assert_locked(thread_call_group_t group) +{ + lck_ticket_assert_owned(&group->tcg_lock); +} -static zone_t thread_call_zone; -struct thread_call_group { - queue_head_t pending_queue; - uint32_t pending_count; +static spl_t +disable_ints_and_lock(thread_call_group_t group) +{ + spl_t s = splsched(); + thread_call_lock_spin(group); - queue_head_t delayed_queue; + return s; +} - timer_call_data_t delayed_timer; +static void +enable_ints_and_unlock(thread_call_group_t group, spl_t s) +{ + thread_call_unlock(group); + splx(s); +} - struct wait_queue idle_wqueue; - struct wait_queue daemon_wqueue; - uint32_t idle_count, active_count; -}; +/* Lock held */ +static thread_call_group_t +thread_call_get_group(thread_call_t call) +{ + thread_call_index_t index = call->tc_index; + + assert(index >= 0 && index < THREAD_CALL_INDEX_MAX); + + return &thread_call_groups[index]; +} + +/* Lock held */ +static thread_call_flavor_t +thread_call_get_flavor(thread_call_t call) +{ + return (call->tc_flags & THREAD_CALL_FLAG_CONTINUOUS) ? TCF_CONTINUOUS : TCF_ABSOLUTE; +} + +/* Lock held */ +static thread_call_flavor_t +thread_call_set_flavor(thread_call_t call, thread_call_flavor_t flavor) +{ + assert(flavor == TCF_CONTINUOUS || flavor == TCF_ABSOLUTE); + thread_call_flavor_t old_flavor = thread_call_get_flavor(call); + + if (old_flavor != flavor) { + if (flavor == TCF_CONTINUOUS) { + call->tc_flags |= THREAD_CALL_FLAG_CONTINUOUS; + } else { + call->tc_flags &= ~THREAD_CALL_FLAG_CONTINUOUS; + } + } + + return old_flavor; +} + +/* returns true if it was on a queue */ +static bool +thread_call_enqueue_tail( + thread_call_t call, + queue_t new_queue) +{ + queue_t old_queue = call->tc_queue; + + thread_call_group_t group = thread_call_get_group(call); + thread_call_flavor_t flavor = thread_call_get_flavor(call); -typedef struct thread_call_group *thread_call_group_t; + if (old_queue != NULL && + old_queue != &group->delayed_queues[flavor]) { + panic("thread call (%p) on bad queue (old_queue: %p)", call, old_queue); + } + + if (old_queue == &group->delayed_queues[flavor]) { + priority_queue_remove(&group->delayed_pqueues[flavor], &call->tc_pqlink); + } -static struct thread_call_group thread_call_group0; + if (old_queue == NULL) { + enqueue_tail(new_queue, &call->tc_qlink); + } else { + re_queue_tail(new_queue, &call->tc_qlink); + } -static boolean_t thread_call_daemon_awake; + call->tc_queue = new_queue; -#define thread_call_thread_min 4 + return old_queue != NULL; +} -#define internal_call_count 768 +static queue_head_t * +thread_call_dequeue( + thread_call_t call) +{ + queue_t old_queue = call->tc_queue; -static thread_call_data_t internal_call_storage[internal_call_count]; -static queue_head_t thread_call_internal_queue; + thread_call_group_t group = thread_call_get_group(call); + thread_call_flavor_t flavor = thread_call_get_flavor(call); -static __inline__ thread_call_t _internal_call_allocate(void); + if (old_queue != NULL && + old_queue != &group->pending_queue && + old_queue != &group->delayed_queues[flavor]) { + panic("thread call (%p) on bad queue (old_queue: %p)", call, old_queue); + } -static __inline__ void _internal_call_release( - thread_call_t call); + if (old_queue == &group->delayed_queues[flavor]) { + priority_queue_remove(&group->delayed_pqueues[flavor], &call->tc_pqlink); + } -static __inline__ boolean_t _pending_call_enqueue( - thread_call_t call, - thread_call_group_t group), - _delayed_call_enqueue( - thread_call_t call, - thread_call_group_t group, - uint64_t deadline), - _call_dequeue( - thread_call_t call, - thread_call_group_t group); + if (old_queue != NULL) { + remqueue(&call->tc_qlink); -static __inline__ void thread_call_wake( - thread_call_group_t group); + call->tc_queue = NULL; + } + return old_queue; +} -static __inline__ void _set_delayed_call_timer( - thread_call_t call, - thread_call_group_t group); - -static boolean_t _remove_from_pending_queue( - thread_call_func_t func, - thread_call_param_t param0, - boolean_t remove_all), - _remove_from_delayed_queue( - thread_call_func_t func, - thread_call_param_t param0, - boolean_t remove_all); +static queue_head_t * +thread_call_enqueue_deadline( + thread_call_t call, + thread_call_group_t group, + thread_call_flavor_t flavor, + uint64_t deadline) +{ + queue_t old_queue = call->tc_queue; + queue_t new_queue = &group->delayed_queues[flavor]; -static void thread_call_daemon( - thread_call_group_t group), - thread_call_thread( - thread_call_group_t group); + thread_call_flavor_t old_flavor = thread_call_set_flavor(call, flavor); -extern void thread_call_delayed_timer( - timer_call_param_t p0, - timer_call_param_t p1); + if (old_queue != NULL && + old_queue != &group->pending_queue && + old_queue != &group->delayed_queues[old_flavor]) { + panic("thread call (%p) on bad queue (old_queue: %p)", call, old_queue); + } -#define qe(x) ((queue_entry_t)(x)) -#define TC(x) ((thread_call_t)(x)) + if (old_queue == new_queue) { + /* optimize the same-queue case to avoid a full re-insert */ + uint64_t old_deadline = call->tc_pqlink.deadline; + call->tc_pqlink.deadline = deadline; + + if (old_deadline < deadline) { + priority_queue_entry_increased(&group->delayed_pqueues[flavor], + &call->tc_pqlink); + } else { + priority_queue_entry_decreased(&group->delayed_pqueues[flavor], + &call->tc_pqlink); + } + } else { + if (old_queue == &group->delayed_queues[old_flavor]) { + priority_queue_remove(&group->delayed_pqueues[old_flavor], + &call->tc_pqlink); + } + call->tc_pqlink.deadline = deadline; -lck_grp_t thread_call_queues_lck_grp; -lck_grp_t thread_call_lck_grp; -lck_attr_t thread_call_lck_attr; -lck_grp_attr_t thread_call_lck_grp_attr; + priority_queue_insert(&group->delayed_pqueues[flavor], &call->tc_pqlink); + } -#if defined(__i386__) || defined(__x86_64__) -lck_mtx_t thread_call_lock_data; -#else -lck_spin_t thread_call_lock_data; -#endif + if (old_queue == NULL) { + enqueue_tail(new_queue, &call->tc_qlink); + } else if (old_queue != new_queue) { + re_queue_tail(new_queue, &call->tc_qlink); + } + + call->tc_queue = new_queue; + + return old_queue; +} + +uint64_t +thread_call_get_armed_deadline(thread_call_t call) +{ + return call->tc_pqlink.deadline; +} + + +static bool +group_isparallel(thread_call_group_t group) +{ + return (group->tcg_flags & TCG_PARALLEL) != 0; +} + +static bool +thread_call_group_should_add_thread(thread_call_group_t group) +{ + if ((group->active_count + group->blocked_count + group->idle_count) >= THREAD_CALL_GROUP_MAX_THREADS) { + panic("thread_call group '%s' reached max thread cap (%d): active: %d, blocked: %d, idle: %d", + group->tcg_name, THREAD_CALL_GROUP_MAX_THREADS, + group->active_count, group->blocked_count, group->idle_count); + } + + if (group_isparallel(group) == false) { + if (group->pending_count > 0 && group->active_count == 0) { + return true; + } + + return false; + } + + if (group->pending_count > 0) { + if (group->idle_count > 0) { + return false; + } + + uint32_t thread_count = group->active_count; + + /* + * Add a thread if either there are no threads, + * the group has fewer than its target number of + * threads, or the amount of work is large relative + * to the number of threads. In the last case, pay attention + * to the total load on the system, and back off if + * it's high. + */ + if ((thread_count == 0) || + (thread_count < group->target_thread_count) || + ((group->pending_count > THREAD_CALL_ADD_RATIO * thread_count) && + (sched_mach_factor < THREAD_CALL_MACH_FACTOR_CAP))) { + return true; + } + } + + return false; +} + +static void +thread_call_group_setup(thread_call_group_t group) +{ + lck_ticket_init(&group->tcg_lock, &thread_call_lck_grp); + + queue_init(&group->pending_queue); + + for (thread_call_flavor_t flavor = 0; flavor < TCF_COUNT; flavor++) { + queue_init(&group->delayed_queues[flavor]); + priority_queue_init(&group->delayed_pqueues[flavor]); + timer_call_setup(&group->delayed_timers[flavor], thread_call_delayed_timer, group); + } -#define thread_call_lock_spin() \ - lck_mtx_lock_spin_always(&thread_call_lock_data) + timer_call_setup(&group->dealloc_timer, thread_call_dealloc_timer, group); -#define thread_call_unlock() \ - lck_mtx_unlock_always(&thread_call_lock_data) + /* Reverse the wait order so we