Simplify transactions

Commit 4b8e3a885be74c588291c51f798de80bd81a92db makes it so only one
transaction is committed (ie. configures sent) at a time. This commit
removes the now-unnecessary code which was used to support concurrent
committed transactions.

* Instead of containers storing a list of instructions which they've
been sent, it now stores a single instruction.
* Containers now have an ntxnrefs property. Previously we knew how many
references there were by the length of the instruction list.
* Instructions no longer need a ready property. It was used to avoid
marking an instruction ready twice when they were in a list, but this is
now avoided because there is only one instruction and we nullify the
container->instruction pointer when it's ready.
* When a transaction applies, we no longer need to consider releasing
and resaving the surface, as we know there are no other committed
transactions.
* transaction_notify_view_ready has been renamed to
view_notify_view_ready_by_serial to make it consistent with
transaction_notify_view_ready_by_size.
* Out-of-memory checks have been added when creating transactions and
instructions.

2 files changed, 2 insertions, 6 deletions

diff --git a/sway/tree/container.c b/sway/tree/container.c
index 45e54080..eb06edc2 100644
--- a/sway/tree/container.c
+++ b/sway/tree/container.c
@@ -108,7 +108,6 @@ struct sway_container *container_create(enum sway_container_type type) {
 	c->layout = L_NONE;
 	c->type = type;
 	c->alpha = 1.0f;
-	c->instructions = create_list();
 
 	if (type != C_VIEW) {
 		c->children = create_list();
@@ -140,8 +139,8 @@ void container_free(struct sway_container *cont) {
 				"Tried to free container which wasn't marked as destroying")) {
 		return;
 	}
-	if (!sway_assert(cont->instructions->length == 0,
-				"Tried to free container with pending instructions")) {
+	if (!sway_assert(cont->ntxnrefs == 0, "Tried to free container "
+				"which is still referenced by transactions")) {
 		return;
 	}
 	free(cont->name);
@@ -150,7 +149,6 @@ void container_free(struct sway_container *cont) {
 	wlr_texture_destroy(cont->title_focused_inactive);
 	wlr_texture_destroy(cont->title_unfocused);
 	wlr_texture_destroy(cont->title_urgent);
-	list_free(cont->instructions);
 	list_free(cont->children);
 	list_free(cont->current.children);
 
diff --git a/sway/tree/root.c b/sway/tree/root.c
index 79f2194e..068e7911 100644
--- a/sway/tree/root.c
+++ b/sway/tree/root.c
@@ -26,7 +26,6 @@ void root_create(void) {
 	root_container.type = C_ROOT;
 	root_container.layout = L_NONE;
 	root_container.name = strdup("root");
-	root_container.instructions = create_list();
 	root_container.children = create_list();
 	root_container.current.children = create_list();
 	wl_signal_init(&root_container.events.destroy);
@@ -55,7 +54,6 @@ void root_destroy(void) {
 	free(root_container.sway_root);
 
 	// root_container
-	list_free(root_container.instructions);
 	list_free(root_container.children);
 	list_free(root_container.current.children);
 	free(root_container.name);