Fix getting stuck when ProcessManager fifos aren’t open on the other endHEADmaster

1 files changed, 18 insertions, 1 deletions

diff --git a/src/ProcessManager.cpp b/src/ProcessManager.cpp
index e34ebfc..09f725f 100644
--- a/src/ProcessManager.cpp
+++ b/src/ProcessManager.cpp
@@ -1,5 +1,7 @@
 #include "ProcessManager.hpp"
+#include <fcntl.h>
 #include <sys/ioctl.h>
+#include <unistd.h>
 
 #include <QProcess>
 #include <QThread>
@@ -28,8 +30,23 @@ ProcessManager::ProcessManager(const QString &newPrefix, const QString &newId, b
     stdErr.setFileName(prefix + id + "stderr");
     ctrlIn.setFileName(prefix + id + "ctrlin");
     ctrlOut.setFileName(prefix + id + "ctrlout");
+
+    bool reattach = ctrlIn.exists();
+    if(reattach)
+    {
+        int fd = open(ctrlIn.fileName().toLocal8Bit().toStdString().c_str(), O_WRONLY | O_NONBLOCK);
+        if(fd == -1)
+        {
+            reattach = false;
+        }
+        else
+        {
+            close(fd);
+        }
+    }
+
     bool reattaching = false;
-    if(!ctrlIn.exists())
+    if(!reattach)
     {
         if(!QProcess::startDetached("ProcessManager", QStringList() << prefix + id))
         {