glib/gatomic.c

   1 /*
   2  * Copyright © 2011 Ryan Lortie
   3  *
   4  * This library is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * licence, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17  * USA.
  18  *
  19  * Author: Ryan Lortie <desrt@desrt.ca>
  20  */
  21
  22 #include "config.h"
  23
  24 #include "gatomic.h"
  25
  26 /**
  27  * SECTION:atomic_operations
  28  * @title: Atomic Operations
  29  * @short_description: basic atomic integer and pointer operations
  30  * @see_also: #GMutex
  31  *
  32  * The following is a collection of compiler macros to provide atomic
  33  * access to integer and pointer-sized values.
  34  *
  35  * The macros that have 'int' in the name will operate on pointers to
  36  * #gint and #guint.  The macros with 'pointer' in the name will operate
  37  * on pointers to any pointer-sized value, including #gsize.  There is
  38  * no support for 64bit operations on platforms with 32bit pointers
  39  * because it is not generally possible to perform these operations
  40  * atomically.
  41  *
  42  * The get, set and exchange operations for integers and pointers
  43  * nominally operate on #gint and #gpointer, respectively.  Of the
  44  * arithmetic operations, the 'add' operation operates on (and returns)
  45  * signed integer values (#gint and #gssize) and the 'and', 'or', and
  46  * 'xor' operations operate on (and return) unsigned integer values
  47  * (#guint and #gsize).
  48  *
  49  * All of the operations act as a full compiler and (where appropriate)
  50  * hardware memory barrier.  Acquire and release or producer and
  51  * consumer barrier semantics are not available through this API.
  52  *
  53  * It is very important that all accesses to a particular integer or
  54  * pointer be performed using only this API and that different sizes of
  55  * operation are not mixed or used on overlapping memory regions.  Never
  56  * read or assign directly from or to a value -- always use this API.
  57  *
  58  * For simple reference counting purposes you should use
  59  * g_atomic_int_inc() and g_atomic_int_dec_and_test().  Other uses that
  60  * fall outside of simple reference counting patterns are prone to
  61  * subtle bugs and occasionally undefined behaviour.  It is also worth
  62  * noting that since all of these operations require global
  63  * synchronisation of the entire machine, they can be quite slow.  In
  64  * the case of performing multiple atomic operations it can often be
  65  * faster to simply acquire a mutex lock around the critical area,
  66  * perform the operations normally and then release the lock.
  67  **/
  68
  69 /**
  70  * G_ATOMIC_LOCK_FREE:
  71  *
  72  * This macro is defined if the atomic operations of GLib are
  73  * implemented using real hardware atomic operations.  This means that
  74  * the GLib atomic API can be used between processes and safely mixed
  75  * with other (hardware) atomic APIs.
  76  *
  77  * If this macro is not defined, the atomic operations may be
  78  * emulated using a mutex.  In that case, the GLib atomic operations are
  79  * only atomic relative to themselves and within a single process.
  80  **/
  81
  82 /* NOTE CAREFULLY:
  83  *
  84  * This file is the lowest-level part of GLib.
  85  *
  86  * Other lowlevel parts of GLib (threads, slice allocator, g_malloc,
  87  * messages, etc) call into these functions and macros to get work done.
  88  *
  89  * As such, these functions can not call back into any part of GLib
  90  * without risking recursion.
  91  */
  92
  93 #ifdef G_ATOMIC_LOCK_FREE
  94
  95 /* if G_ATOMIC_LOCK_FREE was defined by ./configure then we MUST
  96  * implement the atomic operations in a lock-free manner.
  97  */
  98
  99 #if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
 100 /**
 101  * g_atomic_int_get:
 102  * @atomic: a pointer to a #gint or #guint
 103  *
 104  * Gets the current value of @atomic.
 105  *
 106  * This call acts as a full compiler and hardware
 107  * memory barrier (before the get).
 108  *
 109  * Returns: the value of the integer
 110  *
 111  * Since: 2.4
 112  **/
 113 gint
 114 (g_atomic_int_get) (const volatile gint *atomic)
 115 {
 116   return g_atomic_int_get (atomic);
 117 }
 118
 119 /**
 120  * g_atomic_int_set:
 121  * @atomic: a pointer to a #gint or #guint
 122  * @newval: a new value to store
 123  *
 124  * Sets the value of @atomic to @newval.
