2 * threadpool.c: Microsoft threadpool runtime support
5 * Ludovic Henry (ludovic.henry@xamarin.com)
7 * Copyright 2015 Xamarin, Inc (http://www.xamarin.com)
8 * Licensed under the MIT license. See LICENSE file in the project root for full license information.
12 // Copyright (c) Microsoft. All rights reserved.
13 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
16 // - src/vm/comthreadpool.cpp
17 // - src/vm/win32threadpoolcpp
18 // - src/vm/threadpoolrequest.cpp
19 // - src/vm/hillclimbing.cpp
21 // Ported from C++ to C and adjusted to Mono runtime
24 #define _USE_MATH_DEFINES // needed by MSVC to define math constants
29 #include <mono/metadata/class-internals.h>
30 #include <mono/metadata/exception.h>
31 #include <mono/metadata/gc-internals.h>
32 #include <mono/metadata/object.h>
33 #include <mono/metadata/object-internals.h>
34 #include <mono/metadata/threadpool.h>
35 #include <mono/metadata/threadpool-worker.h>
36 #include <mono/metadata/threadpool-io.h>
37 #include <mono/metadata/w32event.h>
38 #include <mono/utils/atomic.h>
39 #include <mono/utils/mono-compiler.h>
40 #include <mono/utils/mono-complex.h>
41 #include <mono/utils/mono-lazy-init.h>
42 #include <mono/utils/mono-logger.h>
43 #include <mono/utils/mono-logger-internals.h>
44 #include <mono/utils/mono-proclib.h>
45 #include <mono/utils/mono-threads.h>
46 #include <mono/utils/mono-time.h>
47 #include <mono/utils/refcount.h>
48 #include <mono/io-layer/io-layer.h>
52 /* Number of outstanding jobs */
53 gint32 outstanding_request;
54 /* Number of currently executing jobs */
55 gint32 threadpool_jobs;
56 /* Signalled when threadpool_jobs + outstanding_request is 0 */
57 /* Protected by threadpool->domains_lock */
58 MonoCoopCond cleanup_cond;
63 gint16 starting; /* starting, but not yet in worker_callback */
64 gint16 working; /* executing worker_callback */
72 GPtrArray *domains; // ThreadPoolDomain* []
73 MonoCoopMutex domains_lock;
75 GPtrArray *threads; // MonoInternalThread* []
76 MonoCoopMutex threads_lock;
77 MonoCoopCond threads_exit_cond;
79 ThreadPoolCounter counters;
84 MonoThreadPoolWorker *worker;
87 static mono_lazy_init_t status = MONO_LAZY_INIT_STATUS_NOT_INITIALIZED;
89 static ThreadPool* threadpool;
91 #define COUNTER_ATOMIC(threadpool,var,block) \
93 ThreadPoolCounter __old; \
95 g_assert (threadpool); \
96 (var) = __old = COUNTER_READ (threadpool); \
98 if (!(counter._.starting >= 0)) \
99 g_error ("%s: counter._.starting = %d, but should be >= 0", __func__, counter._.starting); \
100 if (!(counter._.working >= 0)) \
101 g_error ("%s: counter._.working = %d, but should be >= 0", __func__, counter._.working); \
102 } while (InterlockedCompareExchange (&threadpool->counters.as_gint32, (var).as_gint32, __old.as_gint32) != __old.as_gint32); \
105 static inline ThreadPoolCounter
106 COUNTER_READ (ThreadPool *threadpool)
108 ThreadPoolCounter counter;
109 counter.as_gint32 = InterlockedRead (&threadpool->counters.as_gint32);
116 mono_coop_mutex_lock (&threadpool->domains_lock);
120 domains_unlock (void)
122 mono_coop_mutex_unlock (&threadpool->domains_lock);
126 destroy (gpointer unused)
128 g_ptr_array_free (threadpool->domains, TRUE);
129 mono_coop_mutex_destroy (&threadpool->domains_lock);
