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Diffstat (limited to 'util/thread-utils.h')
| -rw-r--r-- | util/thread-utils.h | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/util/thread-utils.h b/util/thread-utils.h new file mode 100644 index 000000000..035de699f --- /dev/null +++ b/util/thread-utils.h @@ -0,0 +1,246 @@ +/* + * Copyright (C) the libgit2 contributors. All rights reserved. + * + * This file is part of libgit2, distributed under the GNU GPL v2 with + * a Linking Exception. For full terms see the included COPYING file. + */ +#ifndef INCLUDE_thread_utils_h__ +#define INCLUDE_thread_utils_h__ + +#if defined(__GNUC__) && defined(GIT_THREADS) +# 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 +#endif + +/* Common operations even if threading has been disabled */ +typedef struct { +#if defined(GIT_WIN32) + volatile long val; +#else + volatile int val; +#endif +} git_atomic; + +#ifdef GIT_ARCH_64 + +typedef struct { +#if defined(GIT_WIN32) + __int64 val; +#else + int64_t val; +#endif +} git_atomic64; + +typedef git_atomic64 git_atomic_ssize; + +#define git_atomic_ssize_add git_atomic64_add + +#else + +typedef git_atomic git_atomic_ssize; + +#define git_atomic_ssize_add git_atomic_add + +#endif + +#ifdef GIT_THREADS + +#ifdef GIT_WIN32 +# include "win32/thread.h" +#else +# include "unix/pthread.h" +#endif + +GIT_INLINE(void) git_atomic_set(git_atomic *a, int val) +{ +#if defined(GIT_WIN32) + InterlockedExchange(&a->val, (LONG)val); +#elif defined(__GNUC__) + __sync_lock_test_and_set(&a->val, val); +#else +# error "Unsupported architecture for atomic operations" +#endif +} + +GIT_INLINE(int) git_atomic_inc(git_atomic *a) +{ +#if defined(GIT_WIN32) + return InterlockedIncrement(&a->val); +#elif defined(__GNUC__) + return __sync_add_and_fetch(&a->val, 1); +#else +# error "Unsupported architecture for atomic operations" +#endif +} + +GIT_INLINE(int) git_atomic_add(git_atomic *a, int32_t addend) +{ +#if defined(GIT_WIN32) + return InterlockedExchangeAdd(&a->val, addend); +#elif defined(__GNUC__) + return __sync_add_and_fetch(&a->val, addend); +#else +# error "Unsupported architecture for atomic operations" +#endif +} + +GIT_INLINE(int) git_atomic_dec(git_atomic *a) +{ +#if defined(GIT_WIN32) + return InterlockedDecrement(&a->val); +#elif defined(__GNUC__) + return __sync_sub_and_fetch(&a->val, 1); +#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) + foundval = InterlockedCompareExchangePointer((volatile PVOID *)ptr, newval, oldval); +#elif defined(__GNUC__) + foundval = __sync_val_compare_and_swap(ptr, oldval, newval); +#else +# error "Unsupported architecture for atomic operations" +#endif + return (foundval == oldval) ? oldval : newval; +} + +GIT_INLINE(volatile void *) git___swap( + void * volatile *ptr, void *newval) +{ +#if defined(GIT_WIN32) + return InterlockedExchangePointer(ptr, newval); +#else + return __sync_lock_test_and_set(ptr, newval); +#endif +} + +#ifdef GIT_ARCH_64 + +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__) + return __sync_add_and_fetch(&a->val, addend); +#else +# error "Unsupported architecture for atomic operations" +#endif +} + +#endif + +#else + +#define git_thread unsigned int +#define git_thread_create(thread, start_routine, arg) 0 +#define git_thread_join(id, status) (void)0 + +/* Pthreads Mutex */ +#define git_mutex unsigned int +GIT_INLINE(int) git_mutex_init(git_mutex *mutex) \ + { GIT_UNUSED(mutex); return 0; } +GIT_INLINE(int) git_mutex_lock(git_mutex *mutex) \ + { GIT_UNUSED(mutex); return 0; } +#define git_mutex_unlock(a) (void)0 +#define git_mutex_free(a) (void)0 + +/* Pthreads condition vars */ +#define git_cond unsigned int +#define git_cond_init(c, a) (void)0 +#define git_cond_free(c) (void)0 +#define git_cond_wait(c, l) (void)0 +#define git_cond_signal(c) (void)0 +#define git_cond_broadcast(c) (void)0 + +/* Pthreads rwlock */ +#define git_rwlock unsigned int +#define git_rwlock_init(a) 0 +#define git_rwlock_rdlock(a) 0 +#define git_rwlock_rdunlock(a) (void)0 +#define git_rwlock_wrlock(a) 0 +#define git_rwlock_wrunlock(a) (void)0 +#define git_rwlock_free(a) (void)0 +#define GIT_RWLOCK_STATIC_INIT 0 + + +GIT_INLINE(void) git_atomic_set(git_atomic *a, int val) +{ + a->val = val; +} + +GIT_INLINE(int) git_atomic_inc(git_atomic *a) +{ + return ++a->val; +} + +GIT_INLINE(int) git_atomic_add(git_atomic *a, int32_t addend) +{ + a->val += addend; + return a->val; +} + +GIT_INLINE(int) git_atomic_dec(git_atomic *a) +{ + return --a->val; +} + +GIT_INLINE(void *) git___compare_and_swap( + void * volatile *ptr, void *oldval, void *newval) +{ + if (*ptr == oldval) + *ptr = newval; + else + oldval = newval; + return oldval; +} + +GIT_INLINE(volatile void *) git___swap( + void * volatile *ptr, void *newval) +{ + volatile void *old = *ptr; + *ptr = newval; + return old; +} + +#ifdef GIT_ARCH_64 + +GIT_INLINE(int64_t) git_atomic64_add(git_atomic64 *a, int64_t addend) +{ + a->val += addend; + return a->val; +} + +#endif + +#endif + +GIT_INLINE(int) git_atomic_get(git_atomic *a) +{ + return (int)a->val; +} + +/* Atomically replace oldval with newval + * @return oldval if it was replaced or newval if it was not + */ +#define git__compare_and_swap(P,O,N) \ + git___compare_and_swap((void * volatile *)P, O, N) + +#define git__swap(ptr, val) (void *)git___swap((void * volatile *)&ptr, val) + +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() +#else +# define GIT_MEMORY_BARRIER /* noop */ +#endif + +#endif |