Utils: Introduce FileSystemWatcher.

Remove duplicated classes ProjectExplorer::FileWatcher
and QmlProjectManager::FileSystemWatcher, create
Utils::FileSystemWatcher from them, merging the functionality.

Also use in HelpManager/Maemo, reducing the number
of QFileSystemWatcher instances (and thus, shutdown time).

17 files changed, 104 insertions, 580 deletions

diff --git a/src/plugins/coreplugin/helpmanager.cpp b/src/plugins/coreplugin/helpmanager.cpp
index ae53d2d47e..7a01ce326c 100644
--- a/src/plugins/coreplugin/helpmanager.cpp
+++ b/src/plugins/coreplugin/helpmanager.cpp
@@ -32,13 +32,13 @@
 
 #include "helpmanager.h"
 
-#include "icore.h"
+#include <coreplugin/icore.h>
+#include <utils/filesystemwatcher.h>
 
 #include <QtCore/QDateTime>
 #include <QtCore/QDebug>
 #include <QtCore/QDir>
 #include <QtCore/QFileInfo>
-#include <QtCore/QFileSystemWatcher>
 #include <QtCore/QStringList>
 
 #include <QtHelp/QHelpEngineCore>
@@ -58,7 +58,7 @@ struct HelpManagerPrivate {
 
     bool m_needsSetup;
     QHelpEngineCore *m_helpEngine;
-    QFileSystemWatcher *m_collectionWatcher;
+    Utils::FileSystemWatcher *m_collectionWatcher;
 
     QStringList m_filesToRegister;
     QStringList m_nameSpacesToUnregister;
@@ -429,8 +429,9 @@ void HelpManager::setupHelpManager()
     for (it = d->m_customValues.constBegin(); it != d->m_customValues.constEnd(); ++it)
         setCustomValue(it.key(), it.value());
 
-    d->m_collectionWatcher = new QFileSystemWatcher(QStringList() << collectionFilePath(),
-        this);
+    d->m_collectionWatcher = new Utils::FileSystemWatcher(this);
+    d->m_collectionWatcher->setObjectName(QLatin1String("HelpCollectionWatcher"));
+    d->m_collectionWatcher->addFile(collectionFilePath(), Utils::FileSystemWatcher::WatchAllChanges);
     connect(d->m_collectionWatcher, SIGNAL(fileChanged(QString)), this,
         SLOT(collectionFileModified()));
 