 125  *
 126  * This call acts as a full compiler and hardware
 127  * memory barrier (after the set).
 128  *
 129  * Since: 2.4
 130  */
 131 void
 132 (g_atomic_int_set) (volatile gint *atomic,
 133                     gint           newval)
 134 {
 135   g_atomic_int_set (atomic, newval);
 136 }
 137
 138 /**
 139  * g_atomic_int_inc:
 140  * @atomic: a pointer to a #gint or #guint
 141  *
 142  * Increments the value of @atomic by 1.
 143  *
 144  * Think of this operation as an atomic version of
 145  * <literal>{ *@atomic += 1; }</literal>
 146  *
 147  * This call acts as a full compiler and hardware memory barrier.
 148  *
 149  * Since: 2.4
 150  **/
 151 void
 152 (g_atomic_int_inc) (volatile gint *atomic)
 153 {
 154   g_atomic_int_inc (atomic);
 155 }
 156
 157 /**
 158  * g_atomic_int_dec_and_test:
 159  * @atomic: a pointer to a #gint or #guint
 160  *
 161  * Decrements the value of @atomic by 1.
 162  *
 163  * Think of this operation as an atomic version of
 164  * <literal>{ *@atomic -= 1; return (*@atomic == 0); }</literal>
 165  *
 166  * This call acts as a full compiler and hardware memory barrier.
 167  *
 168  * Returns: %TRUE if the resultant value is zero
 169  *
 170  * Since: 2.4
 171  **/
 172 gboolean
 173 (g_atomic_int_dec_and_test) (volatile gint *atomic)
 174 {
 175   return g_atomic_int_dec_and_test (atomic);
 176 }
 177
 178 /**
 179  * g_atomic_int_compare_and_exchange:
 180  * @atomic: a pointer to a #gint or #guint
 181  * @oldval: the value to compare with
 182  * @newval: the value to conditionally replace with
 183  *
 184  * Compares @atomic to @oldval and, if equal, sets it to @newval.
 185  * If @atomic was not equal to @oldval then no change occurs.
 186  *
 187  * This compare and exchange is done atomically.
 188  *
 189  * Think of this operation as an atomic version of
 190  * <literal>{ if (*@atomic == @oldval) { *@atomic = @newval; return TRUE; } else return FALSE; }</literal>
 191  *
 192  * This call acts as a full compiler and hardware memory barrier.
 193  *
 194  * Returns: %TRUE if the exchange took place
 195  *
 196  * Since: 2.4
 197  **/
 198 gboolean
 199 (g_atomic_int_compare_and_exchange) (volatile gint *atomic,
 200                                      gint           oldval,
 201                                      gint           newval)
 202 {
 203   return g_atomic_int_compare_and_exchange (atomic, oldval, newval);
 204 }
 205
 206 /**
 207  * g_atomic_int_add:
 208  * @atomic: a pointer to a #gint or #guint
 209  * @val: the value to add
 210  *
 211  * Atomically adds @val to the value of @atomic.
 212  *
 213  * Think of this operation as an atomic version of
 214  * <literal>{ tmp = *atomic; *@atomic += @val; return tmp; }</literal>
 215  *
 216  * This call acts as a full compiler and hardware memory barrier.
 217  *
 218  * Before version 2.30, this function did not return a value
 219  * (but g_atomic_int_exchange_and_add() did, and had the same meaning).
 220  *
 221  * Returns: the value of @atomic before the add, signed
 222  *
 223  * Since: 2.4
 224  **/
 225 gint
 226 (g_atomic_int_add) (volatile gint *atomic,
 227                     gint           val)
 228 {
 229   return g_atomic_int_add (atomic, val);
 230 }
 231
 232 /**
 233  * g_atomic_int_and:
 234  * @atomic: a pointer to a #gint or #guint
 235  * @val: the value to 'and'
 236  *
 237  * Performs an atomic bitwise 'and' of the value of @atomic and @val,
 238  * storing the result back in @atomic.
 239  *
 240  * This call acts as a full compiler and hardware memory barrier.
