[PATCH xserver v3 20/24] xwayland: Preliminary support for Present's new window flip mode

Roman Gilg subdiff at gmail.com
Tue Mar 13 15:00:53 UTC 2018


Introduce support for Present's window flip mode. The support is not yet
complete, but works reasonable well for the most important use case, that
is fullscreen applications.

We take a Present flip and if the xwl_window->window has the same dimensions
as the presenting window, the flip is represented by a wl_buffer and attached
to the main wl_surface of the xwl_window.

After commit we are listening for the sync callback in order to tell Present,
that the pixmap flip is not longer pending, for the frame callback in order
to update the msc counter and for the buffer release callback in order to tell
Present that the pixmap is idle again.

The following functionality is missing from this patch:
* (slowed down) flips in case the compositor is not sending frame callbacks,
* queuing events to MSC times,
* per window flips for child windows with smaller size than the xwl_window.

To make use of this functionality Xwayland must run rootless and with
Glamor/GBM.

Signed-off-by: Roman Gilg <subdiff at gmail.com>
---
 hw/xwayland/Makefile.am        |   1 +
 hw/xwayland/meson.build        |   1 +
 hw/xwayland/xwayland-present.c | 366 +++++++++++++++++++++++++++++++++++++++++
 hw/xwayland/xwayland.h         |  30 ++++
 4 files changed, 398 insertions(+)
 create mode 100644 hw/xwayland/xwayland-present.c

diff --git a/hw/xwayland/Makefile.am b/hw/xwayland/Makefile.am
index f44a7de..3378a66 100644
--- a/hw/xwayland/Makefile.am
+++ b/hw/xwayland/Makefile.am
@@ -11,6 +11,7 @@ Xwayland_CFLAGS =				\
 
