Mercurial > sdl-ios-xcode
annotate src/thread/generic/SDL_syssem.c @ 1258:b2283b0ded26
Date: Thu, 19 Jan 2006 20:02:29 +0200
From: Vassilis Virvilis <vasvir@iit.demokritos.gr>
Subject: [SDL] Request: Please reconsider adding tag in SDL_Event
Hi,
Patch in question:
--- include/SDL_events.h 20 Aug 2004 18:57:01 -0000 1.11
+++ include/SDL_events.h 19 Jan 2006 17:35:09 -0000
@@ -214,7 +214,7 @@
} SDL_SysWMEvent;
/* General event structure */
-typedef union {
+typedef union SDL_Event {
Uint8 type;
SDL_ActiveEvent active;
SDL_KeyboardEvent key;
Reasoning:
----------
1) Allows forward declaration of the SDL_Event union in C++. Please
note that in plain C it is possible to forward declare it.
2) Forward declaration is good because it allows encapsulation. It hides
the specific implementation and does not necessarily exposes SDL staff
to my appication's namespace
3) It can't harm plain C because tags are living in a different namespace
than typenames
4) It is already done like this in other places in SDL. Check for example
SDL_KeySym, and SDL_.*Event structures.
5) Right now I have to include SDL/event.h from a C++ header file. See 2)
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 20 Jan 2006 13:07:25 +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 semaphores using mutexes and condition variables */ | |
| 29 | |
| 30 #include <stdlib.h> | |
| 31 | |
| 32 #include "SDL_error.h" | |
| 33 #include "SDL_timer.h" | |
| 34 #include "SDL_thread.h" | |
| 35 #include "SDL_systhread_c.h" | |
| 36 | |
| 37 | |
| 38 #ifdef DISABLE_THREADS | |
| 39 | |
| 40 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 41 { | |
| 42 SDL_SetError("SDL not configured with thread support"); | |
| 43 return (SDL_sem *)0; | |
| 44 } | |
| 45 | |
| 46 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 47 { | |
| 48 return; | |
| 49 } | |
| 50 | |
| 51 int SDL_SemTryWait(SDL_sem *sem) | |
| 52 { | |
| 53 SDL_SetError("SDL not configured with thread support"); | |
| 54 return -1; | |
| 55 } | |
| 56 | |
| 57 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 58 { | |
| 59 SDL_SetError("SDL not configured with thread support"); | |
| 60 return -1; | |
| 61 } | |
| 62 | |
| 63 int SDL_SemWait(SDL_sem *sem) | |
| 64 { | |
| 65 SDL_SetError("SDL not configured with thread support"); | |
| 66 return -1; | |
| 67 } | |
| 68 | |
| 69 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 70 { | |
| 71 return 0; | |
| 72 } | |
| 73 | |
| 74 int SDL_SemPost(SDL_sem *sem) | |
| 75 { | |
| 76 SDL_SetError("SDL not configured with thread support"); | |
| 77 return -1; | |
| 78 } | |
| 79 | |
| 80 #else | |
| 81 | |
| 82 struct SDL_semaphore | |
| 83 { | |
| 84 Uint32 count; | |
| 85 Uint32 waiters_count; | |
| 86 SDL_mutex *count_lock; | |
| 87 SDL_cond *count_nonzero; | |
| 88 }; | |
| 89 | |
| 90 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value) | |
| 91 { | |
| 92 SDL_sem *sem; | |
| 93 | |
| 94 sem = (SDL_sem *)malloc(sizeof(*sem)); | |
| 95 if ( ! sem ) { | |
| 96 SDL_OutOfMemory(); | |
| 97 return(0); | |
| 98 } | |
| 99 sem->count = initial_value; | |
