resolved some bug in the MUX

examples/microhttp/xhttp.c

@@ -509,19 +509,19 @@ static void req_deinit(xh_request *req)
     req->headers.count = 0;
 }
 
-static void accept_connection(context_t *ctx)
+static conn_t *accept_connection(context_t *ctx)
 {
     microtcp_errcode_t errcode;
     microtcp_socket_t *accepted_sock = microtcp_accept(ctx->sock, true, &errcode);
 
     if(accepted_sock == NULL)
-        return; // Failed to accept.
+        return NULL; // Failed to accept.
 
     if(ctx->freelist == NULL)
     {
         // Connection limit reached.
         microtcp_close(accepted_sock);
-        return;
+        return NULL;
     }
 
     conn_t *conn = ctx->freelist;
@@ -534,17 +534,18 @@ static void accept_connection(context_t *ctx)
     conn->sock = accepted_sock;
     req_init(&conn->request);
 
-    if(microtcp_mux_register(ctx->mux, accepted_sock, MICROTCP_MUX_RECV|MICROTCP_MUX_SEND, conn))
+    if(!microtcp_mux_register(ctx->mux, accepted_sock, MICROTCP_MUX_RECV|MICROTCP_MUX_SEND, conn))
     {
         microtcp_close(accepted_sock);
 
         conn->sock = NULL;
         conn->next = ctx->freelist;
         ctx->freelist = conn;
-        return;
+        return NULL;
     }
 
     ctx->connum += 1;
+    return conn;
 }
 
 static void close_connection(context_t *ctx, conn_t *conn)
@@ -960,6 +961,9 @@ static bool upload(conn_t *conn)
                     break;
 
                 // ERROR!
+#ifdef DEBUG
+                fprintf(stderr, "XHTTP :: microtcp_send failed (%s)\n", microtcp_strerror(errcode));
+#endif
                 return 0;
             }
 
@@ -1260,6 +1264,9 @@ static void when_data_is_ready_to_be_read(context_t *ctx, conn_t *conn)
                     break; // Done downloading.
                 if (errcode != MICROTCP_ERRCODE_NONE)
                 {
+#ifdef DEBUG
+                    fprintf(stderr, "XHTTP :: %s\n", microtcp_strerror(errcode));
+#endif
                     // An error occurred.
                     close_connection(ctx, conn);
                     return;
@@ -1466,11 +1473,40 @@ const char *xhttp(unsigned short port, xh_callback callback,
         if (!microtcp_mux_wait(context.mux, &ev))
             continue;
 
+#ifdef DEBUG
+        const char *event_bitset_string;
+        switch (ev.events) {
+            case 0: event_bitset_string = ""; break;
+            case MICROTCP_MUX_RECV: event_bitset_string = "RECV"; break;
+            case MICROTCP_MUX_SEND: event_bitset_string = "SEND"; break;
+            case MICROTCP_MUX_ACCEPT: event_bitset_string = "ACCEPT"; break;
+            case MICROTCP_MUX_RECV | MICROTCP_MUX_SEND: event_bitset_string = "RECV|SEND"; break;
+            case MICROTCP_MUX_RECV | MICROTCP_MUX_ACCEPT: event_bitset_string = "RECV|ACCEPT"; break;
+            case MICROTCP_MUX_SEND | MICROTCP_MUX_ACCEPT: event_bitset_string = "SEND|ACCEPT"; break;
+            case MICROTCP_MUX_RECV | MICROTCP_MUX_SEND | MICROTCP_MUX_ACCEPT: event_bitset_string = "RECV|SEND|ACCEPT"; break;
+            default: event_bitset_string = "???";
+        }
+        fprintf(stderr, "XHTTP :: Event %s\n", event_bitset_string);
+#endif
+
         if(ev.userp == NULL)
         {
+#ifdef DEBUG
+                fprintf(stderr, "XHTTP :: New connection\n");
+#endif
             // New connection.
-            accept_connection(&context);
+            conn_t *newly_accepted = accept_connection(&context);
-            continue;
+            if (!newly_accepted)
+                continue; // For some reason, although a MICROTCP_MUX_ACCEPT
+                          // was received by the MUX, accepting failed.
+                          // Wait for the next event.
+
+            // A connection was accepted. Since it may already
+            // contain data to be read or space to write we continue
+            // by building a fake event ourselves
+            ev.userp = newly_accepted;
+            ev.events = MICROTCP_MUX_RECV | MICROTCP_MUX_SEND;
+            ev.socket = newly_accepted->sock;
         }
 
         conn_t *conn = ev.userp;

makefile

@@ -48,7 +48,7 @@ MEMDBG=valgrind
 LIBDIR = 3p/lib
 INCDIR = 3p/include
 
-CFLAGS = $(CFLAGS_PLATFORM) -I$(INCDIR) -Ibuild/ -Wall -Wextra -DARP_DEBUG -DMICROTCP_DEBUG -DIP_DEBUG -DICMP_DEBUG -DTCP_DEBUG -DMICROTCP_BACKGROUND_THREAD -DMICROTCP_USING_TAP -DMICROTCP_USING_MUX
+CFLAGS = $(CFLAGS_PLATFORM) -I$(INCDIR) -Ibuild/ -Wall -Wextra -DDEBUG=1 -DARP_DEBUG -DMICROTCP_DEBUG -DIP_DEBUG -DICMP_DEBUG -DTCP_DEBUG -DMICROTCP_BACKGROUND_THREAD -DMICROTCP_USING_TAP -DMICROTCP_USING_MUX
 LFLAGS = -ltuntap $(LFLAGS_PLATFORM) -L$(LIBDIR)
 
