mono/io-layer/threads.c

   1 /*
   2  * threads.c:  Thread handles
   3  *
   4  * Author:
   5  *      Dick Porter (dick@ximian.com)
   6  *
   7  * (C) 2002 Ximian, Inc.
   8  */
   9
  10 #include <config.h>
  11 #if HAVE_BOEHM_GC
  12 #include <mono/os/gc_wrapper.h>
  13 #include "mono/utils/mono-hash.h"
  14 #endif
  15 #include <glib.h>
  16 #include <string.h>
  17 #include <pthread.h>
  18 #include <sched.h>
  19 #include <sys/time.h>
  20 #include <errno.h>
  21
  22 #include <mono/io-layer/wapi.h>
  23 #include <mono/io-layer/wapi-private.h>
  24 #include <mono/io-layer/timed-thread.h>
  25 #include <mono/io-layer/handles-private.h>
  26 #include <mono/io-layer/misc-private.h>
  27 #include <mono/io-layer/mono-mutex.h>
  28 #include <mono/io-layer/thread-private.h>
  29 #include <mono/io-layer/mono-spinlock.h>
  30
  31 #undef DEBUG
  32 #undef TLS_DEBUG
  33 #undef TLS_PTHREAD_MUTEX
  34
  35
  36 /* Hash threads with tids. I thought of using TLS for this, but that
  37  * would have to set the data in the new thread, which is more hassle
  38  */
  39 static mono_once_t thread_hash_once = MONO_ONCE_INIT;
  40 static mono_mutex_t thread_hash_mutex = MONO_MUTEX_INITIALIZER;
  41 static GHashTable *thread_hash=NULL;
  42
  43 #if HAVE_BOEHM_GC
  44 static MonoGHashTable *tls_gc_hash = NULL;
  45 #endif
  46
  47 static void thread_close_private (gpointer handle);
  48 static void thread_own (gpointer handle);
  49
  50 struct _WapiHandleOps _wapi_thread_ops = {
  51         NULL,                           /* close_shared */
  52         thread_close_private,           /* close_private */
  53         NULL,                           /* signal */
  54         thread_own,                     /* own */
  55         NULL,                           /* is_owned */
  56 };
  57
  58 static mono_once_t thread_ops_once=MONO_ONCE_INIT;
  59
  60 static void thread_ops_init (void)
  61 {
  62         _wapi_handle_register_capabilities (WAPI_HANDLE_THREAD,
  63                                             WAPI_HANDLE_CAP_WAIT);
  64 }
  65
  66 static void thread_close_private (gpointer handle)
  67 {
  68         struct _WapiHandlePrivate_thread *thread_handle;
  69         gboolean ok;
  70
  71         ok=_wapi_lookup_handle (handle, WAPI_HANDLE_THREAD, NULL,
  72                                 (gpointer *)&thread_handle);
  73         if(ok==FALSE) {
  74                 g_warning (G_GNUC_PRETTY_FUNCTION
  75                            ": error looking up thread handle %p", handle);
  76                 return;
  77         }
  78
  79 #ifdef DEBUG
  80         g_message(G_GNUC_PRETTY_FUNCTION
  81                   ": closing thread handle %p with thread %p id %ld",
  82                   handle, thread_handle->thread,
  83                   thread_handle->thread->id);
  84 #endif
  85
  86         if(thread_handle->thread!=NULL) {
  87                 _wapi_timed_thread_destroy (thread_handle->thread);
  88         }
  89 }
  90
  91 static void thread_own (gpointer handle)
  92 {
  93         struct _WapiHandle_thread *thread_handle;
  94         struct _WapiHandlePrivate_thread *thread_private_handle;
  95         gboolean ok;
  96
  97         ok=_wapi_lookup_handle (handle, WAPI_HANDLE_THREAD,
  98                                 (gpointer *)&thread_handle,
  99                                 (gpointer *)&thread_private_handle);
 100         if(ok==FALSE) {
 101                 g_warning (G_GNUC_PRETTY_FUNCTION
 102                            ": error looking up thread handle %p", handle);
 103                 return;
 104         }
 105
 106         if(thread_private_handle->joined==FALSE) {
 107                 _wapi_timed_thread_join (thread_private_handle->thread, NULL,
 108                                          NULL);
 109                 thread_private_handle->joined=TRUE;
