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authorhjk <qtc-committer@nokia.com>2009-01-26 16:19:24 +0100
committerhjk <qtc-committer@nokia.com>2009-01-26 16:19:24 +0100
commitfe0533de2a634ca377c2d8a0073e0eb2cbf89abf (patch)
tree29d3d30e6cc5a1068a94097a5660bc4d133a205f /src/shared/qtlockedfile/qtlockedfile.cpp
parentc85ba53365d606192069a841ed806979f17d80bc (diff)
downloadqt-creator-fe0533de2a634ca377c2d8a0073e0eb2cbf89abf.tar.gz
Fixes: move all files in shared/* to src/shared/*
Diffstat (limited to 'src/shared/qtlockedfile/qtlockedfile.cpp')
-rw-r--r--src/shared/qtlockedfile/qtlockedfile.cpp162
1 files changed, 162 insertions, 0 deletions
diff --git a/src/shared/qtlockedfile/qtlockedfile.cpp b/src/shared/qtlockedfile/qtlockedfile.cpp
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+/***************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+**
+** Non-Open Source Usage
+**
+** Licensees may use this file in accordance with the Qt Beta Version
+** License Agreement, Agreement version 2.2 provided with the Software or,
+** alternatively, in accordance with the terms contained in a written
+** agreement between you and Nokia.
+**
+** GNU General Public License Usage
+**
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License versions 2.0 or 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the packaging
+** of this file. Please review the following information to ensure GNU
+** General Public Licensing requirements will be met:
+**
+** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt GPL Exception
+** version 1.3, included in the file GPL_EXCEPTION.txt in this package.
+**
+***************************************************************************/
+
+#include "qtlockedfile.h"
+
+namespace SharedTools {
+
+/*!
+ \class QtLockedFile
+
+ \brief The QtLockedFile class extends QFile with advisory locking functions.
+
+ A file may be locked in read or write mode. Multiple instances of
+ \e QtLockedFile, created in multiple processes running on the same
+ machine, may have a file locked in read mode. Exactly one instance
+ may have it locked in write mode. A read and a write lock cannot
+ exist simultaneously on the same file.
+
+ The file locks are advisory. This means that nothing prevents
+ another process from manipulating a locked file using QFile or
+ file system functions offered by the OS. Serialization is only
+ guaranteed if all processes that access the file use
+ QtLockedFile. Also, while holding a lock on a file, a process
+ must not open the same file again (through any API), or locks
+ can be unexpectedly lost.
+
+ The lock provided by an instance of \e QtLockedFile is released
+ whenever the program terminates. This is true even when the
+ program crashes and no destructors are called.
+*/
+
+/*! \enum QtLockedFile::LockMode
+
+ This enum describes the available lock modes.
+
+ \value ReadLock A read lock.
+ \value WriteLock A write lock.
+ \value NoLock Neither a read lock nor a write lock.
+*/
+
+/*!
+ Constructs an unlocked \e QtLockedFile object. This constructor behaves in the same way
+ as \e QFile::QFile().
+
+ \sa QFile::QFile()
+*/
+QtLockedFile::QtLockedFile()
+ : QFile()
+{
+#ifdef Q_OS_WIN
+ m_semaphore_hnd = 0;
+ m_mutex_hnd = 0;
+#endif
+ m_lock_mode = NoLock;
+}
+
+/*!
+ Constructs an unlocked QtLockedFile object with file \a name. This constructor behaves in
+ the same way as \e QFile::QFile(const QString&).
+
+ \sa QFile::QFile()
+*/
+QtLockedFile::QtLockedFile(const QString &name)
+ : QFile(name)
+{
+#ifdef Q_OS_WIN
+ m_semaphore_hnd = 0;
+ m_mutex_hnd = 0;
+#endif
+ m_lock_mode = NoLock;
+}
+
+/*!
+ Returns \e true if this object has a in read or write lock;
+ otherwise returns \e false.
+
+ \sa lockMode()
+*/
+bool QtLockedFile::isLocked() const
+{
+ return m_lock_mode != NoLock;
+}
+
+/*!
+ Returns the type of lock currently held by this object, or \e QtLockedFile::NoLock.
+
+ \sa isLocked()
+*/
+QtLockedFile::LockMode QtLockedFile::lockMode() const
+{
+ return m_lock_mode;
+}
+
+/*!
+ \fn bool QtLockedFile::lock(LockMode mode, bool block = true)
+
+ Obtains a lock of type \a mode.
+
+ If \a block is true, this
+ function will block until the lock is aquired. If \a block is
+ false, this function returns \e false immediately if the lock cannot
+ be aquired.
+
+ If this object already has a lock of type \a mode, this function returns \e true immediately. If this object has a lock of a different type than \a mode, the lock
+ is first released and then a new lock is obtained.
+
+ This function returns \e true if, after it executes, the file is locked by this object,
+ and \e false otherwise.
+
+ \sa unlock(), isLocked(), lockMode()
+*/
+
+/*!
+ \fn bool QtLockedFile::unlock()
+
+ Releases a lock.
+
+ If the object has no lock, this function returns immediately.
+
+ This function returns \e true if, after it executes, the file is not locked by
+ this object, and \e false otherwise.
+
+ \sa lock(), isLocked(), lockMode()
+*/
+
+/*!
+ \fn QtLockedFile::~QtLockedFile()
+
+ Destroys the \e QtLockedFile object. If any locks were held, they are released.
+*/
+
+} // namespace SharedTools