[PATCH weston v4 01/14] libweston: Add more functionality for handling weston_output objects

Armin Krezović krezovic.armin at gmail.com
Fri Sep 30 12:11:02 UTC 2016


This patch implements additional functionality that will be used
for configuring, enabling and disabling weston's outputs. Its
indended use is by the compositors or user programs that want to
be able to configure, enable or disable an output at any time. An
output can only be configured while it's disabled.

The compositor and backend specific functionality is required
for these functions to be useful, and those will come later in
this series.

All the new functions have been documented, so I'll avoid
describing them here.

v2:

 - Minor documentation improvements.
 - Rename output-initialized to output->enabled.
 - Split weston_output_disable() further into
   weston_compositor_remove_output().
 - Rename weston_output_deinit() to weston_output_enable_undo().

 - Make weston_output_disable() call two functions mentioned
   above instead of calling weston_output_disable() directly.
   This means that backend needs to take care of doing backend
   specific disable in backend specific destroy function.

v3:

 - Require output->name to be set before calling
   weston_output_init_pending().
 - Require output->destroying to be set before
   calling weston_compositor_remove_output().
 - Split weston_output_init_pending() into
   weston_compositor_add_pending_output() so pending outputs
   can be announced separately.
 - Require output->disable() to be set in order for
   weston_output_disable() to be usable.
 - Fix output removing regression that happened when
   weston_output_disable() was split.
 - Minor documentation fix.

v4:

 - Bump libweston version to 2 as this patch breaks the ABI.

Reviewed-by: Pekka Paalanen <pekka.paalanen at collabora.co.uk>
Signed-off-by: Armin Krezović <krezovic.armin at gmail.com>
---
 configure.ac           |   6 +-
 libweston/compositor.c | 362 ++++++++++++++++++++++++++++++++++++++++++++-----
 libweston/compositor.h |  33 +++++
 3 files changed, 363 insertions(+), 38 deletions(-)

diff --git a/configure.ac b/configure.ac
index f35e887..671d707 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,9 +3,9 @@ m4_define([weston_minor_version],  [12])
 m4_define([weston_micro_version],  [90])
 m4_define([weston_version],
           [weston_major_version.weston_minor_version.weston_micro_version])
-m4_define([libweston_major_version], [1])
-m4_define([libweston_minor_version], [12])
-m4_define([libweston_patch_version], [90])
+m4_define([libweston_major_version], [2])
+m4_define([libweston_minor_version], [0])
+m4_define([libweston_patch_version], [0])
 
 AC_PREREQ([2.64])
 AC_INIT([weston],
diff --git a/libweston/compositor.c b/libweston/compositor.c
index 8c3872d..e5deeab 100644
--- a/libweston/compositor.c
+++ b/libweston/compositor.c
@@ -4153,41 +4153,6 @@ weston_compositor_reflow_outputs(struct weston_compositor *compositor,
 }
 
 WL_EXPORT void
-weston_output_destroy(struct weston_output *output)
-{
-	struct wl_resource *resource;
-	struct weston_view *view;
-
-	output->destroying = 1;
-
-	wl_list_for_each(view, &output->compositor->view_list, link) {
-		if (view->output_mask & (1u << output->id))
-			weston_view_assign_output(view);
-	}
-
-	wl_event_source_remove(output->repaint_timer);
-
-	weston_presentation_feedback_discard_list(&output->feedback_list);
-
-	weston_compositor_reflow_outputs(output->compositor, output, output->width);
-	wl_list_remove(&output->link);
-
-	wl_signal_emit(&output->compositor->output_destroyed_signal, output);
-	wl_signal_emit(&output->destroy_signal, output);
-
-	free(output->name);
-	pixman_region32_fini(&output->region);
-	pixman_region32_fini(&output->previous_damage);
-	output->compositor->output_id_pool &= ~(1u << output->id);
-
-	wl_resource_for_each(resource, &output->resource_list) {
-		wl_resource_set_destructor(resource, NULL);
-	}
-
-	wl_global_destroy(output->global);
-}
-
-WL_EXPORT void
 weston_output_update_matrix(struct weston_output *output)
 {
 	float magnification;
@@ -4377,6 +4342,8 @@ weston_output_init(struct weston_output *output, struct weston_compositor *c,
 	output->global =
 		wl_global_create(c->wl_display, &wl_output_interface, 3,
 				 output, bind_output);
+
+	output->enabled = true;
 }
 
 /** Adds an output to the compositor's output list and
@@ -4415,6 +4382,325 @@ weston_output_transform_coordinate(struct weston_output *output,
 	*y = p.f[1] / p.f[3];
 }
 