131 g_ptr_array_free (threadpool->threads, TRUE);
132 mono_coop_mutex_destroy (&threadpool->threads_lock);
133 mono_coop_cond_destroy (&threadpool->threads_exit_cond);
135 /* We cannot free the threadpool, because there is a race
136 * on shutdown where a managed thread may request a new
137 * threadpool thread, but we already destroyed the
138 * threadpool. So to avoid a use-after-free, we simply do
139 * not free the threadpool, as we won't be able to access
140 * the threadpool anyway because the ref count will be 0 */
141 // g_free (threadpool);
147 g_assert (!threadpool);
148 threadpool = g_new0 (ThreadPool, 1);
149 g_assert (threadpool);
151 g_assert (sizeof (ThreadPoolCounter) == sizeof (gint32));
153 mono_refcount_init (threadpool, destroy);
155 threadpool->domains = g_ptr_array_new ();
156 mono_coop_mutex_init (&threadpool->domains_lock);
158 threadpool->threads = g_ptr_array_new ();
159 mono_coop_mutex_init (&threadpool->threads_lock);
160 mono_coop_cond_init (&threadpool->threads_exit_cond);
162 threadpool->limit_io_min = mono_cpu_count ();
163 threadpool->limit_io_max = CLAMP (threadpool->limit_io_min * 100, MIN (threadpool->limit_io_min, 200), MAX (threadpool->limit_io_min, 200));
165 mono_threadpool_worker_init (&threadpool->worker);
172 MonoInternalThread *current;
174 /* we make the assumption along the code that we are
175 * cleaning up only if the runtime is shutting down */
176 g_assert (mono_runtime_is_shutting_down ());
178 current = mono_thread_internal_current ();
180 mono_coop_mutex_lock (&threadpool->threads_lock);
182 /* stop all threadpool->threads */
183 for (i = 0; i < threadpool->threads->len; ++i) {
184 MonoInternalThread *thread = (MonoInternalThread*) g_ptr_array_index (threadpool->threads, i);
185 if (thread != current)
186 mono_thread_internal_abort (thread);
189 mono_coop_mutex_unlock (&threadpool->threads_lock);
191 /* give a chance to the other threads to exit */
192 mono_thread_info_yield ();
194 mono_coop_mutex_lock (&threadpool->threads_lock);
197 if (threadpool->threads->len == 0)
200 if (threadpool->threads->len == 1 && g_ptr_array_index (threadpool->threads, 0) == current) {
201 /* We are waiting on ourselves */
205 mono_coop_cond_wait (&threadpool->threads_exit_cond, &threadpool->threads_lock);
208 mono_coop_mutex_unlock (&threadpool->threads_lock);
210 mono_threadpool_worker_cleanup (threadpool->worker);
212 mono_refcount_dec (threadpool);
216 mono_threadpool_enqueue_work_item (MonoDomain *domain, MonoObject *work_item, MonoError *error)
218 static MonoClass *threadpool_class = NULL;
219 static MonoMethod *unsafe_queue_custom_work_item_method = NULL;
220 MonoDomain *current_domain;
224 mono_error_init (error);
225 g_assert (work_item);
227 if (!threadpool_class)
228 threadpool_class = mono_class_load_from_name (mono_defaults.corlib, "System.Threading", "ThreadPool");
230 if (!unsafe_queue_custom_work_item_method)
231 unsafe_queue_custom_work_item_method = mono_class_get_method_from_name (threadpool_class, "UnsafeQueueCustomWorkItem", 2);
232 g_assert (unsafe_queue_custom_work_item_method);
236 args [0] = (gpointer) work_item;
237 args [1] = (gpointer) &f;
239 current_domain = mono_domain_get ();
240 if (current_domain == domain) {