 Xwayland_SOURCES =				\
 	xwayland.c				\
+	xwayland-present.c			\
 	xwayland-input.c			\
 	xwayland-cursor.c			\
 	xwayland-shm.c				\
diff --git a/hw/xwayland/meson.build b/hw/xwayland/meson.build
index 7e24c5d..17f52b4 100644
--- a/hw/xwayland/meson.build
+++ b/hw/xwayland/meson.build
@@ -1,5 +1,6 @@
 srcs = [
     'xwayland.c',
+    'xwayland-present.c',
     'xwayland-input.c',
     'xwayland-cursor.c',
     'xwayland-shm.c',
diff --git a/hw/xwayland/xwayland-present.c b/hw/xwayland/xwayland-present.c
new file mode 100644
index 0000000..f41e864
--- /dev/null
+++ b/hw/xwayland/xwayland-present.c
@@ -0,0 +1,366 @@
+/*
+ * Copyright © 2018 Roman Gilg
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of the
+ * copyright holders not be used in advertising or publicity
+ * pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no
+ * representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied
+ * warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ */
+
+#include "xwayland.h"
+
+#include <present.h>
+
+void
+xwl_present_cleanup(WindowPtr window)
+{
+    struct xwl_window           *xwl_window = xwl_window_of_top(window);
+    struct xwl_present_event    *event, *tmp;
+
+    if (!xwl_window)
+        return;
+
+    if (xwl_window->present_window == window) {
+        if (xwl_window->present_frame_callback) {
+            wl_callback_destroy(xwl_window->present_frame_callback);
+            xwl_window->present_frame_callback = NULL;
+        }
+        xwl_window->present_window = NULL;
+    }
+
+    /* Clear remaining buffer releases and inform Present about free ressources */
+    xorg_list_for_each_entry_safe(event, tmp, &xwl_window->present_release_queue, list) {
+        if (event->present_window == window) {
+            xorg_list_del(&event->list);
+            event->abort = TRUE;
+        }
+    }
+}
+
+static void
+xwl_present_free_event(struct xwl_present_event *event)
+{
+    xorg_list_del(&event->list);
+    free(event);
+}
+
+static void
+xwl_present_buffer_release(void *data, struct wl_buffer *buffer)
+{
+    struct xwl_present_event *event = data;
+
+    if (!event)
+        return;
+    wl_buffer_set_user_data(buffer, NULL);
+
+    event->buffer_released = TRUE;
+
+    if (event->abort) {
+        if (!event->pending)
+            xwl_present_free_event(event);
+        return;
+    }
+
+    if (!event->pending) {
+        present_wnmd_event_notify(event->present_window,
+                                  event->event_id,
+                                  event->xwl_window->present_ust,
+                                  event->xwl_window->present_msc);
+        xwl_present_free_event(event);
+    }
+}
+
+static const struct wl_buffer_listener xwl_present_release_listener = {
+    xwl_present_buffer_release
+};
+
+static void
+xwl_present_frame_callback(void *data,
+               struct wl_callback *callback,
+               uint32_t time)
+{
+    struct xwl_window *xwl_window = data;
+
+    wl_callback_destroy(xwl_window->present_frame_callback);
+    xwl_window->present_frame_callback = NULL;
+
+    xwl_window->present_msc++;
+    xwl_window->present_ust = GetTimeInMicros();
+}
+
+static const struct wl_callback_listener xwl_present_frame_listener = {
+    xwl_present_frame_callback
+};
+
+static void
+xwl_present_sync_callback(void *data,
+               struct wl_callback *callback,
+               uint32_t time)
+{
+    struct xwl_present_event *event = data;
+    struct xwl_window *xwl_window = event->xwl_window;
+
+    event->pending = FALSE;
+
+    if (event->abort) {
+        /* Event might have been aborted */
+        if (event->buffer_released)
+            /* Buffer was already released, cleanup now */
+            xwl_present_free_event(event);
+        return;
+    }
+
+    present_wnmd_event_notify(event->present_window,
+                              event->event_id,
+                              xwl_window->present_ust,
+                              xwl_window->present_msc);
+
+    if (event->buffer_released)
+        /* If the buffer was already released, send the event now again */
+        present_wnmd_event_notify(event->present_window,
+                                  event->event_id,
+                                  xwl_window->present_ust,
+                                  xwl_window->present_msc);
+}
+
+static const struct wl_callback_listener xwl_present_sync_listener = {
+    xwl_present_sync_callback
+};
+
+static RRCrtcPtr
+xwl_present_get_crtc(WindowPtr present_window)
+{
+    struct xwl_window *xwl_window = xwl_window_of_top(present_window);
+    if (xwl_window == NULL)
+        return NULL;
+
+    return xwl_window->present_crtc_fake;
+}
+
+static int
+xwl_present_get_ust_msc(WindowPtr present_window, uint64_t *ust, uint64_t *msc)
+{
+    struct xwl_window *xwl_window = xwl_window_of_top(present_window);
+    if (!xwl_window)
+        return BadAlloc;
+    *ust = xwl_window->present_ust;
+    *msc = xwl_window->present_msc;
+
+    return Success;
+}
+
+static void
+xwl_present_set_present_window(struct xwl_window *xwl_window,
+                               WindowPtr present_window)
+{
+    if (xwl_window->present_window)
+        return;
+
+    xwl_window->present_window = present_window;
+}
+
+/*
+ * Queue an event to report back to the Present extension when the specified
+ * MSC has past
+ */
+static int
+xwl_present_queue_vblank(WindowPtr present_window,
+                         RRCrtcPtr crtc,
+                         uint64_t event_id,
+                         uint64_t msc)
+{
+    /* Not yet implemented
+     */
+    return BadRequest;
+}
+
+/*
+ * Remove a pending vblank event so that it is not reported
+ * to the extension
+ */
+static void
+xwl_present_abort_vblank(WindowPtr present_window,
+                         RRCrtcPtr crtc,
+                         uint64_t event_id,
+                         uint64_t msc)
+{
+    struct xwl_window *xwl_window = xwl_window_of_top(present_window);
+    struct xwl_present_event *event;
+
+    if (!xwl_window)
+        return;
+
+    xorg_list_for_each_entry(event, &xwl_window->present_release_queue, list) {
+        if (event->event_id == event_id) {
+            event->abort = TRUE;
+            return;
+        }
+    }
+}
+
+static void
+xwl_present_flush(WindowPtr window)
+{
+    /* Only called when a Pixmap is copied instead of flipped,
+     * but in this case we wait on the next block_handler.
+     */
+}
+
+static Bool
+xwl_present_check_flip2(RRCrtcPtr crtc,
+                        WindowPtr present_window,
+                        PixmapPtr pixmap,
+                        Bool sync_flip,
+                        PresentFlipReason *reason)
+{
+    struct xwl_window *xwl_window = xwl_window_of_top(present_window);
+
+    if (!xwl_window)
+        return FALSE;
+
+    /*
+     * Do not flip if there is already another child window doing flips.
+     */
+    if (xwl_window->present_window &&
+            xwl_window->present_window != present_window)
+        return FALSE;
+
+    if (!xwl_window->present_crtc_fake)
+        return FALSE;
+    /*
+     * Make sure the client doesn't try to flip to another crtc
+     * than the one created for 'xwl_window'.
+     */
+    if (xwl_window->present_crtc_fake != crtc)
+        return FALSE;
+
+    /*
+     * We currently only allow flips of windows, that have the same
+     * dimensions as their xwl_window parent window. For the case of
+     * different sizes subsurfaces are presumably the way forward.
+     */
+    if (!RegionEqual(&xwl_window->window->winSize, &present_window->winSize))
+        return FALSE;
+
+    return TRUE;
+}
+
+static Bool
+xwl_present_flip(WindowPtr present_window,
+                 RRCrtcPtr crtc,
+                 uint64_t event_id,
+                 uint64_t target_msc,
+                 PixmapPtr pixmap,
+                 Bool sync_flip,
+                 RegionPtr damage)
+{
+    struct xwl_window           *xwl_window = xwl_window_of_top(present_window);
+    BoxPtr                      present_box, damage_box;
+    Bool                        buffer_created;
+    struct wl_buffer            *buffer;
+    struct xwl_present_event    *event;
+
+    present_box = RegionExtents(&present_window->winSize);
+    damage_box = RegionExtents(damage);
+
+    xwl_present_set_present_window(xwl_window, present_window);
+
+    event = malloc(sizeof *event);
+    if (!event)
+        return FALSE;
+
+    buffer = xwl_glamor_pixmap_get_wl_buffer(pixmap,
+                                             present_box->x2 - present_box->x1,
+                                             present_box->y2 - present_box->y1,
+                                             &buffer_created);
+
+    event->event_id = event_id;
+    event->present_window = present_window;
+    event->xwl_window = xwl_window;
+    event->buffer = buffer;
+    event->target_msc = xwl_window->present_msc;
+    event->pending = TRUE;
+    event->abort = FALSE;
+    event->buffer_released = FALSE;
+
+    xorg_list_add(&event->list, &xwl_window->present_release_queue);
+
+    if (buffer_created)
+        wl_buffer_add_listener(buffer, &xwl_present_release_listener, NULL);
+    wl_buffer_set_user_data(buffer, event);
+
+    /* We can flip directly to the main surface (full screen window without clips) */
+    wl_surface_attach(xwl_window->surface, buffer, 0, 0);
+
+    if (!xwl_window->present_frame_callback) {
+        xwl_window->present_frame_callback = wl_surface_frame(xwl_window->surface);
+        wl_callback_add_listener(xwl_window->present_frame_callback,
+                                 &xwl_present_frame_listener,
+                                 xwl_window);
+    }
+
+    wl_surface_damage(xwl_window->surface, 0, 0,
+                      damage_box->x2 - damage_box->x1,
+                      damage_box->y2 - damage_box->y1);
+
+    wl_surface_commit(xwl_window->surface);
+
+    xwl_window->present_sync_callback = wl_display_sync(xwl_window->xwl_screen->display);
+    wl_callback_add_listener(xwl_window->present_sync_callback,
+                             &xwl_present_sync_listener,
+                             event);
+
+    wl_display_flush(xwl_window->xwl_screen->display);
+    return TRUE;
+}
+
+static void
+xwl_present_flips_stop(WindowPtr window)
+{
+    struct xwl_window *xwl_window = xwl_window_of_top(window);
+
+    if (!xwl_window)
+        return;
+
+    assert(xwl_window->present_window == window);
+
+    xwl_window->present_window = NULL;
+}
+
+static present_wnmd_info_rec xwl_present_info = {
+    .version = PRESENT_SCREEN_INFO_VERSION,
+    .get_crtc = xwl_present_get_crtc,
+
+    .get_ust_msc = xwl_present_get_ust_msc,
+    .queue_vblank = xwl_present_queue_vblank,
+    .abort_vblank = xwl_present_abort_vblank,
+
+    .flush = xwl_present_flush,
+
+    .capabilities = PresentCapabilityAsync,
+    .check_flip2 = xwl_present_check_flip2,
+    .flip = xwl_present_flip,
+    .flips_stop = xwl_present_flips_stop
+};
+
+Bool
+xwl_present_init(ScreenPtr screen)
+{
+    return present_wnmd_screen_init(screen, &xwl_present_info);
+}
diff --git a/hw/xwayland/xwayland.h b/hw/xwayland/xwayland.h
index 49fb5ba..dd7d1c6 100644
--- a/hw/xwayland/xwayland.h
+++ b/hw/xwayland/xwayland.h
@@ -68,6 +68,7 @@ struct xwl_screen {
     int listen_fd_count;
     int rootless;
     int glamor;
+    int present;
 