 110         }
 111 }
 112
 113 static void thread_exit(guint32 exitstatus, gpointer handle)
 114 {
 115         struct _WapiHandle_thread *thread_handle;
 116         struct _WapiHandlePrivate_thread *thread_private_handle;
 117         gboolean ok;
 118
 119         ok=_wapi_lookup_handle (handle, WAPI_HANDLE_THREAD,
 120                                 (gpointer *)&thread_handle,
 121                                 (gpointer *)&thread_private_handle);
 122         if(ok==FALSE) {
 123                 g_warning (G_GNUC_PRETTY_FUNCTION
 124                            ": error looking up thread handle %p", handle);
 125                 return;
 126         }
 127
 128         _wapi_handle_lock_handle (handle);
 129
 130 #ifdef DEBUG
 131         g_message (G_GNUC_PRETTY_FUNCTION
 132                    ": Recording thread handle %p exit status", handle);
 133 #endif
 134
 135         thread_handle->exitstatus=exitstatus;
 136         thread_handle->state=THREAD_STATE_EXITED;
 137         _wapi_handle_set_signal_state (handle, TRUE, TRUE);
 138
 139         _wapi_handle_unlock_handle (handle);
 140
 141 #ifdef DEBUG
 142         g_message(G_GNUC_PRETTY_FUNCTION
 143                   ": Recording thread handle %p id %ld status as %d",
 144                   handle, thread_private_handle->thread->id, exitstatus);
 145 #endif
 146
 147         /* Remove this thread from the hash */
 148         mono_mutex_lock(&thread_hash_mutex);
 149         g_hash_table_remove(thread_hash, &thread_private_handle->thread->id);
 150         mono_mutex_unlock(&thread_hash_mutex);
 151
 152         /* The thread is no longer active, so unref it */
 153         _wapi_handle_unref (handle);
 154 }
 155
 156 static void thread_hash_init(void)
 157 {
 158         thread_hash=g_hash_table_new(g_int_hash, g_int_equal);
 159 }
 160
 161 /**
 162  * CreateThread:
 163  * @security: Ignored for now.
 164  * @stacksize: the size in bytes of the new thread's stack. Use 0 to
 165  * default to the normal stack size. (Ignored for now).
 166  * @start: The function that the new thread should start with
 167  * @param: The parameter to give to @start.
 168  * @create: If 0, the new thread is ready to run immediately.  If
 169  * %CREATE_SUSPENDED, the new thread will be in the suspended state,
 170  * requiring a ResumeThread() call to continue running.
 171  * @tid: If non-NULL, the ID of the new thread is stored here.
 172  *
 173  * Creates a new threading handle.
 174  *
 175  * Return value: a new handle, or NULL
 176  */
 177 gpointer CreateThread(WapiSecurityAttributes *security G_GNUC_UNUSED, guint32 stacksize G_GNUC_UNUSED,
 178                       WapiThreadStart start, gpointer param, guint32 create,
 179                       guint32 *tid)
 180 {
 181         struct _WapiHandle_thread *thread_handle;
 182         struct _WapiHandlePrivate_thread *thread_private_handle;
 183         gpointer handle;
 184         gboolean ok;
 185         int ret;
 186
 187         mono_once(&thread_hash_once, thread_hash_init);
 188         mono_once (&thread_ops_once, thread_ops_init);
 189
 190         if(start==NULL) {
 191                 return(NULL);
 192         }
 193
 194         handle=_wapi_handle_new (WAPI_HANDLE_THREAD);
 195         if(handle==_WAPI_HANDLE_INVALID) {
 196                 g_warning (G_GNUC_PRETTY_FUNCTION
 197                            ": error creating thread handle");
 198                 return(NULL);
 199         }
 200
 201         _wapi_handle_lock_handle (handle);
 202
 203         ok=_wapi_lookup_handle (handle, WAPI_HANDLE_THREAD,
 204                                 (gpointer *)&thread_handle,
 205                                 (gpointer *)&thread_private_handle);
 206         if(ok==FALSE) {
 207                 g_warning (G_GNUC_PRETTY_FUNCTION