diff --git a/src/plugins/projectexplorer/filewatcher.cpp b/src/plugins/projectexplorer/filewatcher.cpp
deleted file mode 100644
index 96a0bc2d4d..0000000000
--- a/src/plugins/projectexplorer/filewatcher.cpp
+++ /dev/null
@@ -1,107 +0,0 @@
-/**************************************************************************
-**
-** This file is part of Qt Creator
-**
-** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
-**
-** Contact: Nokia Corporation (info@qt.nokia.com)
-**
-**
-** GNU Lesser General Public License Usage
-**
-** This file may be used under the terms of the GNU Lesser General Public
-** License version 2.1 as published by the Free Software Foundation and
-** appearing in the file LICENSE.LGPL included in the packaging of this file.
-** Please review the following information to ensure the GNU Lesser General
-** Public License version 2.1 requirements will be met:
-** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** In addition, as a special exception, Nokia gives you certain additional
-** rights. These rights are described in the Nokia Qt LGPL Exception
-** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
-**
-** Other Usage
-**
-** Alternatively, this file may be used in accordance with the terms and
-** conditions contained in a signed written agreement between you and Nokia.
-**
-** If you have questions regarding the use of this file, please contact
-** Nokia at qt-info@nokia.com.
-**
-**************************************************************************/
-
-#include "filewatcher.h"
-
-#include <QtCore/QDebug>
-#include <QtCore/QDir>
-#include <QtCore/QFileInfo>
-#include <QtCore/QFileSystemWatcher>
-#include <QtCore/QTimer>
-
-enum { debugWatcher = 0 };
-
-using namespace ProjectExplorer;
-
-int FileWatcher::m_objectCount = 0;
-QHash<QString,int> FileWatcher::m_fileCount;
-QFileSystemWatcher *FileWatcher::m_watcher = 0;
-
-FileWatcher::FileWatcher(QObject *parent) :
-    QObject(parent)
-{
-    if (!m_watcher)
-        m_watcher = new QFileSystemWatcher();
-    ++m_objectCount;
-    connect(m_watcher, SIGNAL(fileChanged(QString)),
-            this, SLOT(slotFileChanged(QString)));
-}
-
-FileWatcher::~FileWatcher()
-{
-    QStringList keys = m_files.keys();
-    foreach(const QString &file, keys)
-        removeFile(file);
-
-    if (--m_objectCount == 0) {
-        delete m_watcher;
-        m_watcher = 0;
-    }
-}
-
-void FileWatcher::slotFileChanged(const QString &file)
-{
-    if (m_files.contains(file)) {
-        QDateTime lastModified = QFileInfo(file).lastModified();
-        if (lastModified != m_files.value(file)) {
-            m_files[file] = lastModified;
-            emit fileChanged(file);
-        }
-    }
-}
-
-void FileWatcher::addFile(const QString &file)
-{
-    const int count = ++m_fileCount[file];
-    Q_ASSERT(count > 0);
-
-    m_files.insert(file, QFileInfo(file).lastModified());
-
-    if (count == 1)
-        m_watcher->addPath(file);
-}
-
-void FileWatcher::removeFile(const QString &file)
-{
-    if (!m_files.contains(file))
-        return;
-
-    const int count = --m_fileCount[file];
-    Q_ASSERT(count >= 0);
-
-    m_files.remove(file);
-
-    if (!count) {
-        m_watcher->removePath(file);
-        m_fileCount.remove(file);
-    }
-}
diff --git a/src/plugins/projectexplorer/filewatcher.h b/src/plugins/projectexplorer/filewatcher.h
deleted file mode 100644
index e5fcedb28d..0000000000
--- a/src/plugins/projectexplorer/filewatcher.h
+++ /dev/null
@@ -1,76 +0,0 @@
-/**************************************************************************
-**
-** This file is part of Qt Creator
-**
-** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
-**
-** Contact: Nokia Corporation (info@qt.nokia.com)
-**
-**
-** GNU Lesser General Public License Usage
-**
-** This file may be used under the terms of the GNU Lesser General Public
-** License version 2.1 as published by the Free Software Foundation and
-** appearing in the file LICENSE.LGPL included in the packaging of this file.
-** Please review the following information to ensure the GNU Lesser General
-** Public License version 2.1 requirements will be met:
-** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** In addition, as a special exception, Nokia gives you certain additional
-** rights. These rights are described in the Nokia Qt LGPL Exception
-** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
-**
-** Other Usage
-**
-** Alternatively, this file may be used in accordance with the terms and
-** conditions contained in a signed written agreement between you and Nokia.
-**
-** If you have questions regarding the use of this file, please contact
-** Nokia at qt-info@nokia.com.
-**
-**************************************************************************/
-
-#ifndef FILEWATCHER_H
-#define FILEWATCHER_H
-
-#include "projectexplorer_export.h"
-
-#include <QtCore/QDateTime>
-#include <QtCore/QHash>
-#include <QtCore/QObject>
-#include <QtCore/QStringList>
-#include <QtCore/QMap>
-
-QT_BEGIN_NAMESPACE
-class QFileSystemWatcher;
-QT_END_NAMESPACE
-
-namespace ProjectExplorer {
-
-class PROJECTEXPLORER_EXPORT FileWatcher : public QObject
-{
-    Q_DISABLE_COPY(FileWatcher)
-    Q_OBJECT
-public:
-    explicit FileWatcher(QObject *parent = 0);
-    virtual ~FileWatcher();
-
-    void addFile(const QString &file);
-    void removeFile(const QString &file);
-signals:
-    void fileChanged(const QString &path);
-    void debugOutout(const QString &path);
-
-private slots:
-    void slotFileChanged(const QString&);
-
-private:
-    static int m_objectCount;
-    static QHash<QString, int> m_fileCount;
-    static QFileSystemWatcher *m_watcher;
-    QMap<QString, QDateTime> m_files;
-};
-
-} // namespace ProjectExplorer
-
-#endif // FILEWATCHER_H
diff --git a/src/plugins/projectexplorer/projectexplorer.pro b/src/plugins/projectexplorer/projectexplorer.pro
index 6adc7b80e8..7b77b27f8f 100644
--- a/src/plugins/projectexplorer/projectexplorer.pro
+++ b/src/plugins/projectexplorer/projectexplorer.pro
@@ -77,7 +77,6 @@ HEADERS += projectexplorer.h \
     userfileaccessor.h \
     cesdkhandler.h \
     gccparser.h \
-    filewatcher.h \
     debugginghelper.h \
     projectexplorersettingspage.h \
     projectwelcomepage.h \
@@ -168,7 +167,6 @@ SOURCES += projectexplorer.cpp \
     cesdkhandler.cpp \
     userfileaccessor.cpp \
     gccparser.cpp \
-    filewatcher.cpp \
     debugginghelper.cpp \
     projectexplorersettingspage.cpp \
     projectwelcomepage.cpp \
diff --git a/src/plugins/qmljstools/qmljsplugindumper.cpp b/src/plugins/qmljstools/qmljsplugindumper.cpp
index 8e1c5f2113..ba4ce8a6ab 100644
--- a/src/plugins/qmljstools/qmljsplugindumper.cpp
+++ b/src/plugins/qmljstools/qmljsplugindumper.cpp
@@ -35,9 +35,9 @@
 
 #include <qmljs/qmljsdocument.h>
 #include <qmljs/qmljsinterpreter.h>
-#include <projectexplorer/filewatcher.h>
 #include <projectexplorer/projectexplorer.h>
 #include <coreplugin/messagemanager.h>
+#include <utils/filesystemwatcher.h>
 
 #include <QtCore/QDir>
 
@@ -49,9 +49,19 @@ using namespace QmlJSTools::Internal;
 PluginDumper::PluginDumper(ModelManager *modelManager)
     : QObject(modelManager)
     , m_modelManager(modelManager)
-    , m_pluginWatcher(new ProjectExplorer::FileWatcher(this))
+    , m_pluginWatcher(0)
 {
-    connect(m_pluginWatcher, SIGNAL(fileChanged(QString)), SLOT(pluginChanged(QString)));
+}
+
+Utils::FileSystemWatcher *PluginDumper::pluginWatcher()
+{
+    if (!m_pluginWatcher) {
+        m_pluginWatcher = new Utils::FileSystemWatcher(this);
+        m_pluginWatcher->setObjectName(QLatin1String("PluginDumperWatcher"));
+        connect(m_pluginWatcher, SIGNAL(fileChanged(QString)),
+                this, SLOT(pluginChanged(QString)));
+    }
+    return m_pluginWatcher;
 }
 
 void PluginDumper::loadPluginTypes(const QString &libraryPath, const QString &importPath, const QString &importUri, const QString &importVersion)
@@ -92,14 +102,14 @@ void PluginDumper::onLoadPluginTypes(const QString &libraryPath, const QString &
     // watch plugin libraries
     foreach (const QmlDirParser::Plugin &plugin, snapshot.libraryInfo(canonicalLibraryPath).plugins()) {
         const QString pluginLibrary = resolvePlugin(canonicalLibraryPath, plugin.path, plugin.name);
-        m_pluginWatcher->addFile(pluginLibrary);
+        pluginWatcher()->addFile(pluginLibrary, Utils::FileSystemWatcher::WatchModifiedDate);
         m_libraryToPluginIndex.insert(pluginLibrary, index);
     }
 
