mono/metadata/threadpool.c

   1 /*
   2  * threadpool.c: global thread pool
   3  *
   4  * Authors:
   5  *   Dietmar Maurer (dietmar@ximian.com)
   6  *   Gonzalo Paniagua Javier (gonzalo@ximian.com)
   7  *
   8  * Copyright 2001-2003 Ximian, Inc (http://www.ximian.com)
   9  * Copyright 2004-2010 Novell, Inc (http://www.novell.com)
  10  * Copyright 2001 Xamarin Inc (http://www.xamarin.com)
  11  */
  12
  13 #include <config.h>
  14 #include <glib.h>
  15
  16 #include <mono/metadata/profiler-private.h>
  17 #include <mono/metadata/threads.h>
  18 #include <mono/metadata/threads-types.h>
  19 #include <mono/metadata/threadpool-internals.h>
  20 #include <mono/metadata/exception.h>
  21 #include <mono/metadata/environment.h>
  22 #include <mono/metadata/mono-config.h>
  23 #include <mono/metadata/mono-mlist.h>
  24 #include <mono/metadata/mono-perfcounters.h>
  25 #include <mono/metadata/socket-io.h>
  26 #include <mono/metadata/mono-cq.h>
  27 #include <mono/metadata/mono-wsq.h>
  28 #include <mono/metadata/mono-ptr-array.h>
  29 #include <mono/metadata/object-internals.h>
  30 #include <mono/io-layer/io-layer.h>
  31 #include <mono/utils/mono-time.h>
  32 #include <mono/utils/mono-proclib.h>
  33 #include <mono/utils/mono-semaphore.h>
  34 #include <mono/utils/atomic.h>
  35 #include <errno.h>
  36 #ifdef HAVE_SYS_TIME_H
  37 #include <sys/time.h>
  38 #endif
  39 #include <sys/types.h>
  40 #include <fcntl.h>
  41 #ifdef HAVE_UNISTD_H
  42 #include <unistd.h>
  43 #endif
  44 #include <string.h>
  45 #include <math.h>
  46 #ifdef HAVE_SYS_SOCKET_H
  47 #include <sys/socket.h>
  48 #endif
  49 #include <mono/utils/mono-poll.h>
  50 #ifdef HAVE_EPOLL
  51 #include <sys/epoll.h>
  52 #endif
  53 #ifdef HAVE_KQUEUE
  54 #include <sys/event.h>
  55 #endif
  56
  57
  58 #ifndef DISABLE_SOCKETS
  59 #include "mono/io-layer/socket-wrappers.h"
  60 #endif
  61
  62 #include "threadpool.h"
  63 #include "threadpool-ms.h"
  64 #include "threadpool-ms-io.h"
  65
  66 static gboolean
  67 use_ms_threadpool (void)
  68 {
  69         static gboolean use_ms_tp = -1;
  70         const gchar *mono_threadpool_env;
  71         if (use_ms_tp != -1)
  72                 return use_ms_tp;
  73         else if (!(mono_threadpool_env = g_getenv ("MONO_THREADPOOL")))
  74                 return use_ms_tp = FALSE;
  75         else if (strcmp (mono_threadpool_env, "microsoft") == 0)
  76                 return use_ms_tp = TRUE;
  77         else
  78                 return use_ms_tp = FALSE;
  79 }
  80
  81 #define THREAD_WANTS_A_BREAK(t) ((t->state & (ThreadState_StopRequested | \
  82                                                 ThreadState_SuspendRequested)) != 0)
  83
  84 /* DEBUG: prints tp data every 2s */
  85 #undef DEBUG
  86
  87 /* mono_thread_pool_init called */
  88 static volatile int tp_inited;
  89
  90 enum {
  91         POLL_BACKEND,
  92         EPOLL_BACKEND,
  93         KQUEUE_BACKEND
  94 };
  95
  96 enum {
  97         MONITOR_STATE_AWAKE,
  98         MONITOR_STATE_FALLING_ASLEEP,
  99         MONITOR_STATE_SLEEPING
 100 };
 101
 102 static SocketIOData socket_io_data;
 103
 104 typedef struct {
 105         MonoSemType lock;
 106         MonoCQ *queue; /* GC root */
 107         MonoSemType new_job;
 108         volatile gint waiting; /* threads waiting for a work item */
 109
 110         /**/
 111         volatile gint pool_status; /* 0 -> not initialized, 1 -> initialized, 2 -> cleaning up */
 112         /* min, max, n and busy -> Interlocked */
 113         volatile gint min_threads;
 114         volatile gint max_threads;
 115         volatile gint nthreads;
 116         volatile gint busy_threads;
 117
 118         void (*async_invoke) (gpointer data);
 119         void *pc_nitems; /* Performance counter for total number of items in added */
 120         void *pc_nthreads; /* Performance counter for total number of active threads */
 121         /**/
 122         volatile gint destroy_thread;
 123 #if DEBUG
 124         volatile gint32 njobs;
 125 #endif
 126         volatile gint32 nexecuted;
 127         gboolean is_io;
 128 } ThreadPool;
 129
 130 static ThreadPool async_tp;
 131 static ThreadPool async_io_tp;
 132
 133 static void async_invoke_thread (gpointer data);
 134 static MonoObject *mono_async_invoke (ThreadPool *tp, MonoAsyncResult *ares);
 135 static void threadpool_free_queue (ThreadPool *tp);
 136 static void threadpool_append_job (ThreadPool *tp, MonoObject *ar);
 137 static void threadpool_append_jobs (ThreadPool *tp, MonoObject **jobs, gint njobs);
 138 static void threadpool_init (ThreadPool *tp, int min_threads, int max_threads, void (*async_invoke) (gpointer));
 139 static void threadpool_start_idle_threads (ThreadPool *tp);
 140 static void threadpool_kill_idle_threads (ThreadPool *tp);
 141 static gboolean threadpool_start_thread (ThreadPool *tp);
 142 static void threadpool_kill_thread (ThreadPool *tp);
 143 static void monitor_thread (gpointer data);
 144 static int get_event_from_state (MonoSocketAsyncResult *state);
 145
 146 static MonoClass *async_call_klass;
 147 static MonoClass *socket_async_call_klass;
 148 static MonoClass *process_async_call_klass;
 149
 150 static GPtrArray *threads;
 151 mono_mutex_t threads_lock;
 152 static GPtrArray *wsqs;
 153 mono_mutex_t wsqs_lock;
 154 static gboolean suspended;
 155
 156 static volatile gint32 monitor_njobs = 0;
 157 static volatile gint32 monitor_state;
 158 static MonoSemType monitor_sem;
 159 static MonoInternalThread *monitor_internal_thread;
 160
 161 /* Hooks */
 162 static MonoThreadPoolFunc tp_start_func;
 163 static MonoThreadPoolFunc tp_finish_func;
 164 static gpointer tp_hooks_user_data;
 165 static MonoThreadPoolItemFunc tp_item_begin_func;
 166 static MonoThreadPoolItemFunc tp_item_end_func;
 167 static gpointer tp_item_user_data;
 168
 169 enum {
 170         AIO_OP_FIRST,
 171         AIO_OP_ACCEPT = 0,
 172         AIO_OP_CONNECT,
 173         AIO_OP_RECEIVE,
 174         AIO_OP_RECEIVEFROM,
 175         AIO_OP_SEND,
 176         AIO_OP_SENDTO,
 177         AIO_OP_RECV_JUST_CALLBACK,
 178         AIO_OP_SEND_JUST_CALLBACK,
 179         AIO_OP_READPIPE,
 180         AIO_OP_CONSOLE2,
 181         AIO_OP_DISCONNECT,
 182         AIO_OP_ACCEPTRECEIVE,
 183         AIO_OP_RECEIVE_BUFFERS,
 184         AIO_OP_SEND_BUFFERS,
 185         AIO_OP_LAST
 186 };
 187
 188 // #include <mono/metadata/tpool-poll.c>
 189 gpointer tp_poll_init (SocketIOData *data);
 190
 191 #ifdef HAVE_EPOLL
 192 #include <mono/metadata/tpool-epoll.c>
 193 #elif defined(USE_KQUEUE_FOR_THREADPOOL)
 194 #include <mono/metadata/tpool-kqueue.c>
 195 #endif
 196 /*
 197  * Functions to check whenever a class is given system class. We need to cache things in MonoDomain since some of the
 198  * assemblies can be unloaded.
