guacamole: remove keep alive thread

This is because the connection is maintained by websocket, a keep alive thread is not necessary
anymore.

nop command can also be removed.

Update #3

Author: changkun

guacamole/src/libguac/guacamole/protocol.h

@@ -120,18 +120,6 @@ int guac_protocol_send_error(guac_socket* socket, const char* error,
 int guac_protocol_send_mouse(guac_socket* socket, int x, int y,
         int button_mask, guac_timestamp timestamp);
 
-/**
- * Sends a nop instruction (null-operation) over the given guac_socket
- * connection.
- *
- * If an error occurs sending the instruction, a non-zero value is
- * returned, and guac_error is set appropriately.
- *
- * @param socket The guac_socket connection to use.
- * @return Zero on success, non-zero on error.
- */
-int guac_protocol_send_nop(guac_socket* socket);
-
 /**
  * Sends a sync instruction over the given guac_socket connection. The
  * current time in milliseconds should be passed in as the timestamp.

guacamole/src/libguac/guacamole/socket-constants.h

@@ -31,11 +31,5 @@
  */
 #define GUAC_SOCKET_OUTPUT_BUFFER_SIZE 8192
 
-/**
- * The number of milliseconds to wait between keep-alive pings on a socket
- * with keep-alive enabled.
- */
-#define GUAC_SOCKET_KEEP_ALIVE_INTERVAL 5000
-
 #endif
 

guacamole/src/libguac/guacamole/socket.h

@@ -103,16 +103,6 @@ struct guac_socket {
      */
     int __ready_buf[3];
 
-    /**
-     * Whether automatic keep-alive is enabled.
-     */
-    int __keep_alive_enabled;
-
-    /**
-     * The keep-alive thread.
-     */
-    pthread_t __keep_alive_thread;
-
 };
 
 /**
@@ -131,15 +121,6 @@ guac_socket* guac_socket_alloc();
  */
 void guac_socket_free(guac_socket* socket);
 
-/**
- * Declares that the given socket must automatically send a keep-alive ping
- * to ensure neither side of the socket times out while the socket is open.
- * This ping will take the form of a "nop" instruction.
- *
- * @param socket
- *     The guac_socket to declare as requiring an automatic keep-alive ping.
- */
-void guac_socket_require_keep_alive(guac_socket* socket);
 
 /**
  * Marks the beginning of a Guacamole protocol instruction.

guacamole/src/libguac/protocol.c

@@ -420,18 +420,6 @@ int guac_protocol_send_name(guac_socket* socket, const char* name) {
 
 }
 
-int guac_protocol_send_nop(guac_socket* socket) {
-
-    int ret_val;
-
-    guac_socket_instruction_begin(socket);
-    ret_val = guac_socket_write_string(socket, "3.nop;");
-    guac_socket_instruction_end(socket);
-
-    return ret_val;
-
-}
-
 int guac_protocol_send_pipe(guac_socket* socket, const guac_stream* stream,
         const char* mimetype, const char* name) {
 

guacamole/src/libguac/socket.c

@@ -42,38 +42,6 @@ char __guac_socket_BASE64_CHARACTERS[64] = {
     '8', '9', '+', '/'
 };
 
-static void* __guac_socket_keep_alive_thread(void* data) {
-
-    /* Calculate sleep interval */
-    struct timespec interval;
-    interval.tv_sec  =  GUAC_SOCKET_KEEP_ALIVE_INTERVAL / 1000;
-    interval.tv_nsec = (GUAC_SOCKET_KEEP_ALIVE_INTERVAL % 1000) * 1000000L;
-
-    /* Socket keep-alive loop */
-    guac_socket* socket = (guac_socket*) data;
-    while (socket->state == GUAC_SOCKET_OPEN) {
-
-        /* Send NOP keep-alive if it's been a while since the last output */
-        guac_timestamp timestamp = guac_timestamp_current();
-        if (timestamp - socket->last_write_timestamp >
-                GUAC_SOCKET_KEEP_ALIVE_INTERVAL) {
-
-            /* Send NOP */
-            if (guac_protocol_send_nop(socket)
-                || guac_socket_flush(socket))
-                break;
-
-        }
-
-        /* Sleep until next keep-alive check */
-        nanosleep(&interval, NULL);
-
-    }
-
-    return NULL;
-
-}
-
 static ssize_t __guac_socket_write(guac_socket* socket,
         const void* buf, size_t count) {
 
@@ -150,9 +118,6 @@ guac_socket* guac_socket_alloc() {
     socket->state = GUAC_SOCKET_OPEN;
     socket->last_write_timestamp = guac_timestamp_current();
 
-    /* No keep alive ping by default */
-    socket->__keep_alive_enabled = 0;
-
     /* No handlers yet */
     socket->read_handler   = NULL;
     socket->write_handler  = NULL;
@@ -166,15 +131,6 @@ guac_socket* guac_socket_alloc() {
 
 }
 
-void guac_socket_require_keep_alive(guac_socket* socket) {
-
-    /* Start keep-alive thread */
-    socket->__keep_alive_enabled = 1;
-    pthread_create(&(socket->__keep_alive_thread), NULL,
-                __guac_socket_keep_alive_thread, (void*) socket);
-
-}
-
 void guac_socket_instruction_begin(guac_socket* socket) {
 
     /* Call instruction begin handler if defined */
@@ -202,10 +158,6 @@ void guac_socket_free(guac_socket* socket) {
     /* Mark as closed */
     socket->state = GUAC_SOCKET_CLOSED;
 
-    /* Wait for keep-alive, if enabled */
-    if (socket->__keep_alive_enabled)
-        pthread_join(socket->__keep_alive_thread, NULL);
-
     free(socket);
 }
 

guacamole/src/protocols/vnc/vnc.c

@@ -164,9 +164,6 @@ void* guac_vnc_client_thread(void* data) {
                 "clipboard encoding: '%s'.", settings->clipboard_encoding);
     }
 
-    /* Ensure connection is kept alive during lengthy connects */
-    guac_socket_require_keep_alive(client->socket);
-
     /* Set up libvncclient logging */
     rfbClientLog = guac_vnc_client_log_info;
     rfbClientErr = guac_vnc_client_log_error;