     // watch library xml file
     if (plugin.hasPredumpedQmlTypesFile()) {
         const QString &path = plugin.predumpedQmlTypesFilePath();
-        m_pluginWatcher->addFile(path);
+        pluginWatcher()->addFile(path, Utils::FileSystemWatcher::WatchModifiedDate);
         m_libraryToPluginIndex.insert(path, index);
     }
 
diff --git a/src/plugins/qmljstools/qmljsplugindumper.h b/src/plugins/qmljstools/qmljsplugindumper.h
index 21bd372567..5a4d22c16e 100644
--- a/src/plugins/qmljstools/qmljsplugindumper.h
+++ b/src/plugins/qmljstools/qmljsplugindumper.h
@@ -41,8 +41,8 @@ QT_BEGIN_NAMESPACE
 class QDir;
 QT_END_NAMESPACE
 
-namespace ProjectExplorer {
-class FileWatcher;
+namespace Utils {
+class FileSystemWatcher;
 }
 
 namespace QmlJSTools {
@@ -89,8 +89,10 @@ private:
                           const QString &prefix = QString());
 
 private:
+    Utils::FileSystemWatcher *pluginWatcher();
+
     ModelManager *m_modelManager;
-    ProjectExplorer::FileWatcher *m_pluginWatcher;
+    Utils::FileSystemWatcher *m_pluginWatcher;
     QHash<QProcess *, QString> m_runningQmldumps;
     QList<Plugin> m_plugins;
     QHash<QString, int> m_libraryToPluginIndex;
diff --git a/src/plugins/qmlprojectmanager/fileformat/filefilteritems.cpp b/src/plugins/qmlprojectmanager/fileformat/filefilteritems.cpp
index 87ae0b8535..a934fcb470 100644
--- a/src/plugins/qmlprojectmanager/fileformat/filefilteritems.cpp
+++ b/src/plugins/qmlprojectmanager/fileformat/filefilteritems.cpp
@@ -32,6 +32,9 @@
 
 #include "filefilteritems.h"
 
+#include <utils/filesystemwatcher.h>
+#include <utils/qtcassert.h>
+
 #include <QtCore/QDebug>
 #include <QtCore/QDir>
 #include <QtGui/QImageReader>
@@ -40,14 +43,30 @@ namespace QmlProjectManager {
 
 FileFilterBaseItem::FileFilterBaseItem(QObject *parent) :
         QmlProjectContentItem(parent),
-        m_recurse(RecurseDefault)
+        m_recurse(RecurseDefault),
+        m_dirWatcher(0)
 {
     m_updateFileListTimer.setSingleShot(true);
     m_updateFileListTimer.setInterval(50);
-    connect(&m_dirWatcher, SIGNAL(directoryChanged(QString)), this, SLOT(updateFileList()));
+
     connect(&m_updateFileListTimer, SIGNAL(timeout()), this, SLOT(updateFileListNow()));
 }
 
+Utils::FileSystemWatcher *FileFilterBaseItem::dirWatcher()
+{
+    if (!m_dirWatcher) {
+        m_dirWatcher = new Utils::FileSystemWatcher(1, this); // Separate id, might exceed OS limits.
+        m_dirWatcher->setObjectName(QLatin1String("FileFilterBaseItemWatcher"));
+        connect(m_dirWatcher, SIGNAL(directoryChanged(QString)), this, SLOT(updateFileList()));
+    }
+    return m_dirWatcher;
+}
+
+QStringList FileFilterBaseItem::watchedDirectories() const
+{
+    return m_dirWatcher ? m_dirWatcher->directories() : QStringList();
+}
+
 QString FileFilterBaseItem::directory() const
 {
     return m_rootDir;
@@ -170,7 +189,7 @@ bool FileFilterBaseItem::matchesFile(const QString &filePath) const
         return false;
 
     const QDir fileDir = QFileInfo(filePath).absoluteDir();
-    foreach (const QString &watchedDirectory, m_dirWatcher.directories()) {
+    foreach (const QString &watchedDirectory, watchedDirectories()) {
         if (QDir(watchedDirectory) == fileDir)
             return true;
     }
@@ -233,14 +252,16 @@ void FileFilterBaseItem::updateFileListNow()
     }
 
     // update watched directories
-    const QSet<QString> oldDirs = m_dirWatcher.directories().toSet();
+    const QSet<QString> oldDirs = watchedDirectories().toSet();
     const QSet<QString> unwatchDirs = oldDirs - dirsToBeWatched;
     const QSet<QString> watchDirs = dirsToBeWatched - oldDirs;
 