 241  *
 242  * Think of this operation as an atomic version of
 243  * <literal>{ tmp = *atomic; *@atomic &= @val; return tmp; }</literal>
 244  *
 245  * Returns: the value of @atomic before the operation, unsigned
 246  *
 247  * Since: 2.30
 248  **/
 249 guint
 250 (g_atomic_int_and) (volatile guint *atomic,
 251                     guint           val)
 252 {
 253   return g_atomic_int_and (atomic, val);
 254 }
 255
 256 /**
 257  * g_atomic_int_or:
 258  * @atomic: a pointer to a #gint or #guint
 259  * @val: the value to 'or'
 260  *
 261  * Performs an atomic bitwise 'or' of the value of @atomic and @val,
 262  * storing the result back in @atomic.
 263  *
 264  * Think of this operation as an atomic version of
 265  * <literal>{ tmp = *atomic; *@atomic |= @val; return tmp; }</literal>
 266  *
 267  * This call acts as a full compiler and hardware memory barrier.
 268  *
 269  * Returns: the value of @atomic before the operation, unsigned
 270  *
 271  * Since: 2.30
 272  **/
 273 guint
 274 (g_atomic_int_or) (volatile guint *atomic,
 275                    guint           val)
 276 {
 277   return g_atomic_int_or (atomic, val);
 278 }
 279
 280 /**
 281  * g_atomic_int_xor:
 282  * @atomic: a pointer to a #gint or #guint
 283  * @val: the value to 'xor'
 284  *
 285  * Performs an atomic bitwise 'xor' of the value of @atomic and @val,
 286  * storing the result back in @atomic.
 287  *
 288  * Think of this operation as an atomic version of
 289  * <literal>{ tmp = *atomic; *@atomic ^= @val; return tmp; }</literal>
 290  *
 291  * This call acts as a full compiler and hardware memory barrier.
 292  *
 293  * Returns: the value of @atomic before the operation, unsigned
 294  *
 295  * Since: 2.30
 296  **/
 297 guint
 298 (g_atomic_int_xor) (volatile guint *atomic,
 299                     guint           val)
 300 {
 301   return g_atomic_int_xor (atomic, val);
 302 }
 303
 304
 305 /**
 306  * g_atomic_pointer_get:
 307  * @atomic: a pointer to a #gpointer-sized value
 308  *
 309  * Gets the current value of @atomic.
 310  *
 311  * This call acts as a full compiler and hardware
 312  * memory barrier (before the get).
 313  *
 314  * Returns: the value of the pointer
 315  *
 316  * Since: 2.4
 317  **/
 318 gpointer
 319 (g_atomic_pointer_get) (const volatile void *atomic)
 320 {
 321   return g_atomic_pointer_get ((const volatile gpointer *) atomic);
 322 }
 323
 324 /**
 325  * g_atomic_pointer_set:
 326  * @atomic: a pointer to a #gpointer-sized value
 327  * @newval: a new value to store
 328  *
 329  * Sets the value of @atomic to @newval.
 330  *
 331  * This call acts as a full compiler and hardware
 332  * memory barrier (after the set).
 333  *
 334  * Since: 2.4
 335  **/
 336 void
 337 (g_atomic_pointer_set) (volatile void *atomic,
 338                         gpointer       newval)
 339 {
 340   g_atomic_pointer_set ((volatile gpointer *) atomic, newval);
 341 }
 342
 343 /**
 344  * g_atomic_pointer_compare_and_exchange:
 345  * @atomic: a pointer to a #gpointer-sized value
 346  * @oldval: the value to compare with
 347  * @newval: the value to conditionally replace with
 348  *
 349  * Compares @atomic to @oldval and, if equal, sets it to @newval.
 350  * If @atomic was not equal to @oldval then no change occurs.
 351  *
 352  * This compare and exchange is done atomically.
 353  *
 354  * Think of this operation as an atomic version of
 355  * <literal>{ if (*@atomic == @oldval) { *@atomic = @newval; return TRUE; } else return FALSE; }</literal>
 356  *
 357  * This call acts as a full compiler and hardware memory barrier.
 358  *
 359  * Returns: %TRUE if the exchange took place
 360  *
 361  * Since: 2.4
 362  **/
 363 gboolean
 364 (g_atomic_pointer_compare_and_exchange) (volatile void *atomic,
 365                                          gpointer       oldval,
 366                                          gpointer       newval)
 367 {
 368   return g_atomic_pointer_compare_and_exchange ((volatile gpointer *) atomic,
 369                                                 oldval, newval);
 370 }
 371
 372 /**
 373  * g_atomic_pointer_add:
 374  * @atomic: a pointer to a #gpointer-sized value
 375  * @val: the value to add
 376  *
 377  * Atomically adds @val to the value of @atomic.
