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Diffstat (limited to '3rdparty/SDL2/src/atomic/SDL_atomic.c')
-rw-r--r--3rdparty/SDL2/src/atomic/SDL_atomic.c246
1 files changed, 246 insertions, 0 deletions
diff --git a/3rdparty/SDL2/src/atomic/SDL_atomic.c b/3rdparty/SDL2/src/atomic/SDL_atomic.c
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+++ b/3rdparty/SDL2/src/atomic/SDL_atomic.c
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+/*
+ Simple DirectMedia Layer
+ Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
+
+ This software is provided 'as-is', without any express or implied
+ warranty. In no event will the authors be held liable for any damages
+ arising from the use of this software.
+
+ Permission is granted to anyone to use this software for any purpose,
+ including commercial applications, and to alter it and redistribute it
+ freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software
+ in a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+ 2. Altered source versions must be plainly marked as such, and must not be
+ misrepresented as being the original software.
+ 3. This notice may not be removed or altered from any source distribution.
+*/
+#include "../SDL_internal.h"
+
+#include "SDL_atomic.h"
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1500)
+#include <intrin.h>
+#define HAVE_MSC_ATOMICS 1
+#endif
+
+#if defined(__MACOSX__) /* !!! FIXME: should we favor gcc atomics? */
+#include <libkern/OSAtomic.h>
+#endif
+
+#if !defined(HAVE_GCC_ATOMICS) && defined(__SOLARIS__)
+#include <atomic.h>
+#endif
+
+/*
+ If any of the operations are not provided then we must emulate some
+ of them. That means we need a nice implementation of spin locks
+ that avoids the "one big lock" problem. We use a vector of spin
+ locks and pick which one to use based on the address of the operand
+ of the function.
+
+ To generate the index of the lock we first shift by 3 bits to get
+ rid on the zero bits that result from 32 and 64 bit allignment of
+ data. We then mask off all but 5 bits and use those 5 bits as an
+ index into the table.
+
+ Picking the lock this way insures that accesses to the same data at
+ the same time will go to the same lock. OTOH, accesses to different
+ data have only a 1/32 chance of hitting the same lock. That should
+ pretty much eliminate the chances of several atomic operations on
+ different data from waiting on the same "big lock". If it isn't
+ then the table of locks can be expanded to a new size so long as
+ the new size is a power of two.
+
+ Contributed by Bob Pendleton, bob@pendleton.com
+*/
+
+#if !defined(HAVE_MSC_ATOMICS) && !defined(HAVE_GCC_ATOMICS) && !defined(__MACOSX__) && !defined(__SOLARIS__)
+#define EMULATE_CAS 1
+#endif
+
+#if EMULATE_CAS
+static SDL_SpinLock locks[32];
+
+static SDL_INLINE void
+enterLock(void *a)
+{
+ uintptr_t index = ((((uintptr_t)a) >> 3) & 0x1f);
+
+ SDL_AtomicLock(&locks[index]);
+}
+
+static SDL_INLINE void
+leaveLock(void *a)
+{
+ uintptr_t index = ((((uintptr_t)a) >> 3) & 0x1f);
+
+ SDL_AtomicUnlock(&locks[index]);
+}
+#endif
+
+
+SDL_bool
+SDL_AtomicCAS(SDL_atomic_t *a, int oldval, int newval)
+{
+#ifdef HAVE_MSC_ATOMICS
+ return (_InterlockedCompareExchange((long*)&a->value, (long)newval, (long)oldval) == (long)oldval);
+#elif defined(__MACOSX__) /* !!! FIXME: should we favor gcc atomics? */
+ return (SDL_bool) OSAtomicCompareAndSwap32Barrier(oldval, newval, &a->value);
+#elif defined(HAVE_GCC_ATOMICS)
+ return (SDL_bool) __sync_bool_compare_and_swap(&a->value, oldval, newval);
+#elif defined(__SOLARIS__) && defined(_LP64)
+ return (SDL_bool) ((int) atomic_cas_64((volatile uint64_t*)&a->value, (uint64_t)oldval, (uint64_t)newval) == oldval);
+#elif defined(__SOLARIS__) && !defined(_LP64)
+ return (SDL_bool) ((int) atomic_cas_32((volatile uint32_t*)&a->value, (uint32_t)oldval, (uint32_t)newval) == oldval);
+#elif EMULATE_CAS
+ SDL_bool retval = SDL_FALSE;
+
+ enterLock(a);
+ if (a->value == oldval) {
+ a->value = newval;
+ retval = SDL_TRUE;
+ }
+ leaveLock(a);
+
+ return retval;
+#else
+ #error Please define your platform.
