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>
51 /* Number of outstanding jobs */
52 gint32 outstanding_request;
53 /* Number of currently executing jobs */
54 gint32 threadpool_jobs;
55 /* Signalled when threadpool_jobs + outstanding_request is 0 */
56 /* Protected by threadpool->domains_lock */
57 MonoCoopCond cleanup_cond;
62 gint16 starting; /* starting, but not yet in worker_callback */
63 gint16 working; /* executing worker_callback */
71 GPtrArray *domains; // ThreadPoolDomain* []
72 MonoCoopMutex domains_lock;
74 GPtrArray *threads; // MonoInternalThread* []
75 MonoCoopMutex threads_lock;
76 MonoCoopCond threads_exit_cond;
78 ThreadPoolCounter counters;
83 MonoThreadPoolWorker *worker;
86 static mono_lazy_init_t status = MONO_LAZY_INIT_STATUS_NOT_INITIALIZED;
88 static ThreadPool* threadpool;
90 #define COUNTER_ATOMIC(threadpool,var,block) \
92 ThreadPoolCounter __old; \
94 g_assert (threadpool); \
95 (var) = __old = COUNTER_READ (threadpool); \
97 if (!(counter._.starting >= 0)) \
98 g_error ("%s: counter._.starting = %d, but should be >= 0", __func__, counter._.starting); \
99 if (!(counter._.working >= 0)) \
100 g_error ("%s: counter._.working = %d, but should be >= 0", __func__, counter._.working); \
101 } while (InterlockedCompareExchange (&threadpool->counters.as_gint32, (var).as_gint32, __old.as_gint32) != __old.as_gint32); \
104 static inline ThreadPoolCounter
105 COUNTER_READ (ThreadPool *threadpool)
107 ThreadPoolCounter counter;
108 counter.as_gint32 = InterlockedRead (&threadpool->counters.as_gint32);
115 mono_coop_mutex_lock (&threadpool->domains_lock);
119 domains_unlock (void)
121 mono_coop_mutex_unlock (&threadpool->domains_lock);
125 destroy (gpointer unused)
127 g_ptr_array_free (threadpool->domains, TRUE);
128 mono_coop_mutex_destroy (&threadpool->domains_lock);
130 g_ptr_array_free (threadpool->threads, TRUE);
131 mono_coop_mutex_destroy (&threadpool->threads_lock);
132 mono_coop_cond_destroy (&threadpool->threads_exit_cond);
134 /* We cannot free the threadpool, because there is a race
135 * on shutdown where a managed thread may request a new
136 * threadpool thread, but we already destroyed the
137 * threadpool. So to avoid a use-after-free, we simply do
138 * not free the threadpool, as we won't be able to access
139 * the threadpool anyway because the ref count will be 0 */
140 // g_free (threadpool);
146 g_assert (!threadpool);
147 threadpool = g_new0 (ThreadPool, 1);
148 g_assert (threadpool);
150 g_assert (sizeof (ThreadPoolCounter) == sizeof (gint32));
152 mono_refcount_init (threadpool, destroy);
154 threadpool->domains = g_ptr_array_new ();
155 mono_coop_mutex_init (&threadpool->domains_lock);
157 threadpool->threads = g_ptr_array_new ();
158 mono_coop_mutex_init (&threadpool->threads_lock);
159 mono_coop_cond_init (&threadpool->threads_exit_cond);
161 threadpool->limit_io_min = mono_cpu_count ();
162 threadpool->limit_io_max = CLAMP (threadpool->limit_io_min * 100, MIN (threadpool->limit_io_min, 200), MAX (threadpool->limit_io_min, 200));
164 mono_threadpool_worker_init (&threadpool->worker);
171 MonoInternalThread *current;
173 /* we make the assumption along the code that we are
174 * cleaning up only if the runtime is shutting down */
175 g_assert (mono_runtime_is_shutting_down ());
177 current = mono_thread_internal_current ();
179 mono_coop_mutex_lock (&threadpool->threads_lock);
181 /* stop all threadpool->threads */
182 for (i = 0; i < threadpool->threads->len; ++i) {
183 MonoInternalThread *thread = (MonoInternalThread*) g_ptr_array_index (threadpool->threads, i);
184 if (thread != current)
185 mono_thread_internal_abort (thread);
188 mono_coop_mutex_unlock (&threadpool->threads_lock);
190 /* give a chance to the other threads to exit */
191 mono_thread_info_yield ();
193 mono_coop_mutex_lock (&threadpool->threads_lock);
196 if (threadpool->threads->len == 0)
199 if (threadpool->threads->len == 1 && g_ptr_array_index (threadpool->threads, 0) == current) {
200 /* We are waiting on ourselves */
204 mono_coop_cond_wait (&threadpool->threads_exit_cond, &threadpool->threads_lock);
207 mono_coop_mutex_unlock (&threadpool->threads_lock);