 199  */
 200
 201 static gboolean
 202 is_system_type (MonoDomain *domain, MonoClass *klass)
 203 {
 204         if (domain->system_image == NULL)
 205                 domain->system_image = mono_image_loaded ("System");
 206
 207         return klass->image == domain->system_image;
 208 }
 209
 210 static gboolean
 211 is_corlib_type (MonoDomain *domain, MonoClass *klass)
 212 {
 213         return klass->image == mono_defaults.corlib;
 214 }
 215
 216 #define check_type_cached(domain, ASSEMBLY, _class, _namespace, _name, loc) do { \
 217         if (*loc) \
 218                 return *loc == _class; \
 219         if (is_##ASSEMBLY##_type (domain, _class) && !strcmp (_name, _class->name) && !strcmp (_namespace, _class->name_space)) { \
 220                 *loc = _class; \
 221                 return TRUE; \
 222         } \
 223         return FALSE; \
 224 } while (0) \
 225
 226 #define check_corlib_type_cached(domain, _class, _namespace, _name, loc) check_type_cached (domain, corlib, _class, _namespace, _name, loc)
 227
 228 #define check_system_type_cached(domain, _class, _namespace, _name, loc) check_type_cached (domain, system, _class, _namespace, _name, loc)
 229
 230 static gboolean
 231 is_corlib_asyncresult (MonoDomain *domain, MonoClass *klass)
 232 {
 233         check_corlib_type_cached (domain, klass, "System.Runtime.Remoting.Messaging", "AsyncResult", &domain->corlib_asyncresult_class);
 234 }
 235
 236 static gboolean
 237 is_socketasyncresult (MonoDomain *domain, MonoClass *klass)
 238 {
 239         static MonoClass *socket_async_result_klass = NULL;
 240         check_system_type_cached (domain, klass, "System.Net.Sockets", "SocketAsyncResult", &socket_async_result_klass);
 241 }
 242
 243 static gboolean
 244 is_socketasynccall (MonoDomain *domain, MonoClass *klass)
 245 {
 246         static MonoClass *socket_async_callback_klass = NULL;
 247         check_system_type_cached (domain, klass, "System.Net.Sockets", "SocketAsyncCallback", &socket_async_callback_klass);
 248 }
 249
 250 static gboolean
 251 is_appdomainunloaded_exception (MonoDomain *domain, MonoClass *klass)
 252 {
 253         check_corlib_type_cached (domain, klass, "System", "AppDomainUnloadedException", &domain->ad_unloaded_ex_class);
 254 }
 255
 256 static gboolean
 257 is_sd_process (MonoDomain *domain, MonoClass *klass)
 258 {
 259         check_system_type_cached (domain, klass, "System.Diagnostics", "Process", &domain->process_class);
 260 }
 261
 262 static gboolean
 263 is_sdp_asyncreadhandler (MonoDomain *domain, MonoClass *klass)
 264 {
 265
 266         return (klass->nested_in &&
 267                         is_sd_process (domain, klass->nested_in) &&
 268                 !strcmp (klass->name, "AsyncReadHandler"));
 269 }
 270
 271
 272 #ifdef DISABLE_SOCKETS
 273
 274 void
 275 socket_io_cleanup (SocketIOData *data)
 276 {
 277 }
 278
 279 static int
 280 get_event_from_state (MonoSocketAsyncResult *state)
 281 {
 282         g_assert_not_reached ();
 283         return -1;
 284 }
 285
 286 int
 287 get_events_from_list (MonoMList *list)
 288 {
 289         return 0;
 290 }
 291
 292 #else
 293
 294 void
 295 socket_io_cleanup (SocketIOData *data)
 296 {
 297         mono_mutex_lock (&data->io_lock);
 298         if (data->inited != 2) {
 299                 mono_mutex_unlock (&data->io_lock);
 300                 return;
 301         }
 302         data->inited = 3;
 303         data->shutdown (data->event_data);
 304         mono_mutex_unlock (&data->io_lock);
 305 }
 306
 307 static int
 308 get_event_from_state (MonoSocketAsyncResult *state)
 309 {
 310         switch (state->operation) {
 311         case AIO_OP_ACCEPT:
 312         case AIO_OP_RECEIVE:
 313         case AIO_OP_RECV_JUST_CALLBACK:
 314         case AIO_OP_RECEIVEFROM:
 315         case AIO_OP_READPIPE:
 316         case AIO_OP_ACCEPTRECEIVE:
 317         case AIO_OP_RECEIVE_BUFFERS:
 318                 return MONO_POLLIN;
 319         case AIO_OP_SEND:
 320         case AIO_OP_SEND_JUST_CALLBACK:
 321         case AIO_OP_SENDTO:
 322         case AIO_OP_CONNECT:
 323         case AIO_OP_SEND_BUFFERS:
 324         case AIO_OP_DISCONNECT:
 325                 return MONO_POLLOUT;
 326         default: /* Should never happen */
 327                 g_message ("get_event_from_state: unknown value in switch!!!");
 328                 return 0;
 329         }
 330 }
 331
 332 int
 333 get_events_from_list (MonoMList *list)
 334 {
 335         MonoSocketAsyncResult *state;
 336         int events = 0;
 337
 338         while (list && (state = (MonoSocketAsyncResult *)mono_mlist_get_data (list))) {
 339                 events |= get_event_from_state (state);
 340                 list = mono_mlist_next (list);
 341         }
 342
 343         return events;
 344 }
 345
 346 #define ICALL_RECV(x)   ves_icall_System_Net_Sockets_Socket_Receive_internal (\
 347                                 (SOCKET)(gssize)x->handle, x->buffer, x->offset, x->size,\
 348                                  x->socket_flags, &x->error);
 349
 350 #define ICALL_SEND(x)   ves_icall_System_Net_Sockets_Socket_Send_internal (\
 351                                 (SOCKET)(gssize)x->handle, x->buffer, x->offset, x->size,\
 352                                  x->socket_flags, &x->error);
 353
 354 #endif /* !DISABLE_SOCKETS */
 355
 356 static void
 357 threadpool_jobs_inc (MonoObject *obj)
 358 {
 359         if (obj)
 360                 InterlockedIncrement (&obj->vtable->domain->threadpool_jobs);
 361 }
 362
 363 static gboolean
 364 threadpool_jobs_dec (MonoObject *obj)
 365 {
 366         MonoDomain *domain;
 367         int remaining_jobs;
 368
 369         if (obj == NULL)
 370                 return FALSE;
 371
 372         domain = obj->vtable->domain;
 373         remaining_jobs = InterlockedDecrement (&domain->threadpool_jobs);
 374         if (remaining_jobs == 0 && domain->cleanup_semaphore) {
 375                 ReleaseSemaphore (domain->cleanup_semaphore, 1, NULL);
 376                 return TRUE;
 377         }
 378         return FALSE;
 379 }
 380
 381 MonoObject *
 382 get_io_event (MonoMList **list, gint event)
 383 {
 384         MonoObject *state;
 385         MonoMList *current;
 386         MonoMList *prev;
 387
 388         current = *list;
 389         prev = NULL;
 390         state = NULL;
 391         while (current) {
 392                 state = mono_mlist_get_data (current);
 393                 if (get_event_from_state ((MonoSocketAsyncResult *) state) == event)
 394                         break;
 395
 396                 state = NULL;
 397                 prev = current;
 398                 current = mono_mlist_next (current);
 399         }
 400
 401         if (current) {
 402                 if (prev) {
 403                         mono_mlist_set_next (prev, mono_mlist_next (current));
 404                 } else {
 405                         *list = mono_mlist_next (*list);
 406                 }
 407         }
 408
 409         return state;
 410 }
 411
 412 /*
 413  * select/poll wake up when a socket is closed, but epoll just removes
 414  * the socket from its internal list without notification.
