Disallow multiple instances without a unique rig name

Because of confilicts using the  shared memory to communicate with jt9
only one instance of WSJT-X may run with each unique key (rig name).

Added a QLockFile for each unique  key in the temp directory and logic
to deal with stale locks and retries.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@4465 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

Configuration.cpp

@@ -235,7 +235,7 @@ class Configuration::impl final
 public:
   using FrequencyDelta = Radio::FrequencyDelta;
 
-  explicit impl (Configuration * self, QString const& instance_key, QSettings * settings, bool test_mode, QWidget * parent);
+  explicit impl (Configuration * self, QSettings * settings, QWidget * parent);
   ~impl ();
 
   bool have_rig (bool open_if_closed = true);
@@ -428,8 +428,8 @@ private:
 
 
 // delegate to implementation class
-Configuration::Configuration (QString const& instance_key, QSettings * settings, bool test_mode, QWidget * parent)
+Configuration::Configuration (QSettings * settings, QWidget * parent)
-  : m_ {this, instance_key, settings, test_mode, parent}
+  : m_ {this, settings, parent}
 {
 }
 
@@ -549,7 +549,7 @@ void Configuration::sync_transceiver (bool force_signal, bool enforce_mode_and_s
 }
 
 
-Configuration::impl::impl (Configuration * self, QString const& instance_key, QSettings * settings, bool test_mode, QWidget * parent)
+Configuration::impl::impl (Configuration * self, QSettings * settings, QWidget * parent)
   : QDialog {parent}
   , self_ {self}
   , ui_ {new Ui::configuration_dialog}
@@ -593,8 +593,6 @@ Configuration::impl::impl (Configuration * self, QString const& instance_key, QS
   , default_audio_input_device_selected_ {false}
   , default_audio_output_device_selected_ {false}
 {
-  (void)instance_key;		// quell compiler warning
-
   ui_->setupUi (this);
 
 
@@ -637,11 +635,7 @@ Configuration::impl::impl (Configuration * self, QString const& instance_key, QS
         temp_path_.setPath (temp_location);
       }
 
-    QString unique_directory {instance_key};
+    QString unique_directory {QApplication::applicationName ()};
-    if (test_mode)
-      {
-        unique_directory += " - test_mode";
-      }
     if (!temp_path_.mkpath (unique_directory) || !temp_path_.cd (unique_directory))
       {
         QMessageBox::critical (this, "WSJT-X", tr ("Create temporary directory error: ") + temp_path_.absolutePath ());

Configuration.hpp

@@ -61,7 +61,7 @@ public:
 
   enum DataMode {data_mode_none, data_mode_USB, data_mode_data};
 
-  explicit Configuration (QString const& instance_key, QSettings * settings, bool test_mode, QWidget * parent = nullptr);
+  explicit Configuration (QSettings * settings, QWidget * parent = nullptr);
   ~Configuration ();
 
   int exec ();

main.cpp

@@ -20,6 +20,7 @@
 #include <QStandardPaths>
 #include <QStringList>
 #include <QMessageBox>
+#include <QLockFile>
 
 #if QT_VERSION >= 0x050200
 #include <QCommandLineParser>
@@ -32,12 +33,12 @@
 #include "TraceFile.hpp"
 #include "mainwindow.h"
 
-// Multiple instances:
-QSharedMemory mem_jt9;
-QString       my_key;
 
 int main(int argc, char *argv[])
 {
+  // Multiple instances:
+  QSharedMemory mem_jt9;
+
   QApplication a(argc, argv);
   try
     {
@@ -111,9 +112,42 @@ int main(int argc, char *argv[])
                 }
                 
               a.setApplicationName (a.applicationName () + " - " + temp_name);
+
+              if (parser.isSet (test_option))
+                {
+                  a.setApplicationName (a.applicationName () + " - test");
+                }
             }
           multiple = true;
         }
+
+      // disallow multiple instances with same instance key
+      QLockFile instance_lock {QDir {QStandardPaths::writableLocation (QStandardPaths::TempLocation)}.absoluteFilePath (a.applicationName () + ".lock")};
+      instance_lock.setStaleLockTime (0);
+      auto ok = false;
+      while (!(ok = instance_lock.tryLock ()))
+        {
+          if (QLockFile::LockFailedError == instance_lock.error ())
+            {
+              auto button = QMessageBox::question (nullptr
+                                                   , QApplication::applicationName ()
+                                                   , QObject::tr ("Another instance may be running, try to remove stale lock file?")
+                                                   , QMessageBox::Yes | QMessageBox::Retry | QMessageBox::No
+                                                   , QMessageBox::Yes);
+              switch (button)
+                {
+                case QMessageBox::Yes:
+                  instance_lock.removeStaleLockFile ();
+                  break;
+
+                case QMessageBox::Retry:
+                  break;
+
+                default:
+                  throw std::runtime_error {"Multiple instances must have unique rig names"};
+                }
+            }
+        }
 #endif
 #endif
 