 378  *
 379  * Think of this operation as an atomic version of
 380  * <literal>{ tmp = *atomic; *@atomic += @val; return tmp; }</literal>
 381  *
 382  * This call acts as a full compiler and hardware memory barrier.
 383  *
 384  * Returns: the value of @atomic before the add, signed
 385  *
 386  * Since: 2.30
 387  **/
 388 gssize
 389 (g_atomic_pointer_add) (volatile void *atomic,
 390                         gssize         val)
 391 {
 392   return g_atomic_pointer_add ((volatile gpointer *) atomic, val);
 393 }
 394
 395 /**
 396  * g_atomic_pointer_and:
 397  * @atomic: a pointer to a #gpointer-sized value
 398  * @val: the value to 'and'
 399  *
 400  * Performs an atomic bitwise 'and' of the value of @atomic and @val,
 401  * storing the result back in @atomic.
 402  *
 403  * Think of this operation as an atomic version of
 404  * <literal>{ tmp = *atomic; *@atomic &= @val; return tmp; }</literal>
 405  *
 406  * This call acts as a full compiler and hardware memory barrier.
 407  *
 408  * Returns: the value of @atomic before the operation, unsigned
 409  *
 410  * Since: 2.30
 411  **/
 412 gsize
 413 (g_atomic_pointer_and) (volatile void *atomic,
 414                         gsize          val)
 415 {
 416   return g_atomic_pointer_and ((volatile gpointer *) atomic, val);
 417 }
 418
 419 /**
 420  * g_atomic_pointer_or:
 421  * @atomic: a pointer to a #gpointer-sized value
 422  * @val: the value to 'or'
 423  *
 424  * Performs an atomic bitwise 'or' of the value of @atomic and @val,
 425  * storing the result back in @atomic.
 426  *
 427  * Think of this operation as an atomic version of
 428  * <literal>{ tmp = *atomic; *@atomic |= @val; return tmp; }</literal>
 429  *
 430  * This call acts as a full compiler and hardware memory barrier.
 431  *
 432  * Returns: the value of @atomic before the operation, unsigned
 433  *
 434  * Since: 2.30
 435  **/
 436 gsize
 437 (g_atomic_pointer_or) (volatile void *atomic,
 438                        gsize          val)
 439 {
 440   return g_atomic_pointer_or ((volatile gpointer *) atomic, val);
 441 }
 442
 443 /**
 444  * g_atomic_pointer_xor:
 445  * @atomic: a pointer to a #gpointer-sized value
 446  * @val: the value to 'xor'
 447  *
 448  * Performs an atomic bitwise 'xor' of the value of @atomic and @val,
 449  * storing the result back in @atomic.
 450  *
 451  * Think of this operation as an atomic version of
 452  * <literal>{ tmp = *atomic; *@atomic ^= @val; return tmp; }</literal>
 453  *
 454  * This call acts as a full compiler and hardware memory barrier.
 455  *
 456  * Returns: the value of @atomic before the operation, unsigned
 457  *
 458  * Since: 2.30
 459  **/
 460 gsize
 461 (g_atomic_pointer_xor) (volatile void *atomic,
 462                         gsize          val)
 463 {
 464   return g_atomic_pointer_xor ((volatile gpointer *) atomic, val);
 465 }
 466
 467 #elif defined (G_PLATFORM_WIN32)
 468
 469 #include <windows.h>
 470 #if !defined(_M_AMD64) && !defined (_M_IA64) && !defined(_M_X64) && !(defined _MSC_VER && _MSC_VER <= 1200)
 471 #define InterlockedAnd _InterlockedAnd
 472 #define InterlockedOr _InterlockedOr
 473 #define InterlockedXor _InterlockedXor
 474 #endif
 475
 476 #if !defined (_MSC_VER) || _MSC_VER <= 1200
 477 #include "gmessages.h"
 478 /* Inlined versions for older compiler */
 479 static LONG
 480 _gInterlockedAnd (volatile guint *atomic,
 481                   guint           val)
 482 {
 483   LONG i, j;
 484
 485   j = *atomic;
 486   do {
 487     i = j;
 488     j = InterlockedCompareExchange(atomic, i & val, i);
 489   } while (i != j);
 490
 491   return j;
 492 }
 493 #define InterlockedAnd(a,b) _gInterlockedAnd(a,b)
 494 static LONG
 495 _gInterlockedOr (volatile guint *atomic,
 496                  guint           val)
 497 {
 498   LONG i, j;
 499
 500   j = *atomic;
 501   do {
 502     i = j;
 503     j = InterlockedCompareExchange(atomic, i | val, i);
 504   } while (i != j);
 505
 506   return j;
 507 }
 508 #define InterlockedOr(a,b) _gInterlockedOr(a,b)
