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view docs/man3/SDL_CreateSemaphore.3 @ 1180:bdcb8bb4c831
From: Tyler Montbriand <tsm@accesscomm.ca>
To: sdl@libsdl.org
Date: Fri, 30 Sep 2005 02:24:50 -0600
Subject: [SDL] WinCE timers, continued
Here's a strange timer for Windows CE that doesn't ignore time across
suspends. It uses GetSystemTime to keep the time continuous, and GetTicks to
get finer-grained readings than 1 second. It detects the difference between
the GetTicks time and GetSystemTime time on power-on to keep the error within
one second max.
It's not a patch on the current win32 timer code -- took one look at that and
figured it had more than enough #ifdefs already. It's windows-ce specific.
Another thing I've noticed is that the Windows CE 4.0 and newer API has
functions warn processes about suspends. This is something SDL REALLY needs
for audio in particular, because turning it off while it's playing causes
anything that uses audio to hardlock the system on power-on. Unfortunately I
don't have 4.0 to play with. :(
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Tue, 22 Nov 2005 07:10:07 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
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.TH "SDL_CreateSemaphore" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" .SH "NAME" SDL_CreateSemaphore\- Creates a new semaphore and assigns an initial value to it\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" #include "SDL_thread\&.h" .sp \fBSDL_sem *\fBSDL_CreateSemaphore\fP\fR(\fBUint32 initial_value\fR); .SH "DESCRIPTION" .PP \fBSDL_CreateSemaphore()\fP creates a new semaphore and initializes it with the value \fBinitial_value\fR\&. Each locking operation on the semaphore by \fISDL_SemWait\fR, \fISDL_SemTryWait\fR or \fISDL_SemWaitTimeout\fR will atomically decrement the semaphore value\&. The locking operation will be blocked if the semaphore value is not positive (greater than zero)\&. Each unlock operation by \fISDL_SemPost\fR will atomically increment the semaphore value\&. .SH "RETURN VALUE" .PP Returns a pointer to an initialized semaphore or \fBNULL\fR if there was an error\&. .SH "EXAMPLES" .PP .PP .nf \f(CWSDL_sem *my_sem; my_sem = SDL_CreateSemaphore(INITIAL_SEM_VALUE); if (my_sem == NULL) { return CREATE_SEM_FAILED; }\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_DestroySemaphore\fP\fR, \fI\fBSDL_SemWait\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