 ifeq ($(MEMDBG),drmemory)

src/microtcp.c

@@ -810,6 +810,7 @@ static void ready_to_accept(void *data)
 #endif
 
 #ifdef MICROTCP_USING_MUX
+    MICROTCP_DEBUG_LOG("Signaling ACCEPT to muxes");
     signal_events_to_muxes_associated_to_socket(socket, MICROTCP_MUX_ACCEPT);
 #endif
 }
@@ -903,6 +904,7 @@ static void ready_to_recv(void *data)
 #endif
 
 #ifdef MICROTCP_USING_MUX
+    MICROTCP_DEBUG_LOG("Signaling RECV to muxes");
     signal_events_to_muxes_associated_to_socket(socket, MICROTCP_MUX_RECV);
 #endif
 }
@@ -917,6 +919,7 @@ static void ready_to_send(void *data)
 #endif
 
 #ifdef MICROTCP_USING_MUX
+    MICROTCP_DEBUG_LOG("Signaling SEND to muxes");
     signal_events_to_muxes_associated_to_socket(socket, MICROTCP_MUX_SEND);
 #endif
 }
@@ -978,14 +981,12 @@ microtcp_socket_t *microtcp_accept(microtcp_socket_t *socket,
         if (cnd_init(&socket2->something_to_recv) != thrd_success) {
             errcode2 = MICROTCP_ERRCODE_BADCONDVAR;
             push_unlinked_socket_into_free_list(mtcp, socket2);
-            tcp_connection_destroy(connection);
             goto unlock_and_exit;
         }
         if (cnd_init(&socket2->something_to_send) != thrd_success) {
             errcode2 = MICROTCP_ERRCODE_BADCONDVAR;
             cnd_destroy(&socket2->something_to_recv);
             push_unlinked_socket_into_free_list(mtcp, socket2);
-            tcp_connection_destroy(connection);
             goto unlock_and_exit;
         }
 #endif
@@ -1029,15 +1030,13 @@ size_t microtcp_recv(microtcp_socket_t *socket,
             }
             num = tcp_connection_recv(socket->connection, dst, len);
         }
-#else
+#endif
         if (num == 0) {
             if (no_block)
                 errcode2 = MICROTCP_ERRCODE_WOULDBLOCK;
             else
                 errcode2 = MICROTCP_ERRCODE_CANTBLOCK;
-            goto unlock_and_exit;
         }
-#endif
     }
 unlock_and_exit:
     UNLOCK_WHEN_THREADED(mtcp);
@@ -1075,15 +1074,13 @@ size_t microtcp_send(microtcp_socket_t *socket,
             }
             num = tcp_connection_send(socket->connection, src, len);
         }
-#else
+#endif
         if (num == 0) {
             if (no_block)
                 errcode2 = MICROTCP_ERRCODE_WOULDBLOCK;
             else
                 errcode2 = MICROTCP_ERRCODE_CANTBLOCK;
-            goto unlock_and_exit;
         }
-#endif
     }
 unlock_and_exit:
     UNLOCK_WHEN_THREADED(mtcp);
@@ -1393,6 +1390,9 @@ signal_events_to_muxes_associated_to_socket(microtcp_socket_t *socket, int event
         // interested in.
         int newly_triggered_events = events & entry->events_of_interest;
         
+        if (!newly_triggered_events)
+            MICROTCP_DEBUG_LOG("MUX not interested in these events");
+
         // If there are no previously triggered events by this
         // socket and the socket just generated some events the
         // mux is interested in, then we need to move the socket-mux

src/tcp.c

@@ -238,6 +238,8 @@ static void handle_received_data(tcp_connection_t *connection,
 
         emit_segment(connection, true, false, SIZE_MAX);
 
+        TCP_DEBUG_LOG("Received %d bytes", considered);
+
         // Data is ready to be received by the parent application
         if (connection->callback_ready_to_recv)
             connection->callback_ready_to_recv(connection->callback_data);
@@ -340,6 +342,9 @@ void tcp_process_segment(tcp_state_t *state, ip_address_t sender,
 
     tcp_connection_t *connection = find_connection_associated_to_listener(listener, sender, reordered_src_port);
     if (!connection) {
+
+        TCP_DEBUG_LOG("Connection request from port %d", reordered_src_port);
+
         // Something sent to an open listener. 
 
         // We expect it to be a request to connect,

src/tcp.h

@@ -107,7 +107,7 @@ struct tcp_connection_t {
                       // byte sent and acknowledged by the peer.
 
     char out_buffer[TCP_OUTPUT_BUFFER_SIZE];
-    char in_buffer[TCP_INPUT_BUFFER_SIZE];
+    char  in_buffer[TCP_INPUT_BUFFER_SIZE];
 };
 
 typedef struct {