 509 static LONG
 510 _gInterlockedXor (volatile guint *atomic,
 511                   guint           val)
 512 {
 513   LONG i, j;
 514
 515   j = *atomic;
 516   do {
 517     i = j;
 518     j = InterlockedCompareExchange(atomic, i ^ val, i);
 519   } while (i != j);
 520
 521   return j;
 522 }
 523 #define InterlockedXor(a,b) _gInterlockedXor(a,b)
 524 #endif
 525
 526 /*
 527  * http://msdn.microsoft.com/en-us/library/ms684122(v=vs.85).aspx
 528  */
 529 gint
 530 (g_atomic_int_get) (const volatile gint *atomic)
 531 {
 532   MemoryBarrier ();
 533   return *atomic;
 534 }
 535
 536 void
 537 (g_atomic_int_set) (volatile gint *atomic,
 538                     gint           newval)
 539 {
 540   *atomic = newval;
 541   MemoryBarrier ();
 542 }
 543
 544 void
 545 (g_atomic_int_inc) (volatile gint *atomic)
 546 {
 547   InterlockedIncrement (atomic);
 548 }
 549
 550 gboolean
 551 (g_atomic_int_dec_and_test) (volatile gint *atomic)
 552 {
 553   return InterlockedDecrement (atomic) == 0;
 554 }
 555
 556 gboolean
 557 (g_atomic_int_compare_and_exchange) (volatile gint *atomic,
 558                                      gint           oldval,
 559                                      gint           newval)
 560 {
 561   return InterlockedCompareExchange (atomic, newval, oldval) == oldval;
 562 }
 563
 564 gint
 565 (g_atomic_int_add) (volatile gint *atomic,
 566                     gint           val)
 567 {
 568   return InterlockedExchangeAdd (atomic, val);
 569 }
 570
 571 guint
 572 (g_atomic_int_and) (volatile guint *atomic,
 573                     guint           val)
 574 {
 575   return InterlockedAnd (atomic, val);
 576 }
 577
 578 guint
 579 (g_atomic_int_or) (volatile guint *atomic,
 580                    guint           val)
 581 {
 582   return InterlockedOr (atomic, val);
 583 }
 584
 585 guint
 586 (g_atomic_int_xor) (volatile guint *atomic,
 587                     guint           val)
 588 {
 589   return InterlockedXor (atomic, val);
 590 }
 591
 592
 593 gpointer
 594 (g_atomic_pointer_get) (const volatile void *atomic)
 595 {
 596   const volatile gpointer *ptr = atomic;
 597
 598   MemoryBarrier ();
 599   return *ptr;
 600 }
 601
 602 void
 603 (g_atomic_pointer_set) (volatile void *atomic,
 604                         gpointer       newval)
 605 {
 606   volatile gpointer *ptr = atomic;
 607
 608   *ptr = newval;
 609   MemoryBarrier ();
 610 }
 611
 612 gboolean
 613 (g_atomic_pointer_compare_and_exchange) (volatile void *atomic,
 614                                          gpointer       oldval,
 615                                          gpointer       newval)
 616 {
 617   return InterlockedCompareExchangePointer (atomic, newval, oldval) == oldval;
 618 }
 619
 620 gssize
 621 (g_atomic_pointer_add) (volatile void *atomic,
 622                         gssize         val)
 623 {
 624 #if GLIB_SIZEOF_VOID_P == 8
 625   return InterlockedExchangeAdd64 (atomic, val);
 626 #else
 627   return InterlockedExchangeAdd (atomic, val);
 628 #endif
 629 }
 630
 631 gsize
 632 (g_atomic_pointer_and) (volatile void *atomic,
 633                         gsize          val)
 634 {
 635 #if GLIB_SIZEOF_VOID_P == 8
 636   return InterlockedAnd64 (atomic, val);
 637 #else
 638   return InterlockedAnd (atomic, val);
 639 #endif
 640 }
 641
 642 gsize
 643 (g_atomic_pointer_or) (volatile void *atomic,
 644                        gsize          val)
 645 {
 646 #if GLIB_SIZEOF_VOID_P == 8
 647   return InterlockedOr64 (atomic, val);
 648 #else
 649   return InterlockedOr (atomic, val);
 650 #endif
 651 }
 652
 653 gsize
 654 (g_atomic_pointer_xor) (volatile void *atomic,
 655                         gsize          val)
 656 {
 657 #if GLIB_SIZEOF_VOID_P == 8
 658   return InterlockedXor64 (atomic, val);
 659 #else
 660   return InterlockedXor (atomic, val);
 661 #endif
 662 }
 663 #else
 664
 665 /* This error occurs when ./configure decided that we should be capable
 666  * of lock-free atomics but we find at compile-time that we are not.
