Force transactions to complete in order

This forces transactions to complete in order by using a singly linked
list stored in the sway server.
This commit is contained in:
Ryan Dwyer 2018-06-24 12:33:23 +10:00
parent 32b865e610
commit f08a30d6d0
2 changed files with 74 additions and 18 deletions

View File

@ -47,6 +47,8 @@ struct sway_server {
bool terminating;
struct sway_transaction *head_transaction; // singly linked list
// When a view is being destroyed and is waiting for a transaction to
// complete it will be stored here.
list_t *destroying_containers;

View File

@ -31,6 +31,7 @@ struct sway_transaction {
list_t *instructions; // struct sway_transaction_instruction *
list_t *damage; // struct wlr_box *
size_t num_waiting;
struct sway_transaction *next;
};
struct sway_transaction_instruction {
@ -175,6 +176,7 @@ void transaction_add_damage(struct sway_transaction *transaction,
* Apply a transaction to the "current" state of the tree.
*/
static void transaction_apply(struct sway_transaction *transaction) {
wlr_log(L_DEBUG, "Applying transaction %p", transaction);
int i;
// Apply the instruction state to the container's current state
for (i = 0; i < transaction->instructions->length; ++i) {
@ -203,15 +205,54 @@ static void transaction_apply(struct sway_transaction *transaction) {
}
}
static void progress_queue() {
struct sway_transaction *transaction = server.head_transaction;
struct sway_transaction *next = NULL;
while (transaction && !transaction->num_waiting) {
next = transaction->next;
transaction_apply(transaction);
transaction_destroy(transaction);
transaction = next;
}
server.head_transaction = transaction;
}
static int handle_timeout(void *data) {
struct sway_transaction *transaction = data;
wlr_log(L_DEBUG, "Transaction %p timed out (%li waiting), applying anyway",
wlr_log(L_DEBUG, "Transaction %p timed out (%li waiting)",
transaction, transaction->num_waiting);
transaction_apply(transaction);
transaction_destroy(transaction);
transaction->num_waiting = 0;
progress_queue();
return 0;
}
static bool should_configure(struct sway_container *con,
struct sway_transaction_instruction *instruction) {
if (con->type != C_VIEW) {
return false;
}
if (con->destroying) {
return false;
}
// The settled dimensions are what size the view will be once any pending
// configures have applied (excluding the one we might be configuring now).
// If these match the dimensions that this transaction wants then we don't
// need to configure it.
int settled_width = con->current.view_width;
int settled_height = con->current.view_height;
if (con->instructions->length) {
struct sway_transaction_instruction *last_instruction =
con->instructions->items[con->instructions->length - 1];
settled_width = last_instruction->state.view_width;
settled_height = last_instruction->state.view_height;
}
if (settled_width == instruction->state.view_width &&
settled_height == instruction->state.view_height) {
return false;
}
return true;
}
void transaction_commit(struct sway_transaction *transaction) {
wlr_log(L_DEBUG, "Transaction %p committing with %i instructions",
transaction, transaction->instructions->length);
@ -220,9 +261,7 @@ void transaction_commit(struct sway_transaction *transaction) {
struct sway_transaction_instruction *instruction =
transaction->instructions->items[i];
struct sway_container *con = instruction->container;
if (con->type == C_VIEW && !con->destroying &&
(con->current.view_width != instruction->state.view_width ||
con->current.view_height != instruction->state.view_height)) {
if (should_configure(con, instruction)) {
instruction->serial = view_configure(con->sway_view,
instruction->state.view_x,
instruction->state.view_y,
@ -234,18 +273,33 @@ void transaction_commit(struct sway_transaction *transaction) {
}
list_add(con->instructions, instruction);
}
if (!transaction->num_waiting) {
wlr_log(L_DEBUG, "Transaction %p has nothing to wait for, applying",
transaction);
if (server.head_transaction) {
// There is another transaction in progress - we must add this one to
// the queue so we complete after it.
struct sway_transaction *tail = server.head_transaction;
while (tail->next) {
tail = tail->next;
}
tail->next = transaction;
} else if (transaction->num_waiting) {
// There are no other transactions, but we're not applying immediately
// so we must jump in the queue so others will queue behind us.
server.head_transaction = transaction;
} else {
// There are no other transactions in progress, and this one has nothing
// to wait for, so we can skip the queue.
wlr_log(L_DEBUG, "Transaction %p has nothing to wait for", transaction);
transaction_apply(transaction);
transaction_destroy(transaction);
return;
}
// Set up a timer which the views must respond within
transaction->timer = wl_event_loop_add_timer(server.wl_event_loop,
handle_timeout, transaction);
wl_event_source_timer_update(transaction->timer, TIMEOUT_MS);
if (transaction->num_waiting) {
// Set up a timer which the views must respond within
transaction->timer = wl_event_loop_add_timer(server.wl_event_loop,
handle_timeout, transaction);
wl_event_source_timer_update(transaction->timer, TIMEOUT_MS);
}
// The debug tree shows the pending/live tree. Here is a good place to
// update it, because we make a transaction every time we change the pending
@ -269,14 +323,14 @@ void transaction_notify_view_ready(struct sway_view *view, uint32_t serial) {
}
instruction->ready = true;
// If all views are ready, apply the transaction
// If all views are ready, apply the transaction.
// If the transaction has timed out then its num_waiting will be 0 already.
struct sway_transaction *transaction = instruction->transaction;
if (--transaction->num_waiting == 0) {
if (transaction->num_waiting > 0 && --transaction->num_waiting == 0) {
#if !TRANSACTION_DEBUG
wlr_log(L_DEBUG, "Transaction %p is ready, applying", transaction);
wlr_log(L_DEBUG, "Transaction %p is ready", transaction);
wl_event_source_timer_update(transaction->timer, 0);
transaction_apply(transaction);
transaction_destroy(transaction);
progress_queue();
#endif
}
}