shm: use mremap on pool resize

diff --git a/src/wayland-shm.c b/src/wayland-shm.c
index e071392..62afc3b 100644 (file)
--- a/src/wayland-shm.c
+++ b/src/wayland-shm.c
@@ -25,6 +25,8 @@
  *
  */
 
+#define _GNU_SOURCE
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -38,7 +40,6 @@ struct wl_shm_pool {
        int refcount;
        char *data;
        int size;
-       int fd;
 };
 
 struct wl_shm_buffer {
@@ -57,7 +58,6 @@ shm_pool_unref(struct wl_shm_pool *pool)
                return;
 
        munmap(pool->data, pool->size);
-       close(pool->fd);
        free(pool);
 }
 
@@ -160,17 +160,15 @@ shm_pool_resize(struct wl_client *client, struct wl_resource *resource,
        struct wl_shm_pool *pool = resource->data;
        void *data;
 
-       data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED,
-                   pool->fd, 0);
+       data = mremap(pool->data, pool->size, size, MREMAP_MAYMOVE);
 
        if (data == MAP_FAILED) {
                wl_resource_post_error(resource,
                                       WL_SHM_ERROR_INVALID_FD,
-                                      "failed mmap fd %d", pool->fd);
+                                      "failed mremap");
                return;
        }
 
-       munmap(pool->data, pool->size);
        pool->data = data;
        pool->size = size;
 }
@@ -203,10 +201,10 @@ shm_create_pool(struct wl_client *client, struct wl_resource *resource,
        }
 
        pool->refcount = 1;
-       pool->fd = fd;
        pool->size = size;
        pool->data = mmap(NULL, size,
                          PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+       close(fd);
        if (pool->data == MAP_FAILED) {
                wl_resource_post_error(resource,
                                       WL_SHM_ERROR_INVALID_FD,