 667  */
 668 #error G_ATOMIC_LOCK_FREE defined, but incapable of lock-free atomics.
 669
 670 #endif /* defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) */
 671
 672 #else /* G_ATOMIC_LOCK_FREE */
 673
 674 /* We are not permitted to call into any GLib functions from here, so we
 675  * can not use GMutex.
 676  *
 677  * Fortunately, we already take care of the Windows case above, and all
 678  * non-Windows platforms on which glib runs have pthreads.  Use those.
 679  */
 680 #include <pthread.h>
 681
 682 static pthread_mutex_t g_atomic_lock = PTHREAD_MUTEX_INITIALIZER;
 683
 684 gint
 685 (g_atomic_int_get) (volatile gint *atomic)
 686 {
 687   gint value;
 688
 689   pthread_mutex_lock (&g_atomic_lock);
 690   value = *atomic;
 691   pthread_mutex_unlock (&g_atomic_lock);
 692
 693   return value;
 694 }
 695
 696 void
 697 (g_atomic_int_set) (volatile gint *atomic,
 698                     gint           value)
 699 {
 700   pthread_mutex_lock (&g_atomic_lock);
 701   *atomic = value;
 702   pthread_mutex_unlock (&g_atomic_lock);
 703 }
 704
 705 void
 706 (g_atomic_int_inc) (volatile gint *atomic)
 707 {
 708   pthread_mutex_lock (&g_atomic_lock);
 709   (*atomic)++;
 710   pthread_mutex_unlock (&g_atomic_lock);
 711 }
 712
 713 gboolean
 714 (g_atomic_int_dec_and_test) (volatile gint *atomic)
 715 {
 716   gboolean is_zero;
 717
 718   pthread_mutex_lock (&g_atomic_lock);
 719   is_zero = --(*atomic) == 0;
 720   pthread_mutex_unlock (&g_atomic_lock);
 721
 722   return is_zero;
 723 }
 724
 725 gboolean
 726 (g_atomic_int_compare_and_exchange) (volatile gint *atomic,
 727                                      gint           oldval,
 728                                      gint           newval)
 729 {
 730   gboolean success;
 731
 732   pthread_mutex_lock (&g_atomic_lock);
 733
 734   if ((success = (*atomic == oldval)))
 735     *atomic = newval;
 736
 737   pthread_mutex_unlock (&g_atomic_lock);
 738
 739   return success;
 740 }
 741
 742 gint
 743 (g_atomic_int_add) (volatile gint *atomic,
 744                     gint           val)
 745 {
 746   gint oldval;
 747
 748   pthread_mutex_lock (&g_atomic_lock);
 749   oldval = *atomic;
 750   *atomic = oldval + val;
 751   pthread_mutex_unlock (&g_atomic_lock);
 752
 753   return oldval;
 754 }
 755
 756 guint
 757 (g_atomic_int_and) (volatile guint *atomic,
 758                     guint           val)
 759 {
 760   guint oldval;
 761
 762   pthread_mutex_lock (&g_atomic_lock);
 763   oldval = *atomic;
 764   *atomic = oldval & val;
 765   pthread_mutex_unlock (&g_atomic_lock);
 766
 767   return oldval;
 768 }
 769
 770 guint
 771 (g_atomic_int_or) (volatile guint *atomic,
 772                    guint           val)
 773 {
 774   guint oldval;
 775
 776   pthread_mutex_lock (&g_atomic_lock);
 777   oldval = *atomic;
 778   *atomic = oldval | val;
 779   pthread_mutex_unlock (&g_atomic_lock);
 780
 781   return oldval;
 782 }
 783
 784 guint
 785 (g_atomic_int_xor) (volatile guint *atomic,
 786                     guint           val)
 787 {
 788   guint oldval;
 789
 790   pthread_mutex_lock (&g_atomic_lock);
 791   oldval = *atomic;
 792   *atomic = oldval ^ val;
 793   pthread_mutex_unlock (&g_atomic_lock);
 794
 795   return oldval;
