sdl-ios-xcode: src/thread/generic/SDL

annotate src/thread/generic/SDL_syscond.c @ 3181:030899df1af5

OK, had to add some casts to get SDL_atomic.h to compile with C++. testatomic still compiles and runs.

author	Bob Pendleton <bob@pendleton.com>
date	Tue, 09 Jun 2009 19:39:23 +0000
parents	99210400e8b9
children	f7b03b6838cb

rev	line source
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	1 /*
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	2 SDL - Simple DirectMedia Layer
2859 99210400e8b9 Updated copyright date Sam Lantinga <slouken@libsdl.org> parents: 1895 diff changeset	3 Copyright (C) 1997-2009 Sam Lantinga
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	4
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	5 This library is free software; you can redistribute it and/or
1312 c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges) Sam Lantinga <slouken@libsdl.org> parents: 769 diff changeset	6 modify it under the terms of the GNU Lesser General Public
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	7 License as published by the Free Software Foundation; either
1312 c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges) Sam Lantinga <slouken@libsdl.org> parents: 769 diff changeset	8 version 2.1 of the License, or (at your option) any later version.
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	9
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	10 This library is distributed in the hope that it will be useful,
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	11 but WITHOUT ANY WARRANTY; without even the implied warranty of
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
1312 c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges) Sam Lantinga <slouken@libsdl.org> parents: 769 diff changeset	13 Lesser General Public License for more details.
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	14
1312 c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges) Sam Lantinga <slouken@libsdl.org> parents: 769 diff changeset	15 You should have received a copy of the GNU Lesser General Public
c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges) Sam Lantinga <slouken@libsdl.org> parents: 769 diff changeset	16 License along with this library; if not, write to the Free Software
c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges) Sam Lantinga <slouken@libsdl.org> parents: 769 diff changeset	17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	18
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	19 Sam Lantinga
252 e8157fcb3114 Updated the source with the correct e-mail address Sam Lantinga <slouken@libsdl.org> parents: 0 diff changeset	20 slouken@libsdl.org
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	21 */
1402 d910939febfa Use consistent identifiers for the various platforms we support. Sam Lantinga <slouken@libsdl.org> parents: 1358 diff changeset	22 #include "SDL_config.h"
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	23
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	24 /* An implementation of condition variables using semaphores and mutexes */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	25 /*
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	26 This implementation borrows heavily from the BeOS condition variable
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	27 implementation, written by Christopher Tate and Owen Smith. Thanks!
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	28 */
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	29
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	30 #include "SDL_thread.h"
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	31
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	32 struct SDL_cond
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	33 {
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	34 SDL_mutex *lock;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	35 int waiting;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	36 int signals;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	37 SDL_sem *wait_sem;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	38 SDL_sem *wait_done;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	39 };
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	40
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	41 /* Create a condition variable */
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	42 SDL_cond *
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	43 SDL_CreateCond(void)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	44 {
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	45 SDL_cond *cond;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	46
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	47 cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond));
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	48 if (cond) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	49 cond->lock = SDL_CreateMutex();
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	50 cond->wait_sem = SDL_CreateSemaphore(0);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	51 cond->wait_done = SDL_CreateSemaphore(0);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	52 cond->waiting = cond->signals = 0;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	53 if (!cond->lock \|\| !cond->wait_sem \|\| !cond->wait_done) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	54 SDL_DestroyCond(cond);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	55 cond = NULL;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	56 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	57 } else {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	58 SDL_OutOfMemory();
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	59 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	60 return (cond);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	61 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	62
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	63 /* Destroy a condition variable */
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	64 void
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	65 SDL_DestroyCond(SDL_cond * cond)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	66 {
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	67 if (cond) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	68 if (cond->wait_sem) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	69 SDL_DestroySemaphore(cond->wait_sem);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	70 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	71 if (cond->wait_done) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	72 SDL_DestroySemaphore(cond->wait_done);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	73 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	74 if (cond->lock) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	75 SDL_DestroyMutex(cond->lock);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	76 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	77 SDL_free(cond);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	78 }
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	79 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	80
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	81 /* Restart one of the threads that are waiting on the condition variable */
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	82 int
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	83 SDL_CondSignal(SDL_cond * cond)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	84 {
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	85 if (!cond) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	86 SDL_SetError("Passed a NULL condition variable");
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	87 return -1;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	88 }
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	89
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	90 /* If there are waiting threads not already signalled, then
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	91 signal the condition and wait for the thread to respond.
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	92 */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	93 SDL_LockMutex(cond->lock);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	94 if (cond->waiting > cond->signals) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	95 ++cond->signals;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	96 SDL_SemPost(cond->wait_sem);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	97 SDL_UnlockMutex(cond->lock);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	98 SDL_SemWait(cond->wait_done);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	99 } else {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	100 SDL_UnlockMutex(cond->lock);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	101 }
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	102
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	103 return 0;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	104 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	105
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	106 /* Restart all threads that are waiting on the condition variable */
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	107 int
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	108 SDL_CondBroadcast(SDL_cond * cond)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	109 {