re-use the most recently parked thread from the pool */ + waitq_init(&group->idle_waitq, SYNC_POLICY_REVERSED | SYNC_POLICY_DISABLE_IRQ); +} + +/* + * Simple wrapper for creating threads bound to + * thread call groups. + */ +static void +thread_call_thread_create( + thread_call_group_t group) +{ + thread_t thread; + kern_return_t result; + + int thread_pri = group->tcg_thread_pri; + + result = kernel_thread_start_priority((thread_continue_t)thread_call_thread, + group, thread_pri, &thread); + if (result != KERN_SUCCESS) { + panic("cannot create new thread call thread %d", result); + } + + if (thread_pri <= BASEPRI_KERNEL) { + /* + * THREAD_CALL_PRIORITY_KERNEL and lower don't get to run to completion + * in kernel if there are higher priority threads available. + */ + thread_set_eager_preempt(thread); + } + + char name[MAXTHREADNAMESIZE] = ""; + int group_thread_count = group->idle_count + group->active_count + group->blocked_count; + + snprintf(name, sizeof(name), "thread call %s #%d", group->tcg_name, group_thread_count); + thread_set_thread_name(thread, name); + + thread_deallocate(thread); +} /* * thread_call_initialize: @@ -147,67 +508,63 @@ lck_spin_t thread_call_lock_data; void thread_call_initialize(void) { - thread_call_t call; - thread_call_group_t group = &thread_call_group0; - kern_return_t result; - thread_t thread; - int i; - spl_t s; - - i = sizeof (thread_call_data_t); - thread_call_zone = zinit(i, 4096 * i, 16 * i, "thread_call"); - zone_change(thread_call_zone, Z_CALLERACCT, FALSE); - zone_change(thread_call_zone, Z_NOENCRYPT, TRUE); - - lck_attr_setdefault(&thread_call_lck_attr); - lck_grp_attr_setdefault(&thread_call_lck_grp_attr); - lck_grp_init(&thread_call_queues_lck_grp, "thread_call_queues", &thread_call_lck_grp_attr); - lck_grp_init(&thread_call_lck_grp, "thread_call", &thread_call_lck_grp_attr); - -#if defined(__i386__) || defined(__x86_64__) - lck_mtx_init(&thread_call_lock_data, &thread_call_lck_grp, &thread_call_lck_attr); -#else - lck_spin_init(&thread_call_lock_data, &thread_call_lck_grp, &thread_call_lck_attr); -#endif - queue_init(&group->pending_queue); - queue_init(&group->delayed_queue); - - s = splsched(); - thread_call_lock_spin(); - - timer_call_setup(&group->delayed_timer, thread_call_delayed_timer, group); + nanotime_to_absolutetime(0, THREAD_CALL_DEALLOC_INTERVAL_NS, &thread_call_dealloc_interval_abs); + waitq_init(&daemon_waitq, SYNC_POLICY_DISABLE_IRQ | SYNC_POLICY_FIFO); - wait_queue_init(&group->idle_wqueue, SYNC_POLICY_FIFO); - wait_queue_init(&group->daemon_wqueue, SYNC_POLICY_FIFO); - - queue_init(&thread_call_internal_queue); - for ( - call = internal_call_storage; - call < &internal_call_storage[internal_call_count]; - call++) { - - enqueue_tail(&thread_call_internal_queue, qe(call)); + for (uint32_t i = 0; i < THREAD_CALL_INDEX_MAX; i++) { + thread_call_group_setup(&thread_call_groups[i]); } - thread_call_daemon_awake = TRUE; + _internal_call_init(); - thread_call_unlock(); - splx(s); + thread_t thread; + kern_return_t result; - result = kernel_thread_start_priority((thread_continue_t)thread_call_daemon, group, BASEPRI_PREEMPT + 1, &thread); - if (result != KERN_SUCCESS) + result = kernel_thread_start_priority((thread_continue_t)thread_call_daemon, + NULL, BASEPRI_PREEMPT_HIGH + 1, &thread); + if (result != KERN_SUCCESS) { panic("thread_call_initialize"); + } thread_deallocate(thread); } void thread_call_setup( - thread_call_t call, - thread_call_func_t func, - thread_call_param_t param0) + thread_call_t call, + thread_call_func_t func, + thread_call_param_t param0) +{ + bzero(call, sizeof(*call)); + + *call = (struct thread_call) { + .tc_func = func, + .tc_param0 = param0, + + /* + * Thread calls default to the HIGH group + * unless otherwise specified. + */ + .tc_index = THREAD_CALL_INDEX_HIGH, + }; +} + +static void +_internal_call_init(void) { - call_entry_setup(call, func, param0); + /* Function-only thread calls are only kept in the default HIGH group */ + thread_call_group_t group = &thread_call_groups[THREAD_CALL_INDEX_HIGH]; + + spl_t s = disable_ints_and_lock(group); + + queue_init(&thread_call_internal_queue); + + for (unsigned i = 0; i < INTERNAL_CALL_COUNT; i++) { + enqueue_tail(&thread_call_internal_queue, &internal_call_storage[i].tc_qlink); + thread_call_internal_queue_count++; + } + + enable_ints_and_unlock(group, s); } /* @@ -217,17 +574,41 @@ thread_call_setup( * * Called with thread_call_lock held. */ -static __inline__ thread_call_t -_internal_call_allocate(void) +static thread_call_t +_internal_call_allocate(thread_call_func_t func, thread_call_param_t param0) +{ + /* Function-only thread calls are only kept in the default HIGH group */ + thread_call_group_t group = &thread_call_groups[THREAD_CALL_INDEX_HIGH]; + + spl_t s = disable_ints_and_lock(group); + + thread_call_t call = qe_dequeue_head(&thread_call_internal_queue, + struct thread_call, tc_qlink); + + if (call == NULL) { + panic("_internal_call_allocate: thread_call_internal_queue empty"); + } + + thread_call_internal_queue_count--; + + thread_call_setup(call, func, param0); + call->tc_refs = 0; + call->tc_flags = 0; /* THREAD_CALL_ALLOC not set, do not free back to zone */ + enable_ints_and_unlock(group, s); + + return call; +} + +/* Check if a call is internal and needs to be returned to the internal pool. */ +static bool +_is_internal_call(thread_call_t call) { - thread_call_t call; - - if (queue_empty(&thread_call_internal_queue)) - panic("_internal_call_allocate"); - - call = TC(dequeue_head(&thread_call_internal_queue)); - - return (call); + if (call >= internal_call_storage && + call < &internal_call_storage[INTERNAL_CALL_COUNT]) { + assert((call->tc_flags & THREAD_CALL_ALLOC) == 0); + return true; + } + return false; } /* @@ -236,15 +617,20 @@ _internal_call_allocate(void) * Release an internal callout entry which * is no longer pending (or delayed). * - * Called with thread_call_lock held. + * Called with thread_call_lock held. */ -static __inline__ void -_internal_call_release( - thread_call_t call) +static void +_internal_call_release(thread_call_t call) { - if ( call >= internal_call_storage && - call < &internal_call_storage[internal_call_count] ) - enqueue_head(&thread_call_internal_queue, qe(call)); + assert(_is_internal_call(call)); + + thread_call_group_t group = thread_call_get_group(call); + + assert(group == &thread_call_groups[THREAD_CALL_INDEX_HIGH]); + thread_call_assert_locked(group); + + enqueue_head(&thread_call_internal_queue, &call->tc_qlink); + thread_call_internal_queue_count++; } /* @@ -258,18 +644,36 @@ _internal_call_release( * * Called with thread_call_lock held. */ -static __inline__ boolean_t -_pending_call_enqueue( - thread_call_t call, - thread_call_group_t group) +static bool +_pending_call_enqueue(thread_call_t call, + thread_call_group_t group, + uint64_t now) { - queue_head_t *old_queue; + if ((THREAD_CALL_ONCE | THREAD_CALL_RUNNING) + == (call->tc_flags & (THREAD_CALL_ONCE | THREAD_CALL_RUNNING))) { + call->tc_pqlink.deadline = 0; + + thread_call_flags_t flags = call->tc_flags; + call->tc_flags |= THREAD_CALL_RESCHEDULE; + + assert(call->tc_queue == NULL); + + return flags & THREAD_CALL_RESCHEDULE; + } + + call->tc_pending_timestamp = now; + + bool was_on_queue = thread_call_enqueue_tail(call, &group->pending_queue); - old_queue = call_entry_enqueue_tail(call, &group->pending_queue); + if (!was_on_queue) { + call->tc_submit_count++; + } group->pending_count++; - return (old_queue != NULL); + thread_call_wake(group); + + return was_on_queue; } /* @@ -277,27 +681,42 @@ _pending_call_enqueue( * * Place an entry on the delayed queue, * after existing entries with an earlier - * (or identical) deadline. + * (or identical) deadline. * * Returns TRUE if the entry was already * on a queue. * * Called with thread_call_lock held. */ -static __inline__ boolean_t +static bool _delayed_call_enqueue( - thread_call_t call, - thread_call_group_t group, - uint64_t deadline) + thread_call_t call, + thread_call_group_t group, + uint64_t deadline, + thread_call_flavor_t flavor) { - queue_head_t *old_queue; + if ((THREAD_CALL_ONCE | THREAD_CALL_RUNNING) + == (call->tc_flags & (THREAD_CALL_ONCE | THREAD_CALL_RUNNING))) { + call->tc_pqlink.deadline = deadline; + + thread_call_flags_t flags = call->tc_flags; + call->tc_flags |= THREAD_CALL_RESCHEDULE; + + assert(call->tc_queue == NULL); + thread_call_set_flavor(call, flavor); - old_queue = call_entry_enqueue_deadline(call, &group->delayed_queue, deadline); + return flags & THREAD_CALL_RESCHEDULE; + } + + queue_head_t *old_queue = thread_call_enqueue_deadline(call, group, flavor, deadline); - if (old_queue == &group->pending_queue) + if (old_queue == &group->pending_queue) { group->pending_count--; + } else if (old_queue == NULL) { + call->tc_submit_count++; + } - return (old_queue != NULL); + return old_queue != NULL; } /* @@ -309,179 +728,126 @@ _delayed_call_enqueue( * * Called with thread_call_lock held. */ -static __inline__ boolean_t +static bool _call_dequeue( - thread_call_t call, - thread_call_group_t group) + thread_call_t call, + thread_call_group_t group) { - queue_head_t *old_queue; + queue_head_t *old_queue = thread_call_dequeue(call); + + if (old_queue == NULL) { + return false; + } - old_queue = call_entry_dequeue(call); + call->tc_finish_count++; - if (old_queue == &group->pending_queue) + if (old_queue == &group->pending_queue) { group->pending_count--; + } - return (old_queue != NULL); + return true; } /* - * _set_delayed_call_timer: + * _arm_delayed_call_timer: * - * Reset the timer so that it - * next expires when the entry is due. + * Check if the timer needs to be armed for this flavor, + * and if so, arm it. * - * Called with thread_call_lock held. + * If call is non-NULL, only re-arm the timer if the specified call + * is the first in the queue. + * + * Returns true if the timer was armed/re-armed, false if it was left unset + * Caller should cancel the timer if need be. + * + * Called with thread_call_lock held. */ -static __inline__ void -_set_delayed_call_timer( - thread_call_t call, - thread_call_group_t group) +static bool +_arm_delayed_call_timer(thread_call_t new_call, + thread_call_group_t group, + thread_call_flavor_t flavor) { - timer_call_enter(&group->delayed_timer, call->deadline, 0); + /* No calls implies no timer needed */ + if (queue_empty(&group->delayed_queues[flavor])) { + return false; + } + + thread_call_t call = priority_queue_min(&group->delayed_pqueues[flavor], struct thread_call, tc_pqlink); + + /* We only need to change the hard timer if this new call is the first in the list */ + if (new_call != NULL && new_call != call) { + return false; + } + + assert((call->tc_soft_deadline != 0) && ((call->tc_soft_deadline <= call->tc_pqlink.deadline))); + + uint64_t fire_at = call->tc_soft_deadline; + + if (flavor == TCF_CONTINUOUS) { + assert(call->tc_flags & THREAD_CALL_FLAG_CONTINUOUS); + fire_at = continuoustime_to_absolutetime(fire_at); + } else { + assert((call->tc_flags & THREAD_CALL_FLAG_CONTINUOUS) == 0); + } + + /* + * Note: This picks the soonest-deadline call's leeway as the hard timer's leeway, + * which does not take into account later-deadline timers with a larger leeway. + * This is a valid coalescing behavior, but masks a possible window to + * fire a timer instead of going idle. + */ + uint64_t leeway = call->tc_pqlink.deadline - call->tc_soft_deadline; + + timer_call_enter_with_leeway(&group->delayed_timers[flavor], (timer_call_param_t)flavor, + fire_at, leeway, + TIMER_CALL_SYS_CRITICAL | TIMER_CALL_LEEWAY, + ((call->tc_flags & THREAD_CALL_RATELIMITED) == THREAD_CALL_RATELIMITED)); + + return true; } /* - * _remove_from_pending_queue: + * _cancel_func_from_queue: * * Remove the first (or all) matching - * entries from the pending queue. + * entries from the specified queue. * - * Returns TRUE if any matching entries + * Returns TRUE if any matching entries * were found. * * Called with thread_call_lock held. */ static boolean_t -_remove_from_pending_queue( - thread_call_func_t func, - thread_call_param_t param0, - boolean_t remove_all) -{ - boolean_t call_removed = FALSE; - thread_call_t call; - thread_call_group_t group = &thread_call_group0; - - call = TC(queue_first(&group->pending_queue)); - - while (!queue_end(&group->pending_queue, qe(call))) { - if ( call->func == func && - call->param0 == param0 ) { - thread_call_t next = TC(queue_next(qe(call))); - - _call_dequeue(call, group); +_cancel_func_from_queue(thread_call_func_t func, + thread_call_param_t param0, + thread_call_group_t group, + boolean_t remove_all, + queue_head_t *queue) +{ + boolean_t call_removed = FALSE; + thread_call_t call; - _internal_call_release(call); - - call_removed = TRUE; - if (!remove_all) - break; - - call = next; + qe_foreach_element_safe(call, queue, tc_qlink) { + if (call->tc_func != func || + call->tc_param0 != param0) { + continue; } - else - call = TC(queue_next(qe(call))); - } - - return (call_removed); -} -/* - * _remove_from_delayed_queue: - * - * Remove the first (or all) matching - * entries from the delayed queue. - * - * Returns TRUE if any matching entries - * were found. - * - * Called with thread_call_lock held. - */ -static boolean_t -_remove_from_delayed_queue( - thread_call_func_t func, - thread_call_param_t param0, - boolean_t remove_all) -{ - boolean_t call_removed = FALSE; - thread_call_t call; - thread_call_group_t group = &thread_call_group0; - - call = TC(queue_first(&group->delayed_queue)); - - while (!queue_end(&group->delayed_queue, qe(call))) { - if ( call->func == func && - call->param0 == param0 ) { - thread_call_t next = TC(queue_next(qe(call))); - - _call_dequeue(call, group); - + _call_dequeue(call, group); + + if (_is_internal_call(call)) { _internal_call_release(call); - - call_removed = TRUE; - if (!remove_all) - break; - - call = next; } - else - call = TC(queue_next(qe(call))); - } - - return (call_removed); -} -#ifndef __LP64__ - -/* - * thread_call_func: - * - * Enqueue a function callout. - * - * Guarantees { function, argument } - * uniqueness if unique_call is TRUE. - */ -void -thread_call_func( - thread_call_func_t func, - thread_call_param_t param, - boolean_t unique_call) -{ - thread_call_t call; - thread_call_group_t group = &thread_call_group0; - spl_t s; - - s = splsched(); - thread_call_lock_spin(); - - call = TC(queue_first(&group->pending_queue)); - - while (unique_call && !queue_end(&group->pending_queue, qe(call))) { - if ( call->func == func && - call->param0 == param ) { + call_removed = TRUE; + if (!remove_all) { break; } - - call = TC(queue_next(qe(call))); - } - - if (!unique_call || queue_end(&group->pending_queue, qe(call))) { - call = _internal_call_allocate(); - call->func = func; - call->param0 = param; - call->param1 = NULL; - - _pending_call_enqueue(call, group); - - if (group->active_count == 0) - thread_call_wake(group); - } + } - thread_call_unlock(); - splx(s); + return call_removed; } -#endif /* __LP64__ */ - /* * thread_call_func_delayed: * @@ -490,29 +856,29 @@ thread_call_func( */ void thread_call_func_delayed( - thread_call_func_t func, - thread_call_param_t param, - uint64_t deadline) -{ - thread_call_t call; - thread_call_group_t group = &thread_call_group0; - spl_t s; - - s = splsched(); - thread_call_lock_spin(); - - call = _internal_call_allocate(); - call->func = func; - call->param0 = param; - call->param1 = 0; - - _delayed_call_enqueue(call, group, deadline); - - if (queue_first(&group->delayed_queue) == qe(call)) - _set_delayed_call_timer(call, group); - - thread_call_unlock(); - splx(s); + thread_call_func_t func, + thread_call_param_t param, + uint64_t deadline) +{ + (void)thread_call_enter_delayed_internal(NULL, func, param, 0, deadline, 0, 0); +} + +/* + * thread_call_func_delayed_with_leeway: + * + * Same as thread_call_func_delayed(), but with + * leeway/flags threaded through. + */ + +void +thread_call_func_delayed_with_leeway( + thread_call_func_t func, + thread_call_param_t param, + uint64_t deadline, + uint64_t leeway, + uint32_t flags) +{ + (void)thread_call_enter_delayed_internal(NULL, func, param, 0, deadline, leeway, flags); } /* @@ -526,32 +892,143 @@ thread_call_func_delayed( * in that order. * * Returns TRUE if any calls were cancelled. + * + * This iterates all of the pending or delayed thread calls in the group, + * which is really inefficient. Switch to an allocated thread call instead. + * + * TODO: Give 'func' thread calls their own group, so this silliness doesn't + * affect the main 'high' group. */ boolean_t thread_call_func_cancel( - thread_call_func_t func, - thread_call_param_t param, - boolean_t cancel_all) + thread_call_func_t func, + thread_call_param_t param, + boolean_t cancel_all) +{ + boolean_t result; + + assert(func != NULL); + + /* Function-only thread calls are only kept in the default HIGH group */ + thread_call_group_t group = &thread_call_groups[THREAD_CALL_INDEX_HIGH]; + + spl_t s = disable_ints_and_lock(group); + + if (cancel_all) { + /* exhaustively search every queue, and return true if any search found something */ + result = _cancel_func_from_queue(func, param, group, cancel_all, &group->pending_queue) | + _cancel_func_from_queue(func, param, group, cancel_all, &group->delayed_queues[TCF_ABSOLUTE]) | + _cancel_func_from_queue(func, param, group, cancel_all, &group->delayed_queues[TCF_CONTINUOUS]); + } else { + /* early-exit as soon as we find something, don't search other queues */ + result = _cancel_func_from_queue(func, param, group, cancel_all, &group->pending_queue) || + _cancel_func_from_queue(func, param, group, cancel_all, &group->delayed_queues[TCF_ABSOLUTE]) || + _cancel_func_from_queue(func, param, group, cancel_all, &group->delayed_queues[TCF_CONTINUOUS]); + } + + enable_ints_and_unlock(group, s); + + return result; +} + +/* + * Allocate a thread call with a given priority. Importances other than + * THREAD_CALL_PRIORITY_HIGH or THREAD_CALL_PRIORITY_KERNEL_HIGH will be run in threads + * with eager preemption enabled (i.e. may be aggressively preempted by higher-priority + * threads which are not in the normal "urgent" bands). + */ +thread_call_t +thread_call_allocate_with_priority( + thread_call_func_t func, + thread_call_param_t param0, + thread_call_priority_t pri) +{ + return thread_call_allocate_with_options(func, param0, pri, 0); +} + +thread_call_t +thread_call_allocate_with_options( + thread_call_func_t func, + thread_call_param_t param0, + thread_call_priority_t pri, + thread_call_options_t options) +{ + thread_call_t call = thread_call_allocate(func, param0); + + switch (pri) { + case THREAD_CALL_PRIORITY_HIGH: + call->tc_index = THREAD_CALL_INDEX_HIGH; + break; + case THREAD_CALL_PRIORITY_KERNEL: + call->tc_index = THREAD_CALL_INDEX_KERNEL; + break; + case THREAD_CALL_PRIORITY_USER: + call->tc_index = THREAD_CALL_INDEX_USER; + break; + case THREAD_CALL_PRIORITY_LOW: + call->tc_index = THREAD_CALL_INDEX_LOW; + break; + case THREAD_CALL_PRIORITY_KERNEL_HIGH: + call->tc_index = THREAD_CALL_INDEX_KERNEL_HIGH; + break; + default: + panic("Invalid thread call pri value: %d", pri); + break; + } + + if (options & THREAD_CALL_OPTIONS_ONCE) { + call->tc_flags |= THREAD_CALL_ONCE; + } + if (options & THREAD_CALL_OPTIONS_SIGNAL) { + call->tc_flags |= THREAD_CALL_SIGNAL | THREAD_CALL_ONCE; + } + + return call; +} + +thread_call_t +thread_call_allocate_with_qos(thread_call_func_t func, + thread_call_param_t param0, + int qos_tier, + thread_call_options_t options) { - boolean_t result; - spl_t s; - - s = splsched(); - thread_call_lock_spin(); + thread_call_t call = thread_call_allocate(func, param0); + + switch (qos_tier) { + case THREAD_QOS_UNSPECIFIED: + call->tc_index = THREAD_CALL_INDEX_HIGH; + break; + case THREAD_QOS_LEGACY: + call->tc_index = THREAD_CALL_INDEX_USER; + break; + case THREAD_QOS_MAINTENANCE: + case THREAD_QOS_BACKGROUND: + call->tc_index = THREAD_CALL_INDEX_LOW; + break; + case THREAD_QOS_UTILITY: + call->tc_index = THREAD_CALL_INDEX_QOS_UT; + break; + case THREAD_QOS_USER_INITIATED: + call->tc_index = THREAD_CALL_INDEX_QOS_IN; + break; + case THREAD_QOS_USER_INTERACTIVE: + call->tc_index = THREAD_CALL_INDEX_QOS_UI; + break; + default: + panic("Invalid thread call qos value: %d", qos_tier); + break; + } - if (cancel_all) - result = _remove_from_pending_queue(func, param, cancel_all) | - _remove_from_delayed_queue(func, param, cancel_all); - else - result = _remove_from_pending_queue(func, param, cancel_all) || - _remove_from_delayed_queue(func, param, cancel_all); - - thread_call_unlock(); - splx(s); + if (options & THREAD_CALL_OPTIONS_ONCE) { + call->tc_flags |= THREAD_CALL_ONCE; + } + + /* does not support THREAD_CALL_OPTIONS_SIGNAL */ - return (result); + return call; } + /* * thread_call_allocate: * @@ -559,43 +1036,64 @@ thread_call_func_cancel( */ thread_call_t thread_call_allocate( - thread_call_func_t func, - thread_call_param_t param0) + thread_call_func_t func, + thread_call_param_t param0) { - thread_call_t call = zalloc(thread_call_zone); + thread_call_t call = zalloc(thread_call_zone); - call_entry_setup(call, func, param0); + thread_call_setup(call, func, param0); + call->tc_refs = 1; + call->tc_flags = THREAD_CALL_ALLOC; - return (call); + return call; } /* * thread_call_free: * - * Free a callout entry. + * Release a callout. If the callout is currently + * executing, it will be freed when all invocations + * finish. + * + * If the callout is currently armed to fire again, then + * freeing is not allowed and returns FALSE. The + * client must have canceled the pending invocation before freeing. */ boolean_t thread_call_free( - thread_call_t call) + thread_call_t call) { - spl_t s; - - s = splsched(); - thread_call_lock_spin(); - - if (call->queue != NULL) { - thread_call_unlock(); - splx(s); + thread_call_group_t group = thread_call_get_group(call); - return (FALSE); - } - - thread_call_unlock(); - splx(s); - - zfree(thread_call_zone, call); + spl_t s = disable_ints_and_lock(group); - return (TRUE); + if (call->tc_queue != NULL || + ((call->tc_flags & THREAD_CALL_RESCHEDULE) != 0)) { + thread_call_unlock(group); + splx(s); + + return FALSE; + } + + int32_t refs = --call->tc_refs; + if (refs < 0) { + panic("Refcount negative: %d\n", refs); + } + + if ((THREAD_CALL_SIGNAL | THREAD_CALL_RUNNING) + == ((THREAD_CALL_SIGNAL | THREAD_CALL_RUNNING) & call->tc_flags)) { + thread_call_wait_once_locked(call, s); + /* thread call lock has been unlocked */ + } else { + enable_ints_and_unlock(group, s); + } + + if (refs == 0) { + assert(call->tc_finish_count == call->tc_submit_count); + zfree(thread_call_zone, call); + } + + return TRUE; } /* @@ -608,55 +1106,33 @@ thread_call_free( */ boolean_t thread_call_enter( - thread_call_t call) -{ - boolean_t result = TRUE; - thread_call_group_t group = &thread_call_group0; - spl_t s; - - s = splsched(); - thread_call_lock_spin(); - - if (call->queue != &group->pending_queue) { - result = _pending_call_enqueue(call, group); - - if (group->active_count == 0) - thread_call_wake(group); - } - - call->param1 = 0; - - thread_call_unlock(); - splx(s); - - return (result); + thread_call_t call) +{ + return thread_call_enter1(call, 0); } boolean_t thread_call_enter1( - thread_call_t call, - thread_call_param_t param1) -{ - boolean_t result = TRUE; - thread_call_group_t group = &thread_call_group0; - spl_t s; - - s = splsched(); - thread_call_lock_spin(); - - if (call->queue != &group->pending_queue) { - result = _pending_call_enqueue(call, group); - - if (group->active_count == 0) - thread_call_wake(group); + thread_call_t call, + thread_call_param_t param1) +{ + assert(call->tc_func != NULL); + assert((call->tc_flags & THREAD_CALL_SIGNAL) == 0); + + thread_call_group_t group = thread_call_get_group(call); + bool result = true; + + spl_t s = disable_ints_and_lock(group); + + if (call->tc_queue != &group->pending_queue) { + result = _pending_call_enqueue(call, group, mach_absolute_time()); } - call->param1 = param1; + call->tc_param1 = param1; - thread_call_unlock(); - splx(s); + enable_ints_and_unlock(group, s); - return (result); + return result; } /* @@ -670,53 +1146,172 @@ thread_call_enter1( */ boolean_t thread_call_enter_delayed( - thread_call_t call, - uint64_t deadline) + thread_call_t call, + uint64_t deadline) +{ + assert(call != NULL); + return thread_call_enter_delayed_internal(call, NULL, 0, 0, deadline, 0, 0); +} + +boolean_t +thread_call_enter1_delayed( + thread_call_t call, + thread_call_param_t param1, + uint64_t deadline) +{ + assert(call != NULL); + return thread_call_enter_delayed_internal(call, NULL, 0, param1, deadline, 0, 0); +} + +boolean_t +thread_call_enter_delayed_with_leeway( + thread_call_t call, + thread_call_param_t param1, + uint64_t deadline, + uint64_t