feat: add a new core option --new-instance to skip the core check for a running instance

src/apps/deskflow-core/CoreArgParser.cpp

@@ -27,6 +27,8 @@ CoreArgParser::CoreArgParser(const QStringList &args)
 
   m_helpText = m_parser.helpText().replace("<executable_name>", kCoreBinName);
   m_helpText.replace("[options] coremode", "coremode [options]");
+
+  m_singleInstance = !m_parser.isSet(CoreArgs::multiInstanceOption);
 }
 
 void CoreArgParser::parse()
@@ -95,3 +97,8 @@ bool CoreArgParser::clientMode() const
 {
   return m_clientMode;
 }
+
+bool CoreArgParser::singleInstanceOnly() const
+{
+  return m_singleInstance;
+}

src/apps/deskflow-core/CoreArgParser.h

@@ -33,6 +33,7 @@ public:
   bool version() const;
   bool serverMode() const;
   bool clientMode() const;
+  bool singleInstanceOnly() const;
 
 private:
   [[noreturn]] void showHelpText() const;
@@ -40,5 +41,6 @@ private:
   QString m_helpText;
   bool m_clientMode = false;
   bool m_serverMode = false;
+  bool m_singleInstance = true;
   static const QString s_headerText;
 };

src/apps/deskflow-core/CoreArgs.h

@@ -15,8 +15,10 @@ struct CoreArgs
 {
   inline static const auto helpOption = QCommandLineOption({"h", "help"}, "Display Help on the command line");
   inline static const auto versionOption = QCommandLineOption({"v", "version"}, "Display version information");
+  inline static const auto multiInstanceOption =
+      QCommandLineOption("new-instance", "Skip the check for a running instance, always makes a new instance");
   inline static const auto configOption =
       QCommandLineOption({"s", "settings"}, "override configuration file to use", "configFile");
 
-  inline static const auto options = {helpOption, versionOption, configOption};
+  inline static const auto options = {helpOption, versionOption, multiInstanceOption, configOption};
 };

src/apps/deskflow-core/deskflow-core.cpp

@@ -11,6 +11,7 @@
 #include "arch/Arch.h"
 #include "base/EventQueue.h"
 #include "base/Log.h"
+#include "common/Constants.h"
 #include "common/ExitCodes.h"
 #include "deskflow/ClientApp.h"
 #include "deskflow/ServerApp.h"
@@ -65,20 +66,22 @@ int main(int argc, char **argv)
     return s_exitSuccess;
   }
 
-  // Before we check any more args we need to check for a duplicate process.
-  // Create a shared memory segment with a unique key
-  // This is to prevent a new instance from running if one is already running
-  QSharedMemory sharedMemory("deskflow-core");
+  if (parser.singleInstanceOnly()) {
+    // Before we check any more args we need to check for a duplicate process.
+    // Create a shared memory segment with a unique key
+    // This is to prevent a new instance from running if one is already running
+    QSharedMemory sharedMemory(kCoreBinName);
 
-  // Attempt to attach first and detach in order to clean up stale shm chunks
-  // This can happen if the previous instance was killed or crashed
-  if (sharedMemory.attach())
-    sharedMemory.detach();
+    // Attempt to attach first and detach in order to clean up stale shm chunks
+    // This can happen if the previous instance was killed or crashed
+    if (sharedMemory.attach())
+      sharedMemory.detach();
 
-  // If we can create 1 byte of SHM we are the only instance
-  if (!sharedMemory.create(1)) {
-    LOG_WARN("an instance of deskflow core is already running");
-    return s_exitDuplicate;
+    // If we can create 1 byte of SHM we are the only instance
+    if (!sharedMemory.create(1)) {
+      LOG_WARN("an instance of deskflow core is already running");
+      return s_exitDuplicate;
+    }
   }
 
   parser.parse();