 415  */
 416 void
 417 mono_thread_pool_remove_socket (int sock)
 418 {
 419         MonoMList *list;
 420         MonoSocketAsyncResult *state;
 421         MonoObject *ares;
 422
 423         if (use_ms_threadpool ()) {
 424 #ifndef DISABLE_SOCKETS
 425                 mono_threadpool_ms_io_remove_socket (sock);
 426 #endif
 427                 return;
 428         }
 429
 430         if (socket_io_data.inited == 0)
 431                 return;
 432
 433         mono_mutex_lock (&socket_io_data.io_lock);
 434         if (socket_io_data.sock_to_state == NULL) {
 435                 mono_mutex_unlock (&socket_io_data.io_lock);
 436                 return;
 437         }
 438         list = mono_g_hash_table_lookup (socket_io_data.sock_to_state, GINT_TO_POINTER (sock));
 439         if (list)
 440                 mono_g_hash_table_remove (socket_io_data.sock_to_state, GINT_TO_POINTER (sock));
 441         mono_mutex_unlock (&socket_io_data.io_lock);
 442
 443         while (list) {
 444                 state = (MonoSocketAsyncResult *) mono_mlist_get_data (list);
 445                 if (state->operation == AIO_OP_RECEIVE)
 446                         state->operation = AIO_OP_RECV_JUST_CALLBACK;
 447                 else if (state->operation == AIO_OP_SEND)
 448                         state->operation = AIO_OP_SEND_JUST_CALLBACK;
 449
 450                 ares = get_io_event (&list, MONO_POLLIN);
 451                 threadpool_append_job (&async_io_tp, ares);
 452                 if (list) {
 453                         ares = get_io_event (&list, MONO_POLLOUT);
 454                         threadpool_append_job (&async_io_tp, ares);
 455                 }
 456         }
 457 }
 458
 459 static void
 460 init_event_system (SocketIOData *data)
 461 {
 462 #ifdef HAVE_EPOLL
 463         if (data->event_system == EPOLL_BACKEND) {
 464                 data->event_data = tp_epoll_init (data);
 465                 if (data->event_data == NULL) {
 466                         if (g_getenv ("MONO_DEBUG"))
 467                                 g_message ("Falling back to poll()");
 468                         data->event_system = POLL_BACKEND;
 469                 }
 470         }
 471 #elif defined(USE_KQUEUE_FOR_THREADPOOL)
 472         if (data->event_system == KQUEUE_BACKEND)
 473                 data->event_data = tp_kqueue_init (data);
 474 #endif
 475         if (data->event_system == POLL_BACKEND)
 476                 data->event_data = tp_poll_init (data);
 477 }
 478
 479 static void
 480 socket_io_init (SocketIOData *data)
 481 {
 482         int inited;
 483
 484         if (data->inited >= 2) // 2 -> initialized, 3-> cleaned up
 485                 return;
 486
 487         inited = InterlockedCompareExchange (&data->inited, 1, 0);
 488         if (inited >= 1) {
 489                 while (TRUE) {
 490                         if (data->inited >= 2)
 491                                 return;
 492                         SleepEx (1, FALSE);
 493                 }
 494         }
 495
 496         mono_mutex_lock (&data->io_lock);
 497         data->sock_to_state = mono_g_hash_table_new_type (g_direct_hash, g_direct_equal, MONO_HASH_VALUE_GC);
 498 #ifdef HAVE_EPOLL
 499         data->event_system = EPOLL_BACKEND;
 500 #elif defined(USE_KQUEUE_FOR_THREADPOOL)
 501         data->event_system = KQUEUE_BACKEND;
 502 #else
 503         data->event_system = POLL_BACKEND;
 504 #endif
 505         if (g_getenv ("MONO_DISABLE_AIO") != NULL)
 506                 data->event_system = POLL_BACKEND;
 507
 508         init_event_system (data);
 509         mono_thread_create_internal (mono_get_root_domain (), data->wait, data, TRUE, SMALL_STACK);
 510         mono_mutex_unlock (&data->io_lock);
 511         data->inited = 2;
 512         threadpool_start_thread (&async_io_tp);
 513 }
 514
 515 static void
 516 socket_io_add (MonoAsyncResult *ares, MonoSocketAsyncResult *state)
 517 {
 518         MonoMList *list;
 519         SocketIOData *data = &socket_io_data;
 520         int fd;
 521         gboolean is_new;
 522         int ievt;
 523
 524         socket_io_init (&socket_io_data);
 525         if (mono_runtime_is_shutting_down () || data->inited == 3 || data->sock_to_state == NULL)
 526                 return;
 527         if (async_tp.pool_status == 2)
 528                 return;
 529
 530         MONO_OBJECT_SETREF (state, ares, ares);
 531
 532         fd = GPOINTER_TO_INT (state->handle);
 533         mono_mutex_lock (&data->io_lock);
 534         if (data->sock_to_state == NULL) {
 535                 mono_mutex_unlock (&data->io_lock);
 536                 return;
 537         }
 538         list = mono_g_hash_table_lookup (data->sock_to_state, GINT_TO_POINTER (fd));
 539         if (list == NULL) {
 540                 list = mono_mlist_alloc ((MonoObject*)state);
 541                 is_new = TRUE;
 542         } else {
 543                 list = mono_mlist_append (list, (MonoObject*)state);
 544                 is_new = FALSE;
 545         }
 546
 547         mono_g_hash_table_replace (data->sock_to_state, state->handle, list);
 548         ievt = get_events_from_list (list);
 549         /* The modify function leaves the io_lock critical section. */
 550         data->modify (data, fd, state->operation, ievt, is_new);
 551 }
 552
 553 #ifndef DISABLE_SOCKETS
 554 static gboolean
 555 socket_io_filter (MonoObject *target, MonoObject *state)
 556 {
 557         gint op;
 558         MonoSocketAsyncResult *sock_res;
 559         MonoClass *klass;
 560         MonoDomain *domain;
 561
 562         if (target == NULL || state == NULL)
 563                 return FALSE;
 564
 565         domain = target->vtable->domain;
 566         klass = target->vtable->klass;
 567         if (socket_async_call_klass == NULL && is_socketasynccall (domain, klass))
 568                 socket_async_call_klass = klass;
 569
 570         if (process_async_call_klass == NULL && is_sdp_asyncreadhandler (domain, klass))
 571                 process_async_call_klass = klass;
 572
 573         if (klass != socket_async_call_klass && klass != process_async_call_klass)
 574                 return FALSE;
 575
 576         sock_res = (MonoSocketAsyncResult *) state;
 577         op = sock_res->operation;
 578         if (op < AIO_OP_FIRST || op >= AIO_OP_LAST)
 579                 return FALSE;
 580
 581         return TRUE;
 582 }
 583 #endif /* !DISABLE_SOCKETS */
 584
 585 /* Returns the exception thrown when invoking, if any */
 586 static MonoObject *
 587 mono_async_invoke (ThreadPool *tp, MonoAsyncResult *ares)
 588 {
 589         MonoObject *exc = NULL;
 590
 591         mono_async_result_invoke (ares, &exc);
 592
 593 #if DEBUG
 594         InterlockedDecrement (&tp->njobs);
 595 #endif
 596         if (!tp->is_io)
 597                 InterlockedIncrement (&tp->nexecuted);
 598
 599         if (InterlockedDecrement (&monitor_njobs) == 0)
 600                 monitor_state = MONITOR_STATE_FALLING_ASLEEP;
 601
 602         return exc;
 603 }
 604
 605 static void
 606 threadpool_start_idle_threads (ThreadPool *tp)
 607 {
 608         int n;
 609         guint32 stack_size;
 610
 611         stack_size = (!tp->is_io) ? 0 : SMALL_STACK;
 612         do {
 613                 while (1) {
 614                         n = tp->nthreads;
 615                         if (n >= tp->min_threads)
 616                                 return;
 617                         if (InterlockedCompareExchange (&tp->nthreads, n + 1, n) == n)
 618                                 break;
 619                 }
 620 #ifndef DISABLE_PERFCOUNTERS
 621                 mono_perfcounter_update_value (tp->pc_nthreads, TRUE, 1);
 622 #endif
 623                 mono_thread_create_internal (mono_get_root_domain (), tp->async_invoke, tp, TRUE, stack_size);
 624                 SleepEx (100, TRUE);
 625         } while (1);
 626 }
 627
 628 static void
 629 threadpool_init (ThreadPool *tp, int min_threads, int max_threads, void (*async_invoke) (gpointer))
 630 {
 631         memset (tp, 0, sizeof (ThreadPool));
 632         tp->min_threads = min_threads;
 633         tp->max_threads = max_threads;
 634         tp->async_invoke = async_invoke;
 635         tp->queue = mono_cq_create ();
 636         MONO_SEM_INIT (&tp->new_job, 0);
 637 }
 638
 639 #ifndef DISABLE_PERFCOUNTERS
 640 static void *
 641 init_perf_counter (const char *category, const char *counter)
 642 {
 643         MonoString *category_str;
 644         MonoString *counter_str;
 645         MonoString *machine;
 646         MonoDomain *root;
 647         MonoBoolean custom;
 648         int type;
 649
 650         if (category == NULL || counter == NULL)
 651                 return NULL;
 652         root = mono_get_root_domain ();
 653         category_str = mono_string_new (root, category);
 654         counter_str = mono_string_new (root, counter);
 655         machine = mono_string_new (root, ".");
 656         return mono_perfcounter_get_impl (category_str, counter_str, NULL, machine, &type, &custom);
 657 }
 658 #endif
 659
 660 #ifdef DEBUG
 661 static void
 662 print_pool_info (ThreadPool *tp)
 663 {
 664
 665 //      if (tp->tail - tp->head == 0)
 666 //              return;
 667
 668         g_print ("Pool status? %d\n", InterlockedCompareExchange (&tp->pool_status, 0, 0));
 669         g_print ("Min. threads: %d\n", InterlockedCompareExchange (&tp->min_threads, 0, 0));
 670         g_print ("Max. threads: %d\n", InterlockedCompareExchange (&tp->max_threads, 0, 0));
 671         g_print ("nthreads: %d\n", InterlockedCompareExchange (&tp->nthreads, 0, 0));
 672         g_print ("busy threads: %d\n", InterlockedCompareExchange (&tp->busy_threads, 0, 0));
 673         g_print ("Waiting: %d\n", InterlockedCompareExchange (&tp->waiting, 0, 0));
 674         g_print ("Queued: %d\n", (tp->tail - tp->head));
 675         if (tp == &async_tp) {
 676                 int i;
 677                 mono_mutex_lock (&wsqs_lock);
 678                 for (i = 0; i < wsqs->len; i++) {
 679                         g_print ("\tWSQ %d: %d\n", i, mono_wsq_count (g_ptr_array_index (wsqs, i)));
 680                 }
 681                 mono_mutex_unlock (&wsqs_lock);
 682         } else {
 683                 g_print ("\tSockets: %d\n", mono_g_hash_table_size (socket_io_data.sock_to_state));
 684         }
 685         g_print ("-------------\n");
 686 }
 687
 688 static void
 689 signal_handler (int signo)
 690 {
 691         ThreadPool *tp;
 692
 693         tp = &async_tp;
 694         g_print ("\n-----Non-IO-----\n");
 695         print_pool_info (tp);
 696         tp = &async_io_tp;
 697         g_print ("\n-----IO-----\n");
 698         print_pool_info (tp);
 699         alarm (2);
 700 }
 701 #endif
 702
 703 #define SAMPLES_PERIOD 500
 704 #define HISTORY_SIZE 10
 705 /* number of iteration without any jobs
 706    in the queue before going to sleep */
 707 #define NUM_WAITING_ITERATIONS 10
 708
 709 typedef struct {
 710         gint32 nexecuted;
 711         gint32 nthreads;
 712         gint8 nthreads_diff;
 713 } SamplesHistory;
 714
 715 /*
 716  * returns :
 717  *  -  1 if the number of threads should increase
 718  *  -  0 if it should not change
 719  *  - -1 if it should decrease
 720  *  - -2 in case of error
 721  */
 722 static gint8
 723 monitor_heuristic (gint16 *current, gint16 *history_size, SamplesHistory *history, ThreadPool *tp)
 724 {
 725         int i;
 726         gint8 decision G_GNUC_UNUSED;
 727         gint16 cur, max = 0;
 728         gboolean all_waitsleepjoin;
 729         MonoInternalThread *thread;
 730
 731         /*
 732          * The following heuristic tries to approach the optimal number of threads to maximize jobs throughput. To
 733          * achieve this, it simply stores the number of jobs executed (nexecuted), the number of Threads (nthreads)
 734          * and the decision (nthreads_diff) for the past HISTORY_SIZE periods of time, each period being of
 735          * duration SAMPLES_PERIOD ms. This history gives us an insight into what happened, and to see if we should
 736          * increase or reduce the number of threads by comparing the last period (current) to the best one.
