Integrated websocket communication with hpws (#3)

src/util/util.cpp

@@ -97,4 +97,35 @@ namespace util
         return buffer.data();
     }
 
+    /**
+     * Clears signal mask and signal handlers from the caller.
+     * Called by other processes forked from sagent threads so they get detatched from
+     * the sagent signal setup.
+     */
+    void fork_detach()
+    {
+        // Restore signal handlers to defaults.
+        signal(SIGINT, SIG_DFL);
+        signal(SIGSEGV, SIG_DFL);
+        signal(SIGABRT, SIG_DFL);
+
+        // Remove any signal masks applied by sagent.
+        sigset_t mask;
+        sigemptyset(&mask);
+        pthread_sigmask(SIG_SETMASK, &mask, NULL);
+
+        // Set process group id (so the terminal doesn't send kill signals to forked children).
+        setpgrp();
+    }
+
+    // Applies signal mask to the calling thread.
+    void mask_signal()
+    {
+        sigset_t mask;
+        sigemptyset(&mask);
+        sigaddset(&mask, SIGINT);
+        sigaddset(&mask, SIGPIPE);
+        pthread_sigmask(SIG_BLOCK, &mask, NULL);
+    }
+
 } // namespace util