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It's now possible to disable the fast atomic operations, at a huge performance penalty.

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This commit is contained in:
Sam Lantinga 2011-02-07 22:57:33 -08:00
parent 8253658837
commit 8f205278b1
4 changed files with 30 additions and 1 deletions
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6
configure.in
View file

@ -422,6 +422,12 @@ AC_HELP_STRING([--enable-cpuinfo], [Enable the cpuinfo subsystem [[default=yes]]
if test x$enable_cpuinfo != xyes; then if test x$enable_cpuinfo != xyes; then
AC_DEFINE(SDL_CPUINFO_DISABLED) AC_DEFINE(SDL_CPUINFO_DISABLED)
fi fi
AC_ARG_ENABLE(atomic,
AC_HELP_STRING([--enable-atomic], [Enable the atomic operations [[default=yes]]]),
, enable_atomic=yes)
if test x$enable_atomic != xyes; then
AC_DEFINE(SDL_ATOMIC_DISABLED)
fi
AC_ARG_ENABLE(assembly, AC_ARG_ENABLE(assembly,
AC_HELP_STRING([--enable-assembly], [Enable assembly routines [[default=yes]]]), AC_HELP_STRING([--enable-assembly], [Enable assembly routines [[default=yes]]]),
, enable_assembly=yes) , enable_assembly=yes)

3
include/SDL_atomic.h
View file

@ -141,6 +141,9 @@ void _ReadWriteBarrier(void);
/* Platform specific optimized versions of the atomic functions, /* Platform specific optimized versions of the atomic functions,
* you can disable these by defining SDL_DISABLE_ATOMIC_INLINE * you can disable these by defining SDL_DISABLE_ATOMIC_INLINE
*/ */
#if SDL_ATOMIC_DISABLED
#define SDL_DISABLE_ATOMIC_INLINE
#endif
#ifndef SDL_DISABLE_ATOMIC_INLINE #ifndef SDL_DISABLE_ATOMIC_INLINE
#ifdef HAVE_MSC_ATOMICS #ifdef HAVE_MSC_ATOMICS

1
include/SDL_config.h.in
View file

@ -171,6 +171,7 @@
#undef SDL_DEFAULT_ASSERT_LEVEL #undef SDL_DEFAULT_ASSERT_LEVEL
/* Allow disabling of core subsystems */ /* Allow disabling of core subsystems */
#undef SDL_ATOMIC_DISABLED
#undef SDL_AUDIO_DISABLED #undef SDL_AUDIO_DISABLED
#undef SDL_CPUINFO_DISABLED #undef SDL_CPUINFO_DISABLED
#undef SDL_EVENTS_DISABLED #undef SDL_EVENTS_DISABLED

21
src/atomic/SDL_spinlock.c
View file

@ -22,6 +22,7 @@
#include "SDL_stdinc.h" #include "SDL_stdinc.h"
#include "SDL_atomic.h" #include "SDL_atomic.h"
#include "SDL_mutex.h"
#include "SDL_timer.h" #include "SDL_timer.h"
/* Don't do the check for Visual Studio 2005, it's safe here */ /* Don't do the check for Visual Studio 2005, it's safe here */
@ -33,7 +34,25 @@
SDL_bool SDL_bool
SDL_AtomicTryLock(SDL_SpinLock *lock) SDL_AtomicTryLock(SDL_SpinLock *lock)
{ {
#if defined(_MSC_VER) #if SDL_ATOMIC_DISABLED
/* Terrible terrible damage */
static SDL_mutex *_spinlock_mutex;
if (!_spinlock_mutex) {
/* Race condition on first lock... */
_spinlock_mutex = SDL_CreateMutex();
}
SDL_mutexP(_spinlock_mutex);
if (*lock == 0) {
*lock = 1;
SDL_mutexV(_spinlock_mutex);
return SDL_TRUE;
} else {
SDL_mutexV(_spinlock_mutex);
return SDL_FALSE;
}
#elif defined(_MSC_VER)
SDL_COMPILE_TIME_ASSERT(locksize, sizeof(*lock) == sizeof(long)); SDL_COMPILE_TIME_ASSERT(locksize, sizeof(*lock) == sizeof(long));
return (InterlockedExchange((long*)lock, 1) == 0); return (InterlockedExchange((long*)lock, 1) == 0);