shm: Add request for resizing pools

diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index d70ced7..8f5f6af 100644 (file)
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -173,6 +173,16 @@
        Destroy the pool.
       </description>
     </request>
+
+    <request name="resize">
+      <description summary="change the size of the pool mapping">
+       This request will cause the server to remap the backing memory
+       for the pool from the fd passed when the pool was creating but
+       using the new size.
+      </description>
+
+      <arg name="size" type="int"/>
+    </request>
   </interface>
 
   <interface name="wl_shm" version="1">

diff --git a/src/wayland-shm.c b/src/wayland-shm.c
index 7900ba1..8a8a671 100644 (file)
--- a/src/wayland-shm.c
+++ b/src/wayland-shm.c
@@ -38,13 +38,14 @@ struct wl_shm_pool {
        int refcount;
        char *data;
        int size;
+       int fd;
 };
 
 struct wl_shm_buffer {
        struct wl_buffer buffer;
        int32_t stride;
        uint32_t format;
-       void *data;
+       int offset;
        struct wl_shm_pool *pool;
 };
 
@@ -56,6 +57,7 @@ shm_pool_unref(struct wl_shm_pool *pool)
                return;
 
        munmap(pool->data, pool->size);
+       close(pool->fd);
        free(pool);
 }
 
@@ -120,7 +122,7 @@ shm_pool_create_buffer(struct wl_client *client, struct wl_resource *resource,
        buffer->buffer.height = height;
        buffer->format = format;
        buffer->stride = stride;
-       buffer->data = pool->data + offset;
+       buffer->offset = offset;
        buffer->pool = pool;
        pool->refcount++;
 
@@ -150,9 +152,32 @@ shm_pool_destroy(struct wl_client *client, struct wl_resource *resource)
        wl_resource_destroy(resource);
 }
 
+static void
+shm_pool_resize(struct wl_client *client, struct wl_resource *resource,
+               int32_t size)
+{
+       struct wl_shm_pool *pool = resource->data;
+       void *data;
+
+       data = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED,
+                   pool->fd, 0);
+
+       if (data == MAP_FAILED) {
+               wl_resource_post_error(resource,
+                                      WL_SHM_ERROR_INVALID_FD,
+                                      "failed mmap fd %d", pool->fd);
+               return;
+       }
+
+       munmap(pool->data, pool->size);
+       pool->data = data;
+       pool->size = size;
+}
+
 struct wl_shm_pool_interface shm_pool_interface = {
        shm_pool_create_buffer,
-       shm_pool_destroy
+       shm_pool_destroy,
+       shm_pool_resize
 };
 
 static void
@@ -177,10 +202,10 @@ 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,
@@ -252,7 +277,7 @@ wl_shm_buffer_get_data(struct wl_buffer *buffer_base)
        if (!wl_buffer_is_shm(buffer_base))
                return NULL;
 
-       return buffer->data;
+       return buffer->pool->data + buffer->offset;
 }
 
 WL_EXPORT uint32_t