-    if (!unwatchDirs.isEmpty())
-        m_dirWatcher.removeDirectories(unwatchDirs.toList());
+    if (!unwatchDirs.isEmpty()) {
+        QTC_ASSERT(m_dirWatcher, return ; )
+        m_dirWatcher->removeDirectories(unwatchDirs.toList());
+    }
     if (!watchDirs.isEmpty())
-        m_dirWatcher.addDirectories(watchDirs.toList());
+        dirWatcher()->addDirectories(watchDirs.toList(), Utils::FileSystemWatcher::WatchAllChanges);
 }
 
 bool FileFilterBaseItem::fileMatches(const QString &fileName) const
diff --git a/src/plugins/qmlprojectmanager/fileformat/filefilteritems.h b/src/plugins/qmlprojectmanager/fileformat/filefilteritems.h
index 62b5a2a49d..986b1298b0 100644
--- a/src/plugins/qmlprojectmanager/fileformat/filefilteritems.h
+++ b/src/plugins/qmlprojectmanager/fileformat/filefilteritems.h
@@ -34,7 +34,6 @@
 #define FILEFILTERITEMS_H
 
 #include "qmlprojectitem.h"
-#include "filesystemwatcher.h"
 
 #include <QtCore/QObject>
 #include <QtCore/QSet>
@@ -44,6 +43,10 @@
 
 QT_FORWARD_DECLARE_CLASS(QDir)
 
+namespace Utils {
+class FileSystemWatcher;
+}
+
 namespace QmlProjectManager {
 
 class FileFilterBaseItem : public QmlProjectContentItem {
@@ -91,6 +94,8 @@ private:
 
     bool fileMatches(const QString &fileName) const;
     QSet<QString> filesInSubTree(const QDir &rootDir, const QDir &dir, QSet<QString> *parsedDirs = 0);
+    Utils::FileSystemWatcher *dirWatcher();
+    QStringList watchedDirectories() const;
 
     QString m_rootDir;
     QString m_defaultDir;
@@ -111,7 +116,7 @@ private:
     QStringList m_explicitFiles;
 
     QSet<QString> m_files;
-    FileSystemWatcher m_dirWatcher;
+    Utils::FileSystemWatcher *m_dirWatcher;
     QTimer m_updateFileListTimer;
 