| 100 sem->waiters_count = 0; | |
| 101 | |
| 102 sem->count_lock = SDL_CreateMutex(); | |
| 103 sem->count_nonzero = SDL_CreateCond(); | |
| 104 if ( ! sem->count_lock || ! sem->count_nonzero ) { | |
| 105 SDL_DestroySemaphore(sem); | |
| 106 return(0); | |
| 107 } | |
| 108 | |
| 109 return(sem); | |
| 110 } | |
| 111 | |
| 112 /* WARNING: | |
| 113 You cannot call this function when another thread is using the semaphore. | |
| 114 */ | |
| 115 void SDL_DestroySemaphore(SDL_sem *sem) | |
| 116 { | |
| 117 if ( sem ) { | |
| 118 sem->count = 0xFFFFFFFF; | |
| 119 while ( sem->waiters_count > 0) { | |
| 120 SDL_CondSignal(sem->count_nonzero); | |
| 121 SDL_Delay(10); | |
| 122 } | |
| 123 SDL_DestroyCond(sem->count_nonzero); | |
| 124 SDL_mutexP(sem->count_lock); | |
| 125 SDL_mutexV(sem->count_lock); | |
| 126 SDL_DestroyMutex(sem->count_lock); | |
| 127 free(sem); | |
| 128 } | |
| 129 } | |
| 130 | |
| 131 int SDL_SemTryWait(SDL_sem *sem) | |
| 132 { | |
| 133 int retval; | |
| 134 | |
| 135 if ( ! sem ) { | |
| 136 SDL_SetError("Passed a NULL semaphore"); | |
| 137 return -1; | |
| 138 } | |
| 139 | |
| 140 retval = SDL_MUTEX_TIMEDOUT; | |
| 141 SDL_LockMutex(sem->count_lock); | |
| 142 if ( sem->count > 0 ) { | |
| 143 --sem->count; | |
| 144 retval = 0; | |
| 145 } | |
| 146 SDL_UnlockMutex(sem->count_lock); | |
| 147 | |
| 148 return retval; | |
| 149 } | |
| 150 | |
| 151 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout) | |
| 152 { | |
| 153 int retval; | |
| 154 | |
| 155 if ( ! sem ) { | |
| 156 SDL_SetError("Passed a NULL semaphore"); | |
| 157 return -1; | |
| 158 } | |
| 159 | |
| 160 /* A timeout of 0 is an easy case */ | |
| 161 if ( timeout == 0 ) { | |
| 162 return SDL_SemTryWait(sem); | |
| 163 } | |
| 164 | |
| 165 SDL_LockMutex(sem->count_lock); | |
| 166 ++sem->waiters_count; | |
| 167 retval = 0; | |
| 168 while ( (sem->count == 0) && (retval != SDL_MUTEX_TIMEDOUT) ) { | |
| 169 retval = SDL_CondWaitTimeout(sem->count_nonzero, | |
| 170 sem->count_lock, timeout); | |
| 171 } | |
| 172 --sem->waiters_count; | |
| 173 --sem->count; | |
| 174 SDL_UnlockMutex(sem->count_lock); | |
| 175 | |
| 176 return retval; | |
| 177 } | |
| 178 | |
| 179 int SDL_SemWait(SDL_sem *sem) | |
| 180 { | |
| 181 return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT); | |
| 182 } | |
| 183 | |
| 184 Uint32 SDL_SemValue(SDL_sem *sem) | |
| 185 { | |
| 186 Uint32 value; | |
| 187 | |
| 188 value = 0; | |
| 189 if ( sem ) { | |
| 190 SDL_LockMutex(sem->count_lock); | |
| 191 value = sem->count; | |
| 192 SDL_UnlockMutex(sem->count_lock); | |
| 193 } | |
| 194 return value; | |
| 195 } | |
| 196 | |
| 197 int SDL_SemPost(SDL_sem *sem) | |
| 198 { | |
| 199 if ( ! sem ) { | |
| 200 SDL_SetError("Passed a NULL semaphore"); | |
| 201 return -1; | |
| 202 } | |
| 203 | |
| 204 SDL_LockMutex(sem->count_lock); | |
| 205 if ( sem->waiters_count > 0 ) { | |
| 206 SDL_CondSignal(sem->count_nonzero); | |
| 207 } | |
| 208 ++sem->count; | |
| 209 SDL_UnlockMutex(sem->count_lock); | |
| 210 | |
| 211 return 0; | |
| 212 } | |
| 213 | |
| 214 #endif /* DISABLE_THREADS */ |