 208                            ": error looking up thread handle %p", handle);
 209                 _wapi_handle_unlock_handle (handle);
 210                 return(NULL);
 211         }
 212
 213         /* Hold a reference while the thread is active, because we use
 214          * the handle to store thread exit information
 215          */
 216         _wapi_handle_ref (handle);
 217
 218         thread_handle->state=THREAD_STATE_START;
 219
 220         /* Lock around the thread create, so that the new thread cant
 221          * race us to look up the thread handle in GetCurrentThread()
 222          */
 223         mono_mutex_lock(&thread_hash_mutex);
 224
 225         ret=_wapi_timed_thread_create(&thread_private_handle->thread, NULL,
 226                                       create, start, thread_exit, param,
 227                                       handle);
 228         if(ret!=0) {
 229 #ifdef DEBUG
 230                 g_message(G_GNUC_PRETTY_FUNCTION ": Thread create error: %s",
 231                           strerror(ret));
 232 #endif
 233                 mono_mutex_unlock(&thread_hash_mutex);
 234                 _wapi_handle_unlock_handle (handle);
 235                 _wapi_handle_unref (handle);
 236
 237                 /* And again, because of the reference we took above */
 238                 _wapi_handle_unref (handle);
 239                 return(NULL);
 240         }
 241
 242         g_hash_table_insert(thread_hash, &thread_private_handle->thread->id,
 243                             handle);
 244         mono_mutex_unlock(&thread_hash_mutex);
 245
 246 #ifdef DEBUG
 247         g_message(G_GNUC_PRETTY_FUNCTION
 248                   ": Started thread handle %p thread %p ID %ld", handle,
 249                   thread_private_handle->thread,
 250                   thread_private_handle->thread->id);
 251 #endif
 252
 253         if(tid!=NULL) {
 254 #ifdef PTHREAD_POINTER_ID
 255                 *tid=GPOINTER_TO_UINT(thread_private_handle->thread->id);
 256 #else
 257                 *tid=thread_private_handle->thread->id;
 258 #endif
 259         }
 260
 261         _wapi_handle_unlock_handle (handle);
 262
 263         return(handle);
 264 }
 265
 266 gpointer OpenThread (guint32 access G_GNUC_UNUSED, gboolean inherit G_GNUC_UNUSED, guint32 tid)
 267 {
 268         gpointer ret=NULL;
 269
 270         mono_once(&thread_hash_once, thread_hash_init);
 271         mono_once (&thread_ops_once, thread_ops_init);
 272
 273 #ifdef DEBUG
 274         g_message (G_GNUC_PRETTY_FUNCTION ": looking up thread %d", tid);
 275 #endif
 276
 277         mono_mutex_lock(&thread_hash_mutex);
 278
 279         ret=g_hash_table_lookup(thread_hash, &tid);
 280         mono_mutex_unlock(&thread_hash_mutex);
 281
 282         if(ret!=NULL) {
 283                 _wapi_handle_ref (ret);
 284         }
 285
 286 #ifdef DEBUG
 287         g_message (G_GNUC_PRETTY_FUNCTION ": returning thread handle %p", ret);
 288 #endif
 289
 290         return(ret);
 291 }
 292
 293 /**
 294  * ExitThread:
 295  * @exitcode: Sets the thread's exit code, which can be read from
 296  * another thread with GetExitCodeThread().
 297  *
 298  * Terminates the calling thread.  A thread can also exit by returning
 299  * from its start function. When the last thread in a process
 300  * terminates, the process itself terminates.
 301  */
 302 void ExitThread(guint32 exitcode)
 303 {
 304         _wapi_timed_thread_exit(exitcode);
 305 }
 306
 307 /**
 308  * GetExitCodeThread:
 309  * @handle: The thread handle to query
 310  * @exitcode: The thread @handle exit code is stored here
 311  *
 312  * Finds the exit code of @handle, and stores it in @exitcode.  If the
 313  * thread @handle is still running, the value stored is %STILL_ACTIVE.
 314  *
 315  * Return value: %TRUE, or %FALSE on error.