 
diff --git a/src/plugins/qmlprojectmanager/fileformat/fileformat.pri b/src/plugins/qmlprojectmanager/fileformat/fileformat.pri
index f669492cbf..5edc94b4c9 100644
--- a/src/plugins/qmlprojectmanager/fileformat/fileformat.pri
+++ b/src/plugins/qmlprojectmanager/fileformat/fileformat.pri
@@ -1,8 +1,6 @@
 HEADERS += $$PWD/qmlprojectitem.h \
            $$PWD/filefilteritems.h \
-           $$PWD/qmlprojectfileformat.h \
-           $$PWD/filesystemwatcher.h
+           $$PWD/qmlprojectfileformat.h
 SOURCES += $$PWD/qmlprojectitem.cpp \
            $$PWD/filefilteritems.cpp \
-           $$PWD/qmlprojectfileformat.cpp \
-           $$PWD/filesystemwatcher.cpp
+           $$PWD/qmlprojectfileformat.cpp
diff --git a/src/plugins/qmlprojectmanager/fileformat/filesystemwatcher.cpp b/src/plugins/qmlprojectmanager/fileformat/filesystemwatcher.cpp
deleted file mode 100644
index 86a811fec8..0000000000
--- a/src/plugins/qmlprojectmanager/fileformat/filesystemwatcher.cpp
+++ /dev/null
@@ -1,250 +0,0 @@
-/**************************************************************************
-**
-** This file is part of Qt Creator
-**
-** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
-**
-** Contact: Nokia Corporation (info@qt.nokia.com)
-**
-**
-** GNU Lesser General Public License Usage
-**
-** This file may be used under the terms of the GNU Lesser General Public
-** License version 2.1 as published by the Free Software Foundation and
-** appearing in the file LICENSE.LGPL included in the packaging of this file.
-** Please review the following information to ensure the GNU Lesser General
-** Public License version 2.1 requirements will be met:
-** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** In addition, as a special exception, Nokia gives you certain additional
-** rights. These rights are described in the Nokia Qt LGPL Exception
-** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
-**
-** Other Usage
-**
-** Alternatively, this file may be used in accordance with the terms and
-** conditions contained in a signed written agreement between you and Nokia.
-**
-** If you have questions regarding the use of this file, please contact
-** Nokia at qt-info@nokia.com.
-**
-**************************************************************************/
-
-#include "filesystemwatcher.h"
-
-#include <QtCore/QDebug>
-#include <QtCore/QDir>
-#include <QtCore/QFileInfo>
-#include <QtCore/QFileSystemWatcher>
-#include <QtCore/QTimer>
-
-enum { debug = false };
-
-namespace QmlProjectManager {
-
-int FileSystemWatcher::m_objectCount = 0;
-QHash<QString,int> FileSystemWatcher::m_fileCount;
-QHash<QString,int> FileSystemWatcher::m_directoryCount;
-QFileSystemWatcher *FileSystemWatcher::m_watcher = 0;
-
-FileSystemWatcher::FileSystemWatcher(QObject *parent) :
-    QObject(parent)
-{
-    if (!m_watcher)
-        m_watcher = new QFileSystemWatcher();
-    ++m_objectCount;
-    connect(m_watcher, SIGNAL(fileChanged(QString)),
-            this, SLOT(slotFileChanged(QString)));
-    connect(m_watcher, SIGNAL(directoryChanged(QString)),
-            this, SLOT(slotDirectoryChanged(QString)));
-}
-
-FileSystemWatcher::~FileSystemWatcher()
-{
-    removeFiles(files());
-    removeDirectories(directories());
-
-    if (--m_objectCount == 0) {
-        delete m_watcher;
-        m_watcher = 0;
-    }
-}
-
-void FileSystemWatcher::addFile(const QString &file)
-{
-    addFiles(QStringList(file));
-}
-
-
-#ifdef Q_OS_MAC
-
-// Returns upper limit of file handles that can be opened by this process at once. Exceeding it will probably result in crashes!
-static rlim_t getFileLimit()
-{
-    struct rlimit rl;
-    getrlimit(RLIMIT_NOFILE, &rl);
-    return rl.rlim_cur;
-}
-
-#endif
-
-void FileSystemWatcher::addFiles(const QStringList &files)
-{
-    QStringList toAdd;
-
-    if (debug)
-        qDebug() << Q_FUNC_INFO << files.count();
-
-    foreach (const QString &file, files) {
-        if (m_files.contains(file)) {
-            qWarning() << "FileSystemWatcher: File" << file << "is already being watched";
-            continue;
-        }
-
-#ifdef Q_OS_MAC
-        static rlim_t maxFileOpen = getFileLimit();
-        // We're potentially watching a _lot_ of directories. This might crash qtcreator when we hit the upper limit.
-        // Heuristic is therefore: Don't use more than half of the file handles available in this watcher
-        if ((rlim_t)m_directories.size() + (rlim_t)m_files.size() > maxFileOpen / 2) {
-            qWarning() << "File" << file << "is not watched: Too many file handles are already open (max is" << maxFileOpen;
-            break;
-        }
-#endif
-
-        m_files.append(file);
-
-        const int count = ++m_fileCount[file];
-        Q_ASSERT(count > 0);
-
-        if (count == 1)
-            toAdd << file;
-    }
-
-    if (!toAdd.isEmpty())
-        m_watcher->addPaths(toAdd);
-}
-
-void FileSystemWatcher::removeFile(const QString &file)
-{
-    removeFiles(QStringList(file));
-}
-
-void FileSystemWatcher::removeFiles(const QStringList &files)
-{
-    QStringList toRemove;
-
-    if (debug)
-        qDebug() << Q_FUNC_INFO << files.count();
-
-    foreach (const QString &file, files) {
-        if (!m_files.contains(file)) {
-            qWarning() << "FileSystemWatcher: File" << file << "is not watched";
-            continue;
-        }
-        m_files.removeOne(file);
-        const int count = --m_fileCount[file];
-        Q_ASSERT(count >= 0);
-
-        if (!count) {
-            toRemove << file;
-        }
-    }
-
-    if (!toRemove.isEmpty())
-        m_watcher->removePaths(toRemove);
-}
-
-QStringList FileSystemWatcher::files() const
-{
-    return m_files;
-}
-
-void FileSystemWatcher::addDirectory(const QString &directory)
-{
-    addDirectories(QStringList(directory));
-}
-
-void FileSystemWatcher::addDirectories(const QStringList &directories)
-{
-    QStringList toAdd;
-
-    if (debug)
-        qDebug() << Q_FUNC_INFO << directories.count();
-
-    foreach (const QString &directory, directories) {
-        if (m_directories.contains(directory)) {
-            qWarning() << "Directory" << directory << "is already being watched";
-            continue;
-        }
-
-#ifdef Q_OS_MAC
-        static rlim_t maxFileOpen = getFileLimit();
-        // We're potentially watching a _lot_ of directories. This might crash qtcreator when we hit the upper limit.
-        // Heuristic is therefore: Don't use more than half of the file handles available in this watcher
-        if ((rlim_t)m_directories.size() + (rlim_t)m_files.size() > maxFileOpen / 2) {
-            qWarning() << "Directory" << directory << "is not watched: Too many file handles are already open (max is" << maxFileOpen;
-            break;
-        }
-#endif
-
-        m_directories.append(directory);
-
-        const int count = ++m_directoryCount[directory];
-        Q_ASSERT(count > 0);
-
-        if (count == 1)
-            toAdd << directory;
-    }
-
-    if (!toAdd.isEmpty())
-        m_watcher->addPaths(toAdd);
-}
-
-void FileSystemWatcher::removeDirectory(const QString &directory)
-{
-    removeDirectories(QStringList(directory));
-}
-
-void FileSystemWatcher::removeDirectories(const QStringList &directories)
-{
-    QStringList toRemove;
-
-    if (debug)
-        qDebug() << Q_FUNC_INFO << directories.count();
-
-    foreach (const QString &directory, directories) {
-        if (!m_directories.contains(directory)) {
-            qWarning() << "FileSystemWatcher: Directory" << directory << "is not watched";
-            continue;
-        }
-        m_directories.removeOne(directory);
-
-        const int count = --m_directoryCount[directory];
-        Q_ASSERT(count >= 0);
-
-        if (!count) {
-            toRemove << directory;
-        }
-    }
-    if (!toRemove.isEmpty())
-        m_watcher->removePaths(toRemove);
-}
-
-QStringList FileSystemWatcher::directories() const
-{
-    return m_directories;
-}
-
-void FileSystemWatcher::slotFileChanged(const QString &path)
-{
-    if (m_files.contains(path))
-        emit fileChanged(path);
-}
-
-void FileSystemWatcher::slotDirectoryChanged(const QString &path)
-{
-    if (m_directories.contains(path))
-        emit directoryChanged(path);
-}
-
-} // namespace QmlProjectManager
diff --git a/src/plugins/qmlprojectmanager/fileformat/filesystemwatcher.h b/src/plugins/qmlprojectmanager/fileformat/filesystemwatcher.h
deleted file mode 100644
index 82d86dc713..0000000000
--- a/src/plugins/qmlprojectmanager/fileformat/filesystemwatcher.h
+++ /dev/null
@@ -1,93 +0,0 @@
-/**************************************************************************
-**
-** This file is part of Qt Creator
-**
-** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
-**
-** Contact: Nokia Corporation (info@qt.nokia.com)
-**
-**
-** GNU Lesser General Public License Usage
-**
-** This file may be used under the terms of the GNU Lesser General Public
-** License version 2.1 as published by the Free Software Foundation and
-** appearing in the file LICENSE.LGPL included in the packaging of this file.
-** Please review the following information to ensure the GNU Lesser General
-** Public License version 2.1 requirements will be met:
-** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
-**
-** In addition, as a special exception, Nokia gives you certain additional
-** rights. These rights are described in the Nokia Qt LGPL Exception
-** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
-**
-** Other Usage
-**
-** Alternatively, this file may be used in accordance with the terms and
-** conditions contained in a signed written agreement between you and Nokia.
-**
-** If you have questions regarding the use of this file, please contact
-** Nokia at qt-info@nokia.com.
-**
-**************************************************************************/
-
-#ifndef FSWATCHER_H
-#define FSWATCHER_H
-
-#include <QtCore/QDateTime>
-#include <QtCore/QHash>
-#include <QtCore/QObject>
-#include <QtCore/QStringList>
-#include <QtCore/QMap>
-
-QT_BEGIN_NAMESPACE
-class QTimer;
-class QFileSystemWatcher;
-QT_END_NAMESPACE
-
-namespace QmlProjectManager {
-
-class FileSystemWatcher : public QObject
-{
-    Q_DISABLE_COPY(FileSystemWatcher)
-    Q_OBJECT
-public:
-    explicit FileSystemWatcher(QObject *parent = 0);
-    virtual ~FileSystemWatcher();
-
-    void addFile(const QString &file);
-    void addFiles(const QStringList &files);
-
-    void removeFile(const QString &file);
-    void removeFiles(const QStringList &files);
-
-    QStringList files() const;
-
-    void addDirectory(const QString &file);
-    void addDirectories(const QStringList &files);
-
-    void removeDirectory(const QString &file);
-    void removeDirectories(const QStringList &files);
-
-    QStringList directories() const;
-
-private slots:
-    void slotFileChanged(const QString &path);
-    void slotDirectoryChanged(const QString &path);
-
-signals:
-    void fileChanged(const QString &path);
-    void directoryChanged(const QString &path);
-
-private:
-    QStringList m_files;
-    QStringList m_directories;
-
-    static int m_objectCount;
-    static QHash<QString, int> m_fileCount;
-    static QHash<QString, int> m_directoryCount;
-    static QFileSystemWatcher *m_watcher;
-};
-
-} // namespace QmlProjectManager
-
-#endif // FSWATCHER_H
diff --git a/src/plugins/qmlprojectmanager/qmlproject.cpp b/src/plugins/qmlprojectmanager/qmlproject.cpp
index 5a1907b9e6..6e1771bc10 100644
--- a/src/plugins/qmlprojectmanager/qmlproject.cpp
+++ b/src/plugins/qmlprojectmanager/qmlproject.cpp
@@ -41,11 +41,12 @@
 #include <coreplugin/icore.h>
 #include <coreplugin/messagemanager.h>
 #include <extensionsystem/pluginmanager.h>
-#include <projectexplorer/filewatcher.h>
 #include <qt4projectmanager/qmldumptool.h>
 #include <qt4projectmanager/qtversionmanager.h>
 #include <qmljs/qmljsmodelmanagerinterface.h>
 