209 mono_threadpool_worker_cleanup (threadpool->worker);
211 mono_refcount_dec (threadpool);
215 mono_threadpool_enqueue_work_item (MonoDomain *domain, MonoObject *work_item, MonoError *error)
217 static MonoClass *threadpool_class = NULL;
218 static MonoMethod *unsafe_queue_custom_work_item_method = NULL;
219 MonoDomain *current_domain;
223 mono_error_init (error);
224 g_assert (work_item);
226 if (!threadpool_class)
227 threadpool_class = mono_class_load_from_name (mono_defaults.corlib, "System.Threading", "ThreadPool");
229 if (!unsafe_queue_custom_work_item_method)
230 unsafe_queue_custom_work_item_method = mono_class_get_method_from_name (threadpool_class, "UnsafeQueueCustomWorkItem", 2);
231 g_assert (unsafe_queue_custom_work_item_method);
235 args [0] = (gpointer) work_item;
236 args [1] = (gpointer) &f;
238 current_domain = mono_domain_get ();
239 if (current_domain == domain) {
240 mono_runtime_invoke_checked (unsafe_queue_custom_work_item_method, NULL, args, error);
241 return_val_if_nok (error, FALSE);
243 mono_thread_push_appdomain_ref (domain);
244 if (mono_domain_set (domain, FALSE)) {
245 mono_runtime_invoke_checked (unsafe_queue_custom_work_item_method, NULL, args, error);
246 if (!is_ok (error)) {
247 mono_thread_pop_appdomain_ref ();
250 mono_domain_set (current_domain, TRUE);
252 mono_thread_pop_appdomain_ref ();
257 /* LOCKING: domains_lock must be held */
259 tpdomain_add (ThreadPoolDomain *tpdomain)
265 len = threadpool->domains->len;
266 for (i = 0; i < len; ++i) {
267 if (g_ptr_array_index (threadpool->domains, i) == tpdomain)
272 g_ptr_array_add (threadpool->domains, tpdomain);
275 /* LOCKING: domains_lock must be held. */
277 tpdomain_remove (ThreadPoolDomain *tpdomain)
280 return g_ptr_array_remove (threadpool->domains, tpdomain);
283 /* LOCKING: domains_lock must be held */
284 static ThreadPoolDomain *
285 tpdomain_get (MonoDomain *domain, gboolean create)
288 ThreadPoolDomain *tpdomain;
292 for (i = 0; i < threadpool->domains->len; ++i) {
293 ThreadPoolDomain *tpdomain;
295 tpdomain = (ThreadPoolDomain *)g_ptr_array_index (threadpool->domains, i);
296 if (tpdomain->domain == domain)
303 tpdomain = g_new0 (ThreadPoolDomain, 1);
304 tpdomain->domain = domain;
305 mono_coop_cond_init (&tpdomain->cleanup_cond);
307 tpdomain_add (tpdomain);
313 tpdomain_free (ThreadPoolDomain *tpdomain)
318 /* LOCKING: domains_lock must be held */
319 static ThreadPoolDomain *
320 tpdomain_get_next (ThreadPoolDomain *current)
322 ThreadPoolDomain *tpdomain = NULL;
325 len = threadpool->domains->len;
327 guint i, current_idx = -1;
329 for (i = 0; i < len; ++i) {
330 if (current == g_ptr_array_index (threadpool->domains, i)) {
335 g_assert (current_idx != (guint)-1);
337 for (i = current_idx + 1; i < len + current_idx + 1; ++i) {
338 ThreadPoolDomain *tmp = (ThreadPoolDomain *)g_ptr_array_index (threadpool->domains, i % len);
339 if (tmp->outstanding_request > 0) {
350 try_invoke_perform_wait_callback (MonoObject** exc, MonoError *error)
352 HANDLE_FUNCTION_ENTER ();
353 mono_error_init (error);
354 MonoObject *res = mono_runtime_try_invoke (mono_defaults.threadpool_perform_wait_callback_method, NULL, NULL, exc, error);
355 HANDLE_FUNCTION_RETURN_VAL (res);
359 worker_callback (gpointer unused)
362 ThreadPoolDomain *tpdomain, *previous_tpdomain;
363 ThreadPoolCounter counter;
364 MonoInternalThread *thread;
366 thread = mono_thread_internal_current ();
368 COUNTER_ATOMIC (threadpool, counter, {
369 if (!(counter._.working < 32767 /* G_MAXINT16 */))
370 g_error ("%s: counter._.working = %d, but should be < 32767", __func__, counter._.working);
372 counter._.starting --;
373 counter._.working ++;
376 if (mono_runtime_is_shutting_down ()) {
377 COUNTER_ATOMIC (threadpool, counter, {
378 counter._.working --;
381 mono_refcount_dec (threadpool);
385 mono_coop_mutex_lock (&threadpool->threads_lock);
386 g_ptr_array_add (threadpool->threads, thread);
387 mono_coop_mutex_unlock (&threadpool->threads_lock);
390 * This is needed so there is always an lmf frame in the runtime invoke call below,
391 * so ThreadAbortExceptions are caught even if the thread is in native code.
