haiku/headers/private/kernel/user_mutex.h
Ingo Weinhold 813d4cbe94 * Moved created subdirectory src/system/kernel/lock.cpp to new subdirectory
locks.
* Added syscalls for a new kind of mutex. A mutex consists only of an int32 and
  doesn't require any kernel resources. So it's initialization cannot fail
  (it consists only of setting the mutex value to 0). An uncontended lock or
  unlock operation can basically consist of an atomic_*() in userland. The
  syscalls (when the mutex is contended) are a bit more expensive than semaphore
  operations, though.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36158 a95241bf-73f2-0310-859d-f6bbb57e9c96
2010-04-11 16:07:39 +00:00

30 lines
608 B
C

/*
* Copyright 2010, Ingo Weinhold, ingo_weinhold@gmx.de.
* Distributed under the terms of the MIT License.
*/
#ifndef _KERNEL_USER_MUTEX_H
#define _KERNEL_USER_MUTEX_H
#include <SupportDefs.h>
#ifdef __cplusplus
extern "C" {
#endif
void user_mutex_init();
status_t _user_mutex_lock(int32* mutex, const char* name, uint32 flags,
bigtime_t timeout);
status_t _user_mutex_unlock(int32* mutex, uint32 flags);
status_t _user_mutex_switch_lock(int32* fromMutex, int32* toMutex,
const char* name, uint32 flags, bigtime_t timeout);
#ifdef __cplusplus
}
#endif
#endif /* _KERNEL_USER_MUTEX_H */