[gegl] buffer: make more calls conditional of number of threads being > 1

[Øyvind Kolås <ok src gnome org>]

commit 95adb26c182535a23491d7e7062dde0cfa23fb0c
Author: Øyvind Kolås <pippin gimp org>
Date:   Fri Jul 11 15:44:16 2014 +0200

    buffer: make more calls conditional of number of threads being > 1

 gegl/buffer/gegl-buffer-access.c |    4 ++++
 gegl/buffer/gegl-buffer.c        |   15 +++++++++++----
 gegl/buffer/gegl-sampler.c       |   10 ++++++++--
 3 files changed, 23 insertions(+), 6 deletions(-)
---
diff --git a/gegl/buffer/gegl-buffer-access.c b/gegl/buffer/gegl-buffer-access.c
index a9c71d7..d188aff 100644
--- a/gegl/buffer/gegl-buffer-access.c
+++ b/gegl/buffer/gegl-buffer-access.c
@@ -113,6 +113,7 @@ gegl_buffer_get_pixel (GeglBuffer     *buffer,
       }
     }
 
+  g_rec_mutex_lock (&buffer->tile_storage->mutex);
   {
     gint tile_width  = buffer->tile_width;
     gint tile_height = buffer->tile_height;
@@ -159,6 +160,7 @@ gegl_buffer_get_pixel (GeglBuffer     *buffer,
           }
       }
   }
+  g_rec_mutex_unlock (&buffer->tile_storage->mutex);
 }
 
 static inline void
@@ -177,6 +179,7 @@ __gegl_buffer_set_pixel (GeglBuffer     *buffer,
       x >= abyss->x + abyss->width)
     return;
 
+  g_rec_mutex_lock (&buffer->tile_storage->mutex);
   {
     gint tile_width  = buffer->tile_width;
     gint tile_height = buffer->tile_height;
@@ -229,6 +232,7 @@ __gegl_buffer_set_pixel (GeglBuffer     *buffer,
         gegl_tile_unlock (tile);
       }
   }
+  g_rec_mutex_unlock (&buffer->tile_storage->mutex);
 }
 
 enum _GeglBufferSetFlag {
diff --git a/gegl/buffer/gegl-buffer.c b/gegl/buffer/gegl-buffer.c
index d3716b6..f6e78a8 100644
--- a/gegl/buffer/gegl-buffer.c
+++ b/gegl/buffer/gegl-buffer.c
@@ -1110,14 +1110,18 @@ gegl_buffer_try_lock (GeglBuffer *buffer)
   {
     GeglTileBackend *backend = gegl_buffer_backend (buffer);
 
-    g_mutex_lock (&buffer->tile_storage->mutex);
+    gboolean threaded = gegl_config_threads ()>1;
+    
+    if (threaded)
+      g_mutex_lock (&buffer->tile_storage->mutex);
     if (buffer->lock_count > 0)
       buffer->lock_count++;
     else if (gegl_tile_backend_file_try_lock (GEGL_TILE_BACKEND_FILE (backend)))
       buffer->lock_count++;
     else
       ret = FALSE;
-    g_mutex_unlock (&buffer->tile_storage->mutex);
+    if (threaded)
+      g_mutex_unlock (&buffer->tile_storage->mutex);
   }
 
   return ret;
@@ -1142,9 +1146,11 @@ gegl_buffer_unlock (GeglBuffer *buffer)
 
   if (gegl_buffer_is_shared (buffer))
   {
+    gboolean threaded = gegl_config_threads ()>1;
     GeglTileBackend *backend = gegl_buffer_backend (buffer);
 
-    g_mutex_lock (&buffer->tile_storage->mutex);
+    if (threaded)
+      g_mutex_lock (&buffer->tile_storage->mutex);
 
     buffer->lock_count--;
     g_assert (buffer->lock_count >= 0);
@@ -1152,7 +1158,8 @@ gegl_buffer_unlock (GeglBuffer *buffer)
     if (buffer->lock_count == 0)
       ret = gegl_tile_backend_file_unlock (GEGL_TILE_BACKEND_FILE (backend));
 
-    g_mutex_unlock (&buffer->tile_storage->mutex);
+    if (threaded)
+      g_mutex_unlock (&buffer->tile_storage->mutex);
   }
 
   return ret;
diff --git a/gegl/buffer/gegl-sampler.c b/gegl/buffer/gegl-sampler.c
index 0631df1..59788bf 100644
--- a/gegl/buffer/gegl-sampler.c
+++ b/gegl/buffer/gegl-sampler.c
@@ -37,6 +37,8 @@
 #include "gegl-sampler-nohalo.h"
 #include "gegl-sampler-lohalo.h"
 
+#include "gegl-config.h"
+
 enum
 {
   PROP_0,
@@ -524,6 +526,8 @@ gegl_buffer_sample_at_level (GeglBuffer       *buffer,
   }*/
 
   static GMutex mutex = {0,};
+  gboolean threaded =  gegl_config_threads ()>1;
+
 
   if (!format)
     format = buffer->soft_format;
@@ -534,7 +538,8 @@ gegl_buffer_sample_at_level (GeglBuffer       *buffer,
     gegl_buffer_cl_cache_flush (buffer, &rect);
   }
 
-  g_mutex_lock (&mutex);
+  if (threaded)
+    g_mutex_lock (&mutex);
 
   /* unset the cached sampler if it dosn't match the needs */
   if (buffer->sampler != NULL &&
@@ -562,7 +567,8 @@ gegl_buffer_sample_at_level (GeglBuffer       *buffer,
     }
 
   buffer->sampler->get(buffer->sampler, x, y, scale, dest, repeat_mode);
-  g_mutex_unlock (&mutex);
+  if (threaded)
+    g_mutex_unlock (&mutex);
 }