393 mono_defaults.threadpool_perform_wait_callback_method->save_lmf = TRUE;
397 previous_tpdomain = NULL;
399 while (!mono_runtime_is_shutting_down ()) {
400 gboolean retire = FALSE;
402 if ((thread->state & (ThreadState_AbortRequested | ThreadState_SuspendRequested)) != 0) {
404 mono_thread_interruption_checkpoint ();
408 tpdomain = tpdomain_get_next (previous_tpdomain);
412 tpdomain->outstanding_request --;
413 g_assert (tpdomain->outstanding_request >= 0);
415 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_THREADPOOL, "[%p] worker running in domain %p (outstanding requests %d)",
416 mono_native_thread_id_get (), tpdomain->domain, tpdomain->outstanding_request);
418 g_assert (tpdomain->threadpool_jobs >= 0);
419 tpdomain->threadpool_jobs ++;
423 mono_thread_clr_state (thread, (MonoThreadState)~ThreadState_Background);
424 if (!mono_thread_test_state (thread , ThreadState_Background))
425 ves_icall_System_Threading_Thread_SetState (thread, ThreadState_Background);
427 mono_thread_push_appdomain_ref (tpdomain->domain);
428 if (mono_domain_set (tpdomain->domain, FALSE)) {
429 MonoObject *exc = NULL, *res;
431 res = try_invoke_perform_wait_callback (&exc, &error);
432 if (exc || !mono_error_ok(&error)) {
434 exc = (MonoObject *) mono_error_convert_to_exception (&error);
436 mono_error_cleanup (&error);
437 mono_thread_internal_unhandled_exception (exc);
438 } else if (res && *(MonoBoolean*) mono_object_unbox (res) == FALSE) {
442 mono_domain_set (mono_get_root_domain (), TRUE);
444 mono_thread_pop_appdomain_ref ();
448 tpdomain->threadpool_jobs --;
449 g_assert (tpdomain->threadpool_jobs >= 0);
451 if (tpdomain->outstanding_request + tpdomain->threadpool_jobs == 0 && mono_domain_is_unloading (tpdomain->domain)) {
454 removed = tpdomain_remove (tpdomain);
457 mono_coop_cond_signal (&tpdomain->cleanup_cond);
464 previous_tpdomain = tpdomain;
469 mono_coop_mutex_lock (&threadpool->threads_lock);
471 g_ptr_array_remove_fast (threadpool->threads, thread);
473 mono_coop_cond_signal (&threadpool->threads_exit_cond);
475 mono_coop_mutex_unlock (&threadpool->threads_lock);
477 COUNTER_ATOMIC (threadpool, counter, {
478 counter._.working --;
481 mono_refcount_dec (threadpool);
485 mono_threadpool_cleanup (void)
487 #ifndef DISABLE_SOCKETS
488 mono_threadpool_io_cleanup ();
490 mono_lazy_cleanup (&status, cleanup);
494 mono_threadpool_begin_invoke (MonoDomain *domain, MonoObject *target, MonoMethod *method, gpointer *params, MonoError *error)
496 static MonoClass *async_call_klass = NULL;
497 MonoMethodMessage *message;
498 MonoAsyncResult *async_result;
499 MonoAsyncCall *async_call;
500 MonoDelegate *async_callback = NULL;
501 MonoObject *state = NULL;
503 if (!async_call_klass)
504 async_call_klass = mono_class_load_from_name (mono_defaults.corlib, "System", "MonoAsyncCall");
506 mono_lazy_initialize (&status, initialize);
508 mono_error_init (error);
510 message = mono_method_call_message_new (method, params, mono_get_delegate_invoke (method->klass), (params != NULL) ? (&async_callback) : NULL, (params != NULL) ? (&state) : NULL, error);
511 return_val_if_nok (error, NULL);
513 async_call = (MonoAsyncCall*) mono_object_new_checked (domain, async_call_klass, error);
514 return_val_if_nok (error, NULL);
516 MONO_OBJECT_SETREF (async_call, msg, message);
517 MONO_OBJECT_SETREF (async_call, state, state);
519 if (async_callback) {
520 MONO_OBJECT_SETREF (async_call, cb_method, mono_get_delegate_invoke (((MonoObject*) async_callback)->vtable->klass));
521 MONO_OBJECT_SETREF (async_call, cb_target, async_callback);
