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Check for sem_timedwait(), which isn't available on some systems (inc…

…luding OpenBSD)
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slouken committed Jan 15, 2012
1 parent 53df919 commit f33068bc5ddc0ef16cd53f12d779f2d16933a096
Showing with 29 additions and 0 deletions.
  1. +14 −0 configure.in
  2. +1 −0 include/SDL_config.h.in
  3. +14 −0 src/thread/pthread/SDL_syssem.c
@@ -1994,6 +1994,20 @@ AC_HELP_STRING([--enable-pthread-sem], [use pthread semaphores [[default=yes]]])
])
AC_MSG_RESULT($have_pthread_sem)
fi
if test x$have_pthread_sem = xyes; then
AC_MSG_CHECKING(for sem_timedwait)
have_sem_timedwait=no
AC_TRY_LINK([
#include <pthread.h>
#include <semaphore.h>
],[
sem_timedwait(NULL, NULL);
],[
have_sem_timedwait=yes
AC_DEFINE(HAVE_SEM_TIMEDWAIT)
])
AC_MSG_RESULT($have_sem_timedwait)
fi

# Restore the compiler flags and libraries
CFLAGS="$ac_save_cflags"; LIBS="$ac_save_libs"
@@ -137,6 +137,7 @@
#undef HAVE_CLOCK_GETTIME
#undef HAVE_GETPAGESIZE
#undef HAVE_MPROTECT
#undef HAVE_SEM_TIMEDWAIT

#else
/* We may need some replacement for stdarg.h here */
@@ -98,8 +98,12 @@ int SDL_SemWait(SDL_sem *sem)
int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
{
int retval;
#ifdef HAVE_SEM_TIMEDWAIT
struct timeval now;
struct timespec ts_timeout;
#else
Uint32 end;
#endif

if ( ! sem ) {
SDL_SetError("Passed a NULL semaphore");
@@ -114,6 +118,7 @@ int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
return SDL_SemWait(sem);
}

#ifdef HAVE_SEM_TIMEDWAIT
/* Setup the timeout. sem_timedwait doesn't wait for
* a lapse of time, but until we reach a certain time.
* This time is now plus the timeout.
@@ -141,6 +146,15 @@ int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)

if (retval == -1)
SDL_SetError(strerror(errno));
#else
end = SDL_GetTicks() + timeout;
while ((retval = SDL_SemTryWait(sem)) == SDL_MUTEX_TIMEDOUT) {
if ((SDL_GetTicks() - end) >= 0) {
break;
}
SDL_Delay(0);
}
#endif /* HAVE_SEM_TIMEDWAIT */

return retval;
}

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