haiku/headers/private/kernel/lock.h
Axel Dörfler 2b14cdd11c * Added a mutex_trylock() function.
* Replaced release_sem() with release_sem_etc() for future addition of the
  B_DO_NOT_RESCHEDULE flag.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22308 a95241bf-73f2-0310-859d-f6bbb57e9c96
2007-09-25 16:41:52 +00:00

112 lines
2.7 KiB
C

/*
* Copyright 2002-2007, Axel Dörfler, axeld@pinc-software.de.
* Distributed under the terms of the MIT License.
*
* Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
* Distributed under the terms of the NewOS License.
*/
#ifndef _KERNEL_LOCK_H
#define _KERNEL_LOCK_H
#include <OS.h>
#include <debug.h>
typedef struct recursive_lock {
sem_id sem;
thread_id holder;
int recursion;
} recursive_lock;
typedef struct mutex {
sem_id sem;
thread_id holder;
} mutex;
typedef struct benaphore {
sem_id sem;
int32 count;
} benaphore;
// Note: this is currently a trivial r/w lock implementation
// it will be replaced with something better later - this
// or a similar API will be made publically available at this point.
typedef struct rw_lock {
sem_id sem;
int32 count;
benaphore writeLock;
} rw_lock;
#define RW_MAX_READERS 1000000
#if 0 && KDEBUG // XXX disable this for now, it causes problems when including thread.h here
# include <thread.h>
#define ASSERT_LOCKED_RECURSIVE(r) { ASSERT(thread_get_current_thread_id() == (r)->holder); }
#define ASSERT_LOCKED_MUTEX(m) { ASSERT(thread_get_current_thread_id() == (m)->holder); }
#else
#define ASSERT_LOCKED_RECURSIVE(r)
#define ASSERT_LOCKED_MUTEX(m)
#endif
#ifdef __cplusplus
extern "C" {
#endif
extern status_t recursive_lock_init(recursive_lock *lock, const char *name);
extern void recursive_lock_destroy(recursive_lock *lock);
extern status_t recursive_lock_lock(recursive_lock *lock);
extern void recursive_lock_unlock(recursive_lock *lock);
extern int32 recursive_lock_get_recursion(recursive_lock *lock);
extern status_t mutex_init(mutex *m, const char *name);
extern void mutex_destroy(mutex *m);
extern status_t mutex_trylock(mutex *mutex);
extern status_t mutex_lock(mutex *m);
extern void mutex_unlock(mutex *m);
extern status_t benaphore_init(benaphore *ben, const char *name);
extern void benaphore_destroy(benaphore *ben);
static inline status_t
benaphore_lock_etc(benaphore *ben, uint32 flags, bigtime_t timeout)
{
if (atomic_add(&ben->count, -1) <= 0)
return acquire_sem_etc(ben->sem, 1, flags, timeout);
return B_OK;
}
static inline status_t
benaphore_lock(benaphore *ben)
{
if (atomic_add(&ben->count, -1) <= 0)
return acquire_sem(ben->sem);
return B_OK;
}
static inline status_t
benaphore_unlock(benaphore *ben)
{
if (atomic_add(&ben->count, 1) < 0)
return release_sem(ben->sem);
return B_OK;
}
extern status_t rw_lock_init(rw_lock *lock, const char *name);
extern void rw_lock_destroy(rw_lock *lock);
extern status_t rw_lock_read_lock(rw_lock *lock);
extern status_t rw_lock_read_unlock(rw_lock *lock);
extern status_t rw_lock_write_lock(rw_lock *lock);
extern status_t rw_lock_write_unlock(rw_lock *lock);
#ifdef __cplusplus
}
#endif
#endif /* _KERNEL_LOCK_H */