Mercurial > sdl-ios-xcode
annotate test/torturethread.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 |
| rev | line source |
|---|---|
| 0 | 1 |
| 2 /* Simple test of the SDL threading code */ | |
| 3 | |
| 4 #include <stdio.h> | |
| 5 #include <stdlib.h> | |
| 6 #include <signal.h> | |
| 7 #include <string.h> | |
| 8 | |
| 9 #include "SDL.h" | |
| 10 #include "SDL_thread.h" | |
| 11 | |
| 12 #define NUMTHREADS 10 | |
| 13 | |
| 14 static char volatile time_for_threads_to_die[NUMTHREADS]; | |
| 15 | |
|
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
|
16 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ |
|
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
|
17 static void quit(int rc) |
|
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
|
18 { |
|
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
|
19 SDL_Quit(); |
|
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
|
20 exit(rc); |
|
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
|
21 } |
|
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
|
22 |
| 1769 | 23 int SDLCALL SubThreadFunc(void *data) { |
| 0 | 24 while(! *(int volatile *)data) { |
|
1154
d93862a3d821
Fixed compiler warnings in Watcom C.
Ryan C. Gordon <icculus@icculus.org>
parents:
1151
diff
changeset
|
25 ; /*SDL_Delay(10);*/ /* do nothing */ |
| 0 | 26 } |
| 27 return 0; | |
| 28 } | |
| 29 | |
| 1769 | 30 int SDLCALL ThreadFunc(void *data) { |
| 0 | 31 SDL_Thread *sub_threads[NUMTHREADS]; |
| 32 int flags[NUMTHREADS]; | |
| 33 int i; | |
|
1615
d5298e8f22b3
Ugh, more 64-bit cleanup
Sam Lantinga <slouken@libsdl.org>
parents:
1495
diff
changeset
|
34 int tid = (int)(uintptr_t)data; |
| 0 | 35 |
| 36 fprintf(stderr, "Creating Thread %d\n", tid); | |
| 37 | |
| 38 for(i = 0; i < NUMTHREADS; i++) { | |
| 39 flags[i] = 0; | |
| 40 sub_threads[i] = SDL_CreateThread(SubThreadFunc, &flags[i]); | |
| 41 } | |
| 42 | |
| 43 printf("Thread '%d' waiting for signal\n", tid); | |
| 44 while(time_for_threads_to_die[tid] != 1) { | |
| 45 ; /* do nothing */ | |
| 46 } | |
| 47 | |
| 48 printf("Thread '%d' sending signals to subthreads\n", tid); | |
| 49 for(i = 0; i < NUMTHREADS; i++) { | |
| 50 flags[i] = 1; | |
| 51 SDL_WaitThread(sub_threads[i], NULL); | |
| 52 } | |
| 53 | |
| 54 printf("Thread '%d' exiting!\n", tid); | |
| 55 | |
| 56 return 0; | |
| 57 } | |
| 58 | |
| 59 int main(int argc, char *argv[]) | |
| 60 { | |
| 61 SDL_Thread *threads[NUMTHREADS]; | |
|
1615
d5298e8f22b3
Ugh, more 64-bit cleanup
Sam Lantinga <slouken@libsdl.org>
parents:
1495
diff
changeset
|
62 int i; |
| 0 | 63 |
| 64 /* Load the SDL library */ | |
| 65 if ( SDL_Init(0) < 0 ) { | |
| 66 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
|
67 return(1); |
| 0 | 68 } |
| 69 | |
| 70 signal(SIGSEGV, SIG_DFL); | |
| 71 for(i = 0; i < NUMTHREADS; i++) { | |
| 72 time_for_threads_to_die[i] = 0; | |
|
1615
d5298e8f22b3
Ugh, more 64-bit cleanup
Sam Lantinga <slouken@libsdl.org>
parents:
1495
diff
changeset
|
73 threads[i] = SDL_CreateThread(ThreadFunc, (void *)(uintptr_t)i); |
| 0 | 74 |
| 75 if ( threads[i] == NULL ) { | |
| 76 fprintf(stderr, | |
| 77 "Couldn't create thread: %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
|
78 quit(1); |
| 0 | 79 } |
| 80 } | |
| 81 | |
| 82 for(i = 0; i < NUMTHREADS; i++) { | |
| 83 time_for_threads_to_die[i] = 1; | |
| 84 } | |
| 85 | |
|
1618
3b08574f4c60
*** empty log message ***
Sam Lantinga <slouken@libsdl.org>
parents:
1615
diff
changeset
|
86 for(i = 0; i < NUMTHREADS; i++) { |
| 0 | 87 SDL_WaitThread(threads[i], NULL); |
| 88 } | |
|
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
|
89 SDL_Quit(); |
|
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
|
90 return(0); |
| 0 | 91 } |