241 mono_runtime_invoke_checked (unsafe_queue_custom_work_item_method, NULL, args, error);
242 return_val_if_nok (error, FALSE);
244 mono_thread_push_appdomain_ref (domain);
245 if (mono_domain_set (domain, FALSE)) {
246 mono_runtime_invoke_checked (unsafe_queue_custom_work_item_method, NULL, args, error);
247 if (!is_ok (error)) {
248 mono_thread_pop_appdomain_ref ();
251 mono_domain_set (current_domain, TRUE);
253 mono_thread_pop_appdomain_ref ();
258 /* LOCKING: domains_lock must be held */
260 tpdomain_add (ThreadPoolDomain *tpdomain)
266 len = threadpool->domains->len;
267 for (i = 0; i < len; ++i) {
268 if (g_ptr_array_index (threadpool->domains, i) == tpdomain)
273 g_ptr_array_add (threadpool->domains, tpdomain);
276 /* LOCKING: domains_lock must be held. */
278 tpdomain_remove (ThreadPoolDomain *tpdomain)
281 return g_ptr_array_remove (threadpool->domains, tpdomain);
284 /* LOCKING: domains_lock must be held */
285 static ThreadPoolDomain *
286 tpdomain_get (MonoDomain *domain, gboolean create)
289 ThreadPoolDomain *tpdomain;
293 for (i = 0; i < threadpool->domains->len; ++i) {
294 ThreadPoolDomain *tpdomain;
296 tpdomain = (ThreadPoolDomain *)g_ptr_array_index (threadpool->domains, i);
297 if (tpdomain->domain == domain)
304 tpdomain = g_new0 (ThreadPoolDomain, 1);
305 tpdomain->domain = domain;
306 mono_coop_cond_init (&tpdomain->cleanup_cond);
308 tpdomain_add (tpdomain);
314 tpdomain_free (ThreadPoolDomain *tpdomain)
319 /* LOCKING: domains_lock must be held */
320 static ThreadPoolDomain *
321 tpdomain_get_next (ThreadPoolDomain *current)
323 ThreadPoolDomain *tpdomain = NULL;
326 len = threadpool->domains->len;
328 guint i, current_idx = -1;
330 for (i = 0; i < len; ++i) {
331 if (current == g_ptr_array_index (threadpool->domains, i)) {
336 g_assert (current_idx != (guint)-1);
338 for (i = current_idx + 1; i < len + current_idx + 1; ++i) {
339 ThreadPoolDomain *tmp = (ThreadPoolDomain *)g_ptr_array_index (threadpool->domains, i % len);
340 if (tmp->outstanding_request > 0) {
351 try_invoke_perform_wait_callback (MonoObject** exc, MonoError *error)
353 HANDLE_FUNCTION_ENTER ();
354 mono_error_init (error);
355 MonoObject *res = mono_runtime_try_invoke (mono_defaults.threadpool_perform_wait_callback_method, NULL, NULL, exc, error);
356 HANDLE_FUNCTION_RETURN_VAL (res);
360 worker_callback (gpointer unused)
363 ThreadPoolDomain *tpdomain, *previous_tpdomain;
364 ThreadPoolCounter counter;
365 MonoInternalThread *thread;
367 thread = mono_thread_internal_current ();
369 COUNTER_ATOMIC (threadpool, counter, {
370 if (!(counter._.working < 32767 /* G_MAXINT16 */))
371 g_error ("%s: counter._.working = %d, but should be < 32767", __func__, counter._.working);
373 counter._.starting --;
374 counter._.working ++;
377 if (mono_runtime_is_shutting_down ()) {
378 COUNTER_ATOMIC (threadpool, counter, {
379 counter._.working --;
382 mono_refcount_dec (threadpool);
386 mono_coop_mutex_lock (&threadpool->threads_lock);
387 g_ptr_array_add (threadpool->threads, thread);
388 mono_coop_mutex_unlock (&threadpool->threads_lock);
391 * This is needed so there is always an lmf frame in the runtime invoke call below,
392 * so ThreadAbortExceptions are caught even if the thread is in native code.
