slouken@5003
|
1 |
/*
|
slouken@5535
|
2 |
Simple DirectMedia Layer
|
slouken@5535
|
3 |
Copyright (C) 1997-2011 Sam Lantinga <slouken@libsdl.org>
|
slouken@5003
|
4 |
|
slouken@5535
|
5 |
This software is provided 'as-is', without any express or implied
|
slouken@5535
|
6 |
warranty. In no event will the authors be held liable for any damages
|
slouken@5535
|
7 |
arising from the use of this software.
|
slouken@5003
|
8 |
|
slouken@5535
|
9 |
Permission is granted to anyone to use this software for any purpose,
|
slouken@5535
|
10 |
including commercial applications, and to alter it and redistribute it
|
slouken@5535
|
11 |
freely, subject to the following restrictions:
|
slouken@5003
|
12 |
|
slouken@5535
|
13 |
1. The origin of this software must not be misrepresented; you must not
|
slouken@5535
|
14 |
claim that you wrote the original software. If you use this software
|
slouken@5535
|
15 |
in a product, an acknowledgment in the product documentation would be
|
slouken@5535
|
16 |
appreciated but is not required.
|
slouken@5535
|
17 |
2. Altered source versions must be plainly marked as such, and must not be
|
slouken@5535
|
18 |
misrepresented as being the original software.
|
slouken@5535
|
19 |
3. This notice may not be removed or altered from any source distribution.
|
slouken@5003
|
20 |
*/
|
slouken@5003
|
21 |
#include "SDL_stdinc.h"
|
slouken@5003
|
22 |
|
slouken@5003
|
23 |
#include "SDL_atomic.h"
|
slouken@5225
|
24 |
#include "SDL_mutex.h"
|
slouken@5003
|
25 |
#include "SDL_timer.h"
|
slouken@5003
|
26 |
|
slouken@5073
|
27 |
/* Don't do the check for Visual Studio 2005, it's safe here */
|
slouken@5091
|
28 |
#ifdef __WIN32__
|
slouken@5090
|
29 |
#include "../core/windows/SDL_windows.h"
|
slouken@5091
|
30 |
#endif
|
slouken@5003
|
31 |
|
slouken@5003
|
32 |
/* This function is where all the magic happens... */
|
slouken@5003
|
33 |
SDL_bool
|
slouken@5003
|
34 |
SDL_AtomicTryLock(SDL_SpinLock *lock)
|
slouken@5003
|
35 |
{
|
slouken@5225
|
36 |
#if SDL_ATOMIC_DISABLED
|
slouken@5225
|
37 |
/* Terrible terrible damage */
|
slouken@5225
|
38 |
static SDL_mutex *_spinlock_mutex;
|
slouken@5225
|
39 |
|
slouken@5225
|
40 |
if (!_spinlock_mutex) {
|
slouken@5225
|
41 |
/* Race condition on first lock... */
|
slouken@5225
|
42 |
_spinlock_mutex = SDL_CreateMutex();
|
slouken@5225
|
43 |
}
|
slouken@5225
|
44 |
SDL_mutexP(_spinlock_mutex);
|
slouken@5225
|
45 |
if (*lock == 0) {
|
slouken@5225
|
46 |
*lock = 1;
|
slouken@5225
|
47 |
SDL_mutexV(_spinlock_mutex);
|
slouken@5225
|
48 |
return SDL_TRUE;
|
slouken@5225
|
49 |
} else {
|
slouken@5225
|
50 |
SDL_mutexV(_spinlock_mutex);
|
slouken@5225
|
51 |
return SDL_FALSE;
|
slouken@5225
|
52 |
}
|
slouken@5225
|
53 |
|
slouken@5225
|
54 |
#elif defined(_MSC_VER)
|
slouken@5015
|
55 |
SDL_COMPILE_TIME_ASSERT(locksize, sizeof(*lock) == sizeof(long));
|
slouken@5090
|
56 |
return (InterlockedExchange((long*)lock, 1) == 0);
|
slouken@5003
|
57 |
|
slouken@5095
|
58 |
#elif HAVE_GCC_ATOMICS || HAVE_GCC_SYNC_LOCK_TEST_AND_SET
|
slouken@5004
