/* * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. * * @APPLE_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 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. * * @APPLE_LICENSE_HEADER_END@ */ /* * @OSF_COPYRIGHT@ * */ /*** *** ??? The following lines were picked up when code was incorporated *** into this file from `kern/syscall_subr.c.' These should be moved *** with the code if it moves again. Otherwise, they should be trimmed, *** based on the files included above. ***/ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /*** *** ??? End of lines picked up when code was incorporated *** into this file from `kern/syscall_subr.c.' ***/ #include #include #include #include #include #include #include #include /*** *** ??? The next two files supply the prototypes for `thread_set_policy()' *** and `thread_policy.' These routines cannot stay here if they are *** exported Mach system calls. ***/ #include #include void _mk_sp_thread_unblock( thread_t thread) { if (thread->state & TH_IDLE) return; if (thread->sched_mode & TH_MODE_REALTIME) { thread->realtime.deadline = mach_absolute_time(); thread->realtime.deadline += thread->realtime.constraint; } thread->current_quantum = 0; thread->computation_metered = 0; thread->reason = AST_NONE; } void _mk_sp_thread_done( thread_t old_thread, thread_t new_thread, processor_t processor) { /* * A running thread is being taken off a processor: */ processor->last_dispatch = mach_absolute_time(); if (old_thread->state & TH_IDLE) return; /* * Compute remainder of current quantum. */ if ( first_timeslice(processor) && processor->quantum_end > processor->last_dispatch ) old_thread->current_quantum = (processor->quantum_end - processor->last_dispatch); else old_thread->current_quantum = 0; if (old_thread->sched_mode & TH_MODE_REALTIME) { /* * Cancel the deadline if the thread has * consumed the entire quantum. */ if (old_thread->current_quantum == 0) { old_thread->realtime.deadline = UINT64_MAX; old_thread->reason |= AST_QUANTUM; } } else { /* * For non-realtime threads treat a tiny * remaining quantum as an expired quantum * but include what's left next time. */ if (old_thread->current_quantum < min_std_quantum) { old_thread->reason |= AST_QUANTUM; old_thread->current_quantum += std_quantum; } } /* * If we are doing a direct handoff then * give the remainder of our quantum to * the next guy. */ if ((old_thread->reason & (AST_HANDOFF|AST_QUANTUM)) == AST_HANDOFF) { new_thread->current_quantum = old_thread->current_quantum; old_thread->reason |= AST_QUANTUM; old_thread->current_quantum = 0; } old_thread->last_switch = processor->last_dispatch; old_thread->computation_metered += (old_thread->last_switch - old_thread->computation_epoch); } void _mk_sp_thread_begin( thread_t thread, processor_t processor) { /* * The designated thread is beginning execution: */ if (thread->state & TH_IDLE) { timer_call_cancel(&processor->quantum_timer); processor->timeslice = 1; return; } if (thread->current_quantum == 0) thread_quantum_init(thread); processor->quantum_end = (processor->last_dispatch + thread->current_quantum); timer_call_enter1(&processor->quantum_timer, thread, processor->quantum_end); processor_timeslice_setup(processor, thread); thread->last_switch = processor->last_dispatch; thread->computation_epoch = thread->last_switch; } void _mk_sp_thread_dispatch( thread_t thread) { if (thread->reason & AST_QUANTUM) thread_setrun(thread, SCHED_TAILQ); else if (thread->reason & AST_PREEMPT) thread_setrun(thread, SCHED_HEADQ); else thread_setrun(thread, SCHED_PREEMPT | SCHED_TAILQ); thread->reason = AST_NONE; } /* * thread_policy_common: * * Set scheduling policy & priority for thread. */ static kern_return_t thread_policy_common( thread_t thread, integer_t policy, integer_t priority) { spl_t s; if ( thread == THREAD_NULL || invalid_policy(policy) ) return(KERN_INVALID_ARGUMENT); s = splsched(); thread_lock(thread); if ( !