Mercurial > sdl-ios-xcode
annotate test/testsem.c @ 4216:5b99971a27b4 SDL-1.2
Fixed bug #698
Hans de Goede 2009-02-13 01:10:52 PST
Since the new "glitch free" version of pulseaudio (used in Fedora 10 amongst
others), the sound of SDL using apps (like a simple playmus call) has been
crackling.
While looking in to fixing this I noticed that the current pulseaudio code in
SDL uses pa_simple. However pa_simple uses a thread to pump pulseaudio events
and ipc, given that SDL already has its own thread for audio handling this is
clearly suboptimal, leading to unnecessary context switching IPC, etc. Also
pa_simple does not allow one to implement the WaitAudio() callback for SDL
audiodrivers properly.
Given that my work is mostly a rewrite (although some original pieces remain)
I'm attaching the new .c and .h file, as that is easier to review then the huge
diff.
Let me know if you also want the diff.
This new version has the following features:
-no longer use an additional thread next to the SDL sound thread
-do not crackle with glitch free audio
-when used with a newer pulse, which does glitch free audio, the total latency
is
the same as with the alsa driver
-proper WaitAudio() implementation, saving another mixlen worth of latency
-adds a WaitDone() implementation
This patch has been written in consultancy with Lennart Poetering (the
pulseaudio author) and has been reviewed by him for correct use of the pa API.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Mon, 21 Sep 2009 09:27:08 +0000 |
| parents | 290b5baf2fca |
| children | 782fd950bd46 c121d94672cb 99acf3d856cb |
| rev | line source |
|---|---|
| 0 | 1 |
| 2 /* Simple test of the SDL semaphore code */ | |
| 3 | |
| 4 #include <stdio.h> | |
| 5 #include <stdlib.h> | |
| 6 #include <signal.h> | |
| 7 | |
| 8 #include "SDL.h" | |
| 9 #include "SDL_thread.h" | |
| 10 | |
| 11 #define NUM_THREADS 10 | |
| 12 | |
| 13 static SDL_sem *sem; | |
| 14 int alive = 1; | |
| 15 | |
| 1769 | 16 int SDLCALL ThreadFunc(void *data) |
| 0 | 17 { |
|
1615
d5298e8f22b3
Ugh, more 64-bit cleanup
Sam Lantinga <slouken@libsdl.org>
parents:
1495
diff
changeset
|
18 int threadnum = (int)(uintptr_t)data; |
| 0 | 19 while ( alive ) { |
| 20 SDL_SemWait(sem); | |
|
1495
1dd8bf30a109
Might have fixed 64-bit issues. :)
Sam Lantinga <slouken@libsdl.org>
parents:
1439
diff
changeset
|
21 fprintf(stderr, "Thread number %d has got the semaphore (value = %d)!\n", threadnum, SDL_SemValue(sem)); |
| 0 | 22 SDL_Delay(200); |
| 23 SDL_SemPost(sem); | |
|
1495
1dd8bf30a109
Might have fixed 64-bit issues. :)
Sam Lantinga <slouken@libsdl.org>
parents:
1439
diff
changeset
|
24 fprintf(stderr, "Thread number %d has released the semaphore (value = %d)!\n", threadnum, SDL_SemValue(sem)); |
| 0 | 25 SDL_Delay(1); /* For the scheduler */ |
| 26 } | |
|
1495
1dd8bf30a109
Might have fixed 64-bit issues. :)
Sam Lantinga <slouken@libsdl.org>
parents:
1439
diff
changeset
|
27 printf("Thread number %d exiting.\n", threadnum); |
| 0 | 28 return 0; |
| 29 } | |
| 30 | |
| 31 static void killed(int sig) | |
| 32 { | |
| 33 alive = 0; | |
| 34 } | |
| 35 | |
| 36 int main(int argc, char **argv) | |
| 37 { | |
| 38 SDL_Thread *threads[NUM_THREADS]; | |
|
1495
1dd8bf30a109
Might have fixed 64-bit issues. :)
Sam Lantinga <slouken@libsdl.org>
parents:
1439
diff
changeset
|
39 uintptr_t i; |
|
1dd8bf30a109
Might have fixed 64-bit issues. :)
Sam Lantinga <slouken@libsdl.org>
parents:
1439
diff
changeset
|
40 int init_sem; |
| 0 | 41 |
| 42 if(argc < 2) { | |
| 43 fprintf(stderr,"Usage: %s init_value\n", argv[0]); | |
|
1151
be9c9c8f6d53
Removed atexit() from most of the test programs; atexit(SDL_Quit) isn't safe
Ryan C. Gordon <icculus@icculus.org>
parents:
0
diff
changeset
|
44 return(1); |
| 0 | 45 } |
| 46 | |
| 47 /* Load the SDL library */ | |
| 48 if ( SDL_Init(0) < 0 ) { | |
| 49 fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError()); | |
|
1151
be9c9c8f6d53
Removed atexit() from most of the test programs; atexit(SDL_Quit) isn't safe
Ryan C. Gordon <icculus@icculus.org>
parents:
0
diff
changeset
|
50 return(1); |
| 0 | 51 } |
| 52 signal(SIGTERM, killed); | |
| 53 signal(SIGINT, killed); | |
| 54 | |
| 55 init_sem = atoi(argv[1]); | |
| 56 sem = SDL_CreateSemaphore(init_sem); | |
| 57 | |
| 58 printf("Running %d threads, semaphore value = %d\n", NUM_THREADS, init_sem); | |
| 59 /* Create all the threads */ | |
| 60 for( i = 0; i < NUM_THREADS; ++i ) { | |
| 61 threads[i] = SDL_CreateThread(ThreadFunc, (void*)i); | |
| 62 } | |
| 63 | |
| 64 /* Wait 10 seconds */ | |
| 65 SDL_Delay(10 * 1000); | |
| 66 | |
| 67 /* Wait for all threads to finish */ | |
| 68 printf("Waiting for threads to finish\n"); | |
| 69 alive = 0; | |
| 70 for( i = 0; i < NUM_THREADS; ++i ) { | |
| 71 SDL_WaitThread(threads[i], NULL); | |
| 72 } | |
| 73 printf("Finished waiting for threads\n"); | |
| 74 | |
| 75 SDL_DestroySemaphore(sem); | |
|
1151
be9c9c8f6d53
Removed atexit() from most of the test programs; atexit(SDL_Quit) isn't safe
Ryan C. Gordon <icculus@icculus.org>
parents:
0
diff
changeset
|
76 SDL_Quit(); |
| 0 | 77 return(0); |
| 78 } |