|
59 |
return (__sync_lock_test_and_set(lock, 1) == 0);
|
slouken@5004
|
60 |
|
slouken@5328
|
61 |
#elif defined(__GNUC__) && defined(__arm__) && \
|
slouken@5328
|
62 |
(defined(__ARM_ARCH_4__) || defined(__ARM_ARCH_4T__) || \
|
slouken@5328
|
63 |
defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5TE__))
|
slouken@5003
|
64 |
int result;
|
slouken@5003
|
65 |
__asm__ __volatile__ (
|
slouken@5003
|
66 |
"swp %0, %1, [%2]\n"
|
slouken@5003
|
67 |
: "=&r,&r" (result) : "r,0" (1), "r,r" (lock) : "memory");
|
slouken@5003
|
68 |
return (result == 0);
|
slouken@5004
|
69 |
|
slouken@5097
|
70 |
#elif defined(__GNUC__) && defined(__arm__)
|
slouken@5003
|
71 |
int result;
|
slouken@5003
|
72 |
__asm__ __volatile__ (
|
slouken@5003
|
73 |
"ldrex %0, [%2]\nteq %0, #0\nstrexeq %0, %1, [%2]"
|
slouken@5003
|
74 |
: "=&r" (result) : "r" (1), "r" (lock) : "cc", "memory");
|
slouken@5003
|
75 |
return (result == 0);
|
slouken@5003
|
76 |
|
icculus@5957
|
77 |
#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
|
icculus@5957
|
78 |
int result;
|
icculus@5957
|
79 |
__asm__ __volatile__(
|
icculus@5957
|
80 |
"lock ; xchgl %0, (%1)\n"
|
icculus@5957
|
81 |
: "=r" (result) : "r" (lock), "0" (1) : "cc", "memory");
|
icculus@5957
|
82 |
return (result == 0);
|
icculus@5957
|
83 |
|
icculus@5957
|
84 |
#elif defined(__MACOSX__)
|
icculus@5957
|
85 |
/* Maybe used for PowerPC, but the Intel asm or gcc atomics are favored. */
|
icculus@5957
|
86 |
return OSAtomicCompareAndSwap32Barrier(0, 1, lock);
|
icculus@5957
|
87 |
|
nathanheisey@5557
|
88 |
#elif HAVE_PTHREAD_SPINLOCK
|
nathanheisey@5557
|
89 |
/* pthread instructions */
|
nathanheisey@5557
|
90 |
return (pthread_spin_trylock(lock) == 0);
|
icculus@5957
|
91 |
|
icculus@5957
|
92 |
#else
|
icculus@5956
|
93 |
#error Please implement for your platform.
|
icculus@5956
|
94 |
return SDL_FALSE;
|
slouken@5003
|
95 |
#endif
|
slouken@5003
|
96 |
}
|
slouken@5003
|
97 |
|
slouken@5003
|
98 |
void
|
slouken@5003
|
99 |
SDL_AtomicLock(SDL_SpinLock *lock)
|
slouken@5003
|
100 |
{
|
slouken@5003
|
101 |
/* FIXME: Should we have an eventual timeout? */
|
slouken@5003
|
102 |
while (!SDL_AtomicTryLock(lock)) {
|
slouken@5003
|
103 |
SDL_Delay(0);
|
slouken@5003
|
104 |
}
|
slouken@5003
|
105 |
}
|
slouken@5003
|
106 |
|
slouken@5003
|
107 |
void
|
slouken@5003
|
108 |
SDL_AtomicUnlock(SDL_SpinLock *lock)
|
slouken@5003
|
109 |
{
|
slouken@5095
|
110 |
#if defined(_MSC_VER)
|
slouken@5095
|
111 |
_ReadWriteBarrier();
|
slouken@5003
|
112 |
*lock = 0;
|
slouken@5095
|
113 |
|
slouken@5095
|
114 |
#elif HAVE_GCC_ATOMICS || HAVE_GCC_SYNC_LOCK_TEST_AND_SET
|
slouken@5095
|
115 |
__sync_lock_release(lock);
|
nathanheisey@5557
|
116 |
|
nathanheisey@5557
|
117 |
#elif HAVE_PTHREAD_SPINLOCK
|
nathanheisey@5557
|
118 |
pthread_spin_unlock(lock);
|
nathanheisey@5557
|
119 |
|
slouken@5095
|
120 |
#else
|
slouken@5095
|
121 |
*lock = 0;
|
slouken@5095
|
122 |
#endif
|
slouken@5003
|
123 |
}
|
slouken@5003
|
124 |
|
slouken@5003
|
125 |
/* vi: set ts=4 sw=4 expandtab: */
|