 737          *
 738          * The algorithm can be describe as following :
 739          *  - if we have a better throughput than the best period : we should either increase the number of threads
 740          *     in case we already have more threads, either reduce the number of threads if we have less threads; this
 741          *     is equivalent to move away from the number of threads of the best period, because we are currently better
 742          *  - if we have a worse throughput than the best period : we should either decrease the number of threads if
 743          *     we have more threads, either increase the number of threads if we have less threads;  this is equivalent
 744          *     to get closer to the number of threads of the best period, because we are currently worse
 745          */
 746
 747         *history_size = MIN (*history_size + 1, HISTORY_SIZE);
 748         cur = *current = (*current + 1) % *history_size;
 749
 750         history [cur].nthreads = tp->nthreads;
 751         history [cur].nexecuted = InterlockedExchange (&tp->nexecuted, 0);
 752
 753         if (tp->waiting) {
 754                 /* if we have waiting thread in the pool, then do not create a new one */
 755                 history [cur].nthreads_diff = tp->waiting > 1 ? -1 : 0;
 756                 decision = 0;
 757         } else if (tp->nthreads < tp->min_threads) {
 758                 history [cur].nthreads_diff = 1;
 759                 decision = 1;
 760         } else if (*history_size <= 1) {
 761                 /* first iteration, let's add a thread by default */
 762                 history [cur].nthreads_diff = 1;
 763                 decision = 2;
 764         } else {
 765                 mono_mutex_lock (&threads_lock);
 766                 if (threads == NULL) {
 767                         mono_mutex_unlock (&threads_lock);
 768                         return -2;
 769                 }
 770                 all_waitsleepjoin = TRUE;
 771                 for (i = 0; i < threads->len; ++i) {
 772                         thread = g_ptr_array_index (threads, i);
 773                         if (!(thread->state & ThreadState_WaitSleepJoin)) {
 774                                 all_waitsleepjoin = FALSE;
 775                                 break;
 776                         }
 777                 }
 778                 mono_mutex_unlock (&threads_lock);
 779
 780                 if (all_waitsleepjoin) {
 781                         /* we might be in a condition of starvation/deadlock with tasks waiting for each others */
 782                         history [cur].nthreads_diff = 1;
 783                         decision = 5;
 784                 } else {
 785                         max = cur == 0 ? 1 : 0;
 786                         for (i = 0; i < *history_size; i++) {
 787                                 if (i == cur)
 788                                         continue;
 789                                 if (history [i].nexecuted > history [max].nexecuted)
 790                                         max = i;
 791                         }
 792
 793                         if (history [cur].nexecuted >= history [max].nexecuted) {
 794                                 /* we improved the situation, let's continue ! */
 795                                 history [cur].nthreads_diff = history [cur].nthreads >= history [max].nthreads ? 1 : -1;
 796                                 decision = 3;
 797                         } else {
 798                                 /* we made it worse, let's return to previous situation */
 799                                 history [cur].nthreads_diff = history [cur].nthreads >= history [max].nthreads ? -1 : 1;
 800                                 decision = 4;
 801                         }
 802                 }
 803         }
 804
 805 #if DEBUG
 806         printf ("monitor_thread: decision: %1d, history [current]: {nexecuted: %5d, nthreads: %3d, waiting: %2d, nthreads_diff: %2d}, history [max]: {nexecuted: %5d, nthreads: %3d}\n",
 807                         decision, history [cur].nexecuted, history [cur].nthreads, tp->waiting, history [cur].nthreads_diff, history [max].nexecuted, history [max].nthreads);
 808 #endif
 809
 810         return history [cur].nthreads_diff;
 811 }
 812
 813 static void
 814 monitor_thread (gpointer unused)
 815 {
 816         ThreadPool *pools [2];
 817         MonoInternalThread *thread;
 818         int i;
 819
 820         guint32 ms;
 821         gint8 num_waiting_iterations = 0;
 822
 823         gint16 history_size = 0, current = -1;
 824         SamplesHistory *history = malloc (sizeof (SamplesHistory) * HISTORY_SIZE);
 825
 826         pools [0] = &async_tp;
 827         pools [1] = &async_io_tp;
 828         thread = mono_thread_internal_current ();
 829         ves_icall_System_Threading_Thread_SetName_internal (thread, mono_string_new (mono_domain_get (), "Threadpool monitor"));
 830         while (1) {
 831                 ms = SAMPLES_PERIOD;
 832                 i = 10; //number of spurious awakes we tolerate before doing a round of rebalancing.
 833                 mono_gc_set_skip_thread (TRUE);
 834                 MONO_PREPARE_BLOCKING
 835                 do {
 836                         guint32 ts;
 837                         ts = mono_msec_ticks ();
 838                         if (SleepEx (ms, TRUE) == 0)
 839                                 break;
 840                         ms -= (mono_msec_ticks () - ts);
 841                         if (mono_runtime_is_shutting_down ())
 842                                 break;
 843                         check_for_interruption_critical ();
 844                 } while (ms > 0 && i--);
 845                 MONO_FINISH_BLOCKING
 846                 mono_gc_set_skip_thread (FALSE);
 847
 848                 if (mono_runtime_is_shutting_down ())
 849                         break;
 850
 851                 if (suspended)
 852                         continue;
 853
 854                 /* threadpool is cleaning up */
 855                 if (async_tp.pool_status == 2 || async_io_tp.pool_status == 2)
 856                         break;
 857
 858                 MONO_PREPARE_BLOCKING
 859                 switch (monitor_state) {
 860                 case MONITOR_STATE_AWAKE:
 861                         num_waiting_iterations = 0;
 862                         break;
 863                 case MONITOR_STATE_FALLING_ASLEEP:
 864                         if (++num_waiting_iterations == NUM_WAITING_ITERATIONS) {
 865                                 if (monitor_state == MONITOR_STATE_FALLING_ASLEEP && InterlockedCompareExchange (&monitor_state, MONITOR_STATE_SLEEPING, MONITOR_STATE_FALLING_ASLEEP) == MONITOR_STATE_FALLING_ASLEEP) {
 866                                         MONO_SEM_WAIT (&monitor_sem);
 867
 868                                         num_waiting_iterations = 0;
 869                                         current = -1;
 870                                         history_size = 0;
 871                                 }
 872                         }
 873                         break;
 874                 case MONITOR_STATE_SLEEPING:
 875                         g_assert_not_reached ();
 876                 }
 877                 MONO_FINISH_BLOCKING
 878
 879                 for (i = 0; i < 2; i++) {
 880                         ThreadPool *tp;
 881                         tp = pools [i];
 882
 883                         if (tp->is_io) {
 884                                 if (!tp->waiting && mono_cq_count (tp->queue) > 0)
 885                                         threadpool_start_thread (tp);
 886                         } else {
 887                                 gint8 nthreads_diff = monitor_heuristic (&current, &history_size, history, tp);
 888
 889                                 if (nthreads_diff == 1)
 890                                         threadpool_start_thread (tp);
 891                                 else if (nthreads_diff == -1)
 892                                         threadpool_kill_thread (tp);
 893                         }
 894                 }
 895         }
 896 }
 897
 898 void
 899 mono_thread_pool_init_tls (void)
 900 {
 901         if (use_ms_threadpool ()) {
 902                 mono_threadpool_ms_init_tls ();
 903                 return;
 904         }
 905
 906         mono_wsq_init ();
 907 }
 908
 909 void
 910 mono_thread_pool_init (void)
 911 {
 912         gint threads_per_cpu = 1;
 913         gint thread_count;
 914         gint cpu_count;
 915         int result;
 916
 917         if (use_ms_threadpool ()) {
 918                 mono_threadpool_ms_init ();
 919                 return;
 920         }
 921
 922         cpu_count = mono_cpu_count ();
 923
