haiku/headers/private/shared/RWLockManager.h

132 lines
2.6 KiB
C++

/*
* Copyright 2009, Ingo Weinhold, ingo_weinhold@gmx.de.
* Distributed under the terms of the MIT License.
*/
#ifndef _RW_LOCK_MANAGER_H
#define _RW_LOCK_MANAGER_H
#include <Locker.h>
#include <util/DoublyLinkedList.h>
namespace BPrivate {
class RWLockManager;
class RWLockable {
public:
RWLockable();
private:
struct Waiter : DoublyLinkedListLinkImpl<Waiter> {
Waiter(bool writer)
:
thread(find_thread(NULL)),
writer(writer),
queued(false)
{
}
thread_id thread;
status_t status;
bool writer;
bool queued;
};
typedef DoublyLinkedList<Waiter> WaiterList;
friend class RWLockManager;
private:
thread_id fOwner;
int32 fOwnerCount;
int32 fReaderCount;
WaiterList fWaiters;
};
class RWLockManager {
public:
RWLockManager();
~RWLockManager();
status_t Init() { return fLock.InitCheck(); }
bool Lock() { return fLock.Lock(); }
void Unlock() { return fLock.Unlock(); }
bool ReadLock(RWLockable* lockable);
bool TryReadLock(RWLockable* lockable);
status_t ReadLockWithTimeout(RWLockable* lockable,
bigtime_t timeout);
void ReadUnlock(RWLockable* lockable);
bool WriteLock(RWLockable* lockable);
bool TryWriteLock(RWLockable* lockable);
status_t WriteLockWithTimeout(RWLockable* lockable,
bigtime_t timeout);
void WriteUnlock(RWLockable* lockable);
inline bool GenericLock(bool write, RWLockable* lockable);
inline bool TryGenericLock(bool write,
RWLockable* lockable);
inline status_t GenericLockWithTimeout(bool write,
RWLockable* lockable, bigtime_t timeout);
inline void GenericUnlock(bool write, RWLockable* lockable);
private:
status_t _Wait(RWLockable* lockable, bool writer,
bigtime_t timeout);
void _Unblock(RWLockable* lockable);
private:
BLocker fLock;
};
inline bool
RWLockManager::GenericLock(bool write, RWLockable* lockable)
{
return write ? WriteLock(lockable) : ReadLock(lockable);
}
inline bool
RWLockManager::TryGenericLock(bool write, RWLockable* lockable)
{
return write ? TryWriteLock(lockable) : TryReadLock(lockable);
}
inline status_t
RWLockManager::GenericLockWithTimeout(bool write, RWLockable* lockable,
bigtime_t timeout)
{
return write
? WriteLockWithTimeout(lockable, timeout)
: ReadLockWithTimeout(lockable, timeout);
}
inline void
RWLockManager::GenericUnlock(bool write, RWLockable* lockable)
{
if (write)
WriteUnlock(lockable);
else
ReadUnlock(lockable);
}
} // namespace BPrivate
using BPrivate::RWLockable;
using BPrivate::RWLockManager;
#endif // _RW_LOCK_MANAGER_H