Add read-write mutexes to canvas pixels. New error infrastructure.

1 files changed, 18 insertions, 0 deletions

diff --git a/libdimension/dimension/canvas.h b/libdimension/dimension/canvas.h
index 21d56e4..d40ed1d 100644
--- a/libdimension/dimension/canvas.h
+++ b/libdimension/dimension/canvas.h
@@ -25,6 +25,8 @@
 #ifndef DIMENSION_CANVAS_H
 #define DIMENSION_CANVAS_H
 
+#include <pthread.h>
+
 typedef struct {
   unsigned int x, y;
 
@@ -33,9 +35,25 @@ typedef struct {
    * at (a,b) is accessible as pixels[b*x + a].
    */
   dmnsn_color *pixels;
+
+  /* Read-write locks for each pixel */
+  pthread_rwlock_t *rwlocks;
 } dmnsn_canvas;
 
 dmnsn_canvas *dmnsn_new_canvas(unsigned int x, unsigned int y);
 void dmnsn_delete_canvas(dmnsn_canvas *canvas);
 
+/* These handle the rwlocks correctly */
+dmnsn_color dmnsn_get_pixel(const dmnsn_canvas *canvas,
+                            unsigned int x, unsigned int y);
+void dmnsn_set_pixel(dmnsn_canvas *canvas, dmnsn_color color,
+                     unsigned int x, unsigned int y);
+
+/* Manual locking */
+void dmnsn_rdlock_pixel(const dmnsn_canvas *canvas,
+                        unsigned int x, unsigned int y);
+void dmnsn_wrlock_pixel(dmnsn_canvas *canvas, unsigned int x, unsigned int y);
+void dmnsn_unlock_pixel(const dmnsn_canvas *canvas,
+                        unsigned int x, unsigned int y);
+
 #endif /* DIMENSION_CANVAS_H */