Mercurial > sdl-ios-xcode
annotate test/testtimer.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 /* Test program to check the resolution of the SDL timer on the current | |
| 3 platform | |
| 4 */ | |
| 5 | |
| 6 #include <stdlib.h> | |
| 7 #include <stdio.h> | |
| 8 | |
| 9 #include "SDL.h" | |
| 10 | |
| 11 #define DEFAULT_RESOLUTION 1 | |
| 12 | |
| 13 static int ticks = 0; | |
| 14 | |
| 1769 | 15 static Uint32 SDLCALL ticktock(Uint32 interval) |
| 0 | 16 { |
| 17 ++ticks; | |
| 18 return(interval); | |
| 19 } | |
| 20 | |
| 1769 | 21 static Uint32 SDLCALL callback(Uint32 interval, void *param) |
| 0 | 22 { |
|
1615
d5298e8f22b3
Ugh, more 64-bit cleanup
Sam Lantinga <slouken@libsdl.org>
parents:
1500
diff
changeset
|
23 printf("Timer %d : param = %d\n", interval, (int)(uintptr_t)param); |
| 0 | 24 return interval; |
| 25 } | |
| 26 | |
| 27 int main(int argc, char *argv[]) | |
| 28 { | |
| 29 int desired; | |
| 30 SDL_TimerID t1, t2, t3; | |
| 31 | |
| 32 if ( SDL_Init(SDL_INIT_TIMER) < 0 ) { | |
|
1484
b2b476a4a73c
Added documentation on how to build a completely useless SDL library. :)
Sam Lantinga <slouken@libsdl.org>
parents:
1151
diff
changeset
|
33 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:
766
diff
changeset
|
34 return(1); |
| 0 | 35 } |
| 36 | |
| 37 /* Start the timer */ | |
| 38 desired = 0; | |
| 39 if ( argv[1] ) { | |
| 40 desired = atoi(argv[1]); | |
| 41 } | |
| 42 if ( desired == 0 ) { | |
| 43 desired = DEFAULT_RESOLUTION; | |
| 44 } | |
| 45 SDL_SetTimer(desired, ticktock); | |
| 46 | |
| 47 /* Wait 10 seconds */ | |
| 48 printf("Waiting 10 seconds\n"); | |
| 49 SDL_Delay(10*1000); | |
| 50 | |
| 51 /* Stop the timer */ | |
| 52 SDL_SetTimer(0, NULL); | |
| 53 | |
| 54 /* Print the results */ | |
| 55 if ( ticks ) { | |
| 56 fprintf(stderr, | |
| 57 "Timer resolution: desired = %d ms, actual = %f ms\n", | |
| 58 desired, (double)(10*1000)/ticks); | |
| 59 } | |
| 60 | |
| 61 /* Test multiple timers */ | |
| 62 printf("Testing multiple timers...\n"); | |
| 63 t1 = SDL_AddTimer(100, callback, (void*)1); | |
| 64 if(!t1) | |
|
766
ed57c876700d
Date: Wed, 26 Nov 2003 01:52:02 +0800
Sam Lantinga <slouken@libsdl.org>
parents:
0
diff
changeset
|
65 fprintf(stderr,"Could not create timer 1: %s\n", SDL_GetError()); |
| 0 | 66 t2 = SDL_AddTimer(50, callback, (void*)2); |
| 67 if(!t2) | |
|
766
ed57c876700d
Date: Wed, 26 Nov 2003 01:52:02 +0800
Sam Lantinga <slouken@libsdl.org>
parents:
0
diff
changeset
|
68 fprintf(stderr,"Could not create timer 2: %s\n", SDL_GetError()); |
| 0 | 69 t3 = SDL_AddTimer(233, callback, (void*)3); |
| 70 if(!t3) | |
|
766
ed57c876700d
Date: Wed, 26 Nov 2003 01:52:02 +0800
Sam Lantinga <slouken@libsdl.org>
parents:
0
diff
changeset
|
71 fprintf(stderr,"Could not create timer 3: %s\n", SDL_GetError()); |
| 0 | 72 |
| 73 /* Wait 10 seconds */ | |
| 74 printf("Waiting 10 seconds\n"); | |
| 75 SDL_Delay(10*1000); | |
| 76 | |
| 77 printf("Removing timer 1 and waiting 5 more seconds\n"); | |
| 78 SDL_RemoveTimer(t1); | |
| 79 | |
| 80 SDL_Delay(5*1000); | |
| 81 | |
| 82 SDL_RemoveTimer(t2); | |
| 83 SDL_RemoveTimer(t3); | |
| 84 | |
|
1151
be9c9c8f6d53
Removed atexit() from most of the test programs; atexit(SDL_Quit) isn't safe
Ryan C. Gordon <icculus@icculus.org>
parents:
766
diff
changeset
|
85 SDL_Quit(); |
| 0 | 86 return(0); |
| 87 } |