@@ -124,7 +158,6 @@ int main(int argc, char *argv[])
           throw std::runtime_error {"Cannot find a usable configuration path \"" + config_path.path ().toStdString () + '"'};
         }
       QSettings settings(config_path.absoluteFilePath (a.applicationName () + ".ini"), QSettings::IniFormat);
-
 #if WSJT_QDEBUG_TO_FILE
       // // open a trace file
       TraceFile trace_file {QDir {QApplication::applicationDirPath ()}.absoluteFilePath ("wsjtx_trace.log")};
@@ -135,8 +168,7 @@ int main(int argc, char *argv[])
 
       // Create and initialize shared memory segment
       // Multiple instances: use rig_name as shared memory key
-      my_key = a.applicationName ();
+      mem_jt9.setKey(a.applicationName ());
-      mem_jt9.setKey(my_key);
 
       if(!mem_jt9.attach()) {
         if (!mem_jt9.create(sizeof(jt9com_))) {
@@ -167,7 +199,7 @@ int main(int argc, char *argv[])
                                            ).toBool () ? 1u : 4u;
       }
 
-      MainWindow w(multiple, &settings, &mem_jt9, my_key, downSampleFactor, parser.isSet (test_option));
+      MainWindow w(multiple, &settings, &mem_jt9, downSampleFactor);
       w.show();
 
       QObject::connect (&a, SIGNAL (lastWindowClosed()), &a, SLOT (quit()));

mainwindow.cpp

@@ -68,14 +68,14 @@ private:
 };
 
 //--------------------------------------------------- MainWindow constructor
-MainWindow::MainWindow(bool multiple, QSettings * settings, QSharedMemory *shdmem, QString const& thekey,
+MainWindow::MainWindow(bool multiple, QSettings * settings, QSharedMemory *shdmem,
-                       unsigned downSampleFactor, bool test_mode, QWidget *parent) :
+                       unsigned downSampleFactor, QWidget *parent) :
   QMainWindow(parent),
   m_revision {revision ("$Rev$")},
   m_multiple {multiple},
   m_settings (settings),
   ui(new Ui::MainWindow),
-  m_config (thekey, settings, test_mode, this),
+  m_config (settings, this),
   m_wideGraph (new WideGraph (settings)),
   m_logDlg (new LogQSO (program_title (), settings, &m_config, this)),
   m_dialFreq {0},
@@ -85,7 +85,6 @@ MainWindow::MainWindow(bool multiple, QSettings * settings, QSharedMemory *shdme
   m_diskData {false},
   m_appDir {QApplication::applicationDirPath ()},
   mem_jt9 {shdmem},
-  mykey_jt9 {thekey},
   psk_Reporter (new PSK_Reporter (this)),
   m_msAudioOutputBuffered (0u),
   m_framesAudioInputBuffered (RX_SAMPLE_RATE / 10),
@@ -369,7 +368,7 @@ MainWindow::MainWindow(bool multiple, QSettings * settings, QSharedMemory *shdme
   lockFile.open(QIODevice::ReadWrite);
 
   QStringList jt9_args {
-    "-s", mykey_jt9
+    "-s", QApplication::applicationName ()
       , "-e", QDir::toNativeSeparators (m_appDir)
       , "-a", QDir::toNativeSeparators (m_config.data_path ().absolutePath ())
       };

mainwindow.h

@@ -57,8 +57,8 @@ public:
   using Frequency = Radio::Frequency;
 
   // Multiple instances: call MainWindow() with *thekey
-  explicit MainWindow(bool multiple, QSettings *, QSharedMemory *shdmem, QString const& thekey,
+  explicit MainWindow(bool multiple, QSettings *, QSharedMemory *shdmem,
-                      unsigned downSampleFactor, bool test_mode, QWidget *parent = 0);
+                      unsigned downSampleFactor, QWidget *parent = 0);
   ~MainWindow();
 
 public slots:
@@ -349,8 +349,6 @@ private:
   QRect   m_astroGeom;
 
   QSharedMemory *mem_jt9;
-  // Multiple instances:
-  QString mykey_jt9;
   PSK_Reporter *psk_Reporter;
   SignalMeter *signalMeter;
   LogBook m_logBook;