     CreateScreenResourcesProcPtr CreateScreenResources;
     CloseScreenProcPtr CloseScreen;
@@ -126,6 +127,32 @@ struct xwl_window {
     struct xorg_list link_damage;
     struct wl_callback *frame_callback;
     Bool allow_commits;
+
+    /* present */
+    RRCrtcPtr present_crtc_fake;
+    struct xorg_list present_link;
+    WindowPtr present_window;
+    uint64_t present_msc;
+    uint64_t present_ust;
+
+    struct wl_callback *present_frame_callback;
+    struct wl_callback *present_sync_callback;
+    struct xorg_list present_release_queue;
+};
+
+struct xwl_present_event {
+    uint64_t event_id;
+    uint64_t target_msc;
+
+    Bool abort;
+    Bool pending;
+    Bool buffer_released;
+
+    WindowPtr present_window;
+    struct xwl_window *xwl_window;
+    struct wl_buffer *buffer;
+
+    struct xorg_list list;
 };
 
 #define MODIFIER_META 0x01
@@ -346,6 +373,9 @@ struct wl_buffer *xwl_glamor_pixmap_get_wl_buffer(PixmapPtr pixmap,
                                                   unsigned short height,
                                                   Bool *created);
 
+Bool xwl_present_init(ScreenPtr screen);
+void xwl_present_cleanup(WindowPtr window);
+
 void xwl_screen_release_tablet_manager(struct xwl_screen *xwl_screen);
 
 void xwl_output_get_xdg_output(struct xwl_output *xwl_output);
-- 
2.7.4



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