 316  */
 317 gboolean GetExitCodeThread(gpointer handle, guint32 *exitcode)
 318 {
 319         struct _WapiHandle_thread *thread_handle;
 320         struct _WapiHandlePrivate_thread *thread_private_handle;
 321         gboolean ok;
 322
 323         ok=_wapi_lookup_handle (handle, WAPI_HANDLE_THREAD,
 324                                 (gpointer *)&thread_handle,
 325                                 (gpointer *)&thread_private_handle);
 326         if(ok==FALSE) {
 327                 g_warning (G_GNUC_PRETTY_FUNCTION
 328                            ": error looking up thread handle %p", handle);
 329                 return(FALSE);
 330         }
 331
 332 #ifdef DEBUG
 333         g_message(G_GNUC_PRETTY_FUNCTION
 334                   ": Finding exit status for thread handle %p id %ld", handle,
 335                   thread_private_handle->thread->id);
 336 #endif
 337
 338         if(exitcode==NULL) {
 339 #ifdef DEBUG
 340                 g_message(G_GNUC_PRETTY_FUNCTION
 341                           ": Nowhere to store exit code");
 342 #endif
 343                 return(FALSE);
 344         }
 345
 346         if(thread_handle->state!=THREAD_STATE_EXITED) {
 347 #ifdef DEBUG
 348                 g_message(G_GNUC_PRETTY_FUNCTION
 349                           ": Thread still active (state %d, exited is %d)",
 350                           thread_handle->state, THREAD_STATE_EXITED);
 351 #endif
 352                 *exitcode=STILL_ACTIVE;
 353                 return(TRUE);
 354         }
 355
 356         *exitcode=thread_handle->exitstatus;
 357
 358         return(TRUE);
 359 }
 360
 361 /**
 362  * GetCurrentThreadId:
 363  *
 364  * Looks up the thread ID of the current thread.  This ID can be
 365  * passed to OpenThread() to create a new handle on this thread.
 366  *
 367  * Return value: the thread ID.
 368  */
 369 guint32 GetCurrentThreadId(void)
 370 {
 371         pthread_t tid=pthread_self();
 372
 373 #ifdef PTHREAD_POINTER_ID
 374         return(GPOINTER_TO_UINT(tid));
 375 #else
 376         return(tid);
 377 #endif
 378 }
 379
 380 static gpointer thread_attach(guint32 *tid)
 381 {
 382         struct _WapiHandle_thread *thread_handle;
 383         struct _WapiHandlePrivate_thread *thread_private_handle;
 384         gpointer handle;
 385         gboolean ok;
 386         int ret;
 387
 388         mono_once(&thread_hash_once, thread_hash_init);
 389         mono_once (&thread_ops_once, thread_ops_init);
 390
 391         handle=_wapi_handle_new (WAPI_HANDLE_THREAD);
 392         if(handle==_WAPI_HANDLE_INVALID) {
 393                 g_warning (G_GNUC_PRETTY_FUNCTION
 394                            ": error creating thread handle");
 395                 return(NULL);
 396         }
 397
 398         _wapi_handle_lock_handle (handle);
 399
 400         ok=_wapi_lookup_handle (handle, WAPI_HANDLE_THREAD,
 401                                 (gpointer *)&thread_handle,
 402                                 (gpointer *)&thread_private_handle);
 403         if(ok==FALSE) {
 404                 g_warning (G_GNUC_PRETTY_FUNCTION
 405                            ": error looking up thread handle %p", handle);
 406                 _wapi_handle_unlock_handle (handle);
 407                 return(NULL);
 408         }
 409
 410         /* Hold a reference while the thread is active, because we use
 411          * the handle to store thread exit information
 412          */
 413         _wapi_handle_ref (handle);
 414
 415         thread_handle->state=THREAD_STATE_START;
 416
 417         /* Lock around the thread create, so that the new thread cant
 418          * race us to look up the thread handle in GetCurrentThread()
 419          */
 420         mono_mutex_lock(&thread_hash_mutex);
 421
 422         ret=_wapi_timed_thread_attach(&thread_private_handle->thread,
 423                                       thread_exit, handle);
 424         if(ret!=0) {
 425 #ifdef DEBUG
 426                 g_message(G_GNUC_PRETTY_FUNCTION ": Thread attach error: %s",
 427                           strerror(ret));
 428 #endif
 429                 mono_mutex_unlock(&thread_hash_mutex);
 430                 _wapi_handle_unlock_handle (handle);
 431                 _wapi_handle_unref (handle);
 432
 433                 /* And again, because of the reference we took above */
 434                 _wapi_handle_unref (handle);
 435                 return(NULL);
 436         }
 437
 438         g_hash_table_insert(thread_hash, &thread_private_handle->thread->id,
 439                             handle);
 440         mono_mutex_unlock(&thread_hash_mutex);
 441
 442 #ifdef DEBUG
 443         g_message(G_GNUC_PRETTY_FUNCTION
 444                   ": Attached thread handle %p thread %p ID %ld", handle,
 445                   thread_private_handle->thread,
 446                   thread_private_handle->thread->id);
 447 #endif
 448
 449         if(tid!=NULL) {
 450 #ifdef PTHREAD_POINTER_ID
 451                 *tid=GPOINTER_TO_UINT(thread_private_handle->thread->id);
 452 #else
 453                 *tid=thread_private_handle->thread->id;
 454 #endif
 455         }
 456
 457         _wapi_handle_unlock_handle (handle);
 458
 459         return(handle);
 460 }
 461
 462 /**
 463  * GetCurrentThread:
 464  *
 465  * Looks up the handle associated with the current thread.  Under
 466  * Windows this is a pseudohandle, and must be duplicated with
 467  * DuplicateHandle() for some operations.