+#include <utils/filesystemwatcher.h>
+
 #include <QtCore/QTextStream>
 #include <QtDeclarative/QDeclarativeComponent>
 #include <QtCore/QtDebug>
@@ -56,8 +57,9 @@ QmlProject::QmlProject(Internal::Manager *manager, const QString &fileName)
     : m_manager(manager),
       m_fileName(fileName),
       m_modelManager(ExtensionSystem::PluginManager::instance()->getObject<QmlJS::ModelManagerInterface>()),
-      m_fileWatcher(new ProjectExplorer::FileWatcher(this))
+      m_fileWatcher(new Utils::FileSystemWatcher(this))
 {
+    m_fileWatcher->setObjectName(QLatin1String("QmlProjectWatcher"));
     setProjectContext(Core::Context(QmlProjectManager::Constants::PROJECTCONTEXT));
     setProjectLanguage(Core::Context(QmlProjectManager::Constants::LANG_QML));
 
@@ -67,7 +69,7 @@ QmlProject::QmlProject(Internal::Manager *manager, const QString &fileName)
     m_file = new Internal::QmlProjectFile(this, fileName);
     m_rootNode = new Internal::QmlProjectNode(this, m_file);
 
-    m_fileWatcher->addFile(fileName),
+    m_fileWatcher->addFile(fileName, Utils::FileSystemWatcher::WatchModifiedDate);
     connect(m_fileWatcher, SIGNAL(fileChanged(QString)),
             this, SLOT(refreshProjectFile()));
 
diff --git a/src/plugins/qmlprojectmanager/qmlproject.h b/src/plugins/qmlprojectmanager/qmlproject.h
index 090a834900..9e8c3eaddf 100644
--- a/src/plugins/qmlprojectmanager/qmlproject.h
+++ b/src/plugins/qmlprojectmanager/qmlproject.h
@@ -45,8 +45,8 @@ namespace QmlJS {
 class ModelManagerInterface;
 }
 