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	110 if (!cond) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	111 SDL_SetError("Passed a NULL condition variable");
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	112 return -1;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	113 }
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	114
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	115 /* If there are waiting threads not already signalled, then
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	116 signal the condition and wait for the thread to respond.
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	117 */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	118 SDL_LockMutex(cond->lock);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	119 if (cond->waiting > cond->signals) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	120 int i, num_waiting;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	121
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	122 num_waiting = (cond->waiting - cond->signals);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	123 cond->signals = cond->waiting;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	124 for (i = 0; i < num_waiting; ++i) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	125 SDL_SemPost(cond->wait_sem);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	126 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	127 /* Now all released threads are blocked here, waiting for us.
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	128 Collect them all (and win fabulous prizes!) :-)
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	129 */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	130 SDL_UnlockMutex(cond->lock);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	131 for (i = 0; i < num_waiting; ++i) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	132 SDL_SemWait(cond->wait_done);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	133 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	134 } else {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	135 SDL_UnlockMutex(cond->lock);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	136 }
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	137
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	138 return 0;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	139 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	140
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	141 /* Wait on the condition variable for at most 'ms' milliseconds.
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	142 The mutex must be locked before entering this function!
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	143 The mutex is unlocked during the wait, and locked again after the wait.
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	144
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	145 Typical use:
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	146
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	147 Thread A:
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	148 SDL_LockMutex(lock);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	149 while ( ! condition ) {
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	150 SDL_CondWait(cond);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	151 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	152 SDL_UnlockMutex(lock);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	153
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	154 Thread B:
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	155 SDL_LockMutex(lock);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	156 ...
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	157 condition = true;
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	158 ...
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	159 SDL_UnlockMutex(lock);
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	160 */
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	161 int
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	162 SDL_CondWaitTimeout(SDL_cond * cond, SDL_mutex * mutex, Uint32 ms)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	163 {
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	164 int retval;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	165
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	166 if (!cond) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	167 SDL_SetError("Passed a NULL condition variable");
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	168 return -1;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	169 }
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	170
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	171 /* Obtain the protection mutex, and increment the number of waiters.
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	172 This allows the signal mechanism to only perform a signal if there
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	173 are waiting threads.
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	174 */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	175 SDL_LockMutex(cond->lock);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	176 ++cond->waiting;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	177 SDL_UnlockMutex(cond->lock);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	178
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	179 /* Unlock the mutex, as is required by condition variable semantics */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	180 SDL_UnlockMutex(mutex);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	181
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	182 /* Wait for a signal */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	183 if (ms == SDL_MUTEX_MAXWAIT) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	184 retval = SDL_SemWait(cond->wait_sem);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	185 } else {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	186 retval = SDL_SemWaitTimeout(cond->wait_sem, ms);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	187 }
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	188
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	189 /* Let the signaler know we have completed the wait, otherwise
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	190 the signaler can race ahead and get the condition semaphore
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	191 if we are stopped between the mutex unlock and semaphore wait,
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	192 giving a deadlock. See the following URL for details:
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	193 http://www-classic.be.com/aboutbe/benewsletter/volume_III/Issue40.html
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	194 */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	195 SDL_LockMutex(cond->lock);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	196 if (cond->signals > 0) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	197 /* If we timed out, we need to eat a condition signal */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	198 if (retval > 0) {
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	199 SDL_SemWait(cond->wait_sem);
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	200 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	201 /* We always notify the signal thread that we are done */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	202 SDL_SemPost(cond->wait_done);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	203
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	204 /* Signal handshake complete */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	205 --cond->signals;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	206 }
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	207 --cond->waiting;
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	208 SDL_UnlockMutex(cond->lock);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	209
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	210 /* Lock the mutex, as is required by condition variable semantics */
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	211 SDL_LockMutex(mutex);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	212
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	213 return retval;
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	214 }
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	215
74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	216 /* Wait on the condition variable forever */
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	217 int
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	218 SDL_CondWait(SDL_cond * cond, SDL_mutex * mutex)
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	219 {
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	220 return SDL_CondWaitTimeout(cond, mutex, SDL_MUTEX_MAXWAIT);
0 74212992fb08 Initial revision Sam Lantinga <slouken@lokigames.com> parents: diff changeset	221 }
1895 c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	222
c121d94672cb SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head. Sam Lantinga <slouken@libsdl.org> parents: 1402 diff changeset	223 /* vi: set ts=4 sw=4 expandtab: */

Mercurial > sdl-ios-xcode

annotate src/thread/generic/SDL_syscond.c @ 3181:030899df1af5