libgimpbase: remove the gimp protocol mutex and gp_lock()/gp_unlock()

The protocol is supposed to be used recursively, the locks just
deadlock in some situations. Threaded use of the wire protocol is
simply forbidden.

libgimp/gimp.c

@@ -806,7 +806,6 @@ gimp_run_procedure_with_array (const gchar    *name,
   proc_run.nparams = gimp_value_array_length (arguments);
   proc_run.params  = _gimp_value_array_to_gp_params (arguments, FALSE);
 
-  gp_lock ();
   if (! gp_proc_run_write (_gimp_writechannel, &proc_run, NULL))
     gimp_quit ();
 
@@ -814,7 +813,6 @@ gimp_run_procedure_with_array (const gchar    *name,
     _gimp_plug_in_read_expect_msg (PLUG_IN, &msg, GP_PROC_RETURN);
   else
     _gimp_read_expect_msg (&msg, GP_PROC_RETURN);
-  gp_unlock ();
 
   proc_return = msg.data;
 

libgimp/gimptilebackendplugin.c

@@ -334,7 +334,6 @@ gimp_tile_get (GimpTileBackendPlugin *backend_plugin,
   tile_req.tile_num    = tile->tile_num;
   tile_req.shadow      = priv->shadow;
 
-  gp_lock ();
   if (! gp_tile_req_write (_gimp_writechannel, &tile_req, NULL))
     gimp_quit ();
 
@@ -384,7 +383,6 @@ gimp_tile_get (GimpTileBackendPlugin *backend_plugin,
 
   if (! gp_tile_ack_write (_gimp_writechannel, NULL))
     gimp_quit ();
-  gp_unlock ();
 
   gimp_wire_destroy (&msg);
 }
@@ -404,7 +402,6 @@ gimp_tile_put (GimpTileBackendPlugin *backend_plugin,
   tile_req.tile_num    = 0;
   tile_req.shadow      = 0;
 
-  gp_lock ();
   if (! gp_tile_req_write (_gimp_writechannel, &tile_req, NULL))
     gimp_quit ();
 
@@ -447,7 +444,6 @@ gimp_tile_put (GimpTileBackendPlugin *backend_plugin,
     _gimp_plug_in_read_expect_msg (plug_in, &msg, GP_TILE_ACK);
   else
     _gimp_read_expect_msg (&msg, GP_TILE_ACK);
-  gp_unlock ();
 
   gimp_wire_destroy (&msg);
 }

libgimpbase/gimpbase.def

@@ -279,7 +279,6 @@ EXPORTS
 	gp_extension_ack_write
 	gp_has_init_write
 	gp_init
-	gp_lock
 	gp_proc_install_write
 	gp_proc_return_write
 	gp_proc_run_write
@@ -290,4 +289,3 @@ EXPORTS
 	gp_tile_ack_write
 	gp_tile_data_write
 	gp_tile_req_write
-	gp_unlock

libgimpbase/gimpprotocol.c

@@ -27,7 +27,6 @@
 #include "gimpprotocol.h"
 #include "gimpwire.h"
 
-static GMutex readwrite_mutex;
 
 static void _gp_quit_read                (GIOChannel       *channel,
                                           GimpWireMessage  *msg,
@@ -204,20 +203,6 @@ gp_init (void)
                       _gp_has_init_destroy);
 }
 
-/* lock/unlock the global wire mutex */
-
-void
-gp_lock (void)
-{
-  g_mutex_lock (&readwrite_mutex);
-}
-
-void
-gp_unlock (void)
-{
-  g_mutex_unlock (&readwrite_mutex);
-}
-
 /* public writing API */
 
 gboolean

libgimpbase/gimpprotocol.h

@@ -277,8 +277,6 @@ struct _GPProcUninstall
 
 
 void      gp_init                   (void);
-void      gp_lock                   (void);
-void      gp_unlock                 (void);
 
 gboolean  gp_quit_write             (GIOChannel      *channel,
                                      gpointer         user_data);