leeway, + unsigned int flags) { - boolean_t result = TRUE; - thread_call_group_t group = &thread_call_group0; - spl_t s; + assert(call != NULL); + return thread_call_enter_delayed_internal(call, NULL, 0, param1, deadline, leeway, flags); +} + + +/* + * thread_call_enter_delayed_internal: + * enqueue a callout entry to occur at the stated time + * + * Returns True if the call was already on a queue + * params: + * call - structure encapsulating state of the callout + * alt_func/alt_param0 - if call is NULL, allocate temporary storage using these parameters + * deadline - time deadline in nanoseconds + * leeway - timer slack represented as delta of deadline. + * flags - THREAD_CALL_DELAY_XXX : classification of caller's desires wrt timer coalescing. + * THREAD_CALL_DELAY_LEEWAY : value in leeway is used for timer coalescing. + * THREAD_CALL_CONTINUOUS: thread call will be called according to mach_continuous_time rather + * than mach_absolute_time + */ +boolean_t +thread_call_enter_delayed_internal( + thread_call_t call, + thread_call_func_t alt_func, + thread_call_param_t alt_param0, + thread_call_param_t param1, + uint64_t deadline, + uint64_t leeway, + unsigned int flags) +{ + uint64_t now, sdeadline; - s = splsched(); - thread_call_lock_spin(); + thread_call_flavor_t flavor = (flags & THREAD_CALL_CONTINUOUS) ? TCF_CONTINUOUS : TCF_ABSOLUTE; - result = _delayed_call_enqueue(call, group, deadline); + /* direct mapping between thread_call, timer_call, and timeout_urgency values */ + uint32_t urgency = (flags & TIMEOUT_URGENCY_MASK); - if (queue_first(&group->delayed_queue) == qe(call)) - _set_delayed_call_timer(call, group); + if (call == NULL) { + /* allocate a structure out of internal storage, as a convenience for BSD callers */ + call = _internal_call_allocate(alt_func, alt_param0); + } - call->param1 = 0; + assert(call->tc_func != NULL); + thread_call_group_t group = thread_call_get_group(call); - thread_call_unlock(); - splx(s); + spl_t s = disable_ints_and_lock(group); - return (result); + /* + * kevent and IOTES let you change flavor for an existing timer, so we have to + * support flipping flavors for enqueued thread calls. + */ + if (flavor == TCF_CONTINUOUS) { + now = mach_continuous_time(); + } else { + now = mach_absolute_time(); + } + + call->tc_flags |= THREAD_CALL_DELAYED; + + call->tc_soft_deadline = sdeadline = deadline; + + boolean_t ratelimited = FALSE; + uint64_t slop = timer_call_slop(deadline, now, urgency, current_thread(), &ratelimited); + + if ((flags & THREAD_CALL_DELAY_LEEWAY) != 0 && leeway > slop) { + slop = leeway; + } + + if (UINT64_MAX - deadline <= slop) { + deadline = UINT64_MAX; + } else { + deadline += slop; + } + + if (ratelimited) { + call->tc_flags |= THREAD_CALL_RATELIMITED; + } else { + call->tc_flags &= ~THREAD_CALL_RATELIMITED; + } + + call->tc_param1 = param1; + + call->tc_ttd = (sdeadline > now) ? (sdeadline - now) : 0; + + bool result = _delayed_call_enqueue(call, group, deadline, flavor); + + _arm_delayed_call_timer(call, group, flavor); + +#if CONFIG_DTRACE + DTRACE_TMR5(thread_callout__create, thread_call_func_t, call->tc_func, + uint64_t, (deadline - sdeadline), uint64_t, (call->tc_ttd >> 32), + (unsigned) (call->tc_ttd & 0xFFFFFFFF), call); +#endif + + enable_ints_and_unlock(group, s); + + return result; } -boolean_t -thread_call_enter1_delayed( - thread_call_t call, - thread_call_param_t param1, - uint64_t deadline) +/* + * Remove a callout entry from the queue + * Called with thread_call_lock held + */ +static bool +thread_call_cancel_locked(thread_call_t call) { - boolean_t result = TRUE; - thread_call_group_t group = &thread_call_group0; - spl_t s; + bool canceled; - s = splsched(); - thread_call_lock_spin(); + if (call->tc_flags & THREAD_CALL_RESCHEDULE) { + call->tc_flags &= ~THREAD_CALL_RESCHEDULE; + canceled = true; - result = _delayed_call_enqueue(call, group, deadline); + /* if reschedule was set, it must not have been queued */ + assert(call->tc_queue == NULL); + } else { + bool queue_head_changed = false; - if (queue_first(&group->delayed_queue) == qe(call)) - _set_delayed_call_timer(call, group); + thread_call_flavor_t flavor = thread_call_get_flavor(call); + thread_call_group_t group = thread_call_get_group(call); - call->param1 = param1; + if (call->tc_pqlink.deadline != 0 && + call == priority_queue_min(&group->delayed_pqueues[flavor], struct thread_call, tc_pqlink)) { + assert(call->tc_queue == &group->delayed_queues[flavor]); + queue_head_changed = true; + } - thread_call_unlock(); - splx(s); + canceled = _call_dequeue(call, group); + + if (queue_head_changed) { + if (_arm_delayed_call_timer(NULL, group, flavor) == false) { + timer_call_cancel(&group->delayed_timers[flavor]); + } + } + } - return (result); +#if CONFIG_DTRACE + DTRACE_TMR4(thread_callout__cancel, thread_call_func_t, call->tc_func, + 0, (call->tc_ttd >> 32), (unsigned) (call->tc_ttd & 0xFFFFFFFF)); +#endif + + return canceled; } /* @@ -728,59 +1323,79 @@ thread_call_enter1_delayed( * on a queue. */ boolean_t -thread_call_cancel( - thread_call_t call) -{ - boolean_t result; - thread_call_group_t group = &thread_call_group0; - spl_t s; - - s = splsched(); - thread_call_lock_spin(); - - result = _call_dequeue(call, group); - - thread_call_unlock(); - splx(s); +thread_call_cancel(thread_call_t call) +{ + thread_call_group_t group = thread_call_get_group(call); - return (result); -} + spl_t s = disable_ints_and_lock(group); + + boolean_t result = thread_call_cancel_locked(call); -#ifndef __LP64__ + enable_ints_and_unlock(group, s); + + return result; +} /* - * thread_call_is_delayed: - * - * Returns TRUE if the call is - * currently on a delayed queue. - * - * Optionally returns the expiration time. + * Cancel a thread call. If it cannot be cancelled (i.e. + * is already in flight), waits for the most recent invocation + * to finish. Note that if clients re-submit this thread call, + * it may still be pending or in flight when thread_call_cancel_wait + * returns, but all requests to execute this work item prior + * to the call to thread_call_cancel_wait will have finished. */ boolean_t -thread_call_is_delayed( - thread_call_t call, - uint64_t *deadline) +thread_call_cancel_wait(thread_call_t call) { - boolean_t result = FALSE; - thread_call_group_t group = &thread_call_group0; - spl_t s; + thread_call_group_t group = thread_call_get_group(call); - s = splsched(); - thread_call_lock_spin(); + if ((call->tc_flags & THREAD_CALL_ALLOC) == 0) { + panic("thread_call_cancel_wait: can't wait on thread call whose storage I don't own"); + } - if (call->queue == &group->delayed_queue) { - if (deadline != NULL) - *deadline = call->deadline; - result = TRUE; + if (!ml_get_interrupts_enabled()) { + panic("unsafe thread_call_cancel_wait"); } - thread_call_unlock(); - splx(s); + thread_t self = current_thread(); - return (result); + if ((thread_get_tag_internal(self) & THREAD_TAG_CALLOUT) && + self->thc_state && self->thc_state->thc_call == call) { + panic("thread_call_cancel_wait: deadlock waiting on self from inside call: %p to function %p", + call, call->tc_func); + } + + spl_t s = disable_ints_and_lock(group); + + boolean_t canceled = thread_call_cancel_locked(call); + + if ((call->tc_flags & THREAD_CALL_ONCE) == THREAD_CALL_ONCE) { + /* + * A cancel-wait on a 'once' call will both cancel + * the pending call and wait for the in-flight call + */ + + thread_call_wait_once_locked(call, s); + /* thread call lock unlocked */ + } else { + /* + * A cancel-wait on a normal call will only wait for the in-flight calls + * if it did not cancel the pending call. + * + * TODO: This seems less than useful - shouldn't it do the wait as well? + */ + + if (canceled == FALSE) { + thread_call_wait_locked(call, s); + /* thread call lock unlocked */ + } else { + enable_ints_and_unlock(group, s); + } + } + + return canceled; } -#endif /* __LP64__ */ /* * thread_call_wake: @@ -791,18 +1406,42 @@ thread_call_is_delayed( * create additional call threads. * * Called with thread_call_lock held. + * + * For high-priority group, only does wakeup/creation if there are no threads + * running. */ -static __inline__ void +static void thread_call_wake( - thread_call_group_t group) + thread_call_group_t group) { - if (group->idle_count > 0 && wait_queue_wakeup_one(&group->idle_wqueue, NO_EVENT, THREAD_AWAKENED, -1) == KERN_SUCCESS) { - group->idle_count--; group->active_count++; - } - else - if (!thread_call_daemon_awake) { - thread_call_daemon_awake = TRUE; - wait_queue_wakeup_one(&group->daemon_wqueue, NO_EVENT, THREAD_AWAKENED, -1); + /* + * New behavior: use threads if you've got 'em. + * Traditional behavior: wake only if no threads running. + */ + if (group_isparallel(group) || group->active_count == 0) { + if (group->idle_count) { + __assert_only kern_return_t kr; + + kr = waitq_wakeup64_one(&group->idle_waitq, NO_EVENT64, + THREAD_AWAKENED, WAITQ_ALL_PRIORITIES); + assert(kr == KERN_SUCCESS); + + group->idle_count--; + group->active_count++; + + if (group->idle_count == 0 && (group->tcg_flags & TCG_DEALLOC_ACTIVE) == TCG_DEALLOC_ACTIVE) { + if (timer_call_cancel(&group->dealloc_timer) == TRUE) { + group->tcg_flags &= ~TCG_DEALLOC_ACTIVE; + } + } + } else { + if (thread_call_group_should_add_thread(group) && + os_atomic_cmpxchg(&thread_call_daemon_awake, + false, true, relaxed)) { + waitq_wakeup64_all(&daemon_waitq, NO_EVENT64, + THREAD_AWAKENED, WAITQ_ALL_PRIORITIES); + } + } } } @@ -813,26 +1452,162 @@ thread_call_wake( */ static void sched_call_thread( - int type, -__unused thread_t thread) + int type, + thread_t thread) { - thread_call_group_t group = &thread_call_group0; + thread_call_group_t group; - thread_call_lock_spin(); + assert(thread_get_tag_internal(thread) & THREAD_TAG_CALLOUT); + assert(thread->thc_state != NULL); - switch (type) { + group = thread->thc_state->thc_group; + assert((group - &thread_call_groups[0]) < THREAD_CALL_INDEX_MAX); + + thread_call_lock_spin(group); + switch (type) { case SCHED_CALL_BLOCK: - if (--group->active_count == 0 && group->pending_count > 0) + assert(group->active_count); + --group->active_count; + group->blocked_count++; + if (group->pending_count > 0) { thread_call_wake(group); + } break; case SCHED_CALL_UNBLOCK: + assert(group->blocked_count); + --group->blocked_count; group->active_count++; break; } - thread_call_unlock(); + thread_call_unlock(group); +} + +/* + * Interrupts disabled, lock held; returns the same way. + * Only called on thread calls whose storage we own. Wakes up + * anyone who might be waiting on this work item and frees it + * if the client has so requested. + */ +static bool +thread_call_finish(thread_call_t call, thread_call_group_t group, spl_t *s) +{ + assert(thread_call_get_group(call) == group); + + bool repend = false; + bool signal = call->tc_flags & THREAD_CALL_SIGNAL; + + call->tc_finish_count++; + + if (!signal) { + /* The thread call thread owns a ref until the call is finished */ + if (call->tc_refs <= 0) { + panic("thread_call_finish: detected over-released thread call: %p", call); + } + call->tc_refs--; + } + + thread_call_flags_t old_flags = call->tc_flags; + call->tc_flags &= ~(THREAD_CALL_RESCHEDULE | THREAD_CALL_RUNNING | THREAD_CALL_WAIT); + + if (call->tc_refs != 0 && (old_flags & THREAD_CALL_RESCHEDULE) != 0) { + assert(old_flags & THREAD_CALL_ONCE); + thread_call_flavor_t flavor = thread_call_get_flavor(call); + + if (old_flags & THREAD_CALL_DELAYED) { + uint64_t now = mach_absolute_time(); + if (flavor == TCF_CONTINUOUS) { + now = absolutetime_to_continuoustime(now); + } + if (call->tc_soft_deadline <= now) { + /* The deadline has already expired, go straight to pending */ + call->tc_flags &= ~(THREAD_CALL_DELAYED | THREAD_CALL_RATELIMITED); + call->tc_pqlink.deadline = 0; + } + } + + if (call->tc_pqlink.deadline) { + _delayed_call_enqueue(call, group, call->tc_pqlink.deadline, flavor); + if (!signal) { + _arm_delayed_call_timer(call, group, flavor); + } + } else if (signal) { + call->tc_submit_count++; + repend = true; + } else { + _pending_call_enqueue(call, group, mach_absolute_time()); + } + } + + if (!signal && (call->tc_refs == 0)) { + if ((old_flags & THREAD_CALL_WAIT) != 0) { + panic("Someone waiting on a thread call that is scheduled for free: %p\n", call->tc_func); + } + + assert(call->tc_finish_count == call->tc_submit_count); + + enable_ints_and_unlock(group, *s); + + zfree(thread_call_zone, call); + + *s = disable_ints_and_lock(group); + } + + if ((old_flags & THREAD_CALL_WAIT) != 0) { + /* + * Dropping lock here because the sched call for the + * high-pri group can take the big lock from under + * a thread lock. + */ + thread_call_unlock(group); + thread_wakeup((event_t)call); + thread_call_lock_spin(group); + /* THREAD_CALL_SIGNAL call may have been freed */ + } + + return repend; +} + +/* + * thread_call_invoke + * + * Invoke the function provided for this thread call + * + * Note that the thread call object can be deallocated by the function if we do not control its storage. + */ +static void __attribute__((noinline)) +thread_call_invoke(thread_call_func_t func, + thread_call_param_t param0, + thread_call_param_t param1, + __unused thread_call_t call) +{ +#if DEVELOPMENT || DEBUG + KERNEL_DEBUG_CONSTANT( + MACHDBG_CODE(DBG_MACH_SCHED, MACH_CALLOUT) | DBG_FUNC_START, + VM_KERNEL_UNSLIDE(func), VM_KERNEL_ADDRHIDE(param0), VM_KERNEL_ADDRHIDE(param1), 0, 0); +#endif /* DEVELOPMENT || DEBUG */ + +#if CONFIG_DTRACE + uint64_t tc_ttd = call->tc_ttd; + boolean_t is_delayed = call->tc_flags & THREAD_CALL_DELAYED; + DTRACE_TMR6(thread_callout__start, thread_call_func_t, func, int, 0, int, (tc_ttd >> 32), + (unsigned) (tc_ttd & 0xFFFFFFFF), is_delayed, call); +#endif + + (*func)(param0, param1); + +#if CONFIG_DTRACE + DTRACE_TMR6(thread_callout__end, thread_call_func_t, func, int, 0, int, (tc_ttd >> 32), + (unsigned) (tc_ttd & 0xFFFFFFFF), is_delayed, call); +#endif + +#if DEVELOPMENT || DEBUG + KERNEL_DEBUG_CONSTANT( + MACHDBG_CODE(DBG_MACH_SCHED, MACH_CALLOUT) | DBG_FUNC_END, + VM_KERNEL_UNSLIDE(func), 0, 0, 0, 0); +#endif /* DEVELOPMENT || DEBUG */ } /* @@ -840,159 +1615,601 @@ __unused thread_t thread) */ static void thread_call_thread( - thread_call_group_t group) + thread_call_group_t group, + wait_result_t wres) { - thread_t self = current_thread(); + thread_t self = current_thread(); + + if ((thread_get_tag_internal(self) & THREAD_TAG_CALLOUT) == 0) { + (void)thread_set_tag_internal(self, THREAD_TAG_CALLOUT); + } + + /* + * A wakeup with THREAD_INTERRUPTED indicates that + * we should terminate. + */ + if (wres == THREAD_INTERRUPTED) { + thread_terminate(self); + + /* NOTREACHED */ + panic("thread_terminate() returned?"); + } - (void) splsched(); - thread_call_lock_spin(); + spl_t s = disable_ints_and_lock(group); + + struct thread_call_thread_state thc_state = { .thc_group = group }; + self->thc_state = &thc_state; thread_sched_call(self, sched_call_thread); - while (group->pending_count > 0) { - thread_call_t call; - thread_call_func_t func; - thread_call_param_t param0, param1; + while (group->pending_count > 0) { + thread_call_t call = qe_dequeue_head(&group->pending_queue, + struct thread_call, tc_qlink); + assert(call != NULL); - call = TC(dequeue_head(&group->pending_queue)); group->pending_count--; + if (group->pending_count == 0) { + assert(queue_empty(&group->pending_queue)); + } + + thread_call_func_t func = call->tc_func; + thread_call_param_t param0 = call->tc_param0; + thread_call_param_t param1 = call->tc_param1; + + call->tc_queue = NULL; + + if (_is_internal_call(call)) { + _internal_call_release(call); + } - func = call->func; - param0 = call->param0; - param1 = call->param1; - - call->queue = NULL; + /* + * Can only do wakeups for thread calls whose storage + * we control. + */ + bool needs_finish = false; + if (call->tc_flags & THREAD_CALL_ALLOC) { + needs_finish = true; + call->tc_flags |= THREAD_CALL_RUNNING; + call->tc_refs++; /* Delay free until we're done */ + } - _internal_call_release(call); + thc_state.thc_call = call; + thc_state.thc_call_pending_timestamp = call->tc_pending_timestamp; + thc_state.thc_call_soft_deadline = call->tc_soft_deadline; + thc_state.thc_call_hard_deadline = call->tc_pqlink.deadline; + thc_state.thc_func = func; + thc_state.thc_param0 = param0; + thc_state.thc_param1 = param1; + thc_state.thc_IOTES_invocation_timestamp = 0; - thread_call_unlock(); - (void) spllo(); + enable_ints_and_unlock(group, s); - KERNEL_DEBUG_CONSTANT( - MACHDBG_CODE(DBG_MACH_SCHED,MACH_CALLOUT) | DBG_FUNC_NONE, - func, param0, param1, 