Alive thread implemented

main.cpp

@@ -26,13 +26,26 @@ public:
     ShmQueue *result_queue;
     ShmQueue *event_queue;
     Rktwebview_qt *webview_handler;
+    bool quit;
 
     // QThread interface
 protected:
     void run();
 };
 
+class Alive : public QThread
+{
+public:
+    Handler *handler;
+    ShmQueue *alive_queue;
+    bool alive_timeout;
+
+protected:
+    void run();
+};
+
 static Handler *_handler;
+static Alive   *_alive;
 
 static void event_cb(rkt_data_t *data)
 {
@@ -58,7 +71,7 @@ int main(int argc, char *argv[])
         INFO1("Starting at %s", ctime(&my_time));
     }
 
-    if (argc < 6) {
+    if (argc < 7) {
         ERROR1("%s: wrong number of arguments\n", me);
         exit(1);
     }
@@ -68,14 +81,16 @@ int main(int argc, char *argv[])
     const char *cmd_slot_str = argv[3];
     const char *res_slot_str = argv[4];
     const char *evt_slot_str = argv[5];
+    const char *alive_slot_str = argv[6];
 
     size_t shm_size = atoi(shm_size_str);
     int cmd_slot = atoi(cmd_slot_str);
     int res_slot = atoi(res_slot_str);
     int evt_slot = atoi(evt_slot_str);
+    int alive_slot = atoi(alive_slot_str);
 
-    MKLOGSTMT(LOG_INFO, fprintf(stderr, "%s %s %s %s %s %s\n", me, shm_name, shm_size_str, cmd_slot_str, res_slot_str, evt_slot_str));
-    MKLOGSTMT(LOG_INFO, fprintf(stderr, "%s %s %ld %d %d %d\n", me, shm_name, shm_size, cmd_slot, res_slot, evt_slot));
+    MKLOGSTMT(LOG_INFO, fprintf(stderr, "%s %s %s %s %s %s %s\n", me, shm_name, shm_size_str, cmd_slot_str, res_slot_str, evt_slot_str, alive_slot_str));
+    MKLOGSTMT(LOG_INFO, fprintf(stderr, "%s %s %ld %d %d %d %d\n", me, shm_name, shm_size, cmd_slot, res_slot, evt_slot, alive_slot));
 
     if (!(shm_size > 0 && cmd_slot > 0 && res_slot > 0 && evt_slot > 0)) {
         ERROR1("%s: Invalid shm size or slots\n", me);
@@ -91,14 +106,38 @@ int main(int argc, char *argv[])
     handler->webview_handler = new Rktwebview_qt(argc, argv);
     handler->start();
 
+    Alive *alive = new Alive();
+    _alive = alive;
+    alive->handler = handler;
+    alive->alive_timeout = false;
+    alive->alive_queue = new ShmQueue(handler->shm, alive_slot, false);
+    alive->start();
+
     handler->webview_handler->initApp();
     handler->webview_handler->execApp();
 
     INFO0("waiting for thread to end\n");
     handler->wait();
+    INFO0("Handler thread stopped\n");
+    alive->wait();
+    INFO0("Alive thread stopped\n");
+
+    if (alive->alive_timeout) {
+        // take ownership over all queues and SHM, because we didn't get an alive message
+        // and probably the racket side has crashed because of that.
+        ERROR0("Taking ownership of shared memory, shared queues and shared semaphores\n");
+        handler->command_queue->takeOwnership();
+        handler->result_queue->takeOwnership();
+        handler->event_queue->takeOwnership();
+        handler->shm->takeOwnership();
+        alive->alive_queue->takeOwnership();
+    }
 
     INFO0("cleaning up shm\n");
 
+    delete alive->alive_queue;
+    delete alive;
+
     delete handler->webview_handler;
     delete handler->command_queue;
     delete handler->result_queue;
@@ -116,14 +155,28 @@ int main(int argc, char *argv[])
 
 void Handler::run()
 {
-    bool quit = false;
+    int wait_ms = 10 * 1000; // 10 seconds.
     while (!quit) {
         int cmd;
         std::string data;
-        command_queue->dequeue(cmd, data, true);
+        bool something_came = command_queue->dequeue(cmd, data, wait_ms);
+        if (!something_came) {
+            DEBUG1("No command received last %d seconds\n", wait_ms / 1000);
+            cmd = CMD_NOOP;
+        }
         QJsonObject data_obj = QJsonDocument::fromJson(data.c_str()).object();
 
         switch(cmd) {
+            case CMD_NOOP: {
+                if (quit) {
+                    DEBUG1("Alive timeout, quit = %d\n", quit);
+                    webview_handler->closeAllWindows();
+                    DEBUG0("Closed all windows\n");
+                    webview_handler->rktQuit();
+                    DEBUG0("Quit application\n");
+                }
+            }
+            break;
             case CMD_QUIT: {
                 INFO0("Got quit message\n");
                 webview_handler->rktQuit();
@@ -341,4 +394,31 @@ void Handler::run()
             }
         }
     }
+    DEBUG0("Exiting handler thread\n");
+}
+
+void Alive::run()
+{
+    int wait_ms = 10 * 1000;
+    int ping_no;
+    std::string data;
+    bool go_on = true;
+    while (go_on) {
+        bool something_came = alive_queue->dequeue(ping_no, data, wait_ms);
+        if (!something_came) {
+            ERROR0("No alive message received, stopping alive loop and quitting rktwebview_prg\n");
+            handler->quit = true;
+            handler->command_queue->enqueue(CMD_NOOP);
+            alive_timeout = true;
+            go_on = false;
+        } else {
+            if (ping_no == CMD_ALIVE_QUIT) {
+                DEBUG0("Got Quit ping for alive thread\n");
+                go_on = false;
+            } else {
+                DEBUG1("Got alive ping: %d\n", ping_no);
+            }
+        }
+    }
+    DEBUG0("Exiting alive thread\n");
 }