From a0907e46586806d2f4fea9fdeb0a6241a96b3d1b Mon Sep 17 00:00:00 2001
From: Don Gagne <don@thegagnes.com>
Date: Wed, 30 Nov 2016 18:55:19 -0800
Subject: [PATCH] Single instance app guarding mechanism
---
qgroundcontrol.pro | 2 ++
src/RunGuard.cc | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
src/RunGuard.h | 38 ++++++++++++++++++++++++
src/main.cc | 20 +++++--------
4 files changed, 135 insertions(+), 12 deletions(-)
create mode 100644 src/RunGuard.cc
create mode 100644 src/RunGuard.h
diff --git a/qgroundcontrol.pro b/qgroundcontrol.pro
index f056999..85adc4f 100644
--- a/qgroundcontrol.pro
+++ b/qgroundcontrol.pro
@@ -529,6 +529,7 @@ HEADERS += \
src/Joystick/JoystickSDL.h \
src/QGCFileDialog.h \
src/QGCMessageBox.h \
+ src/RunGuard.h \
src/ViewWidgets/CustomCommandWidget.h \
src/ViewWidgets/CustomCommandWidgetController.h \
src/ViewWidgets/ViewWidgetController.h \
@@ -677,6 +678,7 @@ SOURCES += \
src/GPS/RTCM/RTCMMavlink.cc \
src/Joystick/JoystickSDL.cc \
src/QGCFileDialog.cc \
+ src/RunGuard.cc \
src/ViewWidgets/CustomCommandWidget.cc \
src/ViewWidgets/CustomCommandWidgetController.cc \
src/ViewWidgets/ViewWidgetController.cc \
diff --git a/src/RunGuard.cc b/src/RunGuard.cc
new file mode 100644
index 0000000..5e8a492
--- /dev/null
+++ b/src/RunGuard.cc
@@ -0,0 +1,87 @@
+/****************************************************************************
+ *
+ * (c) 2009-2016 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+ *
+ * QGroundControl is licensed according to the terms in the file
+ * COPYING.md in the root of the source code directory.
+ *
+ ****************************************************************************/
+
+#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();
+}
diff --git a/src/RunGuard.h b/src/RunGuard.h
new file mode 100644
index 0000000..0e82f5b
--- /dev/null
+++ b/src/RunGuard.h
@@ -0,0 +1,38 @@
+/****************************************************************************
+ *
+ * (c) 2009-2016 QGROUNDCONTROL PROJECT <http://www.qgroundcontrol.org>
+ *
+ * QGroundControl is licensed according to the terms in the file
+ * COPYING.md in the root of the source code directory.
+ *
+ ****************************************************************************/
+
+#ifndef RunGuard_H
+#define RunGuard_H
+
+#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 )
+};
+
+#endif
diff --git a/src/main.cc b/src/main.cc
index 80000cd..4dec260 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -27,10 +27,9 @@
#include "QGCApplication.h"
#include "AppMessages.h"
-#define SINGLE_INSTANCE_PORT 14499
-
#ifndef __mobile__
#include "QGCSerialPortInfo.h"
+ #include "RunGuard.h"
#endif
#ifdef UNITTEST_BUILD
@@ -103,6 +102,13 @@ jint JNI_OnLoad(JavaVM* vm, void* reserved)
int main(int argc, char *argv[])
{
+#ifndef __mobile__
+ RunGuard guard("QGroundControlRunGuardKey");
+ if (!guard.tryToRun()) {
+ return 0;
+ }
+#endif
+
#ifdef Q_OS_UNIX
//Force writing to the console on UNIX/BSD devices
if (!qEnvironmentVariableIsSet("QT_LOGGING_TO_CONSOLE"))
@@ -112,16 +118,6 @@ int main(int argc, char *argv[])
// install the message handler
AppMessages::installHandler();
-#ifndef __mobile__
- //-- Test for another instance already running. If that's the case, we simply exit.
- QHostAddress host("127.0.0.1");
- QUdpSocket socket;
- if(!socket.bind(host, SINGLE_INSTANCE_PORT, QAbstractSocket::DontShareAddress)) {
- qWarning() << "Another instance already running. Exiting.";
- exit(-1);
- }
-#endif
-
#ifdef Q_OS_MAC
#ifndef __ios__
// Prevent Apple's app nap from screwing us over