[Mesa-dev] [RFC 02/12] dri: extend fence extension to support native fd fences

[Chad Versace]

From: Rob Clark <robclark at freedesktop.org>

Required to implement EGL_ANDROID_native_fence_sync.

Signed-off-by: Rob Clark <robclark at freedesktop.org>
---
 include/GL/internal/dri_interface.h | 44 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/include/GL/internal/dri_interface.h b/include/GL/internal/dri_interface.h
index d0b1bc6..c6ea464 100644
--- a/include/GL/internal/dri_interface.h
+++ b/include/GL/internal/dri_interface.h
@@ -340,12 +340,19 @@ struct __DRI2throttleExtensionRec {
  */
 
 #define __DRI2_FENCE "DRI2_Fence"
-#define __DRI2_FENCE_VERSION 1
+#define __DRI2_FENCE_VERSION 2
 
 #define __DRI2_FENCE_TIMEOUT_INFINITE     0xffffffffffffffffllu
 
 #define __DRI2_FENCE_FLAG_FLUSH_COMMANDS  (1 << 0)
 
+/**
+ * \name Capabilities that might be returned by __DRI2fenceExtensionRec::get_capabilities
+ */
+/*@{*/
+#define __DRI_FENCE_CAP_NATIVE_FD 1
+/*@}*/
+
 struct __DRI2fenceExtensionRec {
    __DRIextension base;
 
@@ -390,6 +397,41 @@ struct __DRI2fenceExtensionRec {
     *                sense with this function (right now there are none)
     */
    void (*server_wait_sync)(__DRIcontext *ctx, void *fence, unsigned flags);
+
+   /**
+    * Query for general capabilities of the driver that concern fences.
+    * Returns a bitmask of __DRI_FENCE_CAP_x
+    *
+    * \since 2
+    */
+   unsigned (*get_capabilities)(__DRIscreen *screen);
+
+   /**
+    * Create an fd (file descriptor) associated fence.  If the fence fd
+    * is -1, this behaves similarly to create_fence() except that when
+    * rendering is flushed the driver creates a fence fd.  Otherwise,
+    * the driver wraps an existing fence fd.
+    *
+    * This is used to implement the EGL_ANDROID_native_fence_sync extension.
+    *
+    * \since 2
+    *
+    * \param ctx     the context associated with the fence
+    * \param fd      the fence fd or -1
+    */
+   void *(*create_fence_fd)(__DRIcontext *ctx, int fd);
+
+   /**
+    * For fences created with create_fence_fd(), after rendering is flushed,
+    * this retrieves the native fence fd.  Caller takes ownership of the
+    * fd and will close() it when it is no longer needed.
+    *
+    * \since 2
+    *
+    * \param screen  the screen associated with the fence
+    * \param fence   the fence
+    */
+   int (*get_fence_fd)(__DRIscreen *screen, void *fence);
 };
 
 
-- 
2.10.0