 468  *
 469  * Return value: The current thread handle, or %NULL on failure.
 470  * (Unknown whether Windows has a possible failure here.  It may be
 471  * necessary to implement the pseudohandle-constant behaviour).
 472  */
 473 gpointer GetCurrentThread(void)
 474 {
 475         gpointer ret=NULL;
 476         guint32 tid;
 477
 478         mono_once(&thread_hash_once, thread_hash_init);
 479         mono_once (&thread_ops_once, thread_ops_init);
 480
 481         tid=GetCurrentThreadId();
 482
 483         mono_mutex_lock(&thread_hash_mutex);
 484
 485         ret=g_hash_table_lookup(thread_hash, &tid);
 486         mono_mutex_unlock(&thread_hash_mutex);
 487
 488         if (!ret) {
 489                 ret = thread_attach (NULL);
 490         }
 491
 492         return(ret);
 493 }
 494
 495 /**
 496  * ResumeThread:
 497  * @handle: the thread handle to resume
 498  *
 499  * Decrements the suspend count of thread @handle. A thread can only
 500  * run if its suspend count is zero.
 501  *
 502  * Return value: the previous suspend count, or 0xFFFFFFFF on error.
 503  */
 504 guint32 ResumeThread(gpointer handle)
 505 {
 506         struct _WapiHandle_thread *thread_handle;
 507         struct _WapiHandlePrivate_thread *thread_private_handle;
 508         gboolean ok;
 509
 510         ok=_wapi_lookup_handle (handle, WAPI_HANDLE_THREAD,
 511                                 (gpointer *)&thread_handle,
 512                                 (gpointer *)&thread_private_handle);
 513         if(ok==FALSE) {
 514                 g_warning (G_GNUC_PRETTY_FUNCTION
 515                            ": error looking up thread handle %p", handle);
 516                 return(0xFFFFFFFF);
 517         }
 518
 519         /* This is still a kludge that only copes with starting a
 520          * thread that was suspended on create, so don't bother with
 521          * the suspend count crap yet
 522          */
 523         _wapi_timed_thread_resume (thread_private_handle->thread);
 524
 525         return(0xFFFFFFFF);
 526 }
 527
 528 /**
 529  * SuspendThread:
 530  * @handle: the thread handle to suspend
 531  *
 532  * Increments the suspend count of thread @handle. A thread can only
 533  * run if its suspend count is zero.
 534  *
 535  * Return value: the previous suspend count, or 0xFFFFFFFF on error.
 536  */
 537 guint32 SuspendThread(gpointer handle G_GNUC_UNUSED)
 538 {
 539         return(0xFFFFFFFF);
 540 }
 541
 542 /*
 543  * We assume here that TLS_MINIMUM_AVAILABLE is less than
 544  * PTHREAD_KEYS_MAX, allowing enough overhead for a few TLS keys for
 545  * library usage.
 546  *
 547  * Currently TLS_MINIMUM_AVAILABLE is 64 and _POSIX_THREAD_KEYS_MAX
 548  * (the minimum value for PTHREAD_KEYS_MAX) is 128, so we should be
 549  * fine.
 550  */
 551
 552 static pthread_key_t TLS_keys[TLS_MINIMUM_AVAILABLE];
 553 static gboolean TLS_used[TLS_MINIMUM_AVAILABLE]={FALSE};
 554 #ifdef TLS_PTHREAD_MUTEX
 555 static mono_mutex_t TLS_mutex=MONO_MUTEX_INITIALIZER;
 556 #else
 557 static guint32 TLS_spinlock=0;
 558 #endif
 559
 560 /**
 561  * TlsAlloc:
 562  *
 563  * Allocates a Thread Local Storage (TLS) index.  Any thread in the
 564  * same process can use this index to store and retrieve values that
 565  * are local to that thread.
