diff options
Diffstat (limited to 'src/thread-utils.h')
| -rw-r--r-- | src/thread-utils.h | 161 |
1 files changed, 140 insertions, 21 deletions
diff --git a/src/thread-utils.h b/src/thread-utils.h index 035de699f..e0bb381b2 100644 --- a/src/thread-utils.h +++ b/src/thread-utils.h @@ -7,12 +7,31 @@ #ifndef INCLUDE_thread_utils_h__ #define INCLUDE_thread_utils_h__ -#if defined(__GNUC__) && defined(GIT_THREADS) +#if defined(GIT_THREADS) + +#if defined(__clang__) + +# if (__clang_major__ < 3 || (__clang_major__ == 3 && __clang_minor__ < 1)) +# error Atomic primitives do not exist on this version of clang; configure libgit2 with -DTHREADSAFE=OFF +# else +# define GIT_BUILTIN_ATOMIC +# endif + +#elif defined(__GNUC__) + # if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)) # error Atomic primitives do not exist on this version of gcc; configure libgit2 with -DTHREADSAFE=OFF # endif +# if (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 7)) +# define GIT_BUILTIN_ATOMIC +# else +# define GIT_BUILTIN_SYNC +# endif + #endif +#endif /* GIT_THREADS */ + /* Common operations even if threading has been disabled */ typedef struct { #if defined(GIT_WIN32) @@ -26,21 +45,25 @@ typedef struct { typedef struct { #if defined(GIT_WIN32) - __int64 val; + volatile __int64 val; #else - int64_t val; + volatile int64_t val; #endif } git_atomic64; typedef git_atomic64 git_atomic_ssize; +#define git_atomic_ssize_set git_atomic64_set #define git_atomic_ssize_add git_atomic64_add +#define git_atomic_ssize_get git_atomic64_get #else typedef git_atomic git_atomic_ssize; +#define git_atomic_ssize_set git_atomic_set #define git_atomic_ssize_add git_atomic_add +#define git_atomic_ssize_get git_atomic_get #endif @@ -56,7 +79,9 @@ GIT_INLINE(void) git_atomic_set(git_atomic *a, int val) { #if defined(GIT_WIN32) InterlockedExchange(&a->val, (LONG)val); -#elif defined(__GNUC__) +#elif defined(GIT_BUILTIN_ATOMIC) + __atomic_store_n(&a->val, val, __ATOMIC_SEQ_CST); +#elif defined(GIT_BUILTIN_SYNC) __sync_lock_test_and_set(&a->val, val); #else # error "Unsupported architecture for atomic operations" @@ -67,7 +92,9 @@ GIT_INLINE(int) git_atomic_inc(git_atomic *a) { #if defined(GIT_WIN32) return InterlockedIncrement(&a->val); -#elif defined(__GNUC__) +#elif defined(GIT_BUILTIN_ATOMIC) + return __atomic_add_fetch(&a->val, 1, __ATOMIC_SEQ_CST); +#elif defined(GIT_BUILTIN_SYNC) return __sync_add_and_fetch(&a->val, 1); #else # error "Unsupported architecture for atomic operations" @@ -78,7 +105,9 @@ GIT_INLINE(int) git_atomic_add(git_atomic *a, int32_t addend) { #if defined(GIT_WIN32) return InterlockedExchangeAdd(&a->val, addend); -#elif defined(__GNUC__) +#elif defined(GIT_BUILTIN_ATOMIC) + return __atomic_add_fetch(&a->val, addend, __ATOMIC_SEQ_CST); +#elif defined(GIT_BUILTIN_SYNC) return __sync_add_and_fetch(&a->val, addend); #else # error "Unsupported architecture for atomic operations" @@ -89,25 +118,45 @@ GIT_INLINE(int) git_atomic_dec(git_atomic *a) { #if defined(GIT_WIN32) return InterlockedDecrement(&a->val); -#elif defined(__GNUC__) +#elif defined(GIT_BUILTIN_ATOMIC) + return __atomic_sub_fetch(&a->val, 1, __ATOMIC_SEQ_CST); +#elif defined(GIT_BUILTIN_SYNC) return __sync_sub_and_fetch(&a->val, 1); #else # error "Unsupported architecture for atomic operations" #endif } +GIT_INLINE(int) git_atomic_get(git_atomic *a) +{ +#if defined(GIT_WIN32) + return (int)InterlockedCompareExchange(&a->val, 0, 0); +#elif defined(GIT_BUILTIN_ATOMIC) + return __atomic_load_n(&a->val, __ATOMIC_SEQ_CST); +#elif defined(GIT_BUILTIN_SYNC) + return __sync_val_compare_and_swap(&a->val, 0, 0); +#else +# error "Unsupported architecture for atomic operations" +#endif +} + GIT_INLINE(void *) git___compare_and_swap( void * volatile *ptr, void *oldval, void *newval) { - volatile void *foundval; #if defined(GIT_WIN32) + volatile void *foundval; foundval = InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval); -#elif defined(__GNUC__) + return (foundval == oldval) ? oldval : newval; +#elif defined(GIT_BUILTIN_ATOMIC) + bool success = __atomic_compare_exchange(ptr, &oldval, &newval, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST); + return