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#ifndef INCLUDE_thread_utils_h__
#define INCLUDE_thread_utils_h__
#if defined(GIT_HAS_PTHREAD)
typedef pthread_mutex_t git_lck;
# define GITLCK_INIT PTHREAD_MUTEX_INITIALIZER
# define gitlck_init(a) pthread_mutex_init(a, NULL)
# define gitlck_lock(a) pthread_mutex_lock(a)
# define gitlck_unlock(a) pthread_mutex_unlock(a)
# define gitlck_free(a) pthread_mutex_destroy(a)
# if defined(GIT_HAS_ASM_ATOMIC)
# include <asm/atomic.h>
typedef atomic_t git_refcnt;
# define gitrc_init(a) atomic_set(a, 0)
# define gitrc_inc(a) atomic_inc_return(a)
# define gitrc_dec(a) atomic_dec_and_test(a)
# define gitrc_free(a) (void)0
# else
typedef struct { git_lck lock; int counter; } git_refcnt;
/** Initialize to 0. No memory barrier is issued. */
GIT_INLINE(void) gitrc_init(git_refcnt *p)
{
gitlck_init(&p->lock);
p->counter = 0;
}
/**
* Increment.
*
* Atomically increments @p by 1. A memory barrier is also
* issued before and after the operation.
*
* @param p pointer of type git_refcnt
*/
GIT_INLINE(void) gitrc_inc(git_refcnt *p)
{
gitlck_lock(&p->lock);
p->counter++;
gitlck_unlock(&p->lock);
}
/**
* Decrement and test.
*
* Atomically decrements @p by 1 and returns true if the
* result is 0, or false for all other cases. A memory
* barrier is also issued before and after the operation.
*
* @param p pointer of type git_refcnt
*/
GIT_INLINE(int) gitrc_dec(git_refcnt *p)
{
int c;
gitlck_lock(&p->lock);
c = --p->counter;
gitlck_unlock(&p->lock);
return !c;
}
/** Free any resources associated with the counter. */
# define gitrc_free(p) gitlck_free(&(p)->lock)
# endif
#elif defined(GIT_THREADS)
# error GIT_THREADS but no git_lck implementation
#else
typedef struct { int dummy; } git_lck;
# define GIT_MUTEX_INIT {}
# define gitlck_init(a) (void)0
# define gitlck_lock(a) (void)0
# define gitlck_unlock(a) (void)0
# define gitlck_free(a) (void)0
typedef struct { int counter; } git_refcnt;
# define gitrc_init(a) ((a)->counter = 0)
# define gitrc_inc(a) ((a)->counter++)
# define gitrc_dec(a) (--(a)->counter == 0)
# define gitrc_free(a) (void)0
#endif
extern int git_online_cpus(void);
#endif /* INCLUDE_thread_utils_h__ */
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