 566  *
 567  * Return value: The index value, or %TLS_OUT_OF_INDEXES if no index
 568  * is available.
 569  */
 570 guint32 TlsAlloc(void)
 571 {
 572         guint32 i;
 573
 574 #ifdef TLS_PTHREAD_MUTEX
 575         mono_mutex_lock(&TLS_mutex);
 576 #else
 577         MONO_SPIN_LOCK (TLS_spinlock);
 578 #endif
 579
 580         for(i=0; i<TLS_MINIMUM_AVAILABLE; i++) {
 581                 if(TLS_used[i]==FALSE) {
 582                         TLS_used[i]=TRUE;
 583                         pthread_key_create(&TLS_keys[i], NULL);
 584
 585 #ifdef TLS_PTHREAD_MUTEX
 586                         mono_mutex_unlock(&TLS_mutex);
 587 #else
 588                         MONO_SPIN_UNLOCK (TLS_spinlock);
 589 #endif
 590
 591 #ifdef TLS_DEBUG
 592                         g_message (G_GNUC_PRETTY_FUNCTION ": returning key %d",
 593                                    i);
 594 #endif
 595
 596                         return(i);
 597                 }
 598         }
 599
 600 #ifdef TLS_PTHREAD_MUTEX
 601         mono_mutex_unlock(&TLS_mutex);
 602 #else
 603         MONO_SPIN_UNLOCK (TLS_spinlock);
 604 #endif
 605
 606 #ifdef TLS_DEBUG
 607         g_message (G_GNUC_PRETTY_FUNCTION ": out of indices");
 608 #endif
 609
 610
 611         return(TLS_OUT_OF_INDEXES);
 612 }
 613
 614 #define MAKE_GC_ID(idx) (GUINT_TO_POINTER((idx)|(GetCurrentThreadId()<<8)))
 615
 616 /**
 617  * TlsFree:
 618  * @idx: The TLS index to free
 619  *
 620  * Releases a TLS index, making it available for reuse.  This call
 621  * will delete any TLS data stored under index @idx in all threads.
 622  *
 623  * Return value: %TRUE on success, %FALSE otherwise.
 624  */
 625 gboolean TlsFree(guint32 idx)
 626 {
 627 #ifdef TLS_DEBUG
 628         g_message (G_GNUC_PRETTY_FUNCTION ": freeing key %d", idx);
 629 #endif
 630
 631 #ifdef TLS_PTHREAD_MUTEX
 632         mono_mutex_lock(&TLS_mutex);
 633 #else
 634         MONO_SPIN_LOCK (TLS_spinlock);
 635 #endif
 636
 637         if(TLS_used[idx]==FALSE) {
 638 #ifdef TLS_PTHREAD_MUTEX
 639                 mono_mutex_unlock(&TLS_mutex);
 640 #else
 641                 MONO_SPIN_UNLOCK (TLS_spinlock);
 642 #endif
 643                 return(FALSE);
 644         }
 645
 646         TLS_used[idx]=FALSE;
 647         pthread_key_delete(TLS_keys[idx]);
 648
 649 #if HAVE_BOEHM_GC
 650         mono_g_hash_table_remove (tls_gc_hash, MAKE_GC_ID (idx));
 651 #endif
 652
 653 #ifdef TLS_PTHREAD_MUTEX
 654         mono_mutex_unlock(&TLS_mutex);
 655 #else
 656         MONO_SPIN_UNLOCK (TLS_spinlock);
 657 #endif
 658
 659         return(TRUE);
 660 }
 661
 662 /**
 663  * TlsGetValue:
 664  * @idx: The TLS index to retrieve
 665  *
 666  * Retrieves the TLS data stored under index @idx.
 667  *
 668  * Return value: The value stored in the TLS index @idx in the current
 669  * thread, or %NULL on error.  As %NULL can be a valid return value,
 670  * in this case GetLastError() returns %ERROR_SUCCESS.
 671  */
 672 gpointer TlsGetValue(guint32 idx)
 673 {
 674         gpointer ret;
 675
 676 #ifdef TLS_DEBUG
 677         g_message (G_GNUC_PRETTY_FUNCTION ": looking up key %d", idx);
 678 #endif
 679
 680         ret=pthread_getspecific(TLS_keys[idx]);
 681
 682 #ifdef TLS_DEBUG
 683         g_message (G_GNUC_PRETTY_FUNCTION ": returning %p", ret);
 684 #endif
 685
 686         return(ret);
 687 }
 688
 689 /**
 690  * TlsSetValue:
 691  * @idx: The TLS index to store
 692  * @value: The value to store under index @idx
 693  *
 694  * Stores @value at TLS index @idx.
