+++ /dev/null
-/****************************************************************************
-**
-** Copyright (C) Qxt Foundation. Some rights reserved.
-**
-** This file is part of the QxtCore module of the Qt eXTension library
-**
-** This library is free software; you can redistribute it and/or modify it
-** under the terms of th Common Public License, version 1.0, as published by
-** IBM.
-**
-** This file is provided "AS IS", without WARRANTIES OR CONDITIONS OF ANY
-** KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT LIMITATION, ANY
-** WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY OR
-** FITNESS FOR A PARTICULAR PURPOSE.
-**
-** You should have received a copy of the CPL along with this file.
-** See the LICENSE file and the cpl1.0.txt file included with the source
-** distribution for more information. If you did not receive a copy of the
-** license, contact the Qxt Foundation.
-**
-** <http://libqxt.sourceforge.net> <foundation@libqxt.org>
-**
-****************************************************************************/
-#include "qxtfilelock.h"
-#include "qxtfilelock_p.h"
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <fcntl.h>
-/*include pthread to make errno threadsafe*/
-#include <pthread.h>
-#include <errno.h>
-#include <QPointer>
-#include <QMutableLinkedListIterator>
-#include <QDebug>
-
-/*!
- * \internal this class is used on *nix to register all locks created by a process and to let locks on *nix act like locks on windows
- */
-class QxtFileLockRegistry
-{
-public:
- bool registerLock(QxtFileLock *lock );
- bool removeLock(QxtFileLock *lock );
- static QxtFileLockRegistry& instance();
-
-private:
- QLinkedList < QPointer<QxtFileLock> > procLocks;
- QMutex registryMutex;
- QxtFileLockRegistry();
-};
-
-QxtFileLockRegistry::QxtFileLockRegistry()
-{}
-
-QxtFileLockRegistry& QxtFileLockRegistry::instance()
-{
- static QxtFileLockRegistry instance;
- return instance;
-}
-
-/*!
- * \internal this function locks the lockregistry and checks if there is a collision between the process locks
- * \internal if there is no collision it inserts the lock into the registry and returns
- * \internal return true for success
- */
-bool QxtFileLockRegistry::registerLock(QxtFileLock * lock )
-{
- QMutexLocker locker(&this->registryMutex);
-
- QFile *fileToLock = lock ->file();
-
- if (fileToLock)
- {
- struct stat fileInfo;
- if ( fstat(fileToLock->handle(),&fileInfo) < 0 )
- return false;
-
- int newLockStart = lock ->offset();
- int newLockEnd = lock ->offset()+lock ->length();
-
- QMutableLinkedListIterator< QPointer<QxtFileLock> >iterator(this->procLocks);
-
- while (iterator.hasNext())
- {
- QPointer<QxtFileLock> currLock = iterator.next();
- if (currLock && currLock->file() && currLock->file()->isOpen())
- {
- struct stat currFileInfo;
-
- /*first check if the current lock is on the same file*/
- if ( fstat(currLock->file()->handle(),&currFileInfo) < 0 )
- {
- /*that should never happen because a closing file should remove all locks*/
- Q_ASSERT(false);
- continue;
- }
-
- if (currFileInfo.st_dev == fileInfo.st_dev && currFileInfo.st_ino == fileInfo.st_ino)
- {
- /*same file, check if our locks are in conflict*/
- int currLockStart = currLock->offset();
- int currLockEnd = currLock->offset()+currLock->length();
-
- /*do we have to check for threads here?*/
- if (newLockEnd >= currLockStart && newLockStart <= currLockEnd)
