1 files changed, 9 insertions, 2 deletions
diff --git a/src/display.h b/src/display.h
index da1b991..0aea348 100644
--- a/src/display.h
+++ b/src/display.h
@@ -21,18 +21,19 @@
 #ifndef DISPLAY_H_
 #define DISPLAY_H_
 
+#include <glib.h>
 #include <xcb/xcb.h>
 #include <xcb/damage.h>
 #include <xcb/shm.h>
 
-
 struct session_struct;
 
 /*----------------------------------------------------------------------------
 **  Structure definitions
 **--------------------------------------------------------------------------*/
 typedef struct {
-    int shmid;
+    int shmid;      /* if shmid is -1: the shm_segment_t is "empty", other members are undefined */
+    size_t size;
     xcb_shm_seg_t shmseg;
     void *shmaddr;
 } shm_segment_t;
@@ -63,6 +64,12 @@ typedef struct {
     shm_image_t *fullscreen;
     shm_image_t *scanline;
 
+    /* The SHM cache holds up to 10 segments, this provides a good cache
+     * hit rate while keeping memory usage reasonable.
+     */
+    shm_segment_t shm_cache[10];
+    GMutex shm_cache_mutex;
+
     pthread_t event_thread;
     struct session_struct *session;
 } display_t;