 924         if (tp_inited == 2)
 925                 return;
 926
 927         result = InterlockedCompareExchange (&tp_inited, 1, 0);
 928         if (result == 1) {
 929                 while (1) {
 930                         SleepEx (1, FALSE);
 931                         if (tp_inited == 2)
 932                                 return;
 933                 }
 934         }
 935
 936         MONO_GC_REGISTER_ROOT_FIXED (socket_io_data.sock_to_state);
 937         mono_mutex_init_recursive (&socket_io_data.io_lock);
 938         if (g_getenv ("MONO_THREADS_PER_CPU") != NULL) {
 939                 threads_per_cpu = atoi (g_getenv ("MONO_THREADS_PER_CPU"));
 940                 if (threads_per_cpu < 1)
 941                         threads_per_cpu = 1;
 942         }
 943
 944         thread_count = MIN (cpu_count * threads_per_cpu, 100 * cpu_count);
 945         threadpool_init (&async_tp, thread_count, MAX (100 * cpu_count, thread_count), async_invoke_thread);
 946         threadpool_init (&async_io_tp, cpu_count * 2, cpu_count * 4, async_invoke_thread);
 947         async_io_tp.is_io = TRUE;
 948
 949         async_call_klass = mono_class_from_name (mono_defaults.corlib, "System", "MonoAsyncCall");
 950         g_assert (async_call_klass);
 951
 952         mono_mutex_init (&threads_lock);
 953         threads = g_ptr_array_sized_new (thread_count);
 954         g_assert (threads);
 955
 956         mono_mutex_init_recursive (&wsqs_lock);
 957         wsqs = g_ptr_array_sized_new (MAX (100 * cpu_count, thread_count));
 958
 959 #ifndef DISABLE_PERFCOUNTERS
 960         async_tp.pc_nitems = init_perf_counter ("Mono Threadpool", "Work Items Added");
 961         g_assert (async_tp.pc_nitems);
 962
 963         async_io_tp.pc_nitems = init_perf_counter ("Mono Threadpool", "IO Work Items Added");
 964         g_assert (async_io_tp.pc_nitems);
 965
 966         async_tp.pc_nthreads = init_perf_counter ("Mono Threadpool", "# of Threads");
 967         g_assert (async_tp.pc_nthreads);
 968
 969         async_io_tp.pc_nthreads = init_perf_counter ("Mono Threadpool", "# of IO Threads");
 970         g_assert (async_io_tp.pc_nthreads);
 971 #endif
 972         tp_inited = 2;
 973 #ifdef DEBUG
 974         signal (SIGALRM, signal_handler);
 975         alarm (2);
 976 #endif
 977
 978         MONO_SEM_INIT (&monitor_sem, 0);
 979         monitor_state = MONITOR_STATE_AWAKE;
 980         monitor_njobs = 0;
 981 }
 982
 983 static MonoAsyncResult *
 984 create_simple_asyncresult (MonoObject *target, MonoObject *state)
 985 {
 986         MonoDomain *domain = mono_domain_get ();
 987         MonoAsyncResult *ares;
 988
 989         /* Don't call mono_async_result_new() to avoid capturing the context */
 990         ares = (MonoAsyncResult *) mono_object_new (domain, mono_defaults.asyncresult_class);
 991         MONO_OBJECT_SETREF (ares, async_delegate, target);
 992         MONO_OBJECT_SETREF (ares, async_state, state);
 993         return ares;
 994 }
 995
 996 void
 997 icall_append_io_job (MonoObject *target, MonoSocketAsyncResult *state)
 998 {
 999         MonoAsyncResult *ares;
1000
1001         ares = create_simple_asyncresult (target, (MonoObject *) state);
1002
1003         if (use_ms_threadpool ()) {
1004 #ifndef DISABLE_SOCKETS
1005                 mono_threadpool_ms_io_add (ares, state);
1006 #endif
1007                 return;
1008         }
1009
1010         socket_io_add (ares, state);
1011 }
1012
1013 MonoAsyncResult *
1014 mono_thread_pool_add (MonoObject *target, MonoMethodMessage *msg, MonoDelegate *async_callback,
1015                       MonoObject *state)
1016 {
1017         MonoDomain *domain;
1018         MonoAsyncResult *ares;
1019         MonoAsyncCall *ac;
1020
1021         if (use_ms_threadpool ())
1022                 return mono_threadpool_ms_add (target, msg, async_callback, state);
1023
1024         domain = mono_domain_get ();
1025
1026         ac = (MonoAsyncCall*)mono_object_new (domain, async_call_klass);
1027         MONO_OBJECT_SETREF (ac, msg, msg);
1028         MONO_OBJECT_SETREF (ac, state, state);
1029
1030         if (async_callback) {
1031                 ac->cb_method = mono_get_delegate_invoke (((MonoObject *)async_callback)->vtable->klass);
1032                 MONO_OBJECT_SETREF (ac, cb_target, async_callback);
1033         }
1034
1035         ares = mono_async_result_new (domain, NULL, ac->state, NULL, (MonoObject*)ac);
1036         MONO_OBJECT_SETREF (ares, async_delegate, target);
1037
1038 #ifndef DISABLE_SOCKETS
1039         if (socket_io_filter (target, state)) {
1040                 socket_io_add (ares, (MonoSocketAsyncResult *) state);
1041                 return ares;
1042         }
1043 #endif
1044         threadpool_append_job (&async_tp, (MonoObject *) ares);
1045         return ares;
1046 }
1047
1048 MonoObject *
1049 mono_thread_pool_finish (MonoAsyncResult *ares, MonoArray **out_args, MonoObject **exc)
1050 {
1051         MonoAsyncCall *ac;
1052         HANDLE wait_event;
1053
1054         if (use_ms_threadpool ()) {
1055                 return mono_threadpool_ms_finish (ares, out_args, exc);
1056         }
1057
1058         *exc = NULL;
1059         *out_args = NULL;
1060
1061         /* check if already finished */
1062         mono_monitor_enter ((MonoObject *) ares);
1063
1064         if (ares->endinvoke_called) {
1065                 *exc = (MonoObject *) mono_get_exception_invalid_operation (NULL);
1066                 mono_monitor_exit ((MonoObject *) ares);
1067                 return NULL;
1068         }
1069
1070         ares->endinvoke_called = 1;
1071         /* wait until we are really finished */
1072         if (!ares->completed) {
1073                 if (ares->handle == NULL) {
1074                         wait_event = CreateEvent (NULL, TRUE, FALSE, NULL);
1075                         g_assert(wait_event != 0);
1076                         MONO_OBJECT_SETREF (ares, handle, (MonoObject *) mono_wait_handle_new (mono_object_domain (ares), wait_event));
1077                 } else {
1078                         wait_event = mono_wait_handle_get_handle ((MonoWaitHandle *) ares->handle);
1079                 }
1080                 mono_monitor_exit ((MonoObject *) ares);
1081                 MONO_PREPARE_BLOCKING
1082                 WaitForSingleObjectEx (wait_event, INFINITE, TRUE);
1083                 MONO_FINISH_BLOCKING
1084         } else {
1085                 mono_monitor_exit ((MonoObject *) ares);
1086         }
1087
1088         ac = (MonoAsyncCall *) ares->object_data;
1089         g_assert (ac != NULL);
1090         *exc = ac->msg->exc; /* FIXME: GC add write barrier */
1091         *out_args = ac->out_args;
1092
1093         return ac->res;
1094 }
1095
1096 static void
1097 threadpool_kill_idle_threads (ThreadPool *tp)
1098 {
1099         gint n;
1100
1101         n = (gint) InterlockedCompareExchange (&tp->max_threads, 0, -1);
1102         while (n) {
1103                 n--;
1104                 MONO_SEM_POST (&tp->new_job);
1105         }
1106 }
1107
1108 void
1109 mono_thread_pool_cleanup (void)
1110 {
1111         if (use_ms_threadpool ()) {
1112                 mono_threadpool_ms_cleanup ();
1113                 return;
1114         }
1115
1116         if (InterlockedExchange (&async_io_tp.pool_status, 2) == 1) {
1117                 socket_io_cleanup (&socket_io_data); /* Empty when DISABLE_SOCKETS is defined */
1118                 threadpool_kill_idle_threads (&async_io_tp);
1119         }
1120
1121         if (async_io_tp.queue != NULL) {
1122                 MONO_SEM_DESTROY (&async_io_tp.new_job);
1123                 threadpool_free_queue (&async_io_tp);
1124         }
1125
1126
1127         if (InterlockedExchange (&async_tp.pool_status, 2) == 1) {
1128                 threadpool_kill_idle_threads (&async_tp);
1129                 threadpool_free_queue (&async_tp);
1130         }
1131
1132         if (threads) {
1133                 mono_mutex_lock (&threads_lock);
1134                 if (threads)
1135                         g_ptr_array_free (threads, FALSE);
1136                 threads = NULL;
1137                 mono_mutex_unlock (&threads_lock);
1138         }
1139
1140         if (wsqs) {
1141                 mono_mutex_lock (&wsqs_lock);
1142                 mono_wsq_cleanup ();
1143                 if (wsqs)
1144                         g_ptr_array_free (wsqs, TRUE);
1145                 wsqs = NULL;
1146                 mono_mutex_unlock (&wsqs_lock);
1147                 MONO_SEM_DESTROY (&async_tp.new_job);
1148         }
1149
1150         MONO_SEM_DESTROY (&monitor_sem);
1151 }
1152
1153 static gboolean
1154 threadpool_start_thread (ThreadPool *tp)
1155 {
1156         gint n;
1157         guint32 stack_size;
1158         MonoInternalThread *thread;
1159
