diff options
| -rw-r--r-- | src/cache.c | 2 | ||||
| -rw-r--r-- | src/odb.c | 6 | ||||
| -rw-r--r-- | src/pool.c | 11 | ||||
| -rw-r--r-- | src/thread-utils.h | 161 | ||||
| -rw-r--r-- | src/util.h | 4 |
5 files changed, 152 insertions, 32 deletions
diff --git a/src/cache.c b/src/cache.c index 1d2c0158d..a76da50d7 100644 --- a/src/cache.c +++ b/src/cache.c @@ -168,7 +168,7 @@ static void *cache_store(git_cache *cache, git_cached_obj *entry) return entry; /* soften the load on the cache */ - if (git_cache__current_storage.val > git_cache__max_storage) + if (git_atomic_ssize_get(&git_cache__current_storage) > git_cache__max_storage) cache_evict_entries(cache); /* not found */ @@ -44,8 +44,8 @@ typedef struct static git_cache *odb_cache(git_odb *odb) { - if (odb->rc.owner != NULL) { - git_repository *owner = odb->rc.owner; + git_repository *owner = GIT_REFCOUNT_OWNER(odb); + if (owner != NULL) { return &owner->objects; } @@ -664,7 +664,7 @@ int git_odb_open(git_odb **out, const char *objects_dir) int git_odb__set_caps(git_odb *odb, int caps) { if (caps == GIT_ODB_CAP_FROM_OWNER) { - git_repository *repo = odb->rc.owner; + git_repository *repo = GIT_REFCOUNT_OWNER(odb); int val; if (!repo) { diff --git a/src/pool.c b/src/pool.c index cb98f1af1..34d0adc1f 100644 --- a/src/pool.c +++ b/src/pool.c @@ -23,17 +23,18 @@ static void *pool_alloc_page(git_pool *pool, size_t size); static size_t pool_system_page_size(void) { - static size_t size = 0; + static git_atomic_ssize cached_size = {0}; + size_t page_size = 0; - if (!size) { - size_t page_size; + if ((page_size = (size_t)git_atomic_ssize_get(&cached_size)) == 0) { if (git__page_size(&page_size) < 0) page_size = 4096; /* allow space for malloc overhead */ - size = (page_size - (2 * sizeof(void *)) - sizeof(git_pool_page)); + page_size -= (2 * sizeof(void *)) + sizeof(git_pool_page); + git_atomic_ssize_set(&cached_size, (int64_t)page_size); } - return size; + return page_size; } #ifndef GIT_DEBUG_POOL 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 diff --git a/src/util.h b/src/util.h index b49850d23..f49989f7e 100644 --- a/src/util.h +++ b/src/util.h @@ -186,10 +186,10 @@ typedef void (*git_refcount_freeptr)(void *r); } #define GIT_REFCOUNT_OWN(r, o) { \ - (r)->rc.owner = o; \ + (void)git__swap((r)->rc.owner, o); \ } -#define GIT_REFCOUNT_OWNER(r) ((r)->rc.owner) +#define GIT_REFCOUNT_OWNER(r) git__load((r)->rc.owner) #define GIT_REFCOUNT_VAL(r) git_atomic_get((r)->rc.refcount) |