Zander671/river
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

transactions: handle preemption properly

Browse Source 
when a transaction interrupts an ongoing transaction, we must be careful
to handle the configures properly. This commit adds a new member to view
so that we can store the dimensions sent with the last configure in
order to determine if the preempting transaction should override the
ongoing configure or not.

Additionally, some views do not ack a configure if they already have the
requested dimensions. This can happen if a pending configure setting
alternative dimensions is overridden, so in this case we do not wait for
an ack before committing the transaction.
This commit is contained in:
Isaac Freund
2020-06-08 00:10:30 +02:00
parent 7b1e07d3d5
commit c0d7e71ec4
6 changed files with 94 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

61
river/Root.zig
View File

@ -132,27 +132,57 @@ fn startTransaction(self: *Self) void {
var view_it = ViewStack(View).iterator(output.views.first, std.math.maxInt(u32));
while (view_it.next()) |view_node| {
const view = &view_node.view;
// Clear the serial in case this transaction is interrupting a prior one.
view.pending_serial = null;
if (view.needsConfigure()) {
view.configure();
self.pending_configures += 1;
switch (view.configureAction()) {
.override => {
view.configure();
// Some clients do not ack a configure if the requested
// size is the same as their current size. Configures of
// this nature may be sent if a pending configure is
// interrupted by a configure returning to the original
// size.
if (view.pending_box.?.width == view.current_box.width and
view.pending_box.?.height == view.current_box.height)
{
view.pending_serial = null;
} else {
std.debug.assert(view.pending_serial != null);
self.pending_configures += 1;
}
},
.new_configure => {
view.configure();
self.pending_configures += 1;
std.debug.assert(view.pending_serial != null);
},
.old_configure => {
self.pending_configures += 1;
view.next_box = null;
std.debug.assert(view.pending_serial != null);
},
.noop => {
view.next_box = null;
std.debug.assert(view.pending_serial == null);
},
}
// If there is a saved buffer present, then this transaction is
// interrupting a previous transaction and we should keep the old
// buffer.
if (view.stashed_buffer == null) {
view.stashBuffer();
// We save the current buffer, so we can send an early
// frame done event to give the client a head start on
// redrawing.
view.sendFrameDone();
}
// If there is a saved buffer present, then this transaction is interrupting
// a previous transaction and we should keep the old buffer.
if (view.stashed_buffer == null) {
view.stashBuffer();
}
}
}
// If there are views that need configures, start a timer and wait for
// configure events before committing.
if (self.pending_configures > 0) {
Log.Debug.log(
"Started transaction with {} pending configures.",
@ -160,11 +190,15 @@ fn startTransaction(self: *Self) void {
);
// Set timeout to 200ms
if (c.wl_event_source_timer_update(self.transaction_timer, 200) < 0) {
if (c.wl_event_source_timer_update(self.transaction_timer, 1000) < 0) {
Log.Error.log("failed to update timer.", .{});
self.commitTransaction();
}
} else {
// No views need configures, clear the current timer in case we are
// interrupting another transaction and commit.
if (c.wl_event_source_timer_update(self.transaction_timer, 0) < 0)
Log.Error.log("Error disarming timer", .{});
self.commitTransaction();
}
}
@ -183,7 +217,7 @@ pub fn notifyConfigured(self: *Self) void {
self.pending_configures -= 1;
if (self.pending_configures == 0) {
// Disarm the timer, as we didn't timeout
if (c.wl_event_source_timer_update(self.transaction_timer, 0) == -1)
if (c.wl_event_source_timer_update(self.transaction_timer, 0) < 0)
Log.Error.log("Error disarming timer", .{});
self.commitTransaction();
}
@ -223,6 +257,7 @@ fn commitTransaction(self: *Self) void {
const view = &view_node.view;
// Ensure that all pending state is cleared
view.pending_serial = null;
std.debug.assert(view.next_box == null);
if (view.pending_box) |state| {
view.current_box = state;
view.pending_box = null;