1160         stack_size = (!tp->is_io) ? 0 : SMALL_STACK;
1161         while (!mono_runtime_is_shutting_down () && (n = tp->nthreads) < tp->max_threads) {
1162                 if (InterlockedCompareExchange (&tp->nthreads, n + 1, n) == n) {
1163 #ifndef DISABLE_PERFCOUNTERS
1164                         mono_perfcounter_update_value (tp->pc_nthreads, TRUE, 1);
1165 #endif
1166                         if (tp->is_io) {
1167                                 thread = mono_thread_create_internal (mono_get_root_domain (), tp->async_invoke, tp, TRUE, stack_size);
1168                         } else {
1169                                 mono_mutex_lock (&threads_lock);
1170                                 thread = mono_thread_create_internal (mono_get_root_domain (), tp->async_invoke, tp, TRUE, stack_size);
1171                                 g_assert (threads != NULL);
1172                                 g_ptr_array_add (threads, thread);
1173                                 mono_mutex_unlock (&threads_lock);
1174                         }
1175                         return TRUE;
1176                 }
1177         }
1178
1179         return FALSE;
1180 }
1181
1182 static void
1183 pulse_on_new_job (ThreadPool *tp)
1184 {
1185         if (tp->waiting)
1186                 MONO_SEM_POST (&tp->new_job);
1187 }
1188
1189 static void
1190 threadpool_kill_thread (ThreadPool *tp)
1191 {
1192         if (tp->destroy_thread == 0 && InterlockedCompareExchange (&tp->destroy_thread, 1, 0) == 0)
1193                 pulse_on_new_job (tp);
1194 }
1195
1196 void
1197 icall_append_job (MonoObject *ar)
1198 {
1199         threadpool_append_jobs (&async_tp, &ar, 1);
1200 }
1201
1202 static void
1203 threadpool_append_job (ThreadPool *tp, MonoObject *ar)
1204 {
1205         threadpool_append_jobs (tp, &ar, 1);
1206 }
1207
1208 void
1209 threadpool_append_async_io_jobs (MonoObject **jobs, gint njobs)
1210 {
1211         threadpool_append_jobs (&async_io_tp, jobs, njobs);
1212 }
1213
1214 static void
1215 threadpool_append_jobs (ThreadPool *tp, MonoObject **jobs, gint njobs)
1216 {
1217         MonoObject *ar;
1218         gint i;
1219
1220         if (mono_runtime_is_shutting_down ())
1221                 return;
1222
1223         if (tp->pool_status == 0 && InterlockedCompareExchange (&tp->pool_status, 1, 0) == 0) {
1224                 if (!tp->is_io) {
1225                         monitor_internal_thread = mono_thread_create_internal (mono_get_root_domain (), monitor_thread, NULL, TRUE, SMALL_STACK);
1226                         monitor_internal_thread->flags |= MONO_THREAD_FLAG_DONT_MANAGE;
1227                         threadpool_start_thread (tp);
1228                 }
1229                 /* Create on demand up to min_threads to avoid startup penalty for apps that don't use
1230                  * the threadpool that much
1231                  */
1232                 if (mono_config_is_server_mode ()) {
1233                         mono_thread_create_internal (mono_get_root_domain (), threadpool_start_idle_threads, tp, TRUE, SMALL_STACK);
1234                 }
1235         }
1236
1237         InterlockedAdd (&monitor_njobs, njobs);
1238
1239         if (monitor_state == MONITOR_STATE_SLEEPING && InterlockedCompareExchange (&monitor_state, MONITOR_STATE_AWAKE, MONITOR_STATE_SLEEPING) == MONITOR_STATE_SLEEPING)
1240                 MONO_SEM_POST (&monitor_sem);
1241
1242         if (monitor_state == MONITOR_STATE_FALLING_ASLEEP)
1243                 InterlockedCompareExchange (&monitor_state, MONITOR_STATE_AWAKE, MONITOR_STATE_FALLING_ASLEEP);
1244
1245         for (i = 0; i < njobs; i++) {
1246                 ar = jobs [i];
1247                 if (ar == NULL || mono_domain_is_unloading (ar->vtable->domain))
1248                         continue; /* Might happen when cleaning domain jobs */
1249                 threadpool_jobs_inc (ar);
1250 #ifndef DISABLE_PERFCOUNTERS
1251                 mono_perfcounter_update_value (tp->pc_nitems, TRUE, 1);
1252 #endif
1253                 if (!tp->is_io && mono_wsq_local_push (ar))
1254                         continue;
1255
1256                 mono_cq_enqueue (tp->queue, ar);
1257         }
1258
1259 #if DEBUG
1260         InterlockedAdd (&tp->njobs, njobs);
1261 #endif
1262
1263         for (i = 0; tp->waiting > 0 && i < MIN(njobs, tp->max_threads); i++)
1264                 pulse_on_new_job (tp);
1265 }
1266
1267 static void
1268 threadpool_clear_queue (ThreadPool *tp, MonoDomain *domain)
1269 {
1270         MonoObject *obj;
1271         MonoMList *other = NULL;
1272         MonoCQ *queue = tp->queue;
1273
1274         if (!queue)
1275                 return;
1276
1277         while (mono_cq_dequeue (queue, &obj)) {
1278                 if (obj == NULL)
1279                         continue;
1280                 if (obj->vtable->domain != domain)
1281                         other = mono_mlist_prepend (other, obj);
1282                 threadpool_jobs_dec (obj);
1283         }
1284
1285         if (mono_runtime_is_shutting_down ())
1286                 return;
1287
1288         while (other) {
1289                 threadpool_append_job (tp, (MonoObject *) mono_mlist_get_data (other));
1290                 other = mono_mlist_next (other);
1291         }
1292 }
1293
1294 static gboolean
1295 remove_sockstate_for_domain (gpointer key, gpointer value, gpointer user_data)
1296 {
1297         MonoMList *list = value;
1298         gboolean remove = FALSE;
1299         while (list) {
1300                 MonoObject *data = mono_mlist_get_data (list);
1301                 if (mono_object_domain (data) == user_data) {
1302                         remove = TRUE;
1303                         mono_mlist_set_data (list, NULL);
1304                 }
1305                 list = mono_mlist_next (list);
1306         }
1307         //FIXME is there some sort of additional unregistration we need to perform here?
1308         return remove;
1309 }
1310
1311 /*
1312  * Clean up the threadpool of all domain jobs.
1313  * Can only be called as part of the domain unloading process as
1314  * it will wait for all jobs to be visible to the interruption code.
1315  */
1316 gboolean
1317 mono_thread_pool_remove_domain_jobs (MonoDomain *domain, int timeout)
1318 {
1319         HANDLE sem_handle;
1320         int result;
1321         guint32 start_time;
1322
1323         if (use_ms_threadpool ()) {
1324                 return mono_threadpool_ms_remove_domain_jobs (domain, timeout);
1325         }
1326
1327         result = TRUE;
1328         start_time = 0;
1329
1330         g_assert (domain->state == MONO_APPDOMAIN_UNLOADING);
1331
1332         threadpool_clear_queue (&async_tp, domain);
1333         threadpool_clear_queue (&async_io_tp, domain);
1334
1335         mono_mutex_lock (&socket_io_data.io_lock);
1336         if (socket_io_data.sock_to_state)
1337                 mono_g_hash_table_foreach_remove (socket_io_data.sock_to_state, remove_sockstate_for_domain, domain);
1338
1339         mono_mutex_unlock (&socket_io_data.io_lock);
1340
1341         /*
1342          * There might be some threads out that could be about to execute stuff from the given domain.
1343          * We avoid that by setting up a semaphore to be pulsed by the thread that reaches zero.
1344          */
1345         sem_handle = CreateSemaphore (NULL, 0, 1, NULL);
1346
1347         domain->cleanup_semaphore = sem_handle;
1348         /*
1349          * The memory barrier here is required to have global ordering between assigning to cleanup_semaphone
1350          * and reading threadpool_jobs.
1351          * Otherwise this thread could read a stale version of threadpool_jobs and wait forever.
1352          */
1353         mono_memory_write_barrier ();
1354
1355         if (domain->threadpool_jobs && timeout != -1)
1356                 start_time = mono_msec_ticks ();
1357         while (domain->threadpool_jobs) {
1358                 MONO_PREPARE_BLOCKING
1359                 WaitForSingleObject (sem_handle, timeout);
1360                 MONO_FINISH_BLOCKING
1361                 if (timeout != -1 && (mono_msec_ticks () - start_time) > timeout) {
1362                         result = FALSE;
1363                         break;
1364                 }
1365         }
1366
1367         domain->cleanup_semaphore = NULL;
1368         CloseHandle (sem_handle);
1369         return result;
1370 }
1371
1372 static void
1373 threadpool_free_queue (ThreadPool *tp)
1374 {
1375         mono_cq_destroy (tp->queue);
1376         tp->queue = NULL;
1377 }
1378
1379 gboolean
1380 mono_thread_pool_is_queue_array (MonoArray *o)
1381 {
1382         if (use_ms_threadpool ()) {
1383                 return mono_threadpool_ms_is_queue_array (o);
1384         }
1385
1386         // gpointer obj = o;
1387
1388         // FIXME: need some fix in sgen code.
