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/*
* 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__
#include "common.h"
/* Common operations even if threading has been disabled */
typedef struct {
#if defined(GIT_WIN32)
volatile long val;
#else
volatile int val;
#endif
} git_atomic;
GIT_INLINE(void) git_atomic_set(git_atomic *a, int val)
{
a->val = val;
}
#ifdef GIT_THREADS
#define git_thread pthread_t
#define git_thread_create(thread, attr, start_routine, arg) pthread_create(thread, attr, start_routine, arg)
#define git_thread_kill(thread) pthread_cancel(thread)
#define git_thread_exit(status) pthread_exit(status)
#define git_thread_join(id, status) pthread_join(id, status)
/* Pthreads Mutex */
#define git_mutex pthread_mutex_t
#define git_mutex_init(a) pthread_mutex_init(a, NULL)
#define git_mutex_lock(a) pthread_mutex_lock(a)
#define git_mutex_unlock(a) pthread_mutex_unlock(a)
#define git_mutex_free(a) pthread_mutex_destroy(a)
/* Pthreads condition vars */
#define git_cond pthread_cond_t
#define git_cond_init(c) pthread_cond_init(c, NULL)
#define git_cond_free(c) pthread_cond_destroy(c)
#define git_cond_wait(c, l) pthread_cond_wait(c, l)
#define git_cond_signal(c) pthread_cond_signal(c)
#define git_cond_broadcast(c) pthread_cond_broadcast(c)
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_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(
volatile void **ptr, void *oldval, void *newval)
{
volatile void *foundval;
#if defined(GIT_WIN32)
foundval = InterlockedCompareExchangePointer(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;
}
#else
#define git_thread unsigned int
#define git_thread_create(thread, attr, start_routine, arg) (void)0
#define git_thread_kill(thread) (void)0
#define git_thread_exit(status) (void)0
#define git_thread_join(id, status) (void)0
/* Pthreads Mutex */
#define git_mutex unsigned int
#define git_mutex_init(a) (void)0
#define git_mutex_lock(a) 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
GIT_INLINE(int) git_atomic_inc(git_atomic *a)
{
return ++a->val;
}
GIT_INLINE(int) git_atomic_dec(git_atomic *a)
{
return --a->val;
}
GIT_INLINE(void *) git___compare_and_swap(
volatile void **ptr, void *oldval, void *newval)
{
if (*ptr == oldval)
*ptr = newval;
else
oldval = newval;
return oldval;
}
#endif
/* 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((volatile void **)P, O, N)
#define git__swap(ptr, val) git__compare_and_swap(&ptr, ptr, val)
extern int git_online_cpus(void);
#if defined(GIT_THREADS) && defined(GIT_WIN32)
# define GIT_MEMORY_BARRIER MemoryBarrier()
#elif defined(GIT_THREADS)
# define GIT_MEMORY_BARRIER __sync_synchronize()
#else
# define GIT_MEMORY_BARRIER /* noop */
#endif
#endif /* INCLUDE_thread_utils_h__ */
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