GUACAMOLE-249: Remove lock around usage of FreeRDP (new library appears threadsafe).

src/protocols/rdp/client.c

@@ -66,9 +66,6 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
     pthread_mutexattr_settype(&(rdp_client->attributes),
             PTHREAD_MUTEX_RECURSIVE);
 
-    /* Init RDP lock */
-    pthread_mutex_init(&(rdp_client->rdp_lock), &(rdp_client->attributes));
-
     /* Set handlers */
     client->join_handler = guac_rdp_user_join_handler;
     client->free_handler = guac_rdp_client_free_handler;

src/protocols/rdp/input.c

@@ -38,14 +38,10 @@ int guac_rdp_user_mouse_handler(guac_user* user, int x, int y, int mask) {
     guac_client* client = user->client;
     guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
 
-    pthread_mutex_lock(&(rdp_client->rdp_lock));
-
     /* Skip if not yet connected */
     freerdp* rdp_inst = rdp_client->rdp_inst;
-    if (rdp_inst == NULL) {
+    if (rdp_inst == NULL)
-        pthread_mutex_unlock(&(rdp_client->rdp_lock));
         return 0;
-    }
 
     /* Store current mouse location/state */
     guac_common_cursor_update(rdp_client->display->cursor, user, x, y, mask);
@@ -118,8 +114,6 @@ int guac_rdp_user_mouse_handler(guac_user* user, int x, int y, int mask) {
         rdp_client->mouse_button_mask = mask;
     }
 
-    pthread_mutex_unlock(&(rdp_client->rdp_lock));
-
     return 0;
 }
 
@@ -155,9 +149,7 @@ int guac_rdp_user_size_handler(guac_user* user, int width, int height) {
     height = height * settings->resolution / user->info.optimal_resolution;
 
     /* Send display update */
-    pthread_mutex_lock(&(rdp_client->rdp_lock));
     guac_rdp_disp_set_size(rdp_client->disp, settings, rdp_inst, width, height);
-    pthread_mutex_unlock(&(rdp_client->rdp_lock));
 
     return 0;
 

src/protocols/rdp/keyboard.c

@@ -102,21 +102,15 @@ static void guac_rdp_send_key_event(guac_rdp_client* rdp_client,
     else
         pressed_flags = KBD_FLAGS_RELEASE;
 
-    pthread_mutex_lock(&(rdp_client->rdp_lock));
-
     /* Skip if not yet connected */
     freerdp* rdp_inst = rdp_client->rdp_inst;
-    if (rdp_inst == NULL) {
+    if (rdp_inst == NULL)
-        pthread_mutex_unlock(&(rdp_client->rdp_lock));
         return;
-    }
 
     /* Send actual key */
     rdp_inst->input->KeyboardEvent(rdp_inst->input,
             flags | pressed_flags, scancode);
 
-    pthread_mutex_unlock(&(rdp_client->rdp_lock));
-
 }
 
 /**
@@ -136,22 +130,16 @@ static void guac_rdp_send_key_event(guac_rdp_client* rdp_client,
 static void guac_rdp_send_unicode_event(guac_rdp_client* rdp_client,
         int codepoint) {
 
-    pthread_mutex_lock(&(rdp_client->rdp_lock));
-
     /* Skip if not yet connected */
     freerdp* rdp_inst = rdp_client->rdp_inst;
-    if (rdp_inst == NULL) {
+    if (rdp_inst == NULL)
-        pthread_mutex_unlock(&(rdp_client->rdp_lock));
         return;
-    }
 
     /* Send Unicode event */
     rdp_inst->input->UnicodeKeyboardEvent(
             rdp_inst->input,
             0, codepoint);
 
-    pthread_mutex_unlock(&(rdp_client->rdp_lock));
-
 }
 
 /**
@@ -171,20 +159,14 @@ static void guac_rdp_send_unicode_event(guac_rdp_client* rdp_client,
 static void guac_rdp_send_synchronize_event(guac_rdp_client* rdp_client,
         int flags) {
 
-    pthread_mutex_lock(&(rdp_client->rdp_lock));
-
     /* Skip if not yet connected */
     freerdp* rdp_inst = rdp_client->rdp_inst;
-    if (rdp_inst == NULL) {
+    if (rdp_inst == NULL)
-        pthread_mutex_unlock(&(rdp_client->rdp_lock));
         return;
-    }
 
     /* Synchronize lock key states */
     rdp_inst->input->SynchronizeEvent(rdp_inst->input, flags);
 
-    pthread_mutex_unlock(&(rdp_client->rdp_lock));
-
 }
 
 /**

src/protocols/rdp/rdp.c

@@ -405,9 +405,7 @@ static int guac_rdp_handle_connection(guac_client* client) {
             && !guac_rdp_disp_reconnect_needed(rdp_client->disp)) {
 
         /* Update remote display size */
-        pthread_mutex_lock(&(rdp_client->rdp_lock));
         guac_rdp_disp_update_size(rdp_client->disp, settings, rdp_inst);
-        pthread_mutex_unlock(&(rdp_client->rdp_lock));
 
         /* Wait for data and construct a reasonable frame */
         int wait_result = rdp_guac_client_wait_for_messages(client,
@@ -423,20 +421,15 @@ static int guac_rdp_handle_connection(guac_client* client) {
                 guac_timestamp frame_end;
                 int frame_remaining;
 
-                pthread_mutex_lock(&(rdp_client->rdp_lock));
-
                 /* Check the libfreerdp fds */
                 if (!freerdp_check_event_handles(rdp_inst->context)) {
 
                     /* Flag connection failure */
                     wait_result = -1;
-                    pthread_mutex_unlock(&(rdp_client->rdp_lock));
                     break;
 
                 }
 
-                pthread_mutex_unlock(&(rdp_client->rdp_lock));
-
                 /* Calculate time remaining in frame */
                 frame_end = guac_timestamp_current();
                 frame_remaining = frame_start + GUAC_RDP_FRAME_DURATION
@@ -469,9 +462,7 @@ static int guac_rdp_handle_connection(guac_client* client) {
         }
 
         /* Test whether the RDP server is closing the connection */
-        pthread_mutex_lock(&(rdp_client->rdp_lock));
         int connection_closing = freerdp_shall_disconnect(rdp_inst);
-        pthread_mutex_unlock(&(rdp_client->rdp_lock));
 
         /* Close connection cleanly if server is disconnecting */
         if (connection_closing)
@@ -497,8 +488,6 @@ static int guac_rdp_handle_connection(guac_client* client) {
         guac_rdp_print_job_free(rdp_client->active_job);
     }
 
-    pthread_mutex_lock(&(rdp_client->rdp_lock));
-
     /* Disconnect client and channels */
     freerdp_disconnect(rdp_inst);
 
@@ -521,8 +510,6 @@ static int guac_rdp_handle_connection(guac_client* client) {
     /* Free display */
     guac_common_display_free(rdp_client->display);
 
-    pthread_mutex_unlock(&(rdp_client->rdp_lock));
-
     /* Client is now disconnected */
     guac_client_log(client, GUAC_LOG_INFO, "Internal RDP client disconnected");
 

src/protocols/rdp/rdp.h

@@ -153,13 +153,6 @@ typedef struct guac_rdp_client {
      */
     guac_common_list* available_svc;
 
-    /**
-     * Lock which is locked and unlocked for each RDP message, and for each
-     * part of the RDP client instance which may be dynamically freed and
-     * reallocated during reconnection.
-     */
-    pthread_mutex_t rdp_lock;
-
     /**
      * Common attributes for locks.
      */