1389         return FALSE;
1390 }
1391
1392 static MonoWSQ *
1393 add_wsq (void)
1394 {
1395         int i;
1396         MonoWSQ *wsq;
1397
1398         mono_mutex_lock (&wsqs_lock);
1399         wsq = mono_wsq_create ();
1400         if (wsqs == NULL) {
1401                 mono_mutex_unlock (&wsqs_lock);
1402                 return NULL;
1403         }
1404         for (i = 0; i < wsqs->len; i++) {
1405                 if (g_ptr_array_index (wsqs, i) == NULL) {
1406                         wsqs->pdata [i] = wsq;
1407                         mono_mutex_unlock (&wsqs_lock);
1408                         return wsq;
1409                 }
1410         }
1411         g_ptr_array_add (wsqs, wsq);
1412         mono_mutex_unlock (&wsqs_lock);
1413         return wsq;
1414 }
1415
1416 static void
1417 remove_wsq (MonoWSQ *wsq)
1418 {
1419         gpointer data;
1420
1421         if (wsq == NULL)
1422                 return;
1423
1424         mono_mutex_lock (&wsqs_lock);
1425         if (wsqs == NULL) {
1426                 mono_mutex_unlock (&wsqs_lock);
1427                 return;
1428         }
1429         g_ptr_array_remove_fast (wsqs, wsq);
1430         data = NULL;
1431         /*
1432          * Only clean this up when shutting down, any other case will error out
1433          * if we're removing a queue that still has work items.
1434          */
1435         if (mono_runtime_is_shutting_down ()) {
1436                 while (mono_wsq_local_pop (&data)) {
1437                         threadpool_jobs_dec (data);
1438                         data = NULL;
1439                 }
1440         }
1441         mono_wsq_destroy (wsq);
1442         mono_mutex_unlock (&wsqs_lock);
1443 }
1444
1445 static void
1446 try_steal (MonoWSQ *local_wsq, gpointer *data, gboolean retry)
1447 {
1448         int i;
1449         int ms;
1450
1451         if (wsqs == NULL || data == NULL || *data != NULL)
1452                 return;
1453
1454         ms = 0;
1455         do {
1456                 if (mono_runtime_is_shutting_down ())
1457                         return;
1458
1459                 MONO_PREPARE_BLOCKING
1460                 mono_mutex_lock (&wsqs_lock);
1461                 MONO_FINISH_BLOCKING
1462                 for (i = 0; wsqs != NULL && i < wsqs->len; i++) {
1463                         MonoWSQ *wsq;
1464
1465                         wsq = wsqs->pdata [i];
1466                         if (wsq == local_wsq || mono_wsq_count (wsq) == 0)
1467                                 continue;
1468                         mono_wsq_try_steal (wsqs->pdata [i], data, ms);
1469                         if (*data != NULL) {
1470                                 mono_mutex_unlock (&wsqs_lock);
1471                                 return;
1472                         }
1473                 }
1474                 mono_mutex_unlock (&wsqs_lock);
1475                 ms += 10;
1476         } while (retry && ms < 11);
1477 }
1478
1479 static gboolean
1480 dequeue_or_steal (ThreadPool *tp, gpointer *data, MonoWSQ *local_wsq)
1481 {
1482         MonoCQ *queue = tp->queue;
1483         if (mono_runtime_is_shutting_down () || !queue)
1484                 return FALSE;
1485         mono_cq_dequeue (queue, (MonoObject **) data);
1486         if (!tp->is_io && !*data)
1487                 try_steal (local_wsq, data, FALSE);
1488         return (*data != NULL);
1489 }
1490
1491 static gboolean
1492 should_i_die (ThreadPool *tp)
1493 {
1494         gboolean result = FALSE;
1495         if (tp->destroy_thread == 1 && InterlockedCompareExchange (&tp->destroy_thread, 0, 1) == 1)
1496                 result = (tp->nthreads > tp->min_threads);
1497         return result;
1498 }
1499
1500 static void
1501 set_tp_thread_info (ThreadPool *tp)
1502 {
1503         const gchar *name;
1504         MonoInternalThread *thread = mono_thread_internal_current ();
1505
1506         mono_profiler_thread_start (thread->tid);
1507         name = (tp->is_io) ? "IO Threadpool worker" : "Threadpool worker";
1508         mono_thread_set_name_internal (thread, mono_string_new (mono_domain_get (), name), FALSE);
1509 }
1510
1511 static void
1512 clear_thread_state (void)
1513 {
1514         MonoInternalThread *thread = mono_thread_internal_current ();
1515         /* If the callee changes the background status, set it back to TRUE */
1516         mono_thread_clr_state (thread , ~ThreadState_Background);
1517         if (!mono_thread_test_state (thread , ThreadState_Background))
1518                 ves_icall_System_Threading_Thread_SetState (thread, ThreadState_Background);
1519 }
1520
1521 void
1522 check_for_interruption_critical (void)
1523 {
1524         MonoInternalThread *thread;
1525         /*RULE NUMBER ONE OF SKIP_THREAD: NEVER POKE MANAGED STATE.*/
1526         mono_gc_set_skip_thread (FALSE);
1527
1528         thread = mono_thread_internal_current ();
1529         if (THREAD_WANTS_A_BREAK (thread))
1530                 mono_thread_interruption_checkpoint ();
1531
1532         /*RULE NUMBER TWO OF SKIP_THREAD: READ RULE NUMBER ONE.*/
1533         mono_gc_set_skip_thread (TRUE);
1534 }
1535
1536 static void
1537 fire_profiler_thread_end (void)
1538 {
1539         MonoInternalThread *thread = mono_thread_internal_current ();
1540         mono_profiler_thread_end (thread->tid);
1541 }
1542
1543 static void
1544 async_invoke_thread (gpointer data)
1545 {
1546         MonoDomain *domain;
1547         MonoWSQ *wsq;
1548         ThreadPool *tp;
1549         gboolean must_die;
1550
1551         tp = data;
1552         wsq = NULL;
1553         if (!tp->is_io)
1554                 wsq = add_wsq ();
1555
1556         set_tp_thread_info (tp);
1557
1558         if (tp_start_func)
1559                 tp_start_func (tp_hooks_user_data);
1560
1561         data = NULL;
1562         for (;;) {
1563                 MonoAsyncResult *ar;
1564                 MonoClass *klass;
1565                 gboolean is_io_task;
1566                 gboolean is_socket;
1567                 int n_naps = 0;
1568
1569                 is_io_task = FALSE;
1570                 ar = (MonoAsyncResult *) data;
1571                 if (ar) {
1572                         InterlockedIncrement (&tp->busy_threads);
1573                         domain = ((MonoObject *)ar)->vtable->domain;
1574 #ifndef DISABLE_SOCKETS
1575                         klass = ((MonoObject *) data)->vtable->klass;
1576                         is_io_task = !is_corlib_asyncresult (domain, klass);
1577                         is_socket = FALSE;
1578                         if (is_io_task) {
1579                                 MonoSocketAsyncResult *state = (MonoSocketAsyncResult *) data;
1580                                 is_socket = is_socketasyncresult (domain, klass);
1581                                 ar = state->ares;
1582                                 switch (state->operation) {
1583                                 case AIO_OP_RECEIVE:
1584                                         state->total = ICALL_RECV (state);
1585                                         break;
1586                                 case AIO_OP_SEND:
1587                                         state->total = ICALL_SEND (state);
1588                                         break;
1589                                 }
1590                         }
1591 #endif
1592                         /* worker threads invokes methods in different domains,
1593                          * so we need to set the right domain here */
1594                         g_assert (domain);
1595
1596                         if (mono_domain_is_unloading (domain) || mono_runtime_is_shutting_down ()) {
1597                                 threadpool_jobs_dec ((MonoObject *)ar);
1598                                 data = NULL;
1599                                 ar = NULL;
1600                                 InterlockedDecrement (&tp->busy_threads);
1601                         } else {
1602                                 mono_thread_push_appdomain_ref (domain);
1603                                 if (threadpool_jobs_dec ((MonoObject *)ar)) {
1604                                         data = NULL;
1605                                         ar = NULL;
1606                                         mono_thread_pop_appdomain_ref ();
1607                                         InterlockedDecrement (&tp->busy_threads);
1608                                         continue;
1609                                 }
1610
1611                                 if (mono_domain_set (domain, FALSE)) {
1612                                         MonoObject *exc;
1613
1614                                         if (tp_item_begin_func)
1615                                                 tp_item_begin_func (tp_item_user_data);
1616
1617                                         exc = mono_async_invoke (tp, ar);
1618                                         if (tp_item_end_func)
1619                                                 tp_item_end_func (tp_item_user_data);
1620                                         if (exc)
1621                                                 mono_internal_thread_unhandled_exception (exc);
1622                                         if (is_socket && tp->is_io) {
1623                                                 MonoSocketAsyncResult *state = (MonoSocketAsyncResult *) data;
1624
1625                                                 if (state->completed && state->callback) {
1626                                                         MonoAsyncResult *cb_ares;
1627                                                         cb_ares = create_simple_asyncresult ((MonoObject *) state->callback,
1628                                                                                                 (MonoObject *) state);
1629                                                         icall_append_job ((MonoObject *) cb_ares);
1630                                                 }
1631                                         }
1632                                         mono_domain_set (mono_get_root_domain (), TRUE);
1633                                 }
1634                                 mono_thread_pop_appdomain_ref ();
1635                                 InterlockedDecrement (&tp->busy_threads);
1636                                 clear_thread_state ();
1637                         }
1638                 }
1639
1640                 ar = NULL;
1641                 data = NULL;