(thread->sched_mode & TH_MODE_REALTIME) && !(thread->safe_mode & TH_MODE_REALTIME) ) { if (!(thread->sched_mode & TH_MODE_FAILSAFE)) { integer_t oldmode = (thread->sched_mode & TH_MODE_TIMESHARE); if (policy == POLICY_TIMESHARE && !oldmode) { thread->sched_mode |= TH_MODE_TIMESHARE; if (thread->state & TH_RUN) pset_share_incr(thread->processor_set); } else if (policy != POLICY_TIMESHARE && oldmode) { thread->sched_mode &= ~TH_MODE_TIMESHARE; if (thread->state & TH_RUN) pset_share_decr(thread->processor_set); } } else { if (policy == POLICY_TIMESHARE) thread->safe_mode |= TH_MODE_TIMESHARE; else thread->safe_mode &= ~TH_MODE_TIMESHARE; } if (priority >= thread->max_priority) priority = thread->max_priority - thread->task_priority; else if (priority >= MINPRI_KERNEL) priority -= MINPRI_KERNEL; else if (priority >= MINPRI_SYSTEM) priority -= MINPRI_SYSTEM; else priority -= BASEPRI_DEFAULT; priority += thread->task_priority; if (priority > thread->max_priority) priority = thread->max_priority; else if (priority < MINPRI) priority = MINPRI; thread->importance = priority - thread->task_priority; set_priority(thread, priority); } thread_unlock(thread); splx(s); return (KERN_SUCCESS); } /* * thread_set_policy * * Set scheduling policy and parameters, both base and limit, for * the given thread. Policy can be any policy implemented by the * processor set, whether enabled or not. */ kern_return_t thread_set_policy( thread_act_t thr_act, processor_set_t pset, policy_t policy, policy_base_t base, mach_msg_type_number_t base_count, policy_limit_t limit, mach_msg_type_number_t limit_count) { thread_t thread; int max, bas; kern_return_t result = KERN_SUCCESS; if ( thr_act == THR_ACT_NULL || pset == PROCESSOR_SET_NULL ) return (KERN_INVALID_ARGUMENT); thread = act_lock_thread(thr_act); if (thread == THREAD_NULL) { act_unlock_thread(thr_act); return(KERN_INVALID_ARGUMENT); } if (pset != thread->processor_set) { act_unlock_thread(thr_act); return(KERN_FAILURE); } switch (policy) { case POLICY_RR: { policy_rr_base_t rr_base = (policy_rr_base_t) base; policy_rr_limit_t rr_limit = (policy_rr_limit_t) limit; if ( base_count != POLICY_RR_BASE_COUNT || limit_count != POLICY_RR_LIMIT_COUNT ) { result = KERN_INVALID_ARGUMENT; break; } bas = rr_base->base_priority; max = rr_limit->max_priority; if (invalid_pri(bas) || invalid_pri(max)) { result = KERN_INVALID_ARGUMENT; break; } break; } case POLICY_FIFO: { policy_fifo_base_t fifo_base = (policy_fifo_base_t) base; policy_fifo_limit_t fifo_limit = (policy_fifo_limit_t) limit; if ( base_count != POLICY_FIFO_BASE_COUNT || limit_count != POLICY_FIFO_LIMIT_COUNT) { result = KERN_INVALID_ARGUMENT; break; } bas = fifo_base->base_priority; max = fifo_limit->max_priority; if (invalid_pri(bas) || invalid_pri(max)) { result = KERN_INVALID_ARGUMENT; break; } break; } case POLICY_TIMESHARE: { policy_timeshare_base_t ts_base = (policy_timeshare_base_t) base; policy_timeshare_limit_t ts_limit = (policy_timeshare_limit_t) limit; if ( base_count != POLICY_TIMESHARE_BASE_COUNT || limit_count != POLICY_TIMESHARE_LIMIT_COUNT ) { result = KERN_INVALID_ARGUMENT; break; } bas = ts_base->base_priority; max = ts_limit->max_priority; if (invalid_pri(bas) || invalid_pri(max)) { result = KERN_INVALID_ARGUMENT; break; } break; } default: result = KERN_INVALID_POLICY; } if (result != KERN_SUCCESS) { act_unlock_thread(thr_act); return(result); } result = thread_policy_common(thread, policy, bas); act_unlock_thread(thr_act); return(result); } /* * thread_policy * * Set scheduling policy and parameters, both base and limit, for * the