394 mono_defaults.threadpool_perform_wait_callback_method->save_lmf = TRUE;
398 previous_tpdomain = NULL;
400 while (!mono_runtime_is_shutting_down ()) {
401 gboolean retire = FALSE;
403 if ((thread->state & (ThreadState_AbortRequested | ThreadState_SuspendRequested)) != 0) {
405 mono_thread_interruption_checkpoint ();
409 tpdomain = tpdomain_get_next (previous_tpdomain);
413 tpdomain->outstanding_request --;
414 g_assert (tpdomain->outstanding_request >= 0);
416 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_THREADPOOL, "[%p] worker running in domain %p (outstanding requests %d)",
417 mono_native_thread_id_get (), tpdomain->domain, tpdomain->outstanding_request);
419 g_assert (tpdomain->threadpool_jobs >= 0);
420 tpdomain->threadpool_jobs ++;
424 mono_thread_clr_state (thread, (MonoThreadState)~ThreadState_Background);
425 if (!mono_thread_test_state (thread , ThreadState_Background))
426 ves_icall_System_Threading_Thread_SetState (thread, ThreadState_Background);
428 mono_thread_push_appdomain_ref (tpdomain->domain);
429 if (mono_domain_set (tpdomain->domain, FALSE)) {
430 MonoObject *exc = NULL, *res;
432 res = try_invoke_perform_wait_callback (&exc, &error);
433 if (exc || !mono_error_ok(&error)) {
435 exc = (MonoObject *) mono_error_convert_to_exception (&error);
437 mono_error_cleanup (&error);
438 mono_thread_internal_unhandled_exception (exc);
439 } else if (res && *(MonoBoolean*) mono_object_unbox (res) == FALSE) {
443 mono_domain_set (mono_get_root_domain (), TRUE);
445 mono_thread_pop_appdomain_ref ();
449 tpdomain->threadpool_jobs --;
450 g_assert (tpdomain->threadpool_jobs >= 0);
452 if (tpdomain->outstanding_request + tpdomain->threadpool_jobs == 0 && mono_domain_is_unloading (tpdomain->domain)) {
455 removed = tpdomain_remove (tpdomain);
458 mono_coop_cond_signal (&tpdomain->cleanup_cond);
465 previous_tpdomain = tpdomain;
470 mono_coop_mutex_lock (&threadpool->threads_lock);
472 g_ptr_array_remove_fast (threadpool->threads, thread);
474 mono_coop_cond_signal (&threadpool->threads_exit_cond);
476 mono_coop_mutex_unlock (&threadpool->threads_lock);
478 COUNTER_ATOMIC (threadpool, counter, {
479 counter._.working --;
482 mono_refcount_dec (threadpool);
486 mono_threadpool_cleanup (void)
488 #ifndef DISABLE_SOCKETS
489 mono_threadpool_io_cleanup ();
491 mono_lazy_cleanup (&status, cleanup);
495 mono_threadpool_begin_invoke (MonoDomain *domain, MonoObject *target, MonoMethod *method, gpointer *params, MonoError *error)
497 static MonoClass *async_call_klass = NULL;
498 MonoMethodMessage *message;
499 MonoAsyncResult *async_result;
500 MonoAsyncCall *async_call;
501 MonoDelegate *async_callback = NULL;
502 MonoObject *state = NULL;
504 if (!async_call_klass)
505 async_call_klass = mono_class_load_from_name (mono_defaults.corlib, "System", "MonoAsyncCall");
507 mono_lazy_initialize (&status, initialize);
509 mono_error_init (error);
511 message = mono_method_call_message_new (method, params, mono_get_delegate_invoke (method->klass), (params != NULL) ? (&async_callback) : NULL, (params != NULL) ? (&state) : NULL, error);
512 return_val_if_nok (error, NULL);
514 async_call = (MonoAsyncCall*) mono_object_new_checked (domain, async_call_klass, error);
515 return_val_if_nok (error, NULL);
517 MONO_OBJECT_SETREF (async_call, msg, message);
518 MONO_OBJECT_SETREF (async_call, state, state);
520 if (async_callback) {
521 MONO_OBJECT_SETREF (async_call, cb_method, mono_get_delegate_invoke (((MonoObject*) async_callback)->vtable->klass));
522 MONO_OBJECT_SETREF (async_call, cb_target, async_callback);