+/** Undoes changes to an output done by weston_output_enable()
+ *
+ * \param output The weston_output object that needs the changes undone.
+ *
+ * Removes the repaint timer.
+ * Destroys the Wayland global assigned to the output.
+ * Destroys pixman regions allocated to the output.
+ * Deallocates output's ID and updates compositor's output_id_pool.
+ */
+static void
+weston_output_enable_undo(struct weston_output *output)
+{
+	wl_event_source_remove(output->repaint_timer);
+
+	wl_global_destroy(output->global);
+
+	pixman_region32_fini(&output->region);
+	pixman_region32_fini(&output->previous_damage);
+	output->compositor->output_id_pool &= ~(1u << output->id);
+
+	output->enabled = false;
+}
+
+/** Removes output from compositor's output list
+ *
+ * \param output The weston_output object that is being removed.
+ *
+ * Presentation feedback is discarded.
+ * Compositor is notified that outputs were changed and
+ * applies the necessary changes.
+ * All views assigned to the weston_output object are
+ * moved to a new output.
+ * Signal is emited to notify all users of the weston_output
+ * object that the output is being destroyed.
+ * wl_output protocol objects referencing this weston_output
+ * are made inert.
+ */
+static void
+weston_compositor_remove_output(struct weston_output *output)
+{
+	struct wl_resource *resource;
+	struct weston_view *view;
+
+	assert(output->destroying);
+
+	wl_list_for_each(view, &output->compositor->view_list, link) {
+		if (view->output_mask & (1u << output->id))
+			weston_view_assign_output(view);
+	}
+
+	weston_presentation_feedback_discard_list(&output->feedback_list);
+
+	weston_compositor_reflow_outputs(output->compositor, output, output->width);
+	wl_list_remove(&output->link);
+
+	wl_signal_emit(&output->compositor->output_destroyed_signal, output);
+	wl_signal_emit(&output->destroy_signal, output);
+
+	wl_resource_for_each(resource, &output->resource_list) {
+		wl_resource_set_destructor(resource, NULL);
+	}
+}
+
+/** Sets the output scale for a given output.
+ *
+ * \param output The weston_output object that the scale is set for.
+ * \param scale  Scale factor for the given output.
+ *
+ * It only supports setting scale for an output that
+ * is not enabled and it can only be ran once.
+ */
+WL_EXPORT void
+weston_output_set_scale(struct weston_output *output,
+			int32_t scale)
+{
+	/* We can only set scale on a disabled output */
+	assert(!output->enabled);
+
+	/* We only want to set scale once */
+	assert(!output->scale);
+
+	output->scale = scale;
+}
+
+/** Sets the output transform for a given output.
+ *
+ * \param output    The weston_output object that the transform is set for.
+ * \param transform Transform value for the given output.
+ *
+ * It only supports setting transform for an output that is
+ * not enabled and it can only be ran once.
+ *
+ * Refer to wl_output::transform section located at
+ * https://wayland.freedesktop.org/docs/html/apa.html#protocol-spec-wl_output
+ * for list of values that can be passed to this function.
+ */
+WL_EXPORT void
+weston_output_set_transform(struct weston_output *output,
+			    uint32_t transform)
+{
+	/* We can only set transform on a disabled output */
+	assert(!output->enabled);
+
+	/* We only want to set transform once */
+	assert(output->transform == UINT32_MAX);
+
+	output->transform = transform;
+}
+
+/** Initializes a weston_output object with enough data so
+ ** an output can be configured.
+ *
+ * \param output     The weston_output object to initialize
+ * \param compositor The compositor instance.
+ *
+ * Sets initial values for fields that are expected to be
+ * configured either by compositors or backends.
+ */
+WL_EXPORT void
+weston_output_init_pending(struct weston_output *output,
+			   struct weston_compositor *compositor)
+{
+	output->compositor = compositor;
+	output->destroying = 0;
+
+	/* Backends must set output->name */
+	assert(output->name);
+
+	wl_list_init(&output->link);
+
+	output->enabled = false;
+
+	/* Add some (in)sane defaults which can be used
+	 * for checking if an output was properly configured
+	 */
+	output->mm_width = 0;
+	output->mm_height = 0;
+	output->scale = 0;
+	/* Can't use -1 on uint32_t and 0 is valid enum value */
+	output->transform = UINT32_MAX;
+}
+
+/** Adds weston_output object to pending output list.
+ *
+ * \param output     The weston_output object to add
+ * \param compositor The compositor instance.
+ *
+ * Also notifies the compositor that an output is pending for
+ * configuration.
+ */
+WL_EXPORT void
+weston_compositor_add_pending_output(struct weston_output *output,
+				     struct weston_compositor *compositor)
+{
+	wl_list_insert(compositor->pending_output_list.prev, &output->link);
+	wl_signal_emit(&compositor->output_pending_signal, output);
+}
+
+/* NOTE: Some documentation is copy/pasted from weston_output_init(), as this
+   is intended to replace it. */
+
+/** Constructs a weston_output object that can be used by the compositor.
+ *
+ * \param output The weston_output object that needs to be enabled.
+ *
+ * Output coordinates are calculated and each new output is by default
+ * assigned to the right of previous one.
+ *
+ * Sets up the transformation, zoom, and geometry of the output using
+ * the properties that need to be configured by the compositor.
+ *
+ * Establishes a repaint timer for the output with the relevant display
+ * object's event loop. See output_repaint_timer_handler().
+ *
+ * The output is assigned an ID. Weston can support up to 32 distinct