success ? oldval : newval; +#elif defined(GIT_BUILTIN_SYNC) + volatile void *foundval; foundval = __sync_val_compare_and_swap(ptr, oldval, newval); + return (foundval == oldval) ? oldval : newval; #else # error "Unsupported architecture for atomic operations" #endif - return (foundval == oldval) ? oldval : newval; } GIT_INLINE(volatile void *) git___swap( @@ -115,8 +164,30 @@ GIT_INLINE(volatile void *) git___swap( { #if defined(GIT_WIN32) return InterlockedExchangePointer(ptr, newval); -#else +#elif defined(GIT_BUILTIN_ATOMIC) + void * volatile foundval; + __atomic_exchange(ptr, &newval, &foundval, __ATOMIC_SEQ_CST); + return foundval; +#elif defined(GIT_BUILTIN_SYNC) return __sync_lock_test_and_set(ptr, newval); +#else +# error "Unsupported architecture for atomic operations" +#endif +} + +GIT_INLINE(volatile void *) git___load(void * volatile *ptr) +{ +#if defined(GIT_WIN32) + void *newval = NULL, *oldval = NULL; + volatile void *foundval = NULL; + foundval = InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval); + return foundval; +#elif defined(GIT_BUILTIN_ATOMIC) + return (volatile void *)__atomic_load_n(ptr, __ATOMIC_SEQ_CST); +#elif defined(GIT_BUILTIN_SYNC) + return (volatile void *)__sync_val_compare_and_swap(ptr, 0, 0); +#else +# error "Unsupported architecture for atomic operations" #endif } @@ -126,13 +197,41 @@ GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend) { #if defined(GIT_WIN32) return InterlockedExchangeAdd64(&a->val, addend); -#elif defined(__GNUC__) +#elif defined(GIT_BUILTIN_ATOMIC) + return __atomic_add_fetch(&a->val, addend, __ATOMIC_SEQ_CST); +#elif defined(GIT_BUILTIN_SYNC) return __sync_add_and_fetch(&a->val, addend); #else # error "Unsupported architecture for atomic operations" #endif } +GIT_INLINE(void) git_atomic64_set(git_atomic64 *a, int64_t val) +{ +#if defined(GIT_WIN32) + InterlockedExchange64(&a->val, val); +#elif defined(GIT_BUILTIN_ATOMIC) + __atomic_store_n(&a->val, val, __ATOMIC_SEQ_CST); +#elif defined(GIT_BUILTIN_SYNC) + __sync_lock_test_and_set(&a->val, val); +#else +# error "Unsupported architecture for atomic operations" +#endif +} + +GIT_INLINE(int64_t) git_atomic64_get(git_atomic64 *a) +{ +#if defined(GIT_WIN32) + return (int64_t)InterlockedCompareExchange64(&a->val, 0, 0); +#elif defined(GIT_BUILTIN_ATOMIC) + return __atomic_load_n(&a->val, __ATOMIC_SEQ_CST); +#elif defined(GIT_BUILTIN_SYNC) + return __sync_val_compare_and_swap(&a->val, 0, 0); +#else +# error "Unsupported architecture for atomic operations" +#endif +} + #endif #else @@ -190,6 +289,11 @@ GIT_INLINE(int) git_atomic_dec(git_atomic *a) return --a->val; } +GIT_INLINE(int) git_atomic_get(git_atomic *a) +{ + return (int)a->val; +} + GIT_INLINE(void *) git___compare_and_swap( void * volatile *ptr, void *oldval, void *newval) { @@ -216,15 +320,20 @@ GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend) return a->val; } -#endif - -#endif +GIT_INLINE(void) git_atomic64_set(git_atomic64 *a, int64_t val) +{ + a->val = val; +} -GIT_INLINE(int) git_atomic_get(git_atomic *a) +GIT_INLINE(int64_t) git_atomic64_get(git_atomic64 *a) { - return (int)a->val; + return (int64_t)a->val; } +#endif + +#endif + /* Atomically replace oldval with newval * @return oldval if it was replaced or newval if it was not */ @@ -233,14 +342,24 @@ GIT_INLINE(int) git_atomic_get(git_atomic *a) #define git__swap(ptr, val) (void *)git___swap((void * volatile *)&ptr, val) +#define git__load(ptr) (void *)git___load((void * volatile *)&ptr) + extern int git_online_cpus(void); -#if defined(GIT_THREADS) && defined(_MSC_VER) -# define GIT_MEMORY_BARRIER MemoryBarrier() -#elif defined(GIT_THREADS) -# define GIT_MEMORY_BARRIER __sync_synchronize() +#if defined(GIT_THREADS) + +# if defined(GIT_WIN32) +# define GIT_MEMORY_BARRIER MemoryBarrier() +# elif defined(GIT_BUILTIN_ATOMIC) +# define GIT_MEMORY_BARRIER __atomic_thread_fence(__ATOMIC_SEQ_CST) +# elif defined(GIT_BUILTIN_SYNC) +# define GIT_MEMORY_BARRIER __sync_synchronize() +# endif + #else + # define GIT_MEMORY_BARRIER /* noop */ + #endif #endif |