525 async_result = mono_async_result_new (domain, NULL, async_call->state, NULL, (MonoObject*) async_call, error);
526 return_val_if_nok (error, NULL);
527 MONO_OBJECT_SETREF (async_result, async_delegate, target);
529 mono_threadpool_enqueue_work_item (domain, (MonoObject*) async_result, error);
530 return_val_if_nok (error, NULL);
536 mono_threadpool_end_invoke (MonoAsyncResult *ares, MonoArray **out_args, MonoObject **exc, MonoError *error)
540 mono_error_init (error);
547 /* check if already finished */
548 mono_monitor_enter ((MonoObject*) ares);
550 if (ares->endinvoke_called) {
551 mono_error_set_invalid_operation(error, "Delegate EndInvoke method called more than once");
552 mono_monitor_exit ((MonoObject*) ares);
556 ares->endinvoke_called = 1;
558 /* wait until we are really finished */
559 if (ares->completed) {
560 mono_monitor_exit ((MonoObject *) ares);
564 wait_event = mono_wait_handle_get_handle ((MonoWaitHandle*) ares->handle);
566 wait_event = mono_w32event_create (TRUE, FALSE);
567 g_assert(wait_event);
568 MonoWaitHandle *wait_handle = mono_wait_handle_new (mono_object_domain (ares), wait_event, error);
569 if (!is_ok (error)) {
570 CloseHandle (wait_event);
573 MONO_OBJECT_SETREF (ares, handle, (MonoObject*) wait_handle);
575 mono_monitor_exit ((MonoObject*) ares);
578 WaitForSingleObjectEx (wait_event, INFINITE, TRUE);
580 mono_w32handle_wait_one (wait_event, MONO_INFINITE_WAIT, TRUE);
585 ac = (MonoAsyncCall*) ares->object_data;
588 *exc = ac->msg->exc; /* FIXME: GC add write barrier */
589 *out_args = ac->out_args;
594 mono_threadpool_remove_domain_jobs (MonoDomain *domain, int timeout)
597 ThreadPoolDomain *tpdomain;
601 g_assert (timeout >= -1);
603 g_assert (mono_domain_is_unloading (domain));
606 end = mono_msec_ticks () + timeout;
608 #ifndef DISABLE_SOCKETS
609 mono_threadpool_io_remove_domain_jobs (domain);
611 if (mono_msec_ticks () > end)
617 * Wait for all threads which execute jobs in the domain to exit.
618 * The is_unloading () check in worker_request () ensures that
619 * no new jobs are added after we enter the lock below.
622 if (!mono_lazy_is_initialized (&status))
625 mono_refcount_inc (threadpool);
629 tpdomain = tpdomain_get (domain, FALSE);
632 mono_refcount_dec (threadpool);
638 while (tpdomain->outstanding_request + tpdomain->threadpool_jobs > 0) {
640 mono_coop_cond_wait (&tpdomain->cleanup_cond, &threadpool->domains_lock);
645 now = mono_msec_ticks();
651 res = mono_coop_cond_timedwait (&tpdomain->cleanup_cond, &threadpool->domains_lock, end - now);
659 /* Remove from the list the worker threads look at */
660 tpdomain_remove (tpdomain);
664 mono_coop_cond_destroy (&tpdomain->cleanup_cond);
665 tpdomain_free (tpdomain);
667 mono_refcount_dec (threadpool);
673 mono_threadpool_suspend (void)
676 mono_threadpool_worker_set_suspended (threadpool->worker, TRUE);
680 mono_threadpool_resume (void)
683 mono_threadpool_worker_set_suspended (threadpool->worker, FALSE);
687 ves_icall_System_Threading_ThreadPool_GetAvailableThreadsNative (gint32 *worker_threads, gint32 *completion_port_threads)
689 ThreadPoolCounter counter;
691 if (!worker_threads || !completion_port_threads)
694 mono_lazy_initialize (&status, initialize);
696 counter = COUNTER_READ (threadpool);
698 *worker_threads = MAX (0, mono_threadpool_worker_get_max (threadpool->worker) - counter._.working);
699 *completion_port_threads = threadpool->limit_io_max;
703 ves_icall_System_Threading_ThreadPool_GetMinThreadsNative (gint32 *worker_threads, gint32 *completion_port_threads)
705 if (!worker_threads || !completion_port_threads)
708 mono_lazy_initialize (&status, initialize);
