My Project
SDL_atomic.h
Go to the documentation of this file.
1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 
59 #ifndef SDL_atomic_h_
60 #define SDL_atomic_h_
61 
62 #include "SDL_stdinc.h"
63 #include "SDL_platform.h"
64 
65 #include "begin_code.h"
66 
67 /* Set up for C function definitions, even when using C++ */
68 #ifdef __cplusplus
69 extern "C" {
70 #endif
71 
87 /* @{ */
88 
89 typedef int SDL_SpinLock;
90 
98 extern DECLSPEC SDL_bool SDLCALL SDL_AtomicTryLock(SDL_SpinLock *lock);
99 
105 extern DECLSPEC void SDLCALL SDL_AtomicLock(SDL_SpinLock *lock);
106 
112 extern DECLSPEC void SDLCALL SDL_AtomicUnlock(SDL_SpinLock *lock);
113 
114 /* @} *//* SDL AtomicLock */
115 
116 
121 #if defined(_MSC_VER) && (_MSC_VER > 1200) && !defined(__clang__)
122 void _ReadWriteBarrier(void);
123 #pragma intrinsic(_ReadWriteBarrier)
124 #define SDL_CompilerBarrier() _ReadWriteBarrier()
125 #elif (defined(__GNUC__) && !defined(__EMSCRIPTEN__)) || (defined(__SUNPRO_C) && (__SUNPRO_C >= 0x5120))
126 /* This is correct for all CPUs when using GCC or Solaris Studio 12.1+. */
127 #define SDL_CompilerBarrier() __asm__ __volatile__ ("" : : : "memory")
128 #elif defined(__WATCOMC__)
129 extern _inline void SDL_CompilerBarrier (void);
130 #pragma aux SDL_CompilerBarrier = "" parm [] modify exact [];
131 #else
132 #define SDL_CompilerBarrier() \
133 { SDL_SpinLock _tmp = 0; SDL_AtomicLock(&_tmp); SDL_AtomicUnlock(&_tmp); }
134 #endif
135 
155 extern DECLSPEC void SDLCALL SDL_MemoryBarrierReleaseFunction(void);
156 extern DECLSPEC void SDLCALL SDL_MemoryBarrierAcquireFunction(void);
157 
158 #if defined(__GNUC__) && (defined(__powerpc__) || defined(__ppc__))
159 #define SDL_MemoryBarrierRelease() __asm__ __volatile__ ("lwsync" : : : "memory")
160 #define SDL_MemoryBarrierAcquire() __asm__ __volatile__ ("lwsync" : : : "memory")
161 #elif defined(__GNUC__) && defined(__aarch64__)
162 #define SDL_MemoryBarrierRelease() __asm__ __volatile__ ("dmb ish" : : : "memory")
163 #define SDL_MemoryBarrierAcquire() __asm__ __volatile__ ("dmb ish" : : : "memory")
164 #elif defined(__GNUC__) && defined(__arm__)
165 #if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) || defined(__ARM_ARCH_7EM__) || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) || defined(__ARM_ARCH_7S__)
166 #define SDL_MemoryBarrierRelease() __asm__ __volatile__ ("dmb ish" : : : "memory")
167 #define SDL_MemoryBarrierAcquire() __asm__ __volatile__ ("dmb ish" : : : "memory")
168 #elif defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6T2__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_5TE__)
169 #ifdef __thumb__
170 /* The mcr instruction isn't available in thumb mode, use real functions */
171 #define SDL_MemoryBarrierRelease() SDL_MemoryBarrierReleaseFunction()
172 #define SDL_MemoryBarrierAcquire() SDL_MemoryBarrierAcquireFunction()
173 #else
174 #define SDL_MemoryBarrierRelease() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" : : "r"(0) : "memory")
175 #define SDL_MemoryBarrierAcquire() __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" : : "r"(0) : "memory")
176 #endif /* __thumb__ */
177 #else
