Mercurial > sdl-ios-xcode
annotate src/thread/generic/SDL_sysmutex.c @ 1240:3b8a43c428bb
From Bug #36:
There are a couple of issues with the selection of Altivec alpha-blitting
routines in CalculateAlphaBlit() in src/video/SDL_Blit_A.c.
1) There's no check for the presence of Altivec when checking if the
Blit32to565PixelAlphaAltivec() routine can be selected.
2) Altivec cannot be used in video memory, and there's no check if the
destination surface is a hardware surface. (Alpha-blitting to a hardware
surface with GPU support is a bad idea, but somebody's bound to do it anyway.)
Patch to fix these attached.
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Sun, 08 Jan 2006 21:18:15 +0000 |
| parents | b8d311d90021 |
| children | c9b51268668f |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
769
b8d311d90021
Updated copyright information for 2004 (Happy New Year!)
Sam Lantinga <slouken@libsdl.org>
parents:
297
diff
changeset
|
3 Copyright (C) 1997-2004 Sam Lantinga |
| 0 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
| 6 modify it under the terms of the GNU Library General Public | |
| 7 License as published by the Free Software Foundation; either | |
| 8 version 2 of the License, or (at your option) any later version. | |
| 9 | |
| 10 This library is distributed in the hope that it will be useful, | |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 Library General Public License for more details. | |
| 14 | |
| 15 You should have received a copy of the GNU Library General Public | |
| 16 License along with this library; if not, write to the Free | |
| 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | |
| 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 | 21 */ |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 /* An implementation of mutexes using semaphores */ | |
| 29 | |
| 30 #include <stdio.h> | |
| 31 #include <stdlib.h> | |
| 32 | |
| 33 #include "SDL_error.h" | |
| 34 #include "SDL_thread.h" | |
| 35 #include "SDL_systhread_c.h" | |
| 36 | |
| 37 | |
| 38 struct SDL_mutex { | |
| 39 int recursive; | |
| 40 Uint32 owner; | |
| 41 SDL_sem *sem; | |
| 42 }; | |
| 43 | |
| 44 /* Create a mutex */ | |
| 45 SDL_mutex *SDL_CreateMutex(void) | |
| 46 { | |
| 47 SDL_mutex *mutex; | |
| 48 | |
| 49 /* Allocate mutex memory */ | |
| 50 mutex = (SDL_mutex *)malloc(sizeof(*mutex)); | |
| 51 if ( mutex ) { | |
| 52 /* Create the mutex semaphore, with initial value 1 */ | |
| 53 mutex->sem = SDL_CreateSemaphore(1); | |
| 54 mutex->recursive = 0; | |
| 55 mutex->owner = 0; | |
| 56 if ( ! mutex->sem ) { | |
| 57 free(mutex); | |
| 58 mutex = NULL; | |
| 59 } | |
| 60 } else { | |
| 61 SDL_OutOfMemory(); | |
| 62 } | |
| 63 return mutex; | |
| 64 } | |
| 65 | |
| 66 /* Free the mutex */ | |
| 67 void SDL_DestroyMutex(SDL_mutex *mutex) | |
| 68 { | |
| 69 if ( mutex ) { | |
| 70 if ( mutex->sem ) { | |
| 71 SDL_DestroySemaphore(mutex->sem); | |
| 72 } | |
| 73 free(mutex); | |
| 74 } | |
| 75 } | |
| 76 | |
| 77 /* Lock the semaphore */ | |
| 78 int SDL_mutexP(SDL_mutex *mutex) | |
| 79 { | |
| 80 #ifdef DISABLE_THREADS | |
| 81 return 0; | |
| 82 #else | |
| 83 Uint32 this_thread; | |
| 84 | |
| 85 if ( mutex == NULL ) { | |
| 86 SDL_SetError("Passed a NULL mutex"); | |
| 87 return -1; | |
| 88 } | |
| 89 | |
| 90 this_thread = SDL_ThreadID(); | |
| 91 if ( mutex->owner == this_thread ) { | |
| 92 ++mutex->recursive; | |
| 93 } else { | |
| 94 /* The order of operations is important. | |
| 95 We set the locking thread id after we obtain the lock | |
| 96 so unlocks from other threads will fail. | |
| 97 */ | |
| 98 SDL_SemWait(mutex->sem); | |
| 99 mutex->owner = this_thread; | |
| 100 mutex->recursive = 0; | |
| 101 } | |
| 102 | |
| 103 return 0; | |
| 104 #endif /* DISABLE_THREADS */ | |
| 105 } | |
| 106 | |
| 107 /* Unlock the mutex */ | |
| 108 int SDL_mutexV(SDL_mutex *mutex) | |
| 109 { | |
| 110 #ifdef DISABLE_THREADS | |
| 111 return 0; | |
| 112 #else | |
| 113 if ( mutex == NULL ) { | |
| 114 SDL_SetError("Passed a NULL mutex"); | |
| 115 return -1; | |
| 116 } | |
| 117 | |
| 118 /* If we don't own the mutex, we can't unlock it */ | |
| 119 if ( SDL_ThreadID() != mutex->owner ) { | |
| 120 SDL_SetError("mutex not owned by this thread"); | |
| 121 return -1; | |
| 122 } | |
| 123 | |
| 124 if ( mutex->recursive ) { | |
| 125 --mutex->recursive; | |
| 126 } else { | |
| 127 /* The order of operations is important. | |
| 128 First reset the owner so another thread doesn't lock | |
| 129 the mutex and set the ownership before we reset it, | |
| 130 then release the lock semaphore. | |
| 131 */ | |
| 132 mutex->owner = 0; | |
| 133 SDL_SemPost(mutex->sem); | |
| 134 } | |
| 135 return 0; | |
| 136 #endif /* DISABLE_THREADS */ | |
| 137 } |