524 async_result = mono_async_result_new (domain, NULL, async_call->state, NULL, (MonoObject*) async_call, error);
525 return_val_if_nok (error, NULL);
526 MONO_OBJECT_SETREF (async_result, async_delegate, target);
528 mono_threadpool_enqueue_work_item (domain, (MonoObject*) async_result, error);
529 return_val_if_nok (error, NULL);
535 mono_threadpool_end_invoke (MonoAsyncResult *ares, MonoArray **out_args, MonoObject **exc, MonoError *error)
539 mono_error_init (error);
546 /* check if already finished */
547 mono_monitor_enter ((MonoObject*) ares);
549 if (ares->endinvoke_called) {
550 mono_error_set_invalid_operation(error, "Delegate EndInvoke method called more than once");
551 mono_monitor_exit ((MonoObject*) ares);
555 ares->endinvoke_called = 1;
557 /* wait until we are really finished */
558 if (ares->completed) {
559 mono_monitor_exit ((MonoObject *) ares);
563 wait_event = mono_wait_handle_get_handle ((MonoWaitHandle*) ares->handle);
565 wait_event = mono_w32event_create (TRUE, FALSE);
566 g_assert(wait_event);
567 MonoWaitHandle *wait_handle = mono_wait_handle_new (mono_object_domain (ares), wait_event, error);
568 if (!is_ok (error)) {
569 mono_w32event_close (wait_event);
572 MONO_OBJECT_SETREF (ares, handle, (MonoObject*) wait_handle);
574 mono_monitor_exit ((MonoObject*) ares);
577 WaitForSingleObjectEx (wait_event, INFINITE, TRUE);
579 mono_w32handle_wait_one (wait_event, MONO_INFINITE_WAIT, TRUE);
584 ac = (MonoAsyncCall*) ares->object_data;
587 *exc = ac->msg->exc; /* FIXME: GC add write barrier */
588 *out_args = ac->out_args;
593 mono_threadpool_remove_domain_jobs (MonoDomain *domain, int timeout)
596 ThreadPoolDomain *tpdomain;
600 g_assert (timeout >= -1);
602 g_assert (mono_domain_is_unloading (domain));
605 end = mono_msec_ticks () + timeout;
607 #ifndef DISABLE_SOCKETS
608 mono_threadpool_io_remove_domain_jobs (domain);
610 if (mono_msec_ticks () > end)
616 * Wait for all threads which execute jobs in the domain to exit.
617 * The is_unloading () check in worker_request () ensures that
618 * no new jobs are added after we enter the lock below.
621 if (!mono_lazy_is_initialized (&status))
624 mono_refcount_inc (threadpool);
628 tpdomain = tpdomain_get (domain, FALSE);
631 mono_refcount_dec (threadpool);
637 while (tpdomain->outstanding_request + tpdomain->threadpool_jobs > 0) {
639 mono_coop_cond_wait (&tpdomain->cleanup_cond, &threadpool->domains_lock);
644 now = mono_msec_ticks();
650 res = mono_coop_cond_timedwait (&tpdomain->cleanup_cond, &threadpool->domains_lock, end - now);
658 /* Remove from the list the worker threads look at */
659 tpdomain_remove (tpdomain);
663 mono_coop_cond_destroy (&tpdomain->cleanup_cond);
664 tpdomain_free (tpdomain);
666 mono_refcount_dec (threadpool);
672 mono_threadpool_suspend (void)
675 mono_threadpool_worker_set_suspended (threadpool->worker, TRUE);
679 mono_threadpool_resume (void)
682 mono_threadpool_worker_set_suspended (threadpool->worker, FALSE);
686 ves_icall_System_Threading_ThreadPool_GetAvailableThreadsNative (gint32 *worker_threads, gint32 *completion_port_threads)
688 ThreadPoolCounter counter;
690 if (!worker_threads || !completion_port_threads)
693 mono_lazy_initialize (&status, initialize);
695 counter = COUNTER_READ (threadpool);
697 *worker_threads = MAX (0, mono_threadpool_worker_get_max (threadpool->worker) - counter._.working);
698 *completion_port_threads = threadpool->limit_io_max;
702 ves_icall_System_Threading_ThreadPool_GetMinThreadsNative (gint32 *worker_threads, gint32 *completion_port_threads)
704 if (!worker_threads || !completion_port_threads)
707 mono_lazy_initialize (&status, initialize);
