Fixed issue 107 and 123, receiver check connection when pop msg failed, and call reconnect function when the connection check result is false

Author: yongke liu

src/libipc/ipc.cpp

@@ -627,7 +627,10 @@ static ipc::buff_t recv(ipc::handle_t h, std::uint64_t tm) {
     for (;;) {
         // pop a new message
         typename queue_t::value_t msg {};
-        if (!wait_for(inf->rd_waiter_, [que, &msg] {
+        if (!wait_for(inf->rd_waiter_, [que, &msg, &h] {
+                if (!que->connected(que->elems())) {
+                    reconnect(&h, true);
+                }
                 return !que->pop(msg);
             }, tm)) {
             // pop failed, just return.

src/libipc/queue.h

@@ -67,6 +67,11 @@ class queue_conn {
         return connected_ != 0;
     }
 
+    template <typename Elems>
+    bool connected(Elems* elems) noexcept {
+        return connected_ & elems->connections();
+    }
+
     circ::cc_t connected_id() const noexcept {
         return connected_;
     }
@@ -77,16 +82,16 @@ class queue_conn {
      -> std::tuple<bool, bool, decltype(std::declval<Elems>().cursor())> {
         if (elems == nullptr) return {};
         // if it's already connected, just return
-        if (connected()) return {connected(), false, 0};
+        if (connected(elems)) return {connected(elems), false, 0};
         connected_ = elems->connect_receiver();
-        return {connected(), true, elems->cursor()};
+        return {connected(elems), true, elems->cursor()};
     }
 
     template <typename Elems>
     bool disconnect(Elems* elems) noexcept {
         if (elems == nullptr) return false;
         // if it's already disconnected, just return false
-        if (!connected()) return false;
+        if (!connected(elems)) return false;
         elems->disconnect_receiver(std::exchange(connected_, 0));
         return true;
     }