+ * outputs, with IDs numbered from 0-31; the compositor's output_id_pool
+ * is referred to and used to find the first available ID number, and
+ * then this ID is marked as used in output_id_pool.
+ *
+ * The output is also assigned a Wayland global with the wl_output
+ * external interface.
+ *
+ * Backend specific function is called to set up the output output.
+ *
+ * Output is added to the compositor's output list
+ *
+ * If the backend specific function fails, the weston_output object
+ * is returned to a state it was before calling this function and
+ * is added to the compositor's pending_output_list in case it needs
+ * to be reconfigured or just so it can be destroyed at shutdown.
+ *
+ * 0 is returned on success, -1 on failure.
+ */
+WL_EXPORT int
+weston_output_enable(struct weston_output *output)
+{
+	struct weston_output *iterator;
+	int x = 0, y = 0;
+
+	assert(output->enable);
+
+	iterator = container_of(output->compositor->output_list.prev,
+				struct weston_output, link);
+
+	if (!wl_list_empty(&output->compositor->output_list))
+		x = iterator->x + iterator->width;
+
+	/* Make sure the width and height are configured */
+	assert(output->mm_width && output->mm_height);
+
+	/* Make sure the scale is set up */
+	assert(output->scale);
+
+	/* Make sure we have a transform set */
+	assert(output->transform != UINT32_MAX);
+
+	/* Remove it from pending/disabled output list */
+	wl_list_remove(&output->link);
+
+	/* TODO: Merge weston_output_init here. */
+	weston_output_init(output, output->compositor, x, y,
+			   output->mm_width, output->mm_height,
+			   output->transform, output->scale);
+
+	/* Enable the output (set up the crtc or create a
+	 * window representing the output, set up the
+	 * renderer, etc)
+	 */
+	if (output->enable(output) < 0) {
+		weston_log("Enabling output \"%s\" failed.\n", output->name);
+
+		weston_output_enable_undo(output);
+		wl_list_insert(output->compositor->pending_output_list.prev,
+			       &output->link);
+		return -1;
+	}
+
+	weston_compositor_add_output(output->compositor, output);
+
+	return 0;
+}
+
+/** Converts a weston_output object to a pending output state, so it
+ ** can be configured again or destroyed.
+ *
+ * \param output The weston_output object that needs to be disabled.
+ *
+ * See weston_output_init_pending() for more information on the
+ * state output is returned to.
+ *
+ * Calls a backend specific function to disable an output, in case
+ * such function exists.
+ *
+ * If the output is being used by the compositor, it is first removed
+ * from weston's output_list (see weston_compositor_remove_output())
+ * and is returned to a state it was before weston_output_enable()
+ * was ran (see weston_output_enable_undo()).
+ *
+ * Output is added to pending_output_list so it will get destroyed
+ * if the output does not get configured again when the compositor
+ * shuts down. If an output is to be used immediately, it needs to
+ * be manually removed from the list (the compositor specific functions
+ * for handling pending outputs will take care of that).
+ *
+ * If backend specific disable function returns negative value,
+ * this function will return too. It can be used as an indicator
+ * that output cannot be disabled at the present time. In that case
+ * backend needs to make sure the output is disabled when it is
+ * possible.
+ */
+WL_EXPORT void
+weston_output_disable(struct weston_output *output)
+{
+	assert(output->disable);
+
+	/* Should we rename this? */
+	output->destroying = 1;
+
+	if (output->disable(output) < 0)
+		return;
+
+	if (output->enabled) {
+		weston_compositor_remove_output(output);
+		weston_output_enable_undo(output);
+
+		/* We need to preserve it somewhere so it can be destroyed on shutdown
+		   if nobody wants to configure it again */
+		wl_list_insert(output->compositor->pending_output_list.prev, &output->link);
+	}
+
+	output->destroying = 0;
+}
+
+/** Emits a signal to indicate that there are outputs waiting to be configured.
+ *
+ * \param compositor The compositor instance
+ */
+WL_EXPORT void
+weston_pending_output_coldplug(struct weston_compositor *compositor)
+{
+	struct weston_output *output, *next;
+
+	wl_list_for_each_safe(output, next, &compositor->pending_output_list, link)
+		wl_signal_emit(&compositor->output_pending_signal, output);
+}
+
+WL_EXPORT void
+weston_output_destroy(struct weston_output *output)
+{
+	output->destroying = 1;
+
+	if (output->enabled) {
+		weston_compositor_remove_output(output);
+		weston_output_enable_undo(output);
+	}
+
+	free(output->name);
+}
+
 static void
 destroy_viewport(struct wl_resource *resource)
 {
@@ -4752,6 +5038,7 @@ weston_compositor_create(struct wl_display *display, void *user_data)
 	wl_signal_init(&ec->hide_input_panel_signal);
 	wl_signal_init(&ec->update_input_panel_signal);
 	wl_signal_init(&ec->seat_created_signal);
+	wl_signal_init(&ec->output_pending_signal);
 	wl_signal_init(&ec->output_created_signal);
 	wl_signal_init(&ec->output_destroyed_signal);
 	wl_signal_init(&ec->output_moved_signal);
@@ -4787,6 +5074,7 @@ weston_compositor_create(struct wl_display *display, void *user_data)
 	wl_list_init(&ec->plane_list);
 	wl_list_init(&ec->layer_list);
 	wl_list_init(&ec->seat_list);
+	wl_list_init(&ec->pending_output_list);
 	wl_list_init(&ec->output_list);
 	wl_list_init(&ec->key_binding_list);
 	wl_list_init(&ec->modifier_binding_list);
@@ -4831,6 +5119,10 @@ weston_compositor_shutdown(struct weston_compositor *ec)
 	wl_list_for_each_safe(output, next, &ec->output_list, link)
 		output->destroy(output);
 