 695  *
 696  * Return value: %TRUE on success, %FALSE otherwise.
 697  */
 698 gboolean TlsSetValue(guint32 idx, gpointer value)
 699 {
 700         int ret;
 701
 702 #ifdef TLS_DEBUG
 703         g_message (G_GNUC_PRETTY_FUNCTION ": setting key %d to %p", idx,
 704                    value);
 705 #endif
 706
 707 #ifdef TLS_PTHREAD_MUTEX
 708         mono_mutex_lock(&TLS_mutex);
 709 #else
 710         MONO_SPIN_LOCK (TLS_spinlock);
 711 #endif
 712
 713         if(TLS_used[idx]==FALSE) {
 714 #ifdef TLS_DEBUG
 715                 g_message (G_GNUC_PRETTY_FUNCTION ": key %d unused", idx);
 716 #endif
 717
 718 #ifdef TLS_PTHREAD_MUTEX
 719                 mono_mutex_unlock(&TLS_mutex);
 720 #else
 721                 MONO_SPIN_UNLOCK (TLS_spinlock);
 722 #endif
 723                 return(FALSE);
 724         }
 725
 726         ret=pthread_setspecific(TLS_keys[idx], value);
 727         if(ret!=0) {
 728 #ifdef TLS_DEBUG
 729                 g_message (G_GNUC_PRETTY_FUNCTION
 730                            ": pthread_setspecific error: %s", strerror (ret));
 731 #endif
 732
 733 #ifdef TLS_PTHREAD_MUTEX
 734                 mono_mutex_unlock(&TLS_mutex);
 735 #else
 736                 MONO_SPIN_UNLOCK (TLS_spinlock);
 737 #endif
 738                 return(FALSE);
 739         }
 740
 741 #if HAVE_BOEHM_GC
 742         if (!tls_gc_hash)
 743                 tls_gc_hash = mono_g_hash_table_new(g_direct_hash, g_direct_equal);
 744         mono_g_hash_table_insert (tls_gc_hash, MAKE_GC_ID (idx), value);
 745 #endif
 746
 747 #ifdef TLS_PTHREAD_MUTEX
 748         mono_mutex_unlock(&TLS_mutex);
 749 #else
 750         MONO_SPIN_UNLOCK (TLS_spinlock);
 751 #endif
 752
 753         return(TRUE);
 754 }
 755
 756 /**
 757  * Sleep:
 758  * @ms: The time in milliseconds to suspend for
 759  *
 760  * Suspends execution of the current thread for @ms milliseconds.  A
 761  * value of zero causes the thread to relinquish its time slice.  A
 762  * value of %INFINITE causes an infinite delay.
 763  */
 764 void Sleep(guint32 ms)
 765 {
 766         struct timespec req, rem;
 767         div_t divvy;
 768         int ret;
 769
 770 #ifdef DEBUG
 771         g_message(G_GNUC_PRETTY_FUNCTION ": Sleeping for %d ms", ms);
 772 #endif
 773
 774         if(ms==0) {
 775                 sched_yield();
 776                 return;
 777         }
 778
 779         /* FIXME: check for INFINITE and sleep forever */
 780         divvy=div((int)ms, 1000);
 781
 782         req.tv_sec=divvy.quot;
 783         req.tv_nsec=divvy.rem*1000000;
 784
 785 again:
 786         ret=nanosleep(&req, &rem);
 787         if(ret==-1) {
 788                 /* Sleep interrupted with rem time remaining */
 789 #ifdef DEBUG
 790                 guint32 rems=rem.tv_sec*1000 + rem.tv_nsec/1000000;
 791
 792                 g_message(G_GNUC_PRETTY_FUNCTION ": Still got %d ms to go",
 793                           rems);
 794 #endif
 795                 req=rem;
 796                 goto again;
 797         }
 798 }
 799
 800 /* FIXME: implement alertable */
 801 void SleepEx(guint32 ms, gboolean alertable)
 802 {
 803         if(alertable==TRUE) {
 804                 g_warning(G_GNUC_PRETTY_FUNCTION ": alertable not implemented");
 805         }
 806
 807         Sleep(ms);
 808 }