ConnectedChildProcess: Wait for process termination on Linux to not leave zombies

This change also avoids the AudioPluginHost leaving zombie child
processes behind.

modules/juce_events/interprocess/juce_ConnectedChildProcess.cpp

@@ -164,9 +164,20 @@ bool ChildProcessCoordinator::launchWorkerProcess (const File& executable, const
     args.add (executable.getFullPathName());
     args.add (getCommandLinePrefix (commandLineUniqueID) + pipeName);
 
-    childProcess.reset (new ChildProcess());
+    childProcess = [&]() -> std::shared_ptr<ChildProcess>
+    {
+        if ((SystemStats::getOperatingSystemType() & SystemStats::Linux) != 0)
+            return ChildProcessManager::getInstance()->createAndStartManagedChildProcess (args, streamFlags);
+
+        auto p = std::make_shared<ChildProcess>();
+
+        if (p->start (args, streamFlags))
+            return p;
+
+        return nullptr;
+    }();
 
-    if (childProcess->start (args, streamFlags))
+    if (childProcess != nullptr)
     {
         connection.reset (new Connection (*this, pipeName, timeoutMs <= 0 ? defaultTimeoutMs : timeoutMs));
 

modules/juce_events/interprocess/juce_ConnectedChildProcess.h

@@ -215,7 +215,7 @@ public:
     bool sendMessageToSlave (const MemoryBlock& mb) { return sendMessageToWorker (mb); }
 
 private:
-    std::unique_ptr<ChildProcess> childProcess;
+    std::shared_ptr<ChildProcess> childProcess;
 
     struct Connection;
     std::unique_ptr<Connection> connection;