cctools-port/cctools/libobjc2/lock.h
2014-11-18 21:05:02 +01:00

71 lines
2.1 KiB
C

/**
* libobjc requires recursive mutexes. These are delegated to the underlying
* threading implementation. This file contains a VERY thin wrapper over the
* Windows and POSIX mutex APIs.
*/
#ifndef __LIBOBJC_LOCK_H_INCLUDED__
#define __LIBOBJC_LOCK_H_INCLUDED__
#ifdef WIN32
#define BOOL _WINBOOL
# include <windows.h>
#undef BOOL
typedef HANDLE mutex_t;
# define INIT_LOCK(x) x = CreateMutex(NULL, FALSE, NULL)
# define LOCK(x) WaitForSingleObject(*x, INFINITE)
# define UNLOCK(x) ReleaseMutex(*x)
# define DESTROY_LOCK(x) CloseHandle(*x)
#else
# include <pthread.h>
typedef pthread_mutex_t mutex_t;
// If this pthread implementation has a static initializer for recursive
// mutexes, use that, otherwise fall back to the portable version
# ifdef PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
# define INIT_LOCK(x) x = (pthread_mutex_t)PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP
# elif defined(PTHREAD_RECURSIVE_MUTEX_INITIALIZER)
# define INIT_LOCK(x) x = (pthread_mutex_t)PTHREAD_RECURSIVE_MUTEX_INITIALIZER
# else
# define INIT_LOCK(x) init_recursive_mutex(&(x))
static inline void init_recursive_mutex(pthread_mutex_t *x)
{
pthread_mutexattr_t recursiveAttributes;
pthread_mutexattr_init(&recursiveAttributes);
pthread_mutexattr_settype(&recursiveAttributes, PTHREAD_MUTEX_RECURSIVE);
pthread_mutex_init(x, &recursiveAttributes);
pthread_mutexattr_destroy(&recursiveAttributes);
}
# endif
# define LOCK(x) pthread_mutex_lock(x)
# define UNLOCK(x) pthread_mutex_unlock(x)
# define DESTROY_LOCK(x) pthread_mutex_destroy(x)
#endif
__attribute__((unused)) static void objc_release_lock(void *x)
{
mutex_t *lock = *(mutex_t**)x;
UNLOCK(lock);
}
/**
* Acquires the lock and automatically releases it at the end of the current
* scope.
*/
#define LOCK_FOR_SCOPE(lock) \
__attribute__((cleanup(objc_release_lock)))\
__attribute__((unused)) mutex_t *lock_pointer = lock;\
LOCK(lock)
/**
* The global runtime mutex.
*/
extern mutex_t runtime_mutex;
#define LOCK_RUNTIME() LOCK(&runtime_mutex)
#define UNLOCK_RUNTIME() UNLOCK(&runtime_mutex)
#define LOCK_RUNTIME_FOR_SCOPE() LOCK_FOR_SCOPE(&runtime_mutex)
#endif // __LIBOBJC_LOCK_H_INCLUDED__