gl-renderer: Add support for fence sync extensions

Check for the EGL_KHR_fence_sync and EGL_ANDROID_native_fence_sync
extensions and get pointers to required extension functions.

These extensions allow us to acquire GPU timestamp information
asynchronously, and are required by the upcoming work to add
rendering begin/end timepoints to the weston timeline.

Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

libweston/gl-renderer.c

@@ -231,6 +231,11 @@ struct gl_renderer {
 	int has_dmabuf_import_modifiers;
 	PFNEGLQUERYDMABUFFORMATSEXTPROC query_dmabuf_formats;
 	PFNEGLQUERYDMABUFMODIFIERSEXTPROC query_dmabuf_modifiers;
+
+	int has_native_fence_sync;
+	PFNEGLCREATESYNCKHRPROC create_sync;
+	PFNEGLDESTROYSYNCKHRPROC destroy_sync;
+	PFNEGLDUPNATIVEFENCEFDANDROIDPROC dup_native_fence_fd;
 };
 
 static PFNEGLGETPLATFORMDISPLAYEXTPROC get_platform_display = NULL;
@@ -3028,6 +3033,17 @@ gl_renderer_setup_egl_extensions(struct weston_compositor *ec)
 	if (weston_check_egl_extension(extensions, "GL_EXT_texture_rg"))
 		gr->has_gl_texture_rg = 1;
 
+	if (weston_check_egl_extension(extensions, "EGL_KHR_fence_sync") &&
+	    weston_check_egl_extension(extensions, "EGL_ANDROID_native_fence_sync")) {
+		gr->create_sync =
+			(void *) eglGetProcAddress("eglCreateSyncKHR");
+		gr->destroy_sync =
+			(void *) eglGetProcAddress("eglDestroySyncKHR");
+		gr->dup_native_fence_fd =
+			(void *) eglGetProcAddress("eglDupNativeFenceFDANDROID");
+		gr->has_native_fence_sync = 1;
+	}
+
 	renderer_setup_egl_client_extensions(gr);
 
 	return 0;

shared/weston-egl-ext.h

@@ -176,6 +176,22 @@ typedef EGLSurface (EGLAPIENTRYP PFNEGLCREATEPLATFORMPIXMAPSURFACEEXTPROC) (EGLD
 #define EGL_PLATFORM_X11_KHR 0x31D5
 #endif
 
+#ifndef EGL_KHR_cl_event2
+#define EGL_KHR_cl_event2 1
+typedef void *EGLSyncKHR;
+#endif /* EGL_KHR_cl_event2 */
+
+#ifndef EGL_KHR_fence_sync
+#define EGL_KHR_fence_sync 1
+typedef EGLSyncKHR (EGLAPIENTRYP PFNEGLCREATESYNCKHRPROC) (EGLDisplay dpy, EGLenum type, const EGLint *attrib_list);
+typedef EGLBoolean (EGLAPIENTRYP PFNEGLDESTROYSYNCKHRPROC) (EGLDisplay dpy, EGLSyncKHR sync);
+#endif /* EGL_KHR_fence_sync */
+
+#ifndef EGL_ANDROID_native_fence_sync
+#define EGL_ANDROID_native_fence_sync 1
+typedef EGLint (EGLAPIENTRYP PFNEGLDUPNATIVEFENCEFDANDROIDPROC) (EGLDisplay dpy, EGLSyncKHR sync);
+#endif /* EGL_ANDROID_native_fence_sync */
+
 #else /* ENABLE_EGL */
 
 /* EGL platform definition are keept to allow compositor-xx.c to build */