+	/* Destroy all pending outputs associated with this compositor */
+	wl_list_for_each_safe(output, next, &ec->pending_output_list, link)
+		output->destroy(output);
+
 	if (ec->renderer)
 		ec->renderer->destroy(ec);
 
diff --git a/libweston/compositor.h b/libweston/compositor.h
index 16db03b..d3d779f 100644
--- a/libweston/compositor.h
+++ b/libweston/compositor.h
@@ -218,6 +218,12 @@ struct weston_output {
 			  uint16_t *b);
 
 	struct weston_timeline_object timeline;
+
+	bool enabled;
+	int scale;
+
+	int (*enable)(struct weston_output *output);
+	int (*disable)(struct weston_output *output);
 };
 
 enum weston_pointer_motion_mask {
@@ -767,6 +773,7 @@ struct weston_compositor {
 	struct wl_signal update_input_panel_signal;
 
 	struct wl_signal seat_created_signal;
+	struct wl_signal output_pending_signal;
 	struct wl_signal output_created_signal;
 	struct wl_signal output_destroyed_signal;
 	struct wl_signal output_moved_signal;
@@ -778,6 +785,7 @@ struct weston_compositor {
 	struct weston_layer fade_layer;
 	struct weston_layer cursor_layer;
 
+	struct wl_list pending_output_list;
 	struct wl_list output_list;
 	struct wl_list seat_list;
 	struct wl_list layer_list;
@@ -1813,6 +1821,31 @@ weston_seat_set_keyboard_focus(struct weston_seat *seat,
 int
 weston_compositor_load_xwayland(struct weston_compositor *compositor);
 
+void
+weston_output_set_scale(struct weston_output *output,
+			int32_t scale);
+
+void
+weston_output_set_transform(struct weston_output *output,
+			    uint32_t transform);
+
+void
+weston_output_init_pending(struct weston_output *output,
+			   struct weston_compositor *compositor);
+
+void
+weston_compositor_add_pending_output(struct weston_output *output,
+				     struct weston_compositor *compositor);
+
+int
+weston_output_enable(struct weston_output *output);
+
+void
+weston_output_disable(struct weston_output *output);
+
+void
+weston_pending_output_coldplug(struct weston_compositor *compositor);
+
 #ifdef  __cplusplus
 }
 #endif
-- 
2.10.0



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