 796 }
 797
 798
 799 gpointer
 800 (g_atomic_pointer_get) (volatile void *atomic)
 801 {
 802   volatile gpointer *ptr = atomic;
 803   gpointer value;
 804
 805   pthread_mutex_lock (&g_atomic_lock);
 806   value = *ptr;
 807   pthread_mutex_unlock (&g_atomic_lock);
 808
 809   return value;
 810 }
 811
 812 void
 813 (g_atomic_pointer_set) (volatile void *atomic,
 814                         gpointer       newval)
 815 {
 816   volatile gpointer *ptr = atomic;
 817
 818   pthread_mutex_lock (&g_atomic_lock);
 819   *ptr = newval;
 820   pthread_mutex_unlock (&g_atomic_lock);
 821 }
 822
 823 gboolean
 824 (g_atomic_pointer_compare_and_exchange) (volatile void *atomic,
 825                                          gpointer       oldval,
 826                                          gpointer       newval)
 827 {
 828   volatile gpointer *ptr = atomic;
 829   gboolean success;
 830
 831   pthread_mutex_lock (&g_atomic_lock);
 832
 833   if ((success = (*ptr == oldval)))
 834     *ptr = newval;
 835
 836   pthread_mutex_unlock (&g_atomic_lock);
 837
 838   return success;
 839 }
 840
 841 gssize
 842 (g_atomic_pointer_add) (volatile void *atomic,
 843                         gssize         val)
 844 {
 845   volatile gssize *ptr = atomic;
 846   gssize oldval;
 847
 848   pthread_mutex_lock (&g_atomic_lock);
 849   oldval = *ptr;
 850   *ptr = oldval + val;
 851   pthread_mutex_unlock (&g_atomic_lock);
 852
 853   return oldval;
 854 }
 855
 856 gsize
 857 (g_atomic_pointer_and) (volatile void *atomic,
 858                         gsize          val)
 859 {
 860   volatile gsize *ptr = atomic;
 861   gsize oldval;
 862
 863   pthread_mutex_lock (&g_atomic_lock);
 864   oldval = *ptr;
 865   *ptr = oldval & val;
 866   pthread_mutex_unlock (&g_atomic_lock);
 867
 868   return oldval;
 869 }
 870
 871 gsize
 872 (g_atomic_pointer_or) (volatile void *atomic,
 873                        gsize          val)
 874 {
 875   volatile gsize *ptr = atomic;
 876   gsize oldval;
 877
 878   pthread_mutex_lock (&g_atomic_lock);
 879   oldval = *ptr;
 880   *ptr = oldval | val;
 881   pthread_mutex_unlock (&g_atomic_lock);
 882
 883   return oldval;
 884 }
 885
 886 gsize
 887 (g_atomic_pointer_xor) (volatile void *atomic,
 888                         gsize          val)
 889 {
 890   volatile gsize *ptr = atomic;
 891   gsize oldval;
 892
 893   pthread_mutex_lock (&g_atomic_lock);
 894   oldval = *ptr;
 895   *ptr = oldval ^ val;
 896   pthread_mutex_unlock (&g_atomic_lock);
 897
 898   return oldval;
 899 }
 900
 901 #endif
 902
 903 /**
 904  * g_atomic_int_exchange_and_add:
 905  * @atomic: a pointer to a #gint
 906  * @val: the value to add
 907  *
 908  * This function existed before g_atomic_int_add() returned the prior
 909  * value of the integer (which it now does).  It is retained only for
 910  * compatibility reasons.  Don't use this function in new code.
 911  *
 912  * Returns: the value of @atomic before the add, signed
 913  * Since: 2.4
 914  * Deprecated: 2.30: Use g_atomic_int_add() instead.
 915  **/
 916 gint
 917 g_atomic_int_exchange_and_add (volatile gint *atomic,
 918                                gint           val)
 919 {
 920   return (g_atomic_int_add) (atomic, val);
 921 }