diff options
Diffstat (limited to 'ecb.h')
| -rw-r--r-- | ecb.h | 24 |
1 files changed, 16 insertions, 8 deletions
@@ -69,12 +69,12 @@ #if ECB_GCC_VERSION(2,5) #if __x86 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory") - #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE - #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE /* better be safe than sorry */ + #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */ + #define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */ #elif __amd64 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory") #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory") - #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") + #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */ #endif #endif #endif @@ -84,19 +84,27 @@ #define ECB_MEMORY_FENCE __sync_synchronize () #define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) #define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); }) - #elif _MSC_VER >= 1400 && 0 /* TODO: only true when using volatiles */ - #define ECB_MEMORY_FENCE do { } while (0) - #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE - #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE + #elif _MSC_VER >= 1400 /* VC++ 2005 */ + #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier) + #define ECB_MEMORY_FENCE _ReadWriteBarrier () + #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */ + #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier () #elif defined(_WIN32) #include <WinNT.h> - #define ECB_MEMORY_FENCE MemoryBarrier () + #define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */ #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE #endif #endif #ifndef ECB_MEMORY_FENCE + /* + * if you get undefined symbol references to pthread_mutex_lock, + * or failure to find pthread.h, then you should implement + * the ECB_MEMORY_FENCE operations for your cpu/compiler + * OR proide pthread.h and link against the posix thread library + * of your system. + */ #include <pthread.h> static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER; |