1642                 must_die = should_i_die (tp);
1643                 if (must_die) {
1644                         mono_wsq_suspend (wsq);
1645                 } else {
1646                         if (tp->is_io || !mono_wsq_local_pop (&data))
1647                                 dequeue_or_steal (tp, &data, wsq);
1648                 }
1649
1650                 n_naps = 0;
1651                 while (!must_die && !data && n_naps < 4) {
1652                         gboolean res;
1653
1654                         InterlockedIncrement (&tp->waiting);
1655
1656                         // Another thread may have added a job into its wsq since the last call to dequeue_or_steal
1657                         // Check all the queues again before entering the wait loop
1658                         dequeue_or_steal (tp, &data, wsq);
1659                         if (data) {
1660                                 InterlockedDecrement (&tp->waiting);
1661                                 break;
1662                         }
1663
1664                         mono_gc_set_skip_thread (TRUE);
1665                         MONO_PREPARE_BLOCKING
1666
1667 #if defined(__OpenBSD__)
1668                         while (mono_cq_count (tp->queue) == 0 && (res = mono_sem_wait (&tp->new_job, TRUE)) == -1) {// && errno == EINTR) {
1669 #else
1670                         while (mono_cq_count (tp->queue) == 0 && (res = mono_sem_timedwait (&tp->new_job, 2000, TRUE)) == -1) {// && errno == EINTR) {
1671 #endif
1672                                 if (mono_runtime_is_shutting_down ())
1673                                         break;
1674                                 check_for_interruption_critical ();
1675                         }
1676                         InterlockedDecrement (&tp->waiting);
1677
1678                         MONO_FINISH_BLOCKING
1679                         mono_gc_set_skip_thread (FALSE);
1680
1681                         if (mono_runtime_is_shutting_down ())
1682                                 break;
1683                         must_die = should_i_die (tp);
1684                         dequeue_or_steal (tp, &data, wsq);
1685                         n_naps++;
1686                 }
1687
1688                 if (!data && !tp->is_io && !mono_runtime_is_shutting_down ()) {
1689                         mono_wsq_local_pop (&data);
1690                         if (data && must_die) {
1691                                 InterlockedCompareExchange (&tp->destroy_thread, 1, 0);
1692                                 pulse_on_new_job (tp);
1693                         }
1694                 }
1695
1696                 if (!data) {
1697                         gint nt;
1698                         gboolean down;
1699                         while (1) {
1700                                 nt = tp->nthreads;
1701                                 down = mono_runtime_is_shutting_down ();
1702                                 if (!down && nt <= tp->min_threads)
1703                                         break;
1704                                 if (down || InterlockedCompareExchange (&tp->nthreads, nt - 1, nt) == nt) {
1705 #ifndef DISABLE_PERFCOUNTERS
1706                                         mono_perfcounter_update_value (tp->pc_nthreads, TRUE, -1);
1707 #endif
1708                                         if (!tp->is_io) {
1709                                                 remove_wsq (wsq);
1710                                         }
1711
1712                                         fire_profiler_thread_end ();
1713
1714                                         if (tp_finish_func)
1715                                                 tp_finish_func (tp_hooks_user_data);
1716
1717                                         if (!tp->is_io) {
1718                                                 if (threads) {
1719                                                         mono_mutex_lock (&threads_lock);
1720                                                         if (threads)
1721                                                                 g_ptr_array_remove_fast (threads, mono_thread_current ()->internal_thread);
1722                                                         mono_mutex_unlock (&threads_lock);
1723                                                 }
1724                                         }
1725
1726                                         return;
1727                                 }
1728                         }
1729                 }
1730         }
1731
1732         g_assert_not_reached ();
1733 }
1734
1735 void
1736 ves_icall_System_Threading_ThreadPool_GetAvailableThreads (gint *workerThreads, gint *completionPortThreads)
1737 {
1738         *workerThreads = async_tp.max_threads - async_tp.busy_threads;
1739         *completionPortThreads = async_io_tp.max_threads - async_io_tp.busy_threads;
1740 }
1741
1742 void
1743 ves_icall_System_Threading_ThreadPool_GetMaxThreads (gint *workerThreads, gint *completionPortThreads)
1744 {
1745         *workerThreads = async_tp.max_threads;
1746         *completionPortThreads = async_io_tp.max_threads;
1747 }
1748
1749 void
1750 ves_icall_System_Threading_ThreadPool_GetMinThreads (gint *workerThreads, gint *completionPortThreads)
1751 {
1752         *workerThreads = async_tp.min_threads;
1753         *completionPortThreads = async_io_tp.min_threads;
1754 }
1755
1756 MonoBoolean
1757 ves_icall_System_Threading_ThreadPool_SetMinThreads (gint workerThreads, gint completionPortThreads)
1758 {
1759         gint max_threads;
1760         gint max_io_threads;
1761
1762         max_threads = async_tp.max_threads;
1763         if (workerThreads <= 0 || workerThreads > max_threads)
1764                 return FALSE;
1765
1766         max_io_threads = async_io_tp.max_threads;
1767         if (completionPortThreads <= 0 || completionPortThreads > max_io_threads)
1768                 return FALSE;
1769
1770         InterlockedExchange (&async_tp.min_threads, workerThreads);
1771         InterlockedExchange (&async_io_tp.min_threads, completionPortThreads);
1772         if (workerThreads > async_tp.nthreads)
1773                 mono_thread_create_internal (mono_get_root_domain (), threadpool_start_idle_threads, &async_tp, TRUE, SMALL_STACK);
1774         if (completionPortThreads > async_io_tp.nthreads)
1775                 mono_thread_create_internal (mono_get_root_domain (), threadpool_start_idle_threads, &async_io_tp, TRUE, SMALL_STACK);
1776         return TRUE;
1777 }
1778
1779 MonoBoolean
1780 ves_icall_System_Threading_ThreadPool_SetMaxThreads (gint workerThreads, gint completionPortThreads)
1781 {
1782         gint min_threads;
1783         gint min_io_threads;
1784         gint cpu_count;
1785
1786         cpu_count = mono_cpu_count ();
1787         min_threads = async_tp.min_threads;
1788         if (workerThreads < min_threads || workerThreads < cpu_count)
1789                 return FALSE;
1790
1791         /* We don't really have the concept of completion ports. Do we care here? */
1792         min_io_threads = async_io_tp.min_threads;
1793         if (completionPortThreads < min_io_threads || completionPortThreads < cpu_count)
1794                 return FALSE;
1795
1796         InterlockedExchange (&async_tp.max_threads, workerThreads);
1797         InterlockedExchange (&async_io_tp.max_threads, completionPortThreads);
1798         return TRUE;
1799 }
1800
1801 /**
1802  * mono_install_threadpool_thread_hooks
1803  * @start_func: the function to be called right after a new threadpool thread is created. Can be NULL.
1804  * @finish_func: the function to be called right before a thredpool thread is exiting. Can be NULL.
1805  * @user_data: argument passed to @start_func and @finish_func.
1806  *
1807  * @start_fun will be called right after a threadpool thread is created and @finish_func right before a threadpool thread exits.
1808  * The calls will be made from the thread itself.
1809  */
1810 void
1811 mono_install_threadpool_thread_hooks (MonoThreadPoolFunc start_func, MonoThreadPoolFunc finish_func, gpointer user_data)
1812 {
1813         tp_start_func = start_func;
1814         tp_finish_func = finish_func;
1815         tp_hooks_user_data = user_data;
1816 }
1817
1818 /**
1819  * mono_install_threadpool_item_hooks
1820  * @begin_func: the function to be called before a threadpool work item processing starts.
1821  * @end_func: the function to be called after a threadpool work item is finished.
1822  * @user_data: argument passed to @begin_func and @end_func.
1823  *
1824  * The calls will be made from the thread itself and from the same AppDomain
1825  * where the work item was executed.
1826  *
1827  */
1828 void
1829 mono_install_threadpool_item_hooks (MonoThreadPoolItemFunc begin_func, MonoThreadPoolItemFunc end_func, gpointer user_data)
1830 {
1831         tp_item_begin_func = begin_func;
1832         tp_item_end_func = end_func;
1833         tp_item_user_data = user_data;
1834 }
1835
1836 void
1837 mono_internal_thread_unhandled_exception (MonoObject* exc)
1838 {
1839         if (mono_runtime_unhandled_exception_policy_get () == MONO_UNHANDLED_POLICY_CURRENT) {
1840                 gboolean unloaded;
1841                 MonoClass *klass;
1842
1843                 klass = exc->vtable->klass;
1844                 unloaded = is_appdomainunloaded_exception (exc->vtable->domain, klass);
1845                 if (!unloaded && klass != mono_defaults.threadabortexception_class) {
1846                         mono_unhandled_exception (exc);
1847                         if (mono_environment_exitcode_get () == 1)
1848                                 exit (255);
1849                 }
1850                 if (klass == mono_defaults.threadabortexception_class)
1851                  mono_thread_internal_reset_abort (mono_thread_internal_current ());
1852         }
1853 }
1854
1855 /*
1856  * Suspend creation of new threads.
1857  */
1858 void
1859 mono_thread_pool_suspend (void)
1860 {
1861         if (use_ms_threadpool ()) {
1862                 mono_threadpool_ms_suspend ();
1863                 return;
1864         }
1865         suspended = TRUE;
1866 }
1867
1868 /*
1869  * Resume creation of new threads.
1870  */
1871 void
1872 mono_thread_pool_resume (void)
1873 {
1874         if (use_ms_threadpool ()) {
1875                 mono_threadpool_ms_resume ();
1876                 return;
1877         }
1878         suspended = FALSE;
1879 }