given thread. Policy must be a policy which is enabled for the * processor set. Change contained threads if requested. */ kern_return_t thread_policy( thread_act_t thr_act, policy_t policy, policy_base_t base, mach_msg_type_number_t count, boolean_t set_limit) { thread_t thread; processor_set_t pset; kern_return_t result = KERN_SUCCESS; policy_limit_t limit; int limcount; policy_rr_limit_data_t rr_limit; policy_fifo_limit_data_t fifo_limit; policy_timeshare_limit_data_t ts_limit; if (thr_act == THR_ACT_NULL) return (KERN_INVALID_ARGUMENT); thread = act_lock_thread(thr_act); pset = thread->processor_set; if ( thread == THREAD_NULL || pset == PROCESSOR_SET_NULL ){ act_unlock_thread(thr_act); return(KERN_INVALID_ARGUMENT); } if ( invalid_policy(policy) || ((POLICY_TIMESHARE | POLICY_RR | POLICY_FIFO) & policy) == 0 ) { act_unlock_thread(thr_act); return(KERN_INVALID_POLICY); } if (set_limit) { /* * Set scheduling limits to base priority. */ switch (policy) { case POLICY_RR: { policy_rr_base_t rr_base; if (count != POLICY_RR_BASE_COUNT) { result = KERN_INVALID_ARGUMENT; break; } limcount = POLICY_RR_LIMIT_COUNT; rr_base = (policy_rr_base_t) base; rr_limit.max_priority = rr_base->base_priority; limit = (policy_limit_t) &rr_limit; break; } case POLICY_FIFO: { policy_fifo_base_t fifo_base; if (count != POLICY_FIFO_BASE_COUNT) { result = KERN_INVALID_ARGUMENT; break; } limcount = POLICY_FIFO_LIMIT_COUNT; fifo_base = (policy_fifo_base_t) base; fifo_limit.max_priority = fifo_base->base_priority; limit = (policy_limit_t) &fifo_limit; break; } case POLICY_TIMESHARE: { policy_timeshare_base_t ts_base; if (count != POLICY_TIMESHARE_BASE_COUNT) { result = KERN_INVALID_ARGUMENT; break; } limcount = POLICY_TIMESHARE_LIMIT_COUNT; ts_base = (policy_timeshare_base_t) base; ts_limit.max_priority = ts_base->base_priority; limit = (policy_limit_t) &ts_limit; break; } default: result = KERN_INVALID_POLICY; break; } } else { /* * Use current scheduling limits. Ensure that the * new base priority will not exceed current limits. */ switch (policy) { case POLICY_RR: { policy_rr_base_t rr_base; if (count != POLICY_RR_BASE_COUNT) { result = KERN_INVALID_ARGUMENT; break; } limcount = POLICY_RR_LIMIT_COUNT; rr_base = (policy_rr_base_t) base; if (rr_base->base_priority > thread->max_priority) { result = KERN_POLICY_LIMIT; break; } rr_limit.max_priority = thread->max_priority; limit = (policy_limit_t) &rr_limit; break; } case POLICY_FIFO: { policy_fifo_base_t fifo_base; if (count != POLICY_FIFO_BASE_COUNT) { result = KERN_INVALID_ARGUMENT; break; } limcount = POLICY_FIFO_LIMIT_COUNT; fifo_base = (policy_fifo_base_t) base; if (fifo_base->base_priority > thread->max_priority) { result = KERN_POLICY_LIMIT; break; } fifo_limit.max_priority = thread->max_priority; limit = (policy_limit_t) &fifo_limit; break; } case POLICY_TIMESHARE: { policy_timeshare_base_t ts_base; if (count != POLICY_TIMESHARE_BASE_COUNT) { result = KERN_INVALID_ARGUMENT; break; } limcount = POLICY_TIMESHARE_LIMIT_COUNT; ts_base = (policy_timeshare_base_t) base; if (ts_base->base_priority > thread->max_priority) { result = KERN_POLICY_LIMIT; break; } ts_limit.max_priority = thread->max_priority; limit = (policy_limit_t) &ts_limit; break; } default: result = KERN_INVALID_POLICY; break; } } act_unlock_thread(thr_act); if (result == KERN_SUCCESS) result = thread_set_policy(thr_act, pset, policy, base, count, limit, limcount); return(result); } /* * Define shifts for simulating (5/8)**n */ shift_data_t wait_shift[32] = { {1,1},{1,3},{1,-3},{2,-7},{3,5},{3,-5},{4,-8},{5,7}, {5,-7},{6,-10},{7,10},{7,-9},{8,-11},{9,12},{9,-11},{10,-13}, {11,14},{11,-13},{12,-15},{13,17},{13,-15},{14,-17},{15,19},{16,18}, {16,-19},{17,22},{18,20},{18,-20},{19,26},{20,22},{20,-22},{21,-27}}; /* * do_priority_computation: * * Calculate new priority for thread based on its base priority plus * accumulated usage. PRI_SHIFT and PRI_SHIFT_2 convert from * usage to priorities. SCHED_SHIFT converts for the scaling * of the sched_usage field by SCHED_SCALE. This scaling comes * from the multiplication by sched_load (thread_timer_delta) * in sched.h. sched_load is calculated as a scaled overload * factor in compute_mach_factor (mach_factor.c). */ #ifdef PRI_SHIFT_2 #if PRI_SHIFT_2 > 0 #define do_priority_computation(thread, pri) \ MACRO_BEGIN \ (pri) = (thread)->priority /* start with base priority */ \ - ((thread)->sched_usage >> (PRI_SHIFT + SCHED_SHIFT)) \ - ((thread)->sched_usage >> (PRI_SHIFT_2 + SCHED_SHIFT)); \ if ((pri) < MINPRI_STANDARD) \ (pri) = MINPRI_STANDARD; \ else \ if ((pri) > MAXPRI_STANDARD) \ (pri) = MAXPRI_STANDARD; \ MACRO_END #else /* PRI_SHIFT_2 */ #define do_priority_computation(thread, pri) \ MACRO_BEGIN \ (pri) = (thread)->priority /* start with base priority */ \ - ((thread)->sched_usage >> (PRI_SHIFT + SCHED_SHIFT)) \ + ((thread)->sched_usage >> (SCHED_SHIFT - PRI_SHIFT_2)); \ if ((pri) < MINPRI_STANDARD) \ (pri) = MINPRI_STANDARD; \ else \ if ((pri) > MAXPRI_STANDARD) \ (pri) = MAXPRI_STANDARD; \ MACRO_END #endif /* PRI_SHIFT_2 */ #else /* defined(PRI_SHIFT_2) */ #define do_priority_computation(thread, pri) \ MACRO_BEGIN \ (pri) = (thread)->priority /* start with base priority */ \ - ((thread)->sched_usage >> (PRI_SHIFT + SCHED_SHIFT)); \ if ((pri) < MINPRI_STANDARD) \ (pri) = MINPRI_STANDARD; \ else \ if ((pri) > MAXPRI_STANDARD) \ (pri) = MAXPRI_STANDARD; \ MACRO_END #endif /* defined(PRI_SHIFT_2) */ void set_priority( register thread_t thread, register int priority) { thread->priority = priority; compute_priority(thread, FALSE); } /* * compute_priority: * * Reset the current scheduled priority of the * thread according to its base priority if the * thread has not been promoted or depressed. * * If the thread is timesharing, adjust according * to recent cpu usage. * * The thread *must* be locked by the caller. */ void compute_priority( register thread_t thread, boolean_t override_depress) { register int priority; if ( !(thread->sched_mode & TH_MODE_PROMOTED) && (!(thread->sched_mode & TH_MODE_ISDEPRESSED) || override_depress ) ) { if (thread->sched_mode & TH_MODE_TIMESHARE) do_priority_computation(thread, priority); else priority = thread->priority; set_sched_pri(thread, priority); } } /* * compute_my_priority: * * Version of compute priority for current thread. * Caller must have thread locked and thread must * be timesharing and not depressed. * * Only used for priority updates. */ void compute_my_priority( register thread_t thread) { register int priority; do_priority_computation(thread, priority); assert(thread->runq == RUN_QUEUE_NULL); thread->sched_pri = priority; } /* * update_priority * * Cause the priority computation of a thread that has been * sleeping or suspended to "catch up" with the system. Thread * *MUST* be locked by caller. If thread is running, then this * can only be called by the thread on itself. */ void update_priority( register thread_t thread) { register unsigned int ticks; register shift_t shiftp; ticks = sched_tick - thread->sched_stamp; assert(ticks != 0); /* * If asleep for more than 30 seconds forget all * cpu_usage, else catch up on missed aging. * 5/8 ** n is approximated by the two shifts * in the wait_shift array. */ thread->sched_stamp += ticks; thread_timer_delta(thread); if (ticks > 30) { thread->cpu_usage = 0; thread->sched_usage = 0; } else { thread->cpu_usage += thread->cpu_delta; thread->sched_usage += thread->sched_delta; shiftp = &wait_shift[ticks]; if (shiftp->shift2 > 0) { thread->cpu_usage = (thread->cpu_usage >> shiftp->shift1) + (thread->cpu_usage >> shiftp->shift2); thread->sched_usage = (thread->sched_usage >> shiftp->shift1) + (thread->sched_usage >> shiftp->shift2); } else { thread->cpu_usage = (thread->cpu_usage >> shiftp->shift1) - (thread->cpu_usage >> -(shiftp->shift2)); thread->sched_usage = (thread->sched_usage >> shiftp->shift1) - (thread->sched_usage >> -(shiftp->shift2)); } } thread->cpu_delta = 0; thread->sched_delta = 0; /* * Check for fail-safe release. */ if ( (thread->sched_mode & TH_MODE_FAILSAFE) && thread->sched_stamp >= thread->safe_release ) { if (!(thread->safe_mode & TH_MODE_TIMESHARE)) { if (thread->safe_mode & TH_MODE_REALTIME) { thread->priority = BASEPRI_RTQUEUES; thread->sched_mode |= TH_MODE_REALTIME; } thread->sched_mode &= ~TH_MODE_TIMESHARE; if (thread->state & TH_RUN) pset_share_decr(thread->processor_set); if (!(thread->sched_mode & TH_MODE_ISDEPRESSED)) set_sched_pri(thread, thread->priority); } thread->safe_mode = 0; thread->sched_mode &= ~TH_MODE_FAILSAFE; } /* * Recompute scheduled priority if appropriate. */ if ( (thread->sched_mode & TH_MODE_TIMESHARE) && !(thread->sched_mode & TH_MODE_PROMOTED) && !(thread->sched_mode & TH_MODE_ISDEPRESSED) ) { register int new_pri; do_priority_computation(thread, new_pri); if (new_pri != thread->sched_pri) { run_queue_t runq; runq = run_queue_remove(thread); thread->sched_pri = new_pri; if (runq != RUN_QUEUE_NULL) thread_setrun(thread, SCHED_TAILQ); } } } /* * thread_switch_continue: * * Continuation routine for a thread switch. * * Just need to arrange the return value gets sent out correctly and that * we cancel the timer or the depression called for by the options to the * thread_switch call. */ void _mk_sp_thread_switch_continue(void) { register thread_t self = current_thread(); int wait_result = self->wait_result; int option = self->saved.swtch.option; if (option == SWITCH_OPTION_WAIT && wait_result != THREAD_TIMED_OUT) thread_cancel_timer(); else if (option == SWITCH_OPTION_DEPRESS) _mk_sp_thread_depress_abort(self, FALSE); thread_syscall_return(KERN_SUCCESS); /*NOTREACHED*/ } /* * thread_switch: * * Context switch. User may supply thread hint. * * Fixed priority threads that call this get what they asked for * even if that violates priority order. */ kern_return_t _mk_sp_thread_switch( thread_act_t hint_act, int option, mach_msg_timeout_t option_time) { register thread_t self = current_thread(); int s; /* * Check and use thr_act hint if appropriate. It is not * appropriate to give a hint that shares the current shuttle. */ if (hint_act != THR_ACT_NULL) { register thread_t thread = act_lock_thread(hint_act); if ( thread != THREAD_NULL && thread != self && thread->top_act == hint_act ) { processor_t processor; s = splsched(); thread_lock(thread); /* * Check if the thread is in the right pset, * is not bound to a different processor, * and that realtime is not involved. * * Next, pull it off its run queue. If it * doesn't come, it's not eligible. */ processor = current_processor(); if (processor->current_pri < BASEPRI_RTQUEUES && thread->sched_pri < BASEPRI_RTQUEUES && thread->processor_set == processor->processor_set && (thread->bound_processor == PROCESSOR_NULL || thread->bound_processor == processor) && run_queue_remove(thread) != RUN_QUEUE_NULL ) { /* * Hah, got it!! */ thread_unlock(thread); act_unlock_thread(hint_act); act_deallocate(hint_act); if (option == SWITCH_OPTION_WAIT) assert_wait_timeout(option_time, THREAD_ABORTSAFE); else if (option == SWITCH_OPTION_DEPRESS) _mk_sp_thread_depress_ms(option_time); self->saved.swtch.option = option; thread_run(self, _mk_sp_thread_switch_continue, thread); /* NOTREACHED */ } thread_unlock(thread); splx(s); } act_unlock_thread(hint_act); act_deallocate(hint_act); } /* * No