application: prevent multiple instances

Change-Id: Id7d28d66934d1c2eef893273d283ba5869a4a72a

main.cpp

@@ -28,8 +28,6 @@
 #include "media/text.h"
 #include "media/file.h"
 #include "globalinstances.h"
-#include "pixbufmanipulator.h"
-#include "lrcinstance.h"
 
 #include <QTranslator>
 #include <QLibraryInfo>
@@ -37,7 +35,10 @@
 
 #include <ciso646>
 
+#include "lrcinstance.h"
 #include "utils.h"
+#include "runguard.h"
+#include "pixbufmanipulator.h"
 
 #ifdef Q_OS_WIN
 #include <windows.h>
@@ -103,6 +104,10 @@ fileDebug(QFile& debugFile)
 int
 main(int argc, char *argv[])
 {
+    RunGuard guard("680b3e5eaf");
+    if (!guard.tryToRun())
+        return 0;
+
 #ifdef Q_OS_WIN
     SetProcessDPIAware();
 #endif // Q_OS_WIN

ring-client-windows.vcxproj

@@ -259,6 +259,7 @@
     <ClCompile Include="regnamedialog.cpp" />
     <ClCompile Include="ringbutton.cpp" />
     <ClCompile Include="ringcontactlineedit.cpp" />
+    <ClCompile Include="runguard.cpp" />
     <ClCompile Include="selectareadialog.cpp" />
     <ClCompile Include="conversationsfilterwidget.cpp">
       <OutputFile Condition="'$(Configuration)|$(Platform)'=='Release|x64'">.\GeneratedFiles\$(ConfigurationName)\%(Filename).moc</OutputFile>
@@ -399,6 +400,7 @@
       <IncludePath Condition="'$(Configuration)|$(Platform)'=='Release|x64'">.\GeneratedFiles\$(ConfigurationName)\.;.\GeneratedFiles;.;$(ProjectDir)..\daemon\contrib\msvc\include;$(ProjectDir)..\lrc\src;$(ProjectDir)..\client-windows\winsparkle\include;$(ProjectDir)..\client-windows\qrencode-win32\qrencode-win32;$(QTDIR)\include;$(QTDIR)\include\QtSvg;$(QTDIR)\include\QtWidgets;$(QTDIR)\include\QtWinExtras;$(QTDIR)\include\QtGui;$(QTDIR)\include\QtANGLE;$(QTDIR)\include\QtXml;$(QTDIR)\include\QtNetwork;$(QTDIR)\include\QtCore;$(QTDIR)\mkspecs\win32-msvc;.\release</IncludePath>
       <Define Condition="'$(Configuration)|$(Platform)'=='Release|x64'">_WINDOWS;UNICODE;_UNICODE;WIN32;WIN64;NIGHTLY_VERSION=20180706;ENABLE_AUTOUPDATE;QT_NO_DEBUG;NDEBUG</Define>
     </QtMoc>
+    <ClInclude Include="runguard.h" />
     <ClInclude Include="settingsitemwidget.h">
       <IncludePath Condition="'$(Configuration)|$(Platform)'=='Release|x64'">.\GeneratedFiles\$(ConfigurationName)\.;.\GeneratedFiles;.;$(ProjectDir)..\daemon\contrib\msvc\include;$(ProjectDir)..\lrc\src;$(ProjectDir)..\client-windows\winsparkle\include;$(ProjectDir)..\client-windows\qrencode-win32\qrencode-win32;$(QTDIR)\include;$(QTDIR)\include\QtSvg;$(QTDIR)\include\QtWidgets;$(QTDIR)\include\QtWinExtras;$(QTDIR)\include\QtGui;$(QTDIR)\include\QtANGLE;$(QTDIR)\include\QtXml;$(QTDIR)\include\QtNetwork;$(QTDIR)\include\QtCore;$(QTDIR)\mkspecs\win32-msvc;.\release;$(QTDIR)\include\QtMultimedia;$(QTDIR)\include\QtMultimediaWidgets</IncludePath>
       <Define Condition="'$(Configuration)|$(Platform)'=='Release|x64'">_WINDOWS;UNICODE;_UNICODE;WIN32;WIN64;NIGHTLY_VERSION=20180706;ENABLE_AUTOUPDATE;QT_NO_DEBUG;NDEBUG;QT_MULTIMEDIA_LIB;QT_MULTIMEDIAWIDGETS_LIB</Define>

ring-client-windows.vcxproj.filters

@@ -198,6 +198,9 @@
     <ClCompile Include="newwizardwidget.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="runguard.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <QtMoc Include="aboutdialog.h">
@@ -774,5 +777,8 @@
     <ClInclude Include="version.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="runguard.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file

runguard.cpp

+// From: https://stackoverflow.com/a/28172162
+
+#include "runguard.h"
+
+#include <QCryptographicHash>
+
+namespace
+{
+
+QString generateKeyHash(const QString& key, const QString& salt)
+{
+    QByteArray data;
+
+    data.append(key.toUtf8());
+    data.append(salt.toUtf8());
+    data = QCryptographicHash::hash(data, QCryptographicHash::Sha1).toHex();
+
+    return data;
+}
+
+}
+
+RunGuard::RunGuard(const QString& key)
+    : key(key)
+    , memLockKey(generateKeyHash(key, "_memLockKey"))
+    , sharedmemKey(generateKeyHash(key, "_sharedmemKey"))
+    , sharedMem(sharedmemKey)
+    , memLock(memLockKey, 1)
+{
+    memLock.acquire();
+    {
+        QSharedMemory fix(sharedmemKey);    // Fix for *nix: http://habrahabr.ru/post/173281/
+        fix.attach();
+    }
+    memLock.release();
+}
+
+RunGuard::~RunGuard()
+{
+    release();
+}
+
+bool RunGuard::isAnotherRunning()
+{
+    if (sharedMem.isAttached())
+        return false;
+
+    memLock.acquire();
+    const bool isRunning = sharedMem.attach();
+    if (isRunning)
+        sharedMem.detach();
+    memLock.release();
+
+    return isRunning;
+}
+
+bool RunGuard::tryToRun()
+{
+    if (isAnotherRunning())   // Extra check
+        return false;
+
+    memLock.acquire();
+    const bool result = sharedMem.create(sizeof(quint64));
+    memLock.release();
+    if (!result) {
+        release();
+        return false;
+    }
+
+    return true;
+}
+
+void RunGuard::release()
+{
+    memLock.acquire();
+    if (sharedMem.isAttached())
+        sharedMem.detach();
+    memLock.release();
+}
\ No newline at end of file

runguard.h

+// From: https://stackoverflow.com/a/28172162
+
+#pragma once
+
+#include <QObject>
+#include <QSharedMemory>
+#include <QSystemSemaphore>
+
+class RunGuard
+{
+
+public:
+    RunGuard(const QString& key);
+    ~RunGuard();
+
+    bool isAnotherRunning();
+    bool tryToRun();
+    void release();
+
+private:
+    const QString key;
+    const QString memLockKey;
+    const QString sharedmemKey;
+
+    QSharedMemory sharedMem;
+    QSystemSemaphore memLock;
+
+    Q_DISABLE_COPY(RunGuard)
+};
\ No newline at end of file