709 *worker_threads = mono_threadpool_worker_get_min (threadpool->worker);
710 *completion_port_threads = threadpool->limit_io_min;
714 ves_icall_System_Threading_ThreadPool_GetMaxThreadsNative (gint32 *worker_threads, gint32 *completion_port_threads)
716 if (!worker_threads || !completion_port_threads)
719 mono_lazy_initialize (&status, initialize);
721 *worker_threads = mono_threadpool_worker_get_max (threadpool->worker);
722 *completion_port_threads = threadpool->limit_io_max;
726 ves_icall_System_Threading_ThreadPool_SetMinThreadsNative (gint32 worker_threads, gint32 completion_port_threads)
728 mono_lazy_initialize (&status, initialize);
730 if (completion_port_threads <= 0 || completion_port_threads > threadpool->limit_io_max)
733 if (!mono_threadpool_worker_set_min (threadpool->worker, worker_threads))
736 threadpool->limit_io_min = completion_port_threads;
742 ves_icall_System_Threading_ThreadPool_SetMaxThreadsNative (gint32 worker_threads, gint32 completion_port_threads)
744 gint cpu_count = mono_cpu_count ();
746 mono_lazy_initialize (&status, initialize);
748 if (completion_port_threads < threadpool->limit_io_min || completion_port_threads < cpu_count)
751 if (!mono_threadpool_worker_set_max (threadpool->worker, worker_threads))
754 threadpool->limit_io_max = completion_port_threads;
760 ves_icall_System_Threading_ThreadPool_InitializeVMTp (MonoBoolean *enable_worker_tracking)
762 if (enable_worker_tracking) {
763 // TODO implement some kind of switch to have the possibily to use it
764 *enable_worker_tracking = FALSE;
767 mono_lazy_initialize (&status, initialize);
771 ves_icall_System_Threading_ThreadPool_NotifyWorkItemComplete (void)
773 if (mono_domain_is_unloading (mono_domain_get ()) || mono_runtime_is_shutting_down ())
776 return mono_threadpool_worker_notify_completed (threadpool->worker);
780 ves_icall_System_Threading_ThreadPool_NotifyWorkItemProgressNative (void)
782 mono_threadpool_worker_notify_completed (threadpool->worker);
786 ves_icall_System_Threading_ThreadPool_ReportThreadStatus (MonoBoolean is_working)
790 mono_error_set_not_implemented (&error, "");
791 mono_error_set_pending_exception (&error);
795 ves_icall_System_Threading_ThreadPool_RequestWorkerThread (void)
798 ThreadPoolDomain *tpdomain;
799 ThreadPoolCounter counter;
801 domain = mono_domain_get ();
802 if (mono_domain_is_unloading (domain))
805 if (!mono_refcount_tryinc (threadpool)) {
806 /* threadpool has been destroyed, we are shutting down */
812 /* synchronize with mono_threadpool_remove_domain_jobs */
813 if (mono_domain_is_unloading (domain)) {
815 mono_refcount_dec (threadpool);
819 tpdomain = tpdomain_get (domain, TRUE);
822 tpdomain->outstanding_request ++;
823 g_assert (tpdomain->outstanding_request >= 1);
827 COUNTER_ATOMIC (threadpool, counter, {
828 if (counter._.starting == 16) {
829 mono_refcount_dec (threadpool);
833 counter._.starting ++;
836 mono_threadpool_worker_enqueue (threadpool->worker, worker_callback, NULL);
841 MonoBoolean G_GNUC_UNUSED
842 ves_icall_System_Threading_ThreadPool_PostQueuedCompletionStatus (MonoNativeOverlapped *native_overlapped)
844 /* This copy the behavior of the current Mono implementation */
846 mono_error_set_not_implemented (&error, "");
847 mono_error_set_pending_exception (&error);
851 MonoBoolean G_GNUC_UNUSED
852 ves_icall_System_Threading_ThreadPool_BindIOCompletionCallbackNative (gpointer file_handle)
854 /* This copy the behavior of the current Mono implementation */
858 MonoBoolean G_GNUC_UNUSED
859 ves_icall_System_Threading_ThreadPool_IsThreadPoolHosted (void)