handoff hint supplied, or hint was wrong. Call thread_block() in * hopes of running something else. If nothing else is runnable, * thread_block will detect this. WARNING: thread_switch with no * option will not do anything useful if the thread calling it is the * highest priority thread (can easily happen with a collection * of timesharing threads). */ if (option == SWITCH_OPTION_WAIT) assert_wait_timeout(option_time, THREAD_ABORTSAFE); else if (option == SWITCH_OPTION_DEPRESS) _mk_sp_thread_depress_ms(option_time); self->saved.swtch.option = option; thread_block_reason(_mk_sp_thread_switch_continue, AST_YIELD); if (option == SWITCH_OPTION_WAIT) thread_cancel_timer(); else if (option == SWITCH_OPTION_DEPRESS) _mk_sp_thread_depress_abort(self, FALSE); return (KERN_SUCCESS); } /* * Depress thread's priority to lowest possible for the specified interval, * with a value of zero resulting in no timeout being scheduled. */ void _mk_sp_thread_depress_abstime( uint64_t interval) { register thread_t self = current_thread(); uint64_t deadline; spl_t s; s = splsched(); thread_lock(self); if (!(self->sched_mode & TH_MODE_ISDEPRESSED)) { processor_t myprocessor = self->last_processor; self->sched_pri = DEPRESSPRI; myprocessor->current_pri = self->sched_pri; self->sched_mode &= ~TH_MODE_PREEMPT; self->sched_mode |= TH_MODE_DEPRESS; if (interval != 0) { clock_absolutetime_interval_to_deadline(interval, &deadline); if (!timer_call_enter(&self->depress_timer, deadline)) self->depress_timer_active++; } } thread_unlock(self); splx(s); } void _mk_sp_thread_depress_ms( mach_msg_timeout_t interval) { uint64_t abstime; clock_interval_to_absolutetime_interval( interval, 1000*NSEC_PER_USEC, &abstime); _mk_sp_thread_depress_abstime(abstime); } /* * Priority depression expiration. */ void thread_depress_expire( timer_call_param_t p0, timer_call_param_t p1) { thread_t thread = p0; spl_t s; s = splsched(); thread_lock(thread); if (--thread->depress_timer_active == 1) { thread->sched_mode &= ~TH_MODE_ISDEPRESSED; compute_priority(thread, FALSE); } thread_unlock(thread); splx(s); } /* * Prematurely abort priority depression if there is one. */ kern_return_t _mk_sp_thread_depress_abort( register thread_t thread, boolean_t abortall) { kern_return_t result = KERN_NOT_DEPRESSED; spl_t s; s = splsched(); thread_lock(thread); if (abortall || !(thread->sched_mode & TH_MODE_POLLDEPRESS)) { if (thread->sched_mode & TH_MODE_ISDEPRESSED) { thread->sched_mode &= ~TH_MODE_ISDEPRESSED; compute_priority(thread, FALSE); result = KERN_SUCCESS; } if (timer_call_cancel(&thread->depress_timer)) thread->depress_timer_active--; } thread_unlock(thread); splx(s); return (result); } void _mk_sp_thread_perhaps_yield( thread_t self) { spl_t s; assert(self == current_thread()); s = splsched(); if (!(self->sched_mode & (TH_MODE_REALTIME|TH_MODE_TIMESHARE))) { extern uint64_t max_poll_computation; extern int sched_poll_yield_shift; uint64_t total_computation, abstime; abstime = mach_absolute_time(); total_computation = abstime - self->computation_epoch; total_computation += self->computation_metered; if (total_computation >= max_poll_computation) { processor_t myprocessor = current_processor(); ast_t preempt; thread_lock(self); if (!(self->sched_mode & TH_MODE_ISDEPRESSED)) { self->sched_pri = DEPRESSPRI; myprocessor->current_pri = self->sched_pri; self->sched_mode &= ~TH_MODE_PREEMPT; } self->computation_epoch = abstime; self->computation_metered = 0; self->sched_mode |= TH_MODE_POLLDEPRESS; abstime += (total_computation >> sched_poll_yield_shift); if (!timer_call_enter(&self->depress_timer, abstime)) self->depress_timer_active++; thread_unlock(self); if ((preempt = csw_check(self, myprocessor)) != AST_NONE) ast_on(preempt); } } splx(s); }