Mercurial > sdl-ios-xcode
view docs/man3/SDL_SemWait.3 @ 2866:e532417a6977
Fixed SDL 1.2 compatibility problem.
The API specifies that SDL_OpenAudio() will fill out the 'desired' audio spec
with the correct samples and size set by the driver. This value is important
since it may be used by applications that size audio buffers, etc.
However, we want to allow advanced applications to call SDL_OpenAudioDevice()
which gets passed a const 'desired' parameter, and have the correct data filled
into the 'obtained' parameter, possibly allowing or not allowing format changes.
So... 'obtained' becomes the audio format the user callback is expected to use,
and we add flags to allow the application to specify which format changes are
allowed.
Note: We really need to add a way to query the 'obtained' audio spec.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sat, 13 Dec 2008 06:36:47 +0000 |
| parents | 546f7c1eb755 |
| children | 1238da4a7112 |
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.TH "SDL_SemWait" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" .SH "NAME" SDL_SemWait \- Lock a semaphore and suspend the thread if the semaphore value is zero\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" #include "SDL_thread\&.h" .sp \fBint \fBSDL_SemWait\fP\fR(\fBSDL_sem *sem\fR); .SH "DESCRIPTION" .PP \fBSDL_SemWait()\fP suspends the calling thread until either the semaphore pointed to by \fBsem\fR has a positive value, the call is interrupted by a signal or error\&. If the call is successful it will atomically decrement the semaphore value\&. .PP After \fBSDL_SemWait()\fP is successful, the semaphore can be released and its count atomically incremented by a successful call to \fISDL_SemPost\fR\&. .SH "RETURN VALUE" .PP Returns \fB0\fR if successful or \fB-1\fR if there was an error (leaving the semaphore unchanged)\&. .SH "EXAMPLES" .PP .PP .nf \f(CWif (SDL_SemWait(my_sem) == -1) { return WAIT_FAILED; } \&.\&.\&. SDL_SemPost(my_sem);\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_CreateSemaphore\fP\fR, \fI\fBSDL_DestroySemaphore\fP\fR, \fI\fBSDL_SemTryWait\fP\fR, \fI\fBSDL_SemWaitTimeout\fP\fR, \fI\fBSDL_SemPost\fP\fR, \fI\fBSDL_SemValue\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00