0, 0); + thc_state.thc_call_start = mach_absolute_time(); - (*func)(param0, param1); + thread_call_invoke(func, param0, param1, call); + + thc_state.thc_call = NULL; if (get_preemption_level() != 0) { int pl = get_preemption_level(); panic("thread_call_thread: preemption_level %d, last callout %p(%p, %p)", - pl, func, param0, param1); + pl, (void *)VM_KERNEL_UNSLIDE(func), param0, param1); } - - (void)thread_funnel_set(self->funnel_lock, FALSE); /* XXX */ - (void) splsched(); - thread_call_lock_spin(); - } + s = disable_ints_and_lock(group); + + if (needs_finish) { + /* Release refcount, may free */ + thread_call_finish(call, group, &s); + } + } thread_sched_call(self, NULL); group->active_count--; - if (group->idle_count < thread_call_thread_min) { + if (self->callout_woken_from_icontext && !self->callout_woke_thread) { + ledger_credit(self->t_ledger, task_ledgers.interrupt_wakeups, 1); + if (self->callout_woken_from_platform_idle) { + ledger_credit(self->t_ledger, task_ledgers.platform_idle_wakeups, 1); + } + } + + self->callout_woken_from_icontext = FALSE; + self->callout_woken_from_platform_idle = FALSE; + self->callout_woke_thread = FALSE; + + self->thc_state = NULL; + + if (group_isparallel(group)) { + /* + * For new style of thread group, thread always blocks. + * If we have more than the target number of threads, + * and this is the first to block, and it isn't active + * already, set a timer for deallocating a thread if we + * continue to have a surplus. + */ group->idle_count++; - wait_queue_assert_wait(&group->idle_wqueue, NO_EVENT, THREAD_UNINT, 0); - - thread_call_unlock(); - (void) spllo(); + if (group->idle_count == 1) { + group->idle_timestamp = mach_absolute_time(); + } + + if (((group->tcg_flags & TCG_DEALLOC_ACTIVE) == 0) && + ((group->active_count + group->idle_count) > group->target_thread_count)) { + thread_call_start_deallocate_timer(group); + } + + /* Wait for more work (or termination) */ + wres = waitq_assert_wait64(&group->idle_waitq, NO_EVENT64, THREAD_INTERRUPTIBLE, 0); + if (wres != THREAD_WAITING) { + panic("kcall worker unable to assert wait?"); + } + + enable_ints_and_unlock(group, s); thread_block_parameter((thread_continue_t)thread_call_thread, group); - /* NOTREACHED */ - } + } else { + if (group->idle_count < group->target_thread_count) { + group->idle_count++; + + waitq_assert_wait64(&group->idle_waitq, NO_EVENT64, THREAD_UNINT, 0); /* Interrupted means to exit */ - thread_call_unlock(); - (void) spllo(); - - thread_terminate(self); + enable_ints_and_unlock(group, s); + + thread_block_parameter((thread_continue_t)thread_call_thread, group); + /* NOTREACHED */ + } + } + + enable_ints_and_unlock(group, s); + + thread_terminate(self); /* NOTREACHED */ } +void +thread_call_start_iotes_invocation(__assert_only thread_call_t call) +{ + thread_t self = current_thread(); + + if ((thread_get_tag_internal(self) & THREAD_TAG_CALLOUT) == 0) { + /* not a thread call thread, might be a workloop IOTES */ + return; + } + + assert(self->thc_state); + assert(self->thc_state->thc_call == call); + + self->thc_state->thc_IOTES_invocation_timestamp = mach_absolute_time(); +} + + /* - * thread_call_daemon: + * thread_call_daemon: walk list of groups, allocating + * threads if appropriate (as determined by + * thread_call_group_should_add_thread()). */ static void -thread_call_daemon_continue( - thread_call_group_t group) +thread_call_daemon_continue(__unused void *arg) { - kern_return_t result; - thread_t thread; + do { + os_atomic_store(&thread_call_daemon_awake, false, relaxed); - (void) splsched(); - thread_call_lock_spin(); - - while (group->active_count == 0 && group->pending_count > 0) { - group->active_count++; + /* Starting at zero happens to be high-priority first. */ + for (int i = 0; i < THREAD_CALL_INDEX_MAX; i++) { + thread_call_group_t group = &thread_call_groups[i]; + + spl_t s = disable_ints_and_lock(group); - thread_call_unlock(); - (void) spllo(); - - result = kernel_thread_start_priority((thread_continue_t)thread_call_thread, group, BASEPRI_PREEMPT, &thread); - if (result != KERN_SUCCESS) - panic("thread_call_daemon"); - - thread_deallocate(thread); - - (void) splsched(); - thread_call_lock_spin(); - } - - thread_call_daemon_awake = FALSE; - wait_queue_assert_wait(&group->daemon_wqueue, NO_EVENT, THREAD_UNINT, 0); - - thread_call_unlock(); - (void) spllo(); - - thread_block_parameter((thread_continue_t)thread_call_daemon_continue, group); + while (thread_call_group_should_add_thread(group)) { + group->active_count++; + + enable_ints_and_unlock(group, s); + + thread_call_thread_create(group); + + s = disable_ints_and_lock(group); + } + + enable_ints_and_unlock(group, s); + } + } while (os_atomic_load(&thread_call_daemon_awake, relaxed)); + + waitq_assert_wait64(&daemon_waitq, NO_EVENT64, THREAD_UNINT, 0); + + if (os_atomic_load(&thread_call_daemon_awake, relaxed)) { + clear_wait(current_thread(), THREAD_AWAKENED); + } + + thread_block_parameter((thread_continue_t)thread_call_daemon_continue, NULL); /* NOTREACHED */ } static void thread_call_daemon( - thread_call_group_t group) + __unused void *arg) { - thread_t self = current_thread(); + thread_t self = current_thread(); self->options |= TH_OPT_VMPRIV; - vm_page_free_reserve(2); /* XXX */ - - thread_call_daemon_continue(group); - /* NOTREACHED */ + vm_page_free_reserve(2); /* XXX */ + + thread_set_thread_name(self, "thread_call_daemon"); + + thread_call_daemon_continue(NULL); + /* NOTREACHED */ +} + +/* + * Schedule timer to deallocate a worker thread if we have a surplus + * of threads (in excess of the group's target) and at least one thread + * is idle the whole time. + */ +static void +thread_call_start_deallocate_timer(thread_call_group_t group) +{ + __assert_only bool already_enqueued; + + assert(group->idle_count > 0); + assert((group->tcg_flags & TCG_DEALLOC_ACTIVE) == 0); + + group->tcg_flags |= TCG_DEALLOC_ACTIVE; + + uint64_t deadline = group->idle_timestamp + thread_call_dealloc_interval_abs; + + already_enqueued = timer_call_enter(&group->dealloc_timer, deadline, 0); + + assert(already_enqueued == false); } +/* non-static so dtrace can find it rdar://problem/31156135&31379348 */ void -thread_call_delayed_timer( - timer_call_param_t p0, - __unused timer_call_param_t p1 -) -{ - thread_call_t call; - thread_call_group_t group = p0; - boolean_t new_pending = FALSE; - uint64_t timestamp; - - thread_call_lock_spin(); - - timestamp = mach_absolute_time(); - - call = TC(queue_first(&group->delayed_queue)); - - while (!queue_end(&group->delayed_queue, qe(call))) { - if (call->deadline <= timestamp) { - _pending_call_enqueue(call, group); - new_pending = TRUE; - } - else +thread_call_delayed_timer(timer_call_param_t p0, timer_call_param_t p1) +{ + thread_call_group_t group = (thread_call_group_t) p0; + thread_call_flavor_t flavor = (thread_call_flavor_t) p1; + + thread_call_t call; + uint64_t now; + + thread_call_lock_spin(group); + + if (flavor == TCF_CONTINUOUS) { + now = mach_continuous_time(); + } else if (flavor == TCF_ABSOLUTE) { + now = mach_absolute_time(); + } else { + panic("invalid timer flavor: %d", flavor); + } + + while ((call = priority_queue_min(&group->delayed_pqueues[flavor], + struct thread_call, tc_pqlink)) != NULL) { + assert(thread_call_get_group(call) == group); + assert(thread_call_get_flavor(call) == flavor); + + /* + * if we hit a call that isn't yet ready to expire, + * then we're done for now + * TODO: The next timer in the list could have a larger leeway + * and therefore be ready to expire. + */ + if (call->tc_soft_deadline > now) { + break; + } + + /* + * If we hit a rate-limited timer, don't eagerly wake it up. + * Wait until it reaches the end of the leeway window. + * + * TODO: What if the next timer is not rate-limited? + * Have a separate rate-limited queue to avoid this + */ + if ((call->tc_flags & THREAD_CALL_RATELIMITED) && + (call->tc_pqlink.deadline > now) && + (ml_timer_forced_evaluation() == FALSE)) { break; - - call = TC(queue_first(&group->delayed_queue)); - } + } + + if (THREAD_CALL_SIGNAL & call->tc_flags) { + __assert_only queue_head_t *old_queue; + old_queue = thread_call_dequeue(call); + assert(old_queue == &group->delayed_queues[flavor]); + + do { + thread_call_func_t func = call->tc_func; + thread_call_param_t param0 = call->tc_param0; + thread_call_param_t param1 = call->tc_param1; + + call->tc_flags |= THREAD_CALL_RUNNING; + + thread_call_unlock(group); + thread_call_invoke(func, param0, param1, call); + thread_call_lock_spin(group); + + /* finish may detect that the call has been re-pended */ + } while (thread_call_finish(call, group, NULL)); + /* call may have been freed by the finish */ + } else { + _pending_call_enqueue(call, group, now); + } + } + + _arm_delayed_call_timer(call, group, flavor); + + thread_call_unlock(group); +} + +static void +thread_call_delayed_timer_rescan(thread_call_group_t group, + thread_call_flavor_t flavor) +{ + thread_call_t call; + uint64_t now; + + spl_t s = disable_ints_and_lock(group); + + assert(ml_timer_forced_evaluation() == TRUE); + + if (flavor == TCF_CONTINUOUS) { + now = mach_continuous_time(); + } else { + now = mach_absolute_time(); + } - if (!queue_end(&group->delayed_queue, qe(call))) - _set_delayed_call_timer(call, group); + qe_foreach_element_safe(call, &group->delayed_queues[flavor], tc_qlink) { + if (call->tc_soft_deadline <= now) { + _pending_call_enqueue(call, group, now); + } else { + uint64_t skew = call->tc_pqlink.deadline - call->tc_soft_deadline; + assert(call->tc_pqlink.deadline >= call->tc_soft_deadline); + /* + * On a latency quality-of-service level change, + * re-sort potentially rate-limited callout. The platform + * layer determines which timers require this. + * + * This trick works by updating the deadline value to + * equal soft-deadline, effectively crushing away + * timer coalescing slop values for any armed + * timer in the queue. + * + * TODO: keep a hint on the timer to tell whether its inputs changed, so we + * only have to crush coalescing for timers that need it. + * + * TODO: Keep a separate queue of timers above the re-sort + * threshold, so we only have to look at those. + */ + if (timer_resort_threshold(skew)) { + _call_dequeue(call, group); + _delayed_call_enqueue(call, group, call->tc_soft_deadline, flavor); + } + } + } + + _arm_delayed_call_timer(NULL, group, flavor); + + enable_ints_and_unlock(group, s); +} - if (new_pending && group->active_count == 0) - thread_call_wake(group); +void +thread_call_delayed_timer_rescan_all(void) +{ + for (int i = 0; i < THREAD_CALL_INDEX_MAX; i++) { + for (thread_call_flavor_t flavor = 0; flavor < TCF_COUNT; flavor++) { + thread_call_delayed_timer_rescan(&thread_call_groups[i], flavor); + } + } +} - thread_call_unlock(); +/* + * Timer callback to tell a thread to terminate if + * we have an excess of threads and at least one has been + * idle for a long time. + */ +static void +thread_call_dealloc_timer( + timer_call_param_t p0, + __unused timer_call_param_t p1) +{ + thread_call_group_t group = (thread_call_group_t)p0; + uint64_t now; + kern_return_t res; + bool terminated = false; + + thread_call_lock_spin(group); + + assert(group->tcg_flags & TCG_DEALLOC_ACTIVE); + + now = mach_absolute_time(); + + if (group->idle_count > 0) { + if (now > group->idle_timestamp + thread_call_dealloc_interval_abs) { + terminated = true; + group->idle_count--; + res = waitq_wakeup64_one(&group->idle_waitq, NO_EVENT64, + THREAD_INTERRUPTED, WAITQ_ALL_PRIORITIES); + if (res != KERN_SUCCESS) { + panic("Unable to wake up idle thread for termination?"); + } + } + } + + group->tcg_flags &= ~TCG_DEALLOC_ACTIVE; + + /* + * If we still have an excess of threads, schedule another + * invocation of this function. + */ + if (group->idle_count > 0 && (group->idle_count + group->active_count > group->target_thread_count)) { + /* + * If we killed someone just now, push out the + * next deadline. + */ + if (terminated) { + group->idle_timestamp = now; + } + + thread_call_start_deallocate_timer(group); + } + + thread_call_unlock(group); +} + +/* + * Wait for the invocation of the thread call to complete + * We know there's only one in flight because of the 'once' flag. + * + * If a subsequent invocation comes in before we wake up, that's OK + * + * TODO: Here is where we will add priority inheritance to the thread executing + * the thread call in case it's lower priority than the current thread + * Priority inheritance for thread_call_wait_once + * + * Takes the thread call lock locked, returns unlocked + * This lets us avoid a spurious take/drop after waking up from thread_block + */ +static bool +thread_call_wait_once_locked(thread_call_t call, spl_t s) +{ + assert(call->tc_flags & THREAD_CALL_ALLOC); + assert(call->tc_flags & THREAD_CALL_ONCE); + + thread_call_group_t group = thread_call_get_group(call); + + if ((call->tc_flags & THREAD_CALL_RUNNING) == 0) { + enable_ints_and_unlock(group, s); + return false; + } + + /* call is running, so we have to wait for it */ + call->tc_flags |= THREAD_CALL_WAIT; + + wait_result_t res = assert_wait(call, THREAD_UNINT); + if (res != THREAD_WAITING) { + panic("Unable to assert wait: %d", res); + } + + enable_ints_and_unlock(group, s); + + res = thread_block(THREAD_CONTINUE_NULL); + if (res != THREAD_AWAKENED) { + panic("Awoken with %d?", res); + } + + /* returns unlocked */ + return true; +} + +/* + * Wait for an in-flight invocation to complete + * Does NOT try to cancel, so the client doesn't need to hold their + * lock while calling this function. + * + * Returns whether or not it had to wait. + * + * Only works for THREAD_CALL_ONCE calls. + */ +boolean_t +thread_call_wait_once(thread_call_t call) +{ + if ((call->tc_flags & THREAD_CALL_ALLOC) == 0) { + panic("thread_call_wait_once: can't wait on thread call whose storage I don't own"); + } + + if ((call->tc_flags & THREAD_CALL_ONCE) == 0) { + panic("thread_call_wait_once: can't wait_once on a non-once call"); + } + + if (!ml_get_interrupts_enabled()) { + panic("unsafe thread_call_wait_once"); + } + + thread_t self = current_thread(); + + if ((thread_get_tag_internal(self) & THREAD_TAG_CALLOUT) && + self->thc_state && self->thc_state->thc_call == call) { + panic("thread_call_wait_once: deadlock waiting on self from inside call: %p to function %p", + call, call->tc_func); + } + + thread_call_group_t group = thread_call_get_group(call); + + spl_t s = disable_ints_and_lock(group); + + bool waited = thread_call_wait_once_locked(call, s); + /* thread call lock unlocked */ + + return waited; +} + + +/* + * Wait for all requested invocations of a thread call prior to now + * to finish. Can only be invoked on thread calls whose storage we manage. + * Just waits for the finish count to catch up to the submit count we find + * at the beginning of our wait. + * + * Called with thread_call_lock held. Returns with lock released. + */ +static void +thread_call_wait_locked(thread_call_t call, spl_t s) +{ + thread_call_group_t group = thread_call_get_group(call); + + assert(call->tc_flags & THREAD_CALL_ALLOC); + + uint64_t submit_count = call->tc_submit_count; + + while (call->tc_finish_count < submit_count) { + call->tc_flags |= THREAD_CALL_WAIT; + + wait_result_t res = assert_wait(call, THREAD_UNINT); + if (res != THREAD_WAITING) { + panic("Unable to assert wait: %d", res); + } + + enable_ints_and_unlock(group, s); + + res = thread_block(THREAD_CONTINUE_NULL); + if (res != THREAD_AWAKENED) { + panic("Awoken with %d?", res); + } + + s = disable_ints_and_lock(group); + } + + enable_ints_and_unlock(group, s); +} + +/* + * Determine whether a thread call is either on a queue or + * currently being executed. + */ +boolean_t +thread_call_isactive(thread_call_t call) +{ + thread_call_group_t group = thread_call_get_group(call); + + spl_t s = disable_ints_and_lock(group); + boolean_t active = (call->tc_submit_count > call->tc_finish_count); + enable_ints_and_unlock(group, s); + + return active; +} + +/* + * adjust_cont_time_thread_calls + * on wake, reenqueue delayed call timer for continuous time thread call groups + */ +void +adjust_cont_time_thread_calls(void) +{ + for (int i = 0; i < THREAD_CALL_INDEX_MAX; i++) { + thread_call_group_t group = &thread_call_groups[i]; + spl_t s = disable_ints_and_lock(group); + + /* only the continuous timers need to be re-armed */ + + _arm_delayed_call_timer(NULL, group, TCF_CONTINUOUS); + enable_ints_and_unlock(group, s); + } }