-namespace ProjectExplorer {
-class FileWatcher;
+namespace Utils {
+class FileSystemWatcher;
 }
 
 namespace QmlProjectManager {
@@ -125,7 +125,7 @@ private:
     // qml based, new format
     QDeclarativeEngine m_engine;
     QWeakPointer<QmlProjectItem> m_projectItem;
-    ProjectExplorer::FileWatcher *m_fileWatcher;
+    Utils::FileSystemWatcher *m_fileWatcher;
 
     Internal::QmlProjectNode *m_rootNode;
 };
diff --git a/src/plugins/qt4projectmanager/qt-maemo/maemoqemumanager.cpp b/src/plugins/qt4projectmanager/qt-maemo/maemoqemumanager.cpp
index 051958fd99..4467833297 100644
--- a/src/plugins/qt4projectmanager/qt-maemo/maemoqemumanager.cpp
+++ b/src/plugins/qt4projectmanager/qt-maemo/maemoqemumanager.cpp
@@ -52,6 +52,7 @@
 
 #include <projectexplorer/projectexplorer.h>
 #include <projectexplorer/session.h>
+#include <utils/filesystemwatcher.h>
 
 #include <QtCore/QDebug>
 #include <QtCore/QDir>
@@ -128,20 +129,22 @@ MaemoQemuManager::MaemoQemuManager(QObject *parent)
         this, SLOT(qemuStatusChanged(QemuStatus, QString)));
 }
 
-QFileSystemWatcher *MaemoQemuManager::runtimeRootWatcher()
+Utils::FileSystemWatcher *MaemoQemuManager::runtimeRootWatcher()
 {
     if (!m_runtimeRootWatcher) {
-        m_runtimeRootWatcher = new QFileSystemWatcher(this);
+        m_runtimeRootWatcher = new Utils::FileSystemWatcher(this);
+        m_runtimeRootWatcher->setObjectName(QLatin1String("MaemoQemuRuntimeRootWatcher"));
         connect(m_runtimeRootWatcher, SIGNAL(directoryChanged(QString)), this,
             SLOT(runtimeRootChanged(QString)));
     }
     return m_runtimeRootWatcher;
 }
 
-QFileSystemWatcher *MaemoQemuManager::runtimeFolderWatcher()
+Utils::FileSystemWatcher *MaemoQemuManager::runtimeFolderWatcher()
 {
     if (!m_runtimeFolderWatcher) {
-        m_runtimeFolderWatcher = new QFileSystemWatcher(this);
+        m_runtimeFolderWatcher = new Utils::FileSystemWatcher(this);
+        m_runtimeFolderWatcher->setObjectName(QLatin1String("MaemoQemuRuntimeFolderWatcher"));
         connect(m_runtimeFolderWatcher, SIGNAL(directoryChanged(QString)), this,
             SLOT(runtimeFolderChanged(QString)));
     }
@@ -185,8 +188,9 @@ void MaemoQemuManager::qtVersionsChanged(const QList<int> &uniqueIds)
                     = MaemoQemuRuntimeParser::parseRuntime(version);
                 if (runtime.isValid()) {
                     m_runtimes.insert(uniqueId, runtime);
-                    if (!runtimeRootWatcher()->directories().contains(runtime.m_watchPath))
-                        runtimeRootWatcher()->addPath(runtime.m_watchPath);
+                    if (!runtimeRootWatcher()->watchesDirectory(runtime.m_watchPath))
+                        runtimeRootWatcher()->addDirectory(runtime.m_watchPath,
+                                                           Utils::FileSystemWatcher::WatchAllChanges);
                 } else {
                     m_runtimes.remove(uniqueId);
                 }
@@ -477,7 +481,8 @@ void MaemoQemuManager::runtimeRootChanged(const QString &directory)
                 if (!QFile::exists(runtime.m_root + QLatin1String("/information"))) {
                     // install might be still in progress
                     uniqueIds.removeAll(uniqueId);
-                    runtimeFolderWatcher()->addPath(runtime.m_root);
+                    runtimeFolderWatcher()->addDirectory(runtime.m_root,
+                                                         Utils::FileSystemWatcher::WatchAllChanges);
                 }
             }
         }
@@ -496,7 +501,7 @@ void MaemoQemuManager::runtimeFolderChanged(const QString &directory)
         }
         notify(uniqueIds);
         if (m_runtimeFolderWatcher)
-            m_runtimeFolderWatcher->removePath(directory);
+            m_runtimeFolderWatcher->removeDirectory(directory);
     }
 }
 
diff --git a/src/plugins/qt4projectmanager/qt-maemo/maemoqemumanager.h b/src/plugins/qt4projectmanager/qt-maemo/maemoqemumanager.h
index c3c9ee75d0..6a673cff57 100644
--- a/src/plugins/qt4projectmanager/qt-maemo/maemoqemumanager.h
+++ b/src/plugins/qt4projectmanager/qt-maemo/maemoqemumanager.h
@@ -43,9 +43,12 @@
 #include <QtGui/QIcon>
 
 QT_FORWARD_DECLARE_CLASS(QAction)
-QT_FORWARD_DECLARE_CLASS(QFileSystemWatcher)
 QT_FORWARD_DECLARE_CLASS(QStringList)
 