710 *worker_threads = mono_threadpool_worker_get_min (threadpool->worker);
711 *completion_port_threads = threadpool->limit_io_min;
715 ves_icall_System_Threading_ThreadPool_GetMaxThreadsNative (gint32 *worker_threads, gint32 *completion_port_threads)
717 if (!worker_threads || !completion_port_threads)
720 mono_lazy_initialize (&status, initialize);
722 *worker_threads = mono_threadpool_worker_get_max (threadpool->worker);
723 *completion_port_threads = threadpool->limit_io_max;
727 ves_icall_System_Threading_ThreadPool_SetMinThreadsNative (gint32 worker_threads, gint32 completion_port_threads)
729 mono_lazy_initialize (&status, initialize);
731 if (completion_port_threads <= 0 || completion_port_threads > threadpool->limit_io_max)
734 if (!mono_threadpool_worker_set_min (threadpool->worker, worker_threads))
737 threadpool->limit_io_min = completion_port_threads;
743 ves_icall_System_Threading_ThreadPool_SetMaxThreadsNative (gint32 worker_threads, gint32 completion_port_threads)
745 gint cpu_count = mono_cpu_count ();
747 mono_lazy_initialize (&status, initialize);
749 if (completion_port_threads < threadpool->limit_io_min || completion_port_threads < cpu_count)
752 if (!mono_threadpool_worker_set_max (threadpool->worker, worker_threads))
755 threadpool->limit_io_max = completion_port_threads;
761 ves_icall_System_Threading_ThreadPool_InitializeVMTp (MonoBoolean *enable_worker_tracking)
763 if (enable_worker_tracking) {
764 // TODO implement some kind of switch to have the possibily to use it
765 *enable_worker_tracking = FALSE;
768 mono_lazy_initialize (&status, initialize);
772 ves_icall_System_Threading_ThreadPool_NotifyWorkItemComplete (void)
774 if (mono_domain_is_unloading (mono_domain_get ()) || mono_runtime_is_shutting_down ())
777 return mono_threadpool_worker_notify_completed (threadpool->worker);
781 ves_icall_System_Threading_ThreadPool_NotifyWorkItemProgressNative (void)
783 mono_threadpool_worker_notify_completed (threadpool->worker);
787 ves_icall_System_Threading_ThreadPool_ReportThreadStatus (MonoBoolean is_working)
791 mono_error_set_not_implemented (&error, "");
792 mono_error_set_pending_exception (&error);
796 ves_icall_System_Threading_ThreadPool_RequestWorkerThread (void)
799 ThreadPoolDomain *tpdomain;
800 ThreadPoolCounter counter;
802 domain = mono_domain_get ();
803 if (mono_domain_is_unloading (domain))
806 if (!mono_refcount_tryinc (threadpool)) {
807 /* threadpool has been destroyed, we are shutting down */
813 /* synchronize with mono_threadpool_remove_domain_jobs */
814 if (mono_domain_is_unloading (domain)) {
816 mono_refcount_dec (threadpool);
820 tpdomain = tpdomain_get (domain, TRUE);
823 tpdomain->outstanding_request ++;
824 g_assert (tpdomain->outstanding_request >= 1);
828 COUNTER_ATOMIC (threadpool, counter, {
829 if (counter._.starting == 16) {
830 mono_refcount_dec (threadpool);
834 counter._.starting ++;
837 mono_threadpool_worker_enqueue (threadpool->worker, worker_callback, NULL);
842 MonoBoolean G_GNUC_UNUSED
843 ves_icall_System_Threading_ThreadPool_PostQueuedCompletionStatus (MonoNativeOverlapped *native_overlapped)
845 /* This copy the behavior of the current Mono implementation */
847 mono_error_set_not_implemented (&error, "");
848 mono_error_set_pending_exception (&error);
852 MonoBoolean G_GNUC_UNUSED
853 ves_icall_System_Threading_ThreadPool_BindIOCompletionCallbackNative (gpointer file_handle)
855 /* This copy the behavior of the current Mono implementation */
859 MonoBoolean G_GNUC_UNUSED
860 ves_icall_System_Threading_ThreadPool_IsThreadPoolHosted (void)