Mercurial > sdl-ios-xcode
annotate src/thread/win32/SDL_sysmutex.c @ 968:4675910b0b7b
Date: Mon, 11 Oct 2004 15:17:27 +0300 (EEST)
From: Hannu Savolainen
Subject: Re: SDL uses obsolete OSS features
I did some work on getting OSS to work better with SDL. There have been
some problems with select which should be fixed now.
I'm having some problems in understanding what is the purpose of the
DSP_WaitAudio() routine. I added a return to the very beginning of this
routine and commendted out the define for USE_BLOCKING_WRITES. At least
lbreakout2 seems to work as well as earlier. The latencies are the same.
An ordinary blocking write does exactly the same thing than DSP_WaitAudio
does. So I would recommend using the USE_BLOCKING_WRITES approach and
removing everything from the DSP_WaitAudio routine. Also enabling
USE_BLOCKING_WRITES makes it possible to simplify DSP_PlayAudio() because
you don't need to handle the partial writes (the do-while loop).
Attached is a patch against SDL-1.2.7. After these changes SDL will use
OSS as it's designed to be used (make it as simple as possible). This code
should work with all OSS implementations because it uses only the very
fundamental features that have been there since the jurassic times.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 12 Nov 2004 21:39:04 +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 /* Mutex functions using the Win32 API */ | |
| 29 | |
| 30 #include <stdio.h> | |
| 31 #include <stdlib.h> | |
| 32 #include <windows.h> | |
| 33 | |
| 34 #include "SDL_error.h" | |
| 35 #include "SDL_mutex.h" | |
| 36 | |
| 37 | |
| 38 struct SDL_mutex { | |
| 39 HANDLE id; | |
| 40 }; | |
| 41 | |
| 42 /* Create a mutex */ | |
| 43 SDL_mutex *SDL_CreateMutex(void) | |
| 44 { | |
| 45 SDL_mutex *mutex; | |
| 46 | |
| 47 /* Allocate mutex memory */ | |
| 48 mutex = (SDL_mutex *)malloc(sizeof(*mutex)); | |
| 49 if ( mutex ) { | |
| 50 /* Create the mutex, with initial value signaled */ | |
| 51 mutex->id = CreateMutex(NULL, FALSE, NULL); | |
| 52 if ( ! mutex->id ) { | |
| 53 SDL_SetError("Couldn't create mutex"); | |
| 54 free(mutex); | |
| 55 mutex = NULL; | |
| 56 } | |
| 57 } else { | |
| 58 SDL_OutOfMemory(); | |
| 59 } | |
| 60 return(mutex); | |
| 61 } | |
| 62 | |
| 63 /* Free the mutex */ | |
| 64 void SDL_DestroyMutex(SDL_mutex *mutex) | |
| 65 { | |
| 66 if ( mutex ) { | |
| 67 if ( mutex->id ) { | |
| 68 CloseHandle(mutex->id); | |
| 69 mutex->id = 0; | |
| 70 } | |
| 71 free(mutex); | |
| 72 } | |
| 73 } | |
| 74 | |
| 75 /* Lock the mutex */ | |
| 76 int SDL_mutexP(SDL_mutex *mutex) | |
| 77 { | |
| 78 if ( mutex == NULL ) { | |
| 79 SDL_SetError("Passed a NULL mutex"); | |
| 80 return -1; | |
| 81 } | |
| 82 if ( WaitForSingleObject(mutex->id, INFINITE) == WAIT_FAILED ) { | |
| 83 SDL_SetError("Couldn't wait on mutex"); | |
| 84 return -1; | |
| 85 } | |
| 86 return(0); | |
| 87 } | |
| 88 | |
| 89 /* Unlock the mutex */ | |
| 90 int SDL_mutexV(SDL_mutex *mutex) | |
| 91 { | |
| 92 if ( mutex == NULL ) { | |
| 93 SDL_SetError("Passed a NULL mutex"); | |
| 94 return -1; | |
| 95 } | |
| 96 if ( ReleaseMutex(mutex->id) == FALSE ) { | |
| 97 SDL_SetError("Couldn't release mutex"); | |
| 98 return -1; | |
| 99 } | |
| 100 return(0); | |
| 101 } |