+namespace Utils {
+class FileSystemWatcher;
+}
+
 namespace ProjectExplorer {
     class BuildConfiguration;
     class Project;
@@ -123,16 +126,16 @@ private:
 private:
     QAction *m_qemuAction;
     QProcess *m_qemuProcess;
-    QFileSystemWatcher *runtimeRootWatcher();
-    QFileSystemWatcher *runtimeFolderWatcher();
+    Utils::FileSystemWatcher *runtimeRootWatcher();
+    Utils::FileSystemWatcher *runtimeFolderWatcher();
 
     int m_runningQtId;
     bool m_userTerminated;
     QIcon m_qemuStarterIcon;
     QMap<int, MaemoQemuRuntime> m_runtimes;
     static MaemoQemuManager *m_instance;
-    QFileSystemWatcher *m_runtimeRootWatcher;
-    QFileSystemWatcher *m_runtimeFolderWatcher;
+    Utils::FileSystemWatcher *m_runtimeRootWatcher;
+    Utils::FileSystemWatcher *m_runtimeFolderWatcher;
 };
 
 }   // namespace Internal
diff --git a/src/plugins/qt4projectmanager/qt-maemo/qt4maemotarget.cpp b/src/plugins/qt4projectmanager/qt-maemo/qt4maemotarget.cpp
index cba94e705f..af1d79e117 100644
--- a/src/plugins/qt4projectmanager/qt-maemo/qt4maemotarget.cpp
+++ b/src/plugins/qt4projectmanager/qt-maemo/qt4maemotarget.cpp
@@ -48,6 +48,8 @@
 #include <projectexplorer/toolchain.h>
 #include <qt4projectmanager/qt4project.h>
 
+#include <utils/filesystemwatcher.h>
+
 #include <QtGui/QApplication>
 #include <QtGui/QMainWindow>
 #include <QtCore/QBuffer>
@@ -109,10 +111,11 @@ bool adaptTagValue(QByteArray &document, const QByteArray &fieldName,
 
 AbstractQt4MaemoTarget::AbstractQt4MaemoTarget(Qt4Project *parent, const QString &id) :
     Qt4BaseTarget(parent, id),
-    m_filesWatcher(new QFileSystemWatcher(this)),
+    m_filesWatcher(new Utils::FileSystemWatcher(this)),
     m_buildConfigurationFactory(new Qt4BuildConfigurationFactory(this)),
     m_isInitialized(false)
 {
+    m_filesWatcher->setObjectName(QLatin1String("Qt4MaemoTarget"));
     setIcon(QIcon(":/projectexplorer/images/MaemoDevice.png"));
     connect(parent, SIGNAL(addedTarget(ProjectExplorer::Target*)),
         this, SLOT(handleTargetAdded(ProjectExplorer::Target*)));
@@ -692,9 +695,9 @@ void AbstractDebBasedQt4MaemoTarget::handleTargetAddedSpecial()
         if (QFileInfo(iconPath).exists())
             setPackageManagerIcon(iconPath);
     }
-    m_filesWatcher->addPath(debianDirPath());
-    m_filesWatcher->addPath(changeLogFilePath());
-    m_filesWatcher->addPath(controlFilePath());
+    m_filesWatcher->addDirectory(debianDirPath(), Utils::FileSystemWatcher::WatchAllChanges);
+    m_filesWatcher->addFile(changeLogFilePath(), Utils::FileSystemWatcher::WatchAllChanges);
+    m_filesWatcher->addFile(controlFilePath(), Utils::FileSystemWatcher::WatchAllChanges);
     connect(m_filesWatcher, SIGNAL(directoryChanged(QString)), this,
         SLOT(handleDebianDirContentsChanged()));
     connect(m_filesWatcher, SIGNAL(fileChanged(QString)), this,
@@ -1017,7 +1020,7 @@ AbstractQt4MaemoTarget::ActionStatus AbstractRpmBasedQt4MaemoTarget::createSpeci
 
 void AbstractRpmBasedQt4MaemoTarget::handleTargetAddedSpecial()
 {
-    m_filesWatcher->addPath(specFilePath());
+    m_filesWatcher->addFile(specFilePath(), Utils::FileSystemWatcher::WatchAllChanges);
     connect(m_filesWatcher, SIGNAL(fileChanged(QString)), this,
         SIGNAL(specFileChanged()));
 }
diff --git a/src/plugins/qt4projectmanager/qt-maemo/qt4maemotarget.h b/src/plugins/qt4projectmanager/qt-maemo/qt4maemotarget.h
index bf996b825c..4546768630 100644
--- a/src/plugins/qt4projectmanager/qt-maemo/qt4maemotarget.h
+++ b/src/plugins/qt4projectmanager/qt-maemo/qt4maemotarget.h
@@ -40,8 +40,10 @@
 #include <QtGui/QIcon>
 
 QT_FORWARD_DECLARE_CLASS(QFile)
-QT_FORWARD_DECLARE_CLASS(QFileSystemWatcher)
 
+namespace Utils {
+class FileSystemWatcher;
+}
 namespace Qt4ProjectManager {
 class Qt4Project;
 namespace Internal {
@@ -92,7 +94,7 @@ protected:
     QSharedPointer<QFile> openFile(const QString &filePath,
         QIODevice::OpenMode mode, QString *error) const;
 
-    QFileSystemWatcher * const m_filesWatcher;
+    Utils::FileSystemWatcher* const m_filesWatcher;
 
 private slots:
     void handleTargetAdded(ProjectExplorer::Target *target);