178 #define SDL_MemoryBarrierRelease() __asm__ __volatile__ ("" : : : "memory")
179 #define SDL_MemoryBarrierAcquire() __asm__ __volatile__ ("" : : : "memory")
180 #endif /* __GNUC__ && __arm__ */
181 #else
182 #if (defined(__SUNPRO_C) && (__SUNPRO_C >= 0x5120))
183 /* This is correct for all CPUs on Solaris when using Solaris Studio 12.1+. */
184 #include <mbarrier.h>
185 #define SDL_MemoryBarrierRelease() __machine_rel_barrier()
186 #define SDL_MemoryBarrierAcquire() __machine_acq_barrier()
187 #else
188 /* This is correct for the x86 and x64 CPUs, and we'll expand this over time. */
189 #define SDL_MemoryBarrierRelease() SDL_CompilerBarrier()
190 #define SDL_MemoryBarrierAcquire() SDL_CompilerBarrier()
191 #endif
192 #endif
193 
198 typedef struct { int value; } SDL_atomic_t;
199 
207 extern DECLSPEC SDL_bool SDLCALL SDL_AtomicCAS(SDL_atomic_t *a, int oldval, int newval);
208 
214 extern DECLSPEC int SDLCALL SDL_AtomicSet(SDL_atomic_t *a, int v);
215 
219 extern DECLSPEC int SDLCALL SDL_AtomicGet(SDL_atomic_t *a);
220 
228 extern DECLSPEC int SDLCALL SDL_AtomicAdd(SDL_atomic_t *a, int v);
229 
233 #ifndef SDL_AtomicIncRef
234 #define SDL_AtomicIncRef(a) SDL_AtomicAdd(a, 1)
235 #endif
236 
243 #ifndef SDL_AtomicDecRef
244 #define SDL_AtomicDecRef(a) (SDL_AtomicAdd(a, -1) == 1)
245 #endif
246 
254 extern DECLSPEC SDL_bool SDLCALL SDL_AtomicCASPtr(void **a, void *oldval, void *newval);
255 
261 extern DECLSPEC void* SDLCALL SDL_AtomicSetPtr(void **a, void* v);
262 
266 extern DECLSPEC void* SDLCALL SDL_AtomicGetPtr(void **a);
267 
268 /* Ends C function definitions when using C++ */
269 #ifdef __cplusplus
270 }
271 #endif
272 
273 #include "close_code.h"
274 
275 #endif /* SDL_atomic_h_ */
276 
277 /* vi: set ts=4 sw=4 expandtab: */
DECLSPEC void *SDLCALL SDL_AtomicGetPtr(void **a)
Get the value of a pointer atomically.
DECLSPEC int SDLCALL SDL_AtomicSet(SDL_atomic_t *a, int v)
Set an atomic variable to a value.
DECLSPEC int SDLCALL SDL_AtomicGet(SDL_atomic_t *a)
Get the value of an atomic variable.
DECLSPEC void *SDLCALL SDL_AtomicSetPtr(void **a, void *v)
Set a pointer to a value atomically.
#define SDL_CompilerBarrier()
Definition: SDL_atomic.h:132
DECLSPEC SDL_bool SDLCALL SDL_AtomicCASPtr(void **a, void *oldval, void *newval)
Set a pointer to a new value if it is currently an old value.
DECLSPEC SDL_bool SDLCALL SDL_AtomicTryLock(SDL_SpinLock *lock)
Try to lock a spin lock by setting it to a non-zero value.
DECLSPEC void SDLCALL SDL_AtomicLock(SDL_SpinLock *lock)
Lock a spin lock by setting it to a non-zero value.
DECLSPEC SDL_bool SDLCALL SDL_AtomicCAS(SDL_atomic_t *a, int oldval, int newval)
Set an atomic variable to a new value if it is currently an old value.
DECLSPEC int SDLCALL SDL_AtomicAdd(SDL_atomic_t *a, int v)
Add to an atomic variable.
A type representing an atomic integer value. It is a struct so people don&#39;t accidentally use numeric ...
Definition: SDL_atomic.h:198
DECLSPEC void SDLCALL SDL_MemoryBarrierReleaseFunction(void)
DECLSPEC void SDLCALL SDL_AtomicUnlock(SDL_SpinLock *lock)
Unlock a spin lock by setting it to 0. Always returns immediately.