+#endif
+}
+
+SDL_bool
+SDL_AtomicCASPtr(void **a, void *oldval, void *newval)
+{
+#if defined(HAVE_MSC_ATOMICS) && (_M_IX86)
+ return (_InterlockedCompareExchange((long*)a, (long)newval, (long)oldval) == (long)oldval);
+#elif defined(HAVE_MSC_ATOMICS) && (!_M_IX86)
+ return (_InterlockedCompareExchangePointer(a, newval, oldval) == oldval);
+#elif defined(__MACOSX__) && defined(__LP64__) /* !!! FIXME: should we favor gcc atomics? */
+ return (SDL_bool) OSAtomicCompareAndSwap64Barrier((int64_t)oldval, (int64_t)newval, (int64_t*) a);
+#elif defined(__MACOSX__) && !defined(__LP64__) /* !!! FIXME: should we favor gcc atomics? */
+ return (SDL_bool) OSAtomicCompareAndSwap32Barrier((int32_t)oldval, (int32_t)newval, (int32_t*) a);
+#elif defined(HAVE_GCC_ATOMICS)
+ return __sync_bool_compare_and_swap(a, oldval, newval);
+#elif defined(__SOLARIS__)
+ return (SDL_bool) (atomic_cas_ptr(a, oldval, newval) == oldval);
+#elif EMULATE_CAS
+ SDL_bool retval = SDL_FALSE;
+
+ enterLock(a);
+ if (*a == oldval) {
+ *a = newval;
+ retval = SDL_TRUE;
+ }
+ leaveLock(a);
+
+ return retval;
+#else
+ #error Please define your platform.
+#endif
+}
+
+int
+SDL_AtomicSet(SDL_atomic_t *a, int v)
+{
+#ifdef HAVE_MSC_ATOMICS
+ return _InterlockedExchange((long*)&a->value, v);
+#elif defined(HAVE_GCC_ATOMICS)
+ return __sync_lock_test_and_set(&a->value, v);
+#elif defined(__SOLARIS__) && defined(_LP64)
+ return (int) atomic_swap_64((volatile uint64_t*)&a->value, (uint64_t)v);
+#elif defined(__SOLARIS__) && !defined(_LP64)
+ return (int) atomic_swap_32((volatile uint32_t*)&a->value, (uint32_t)v);
+#else
+ int value;
+ do {
+ value = a->value;
+ } while (!SDL_AtomicCAS(a, value, v));
+ return value;
+#endif
+}
+
+void*
+SDL_AtomicSetPtr(void **a, void *v)
+{
+#if defined(HAVE_MSC_ATOMICS) && (_M_IX86)
+ return (void *) _InterlockedExchange((long *)a, (long) v);
+#elif defined(HAVE_MSC_ATOMICS) && (!_M_IX86)
+ return _InterlockedExchangePointer(a, v);
+#elif defined(HAVE_GCC_ATOMICS)
+ return __sync_lock_test_and_set(a, v);
+#elif defined(__SOLARIS__)
+ return atomic_swap_ptr(a, v);
+#else
+ void *value;
+ do {
+ value = *a;
+ } while (!SDL_AtomicCASPtr(a, value, v));
+ return value;
+#endif
+}
+
+int
+SDL_AtomicAdd(SDL_atomic_t *a, int v)
+{
+#ifdef HAVE_MSC_ATOMICS
+ return _InterlockedExchangeAdd((long*)&a->value, v);
+#elif defined(HAVE_GCC_ATOMICS)
+ return __sync_fetch_and_add(&a->value, v);
+#elif defined(__SOLARIS__)
+ int pv = a->value;
+ membar_consumer();
+#if defined(_LP64)
+ atomic_add_64((volatile uint64_t*)&a->value, v);
+#elif !defined(_LP64)
+ atomic_add_32((volatile uint32_t*)&a->value, v);
+#endif
+ return pv;
+#else
+ int value;
+ do {
+ value = a->value;
+ } while (!SDL_AtomicCAS(a, value, (value + v)));
+ return value;
+#endif
+}
+
+int
+SDL_AtomicGet(SDL_atomic_t *a)
+{
+ int value;
+ do {
+ value = a->value;
+ } while (!SDL_AtomicCAS(a, value, value));
+ return value;
+}
+
+void *
+SDL_AtomicGetPtr(void **a)
+{
+ void *value;
+ do {
+ value = *a;
+ } while (!SDL_AtomicCASPtr(a, value, value));
+ return value;
+}
+
+#ifdef __thumb__
+#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6T2__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__)
+__asm__(
+" .align 2\n"
+" .globl _SDL_MemoryBarrierRelease\n"
+" .globl _SDL_MemoryBarrierAcquire\n"
+"_SDL_MemoryBarrierRelease:\n"
+"_SDL_MemoryBarrierAcquire:\n"
+" mov r0, #0\n"
+" mcr p15, 0, r0, c7, c10, 5\n"
+" bx lr\n"
+);
+#endif
+#endif
+
+/* vi: set ts=4 sw=4 expandtab: */