- {
- qDebug()<<"we may have a collision";
- qDebug()<<newLockEnd<<" >= "<<currLockStart<<" && "<<newLockStart<<" <= "<<currLockEnd;
-
- /*same lock region if one of both locks are exclusive we have a collision*/
- if (lock ->mode() == QxtFileLock::WriteLockWait || lock ->mode() == QxtFileLock::WriteLock ||
- currLock->mode() == QxtFileLock::WriteLockWait || currLock->mode() == QxtFileLock::WriteLock)
- {
- qDebug()<<"Okay if this is not the same thread using the same handle there is a collision";
- /*the same thread can lock the same region with the same handle*/
-
- qDebug()<<"! ("<<lock ->thread()<<" == "<<currLock->thread()<<" && "<<lock ->file()->handle()<<" == "<<currLock->file()->handle()<<")";
-
- if (! (lock ->thread() == currLock->thread() && lock ->file()->handle() == currLock->file()->handle()))
- {
- qDebug()<<"Collision";
- return false;
- }
- }
- }
- }
- }
- else //remove dead locks
- iterator.remove();
- }
- qDebug()<<"The lock is okay";
- /*here we can insert the lock into the list and return*/
- procLocks.append(QPointer<QxtFileLock>(lock ));
- return true;
-
- }
-
- return false;
-}
-
-bool QxtFileLockRegistry::removeLock(QxtFileLock * lock )
-{
- QMutexLocker locker(&this->registryMutex);
- procLocks.removeAll(lock );
- return true;
-}
-
-bool QxtFileLock::unlock()
-{
- if (file() && file()->isOpen() && isActive())
- {
- /*first remove real lock*/
- int lockmode, locktype;
- int result = -1;
- struct flock lockDesc;
-
- lockmode = F_SETLK;
- locktype = F_UNLCK;
-
- errno = 0;
- do
- {
- lockDesc.l_type = locktype;
- lockDesc.l_whence = SEEK_SET;
- lockDesc.l_start = qxt_d().offset;
- lockDesc.l_len = qxt_d().length;
- lockDesc.l_pid = 0;
- result = fcntl (this->file()->handle(), lockmode, &lockDesc);
- }
- while (result && errno == EINTR);
-
- QxtFileLockRegistry::instance().removeLock(this);
- qxt_d().isLocked = false;
- return true;
- }
- return false;
-}
-
-bool QxtFileLock::lock ()
-{
- if (file() && file()->isOpen() && !isActive())
- {
- /*this has to block if we can get no lock*/
-
- bool locked = false;
-
- while (1)
- {
- locked = QxtFileLockRegistry::instance().registerLock(this);
- if (locked)
- break;
- else
- {
- if (qxt_d().mode == ReadLockWait || qxt_d().mode == WriteLockWait)
- usleep(1000 * 5);
- else
- return false;
- }
- }
-
- /*now get real lock*/
- int lockmode,
- locktype;
-
- int result = -1;
-
- struct flock lockDesc;
-
- switch (qxt_d().mode)
- {
- case ReadLock:
- lockmode = F_SETLK;
- locktype = F_RDLCK;
- break;
-
- case ReadLockWait:
- lockmode = F_SETLKW;
- locktype = F_RDLCK;
- break;
-
- case WriteLock:
- lockmode = F_SETLK;
- locktype = F_WRLCK;
- break;
-
- case WriteLockWait:
- lockmode = F_SETLKW;
- locktype = F_WRLCK;
- break;
-
- default:
- QxtFileLockRegistry::instance().removeLock(this);
- return (false);
- break;
- }
-
- errno = 0;
- do
- {
- lockDesc.l_type = locktype;
- lockDesc.l_whence = SEEK_SET;
- lockDesc.l_start = qxt_d().offset;
- lockDesc.l_len = qxt_d().length;
- lockDesc.l_pid = 0;
- result = fcntl (this->file()->handle(), lockmode, &lockDesc);
- }
- while (result && errno == EINTR);
-
- /*we dot get the lock unregister from lockregistry and return*/
- if (result == -1)
- {
- QxtFileLockRegistry::instance().removeLock(this);
- return false;
- }
-
- qxt_d().isLocked = true;
- return true;
- }
- return false;
-}
-
projects / quassel.git / blobdiff