Bug 137162

Summary:

Web Replay: Playback position updates should be sent before the next event loop input is dispatched

Product:

WebKit

Reporter:

Brian Burg <burg>

Component:

Web Inspector

Assignee:

Brian Burg <burg>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

commit-queue, graouts, joepeck, timothy, webkit-bug-importer

Priority:

Keywords:

InRadar

Version:

528+ (Nightly build)

Hardware:

All

OS:

All

Bug Depends on:

Bug Blocks:

136292, 137078, 137083

Attachments:

Description	Flags
WIP 0a	none
WIP 0b	none
WIP 0c	none
Patch	none

Brian Burg

Reported 2014-09-26 16:44:18 PDT

To drive updates to playback position in the UI we send ReplayPosition coordinates as the backend dispatches inputs. However, right now the semantics of being at a ReplayPosition is currently muddy. The update is currently sent *after* the input at the offset is dispatched. This leads to unexpected results if the debugger pauses while the input is dispatched, and the frontend has a stale playback position when the debugger pauses. What it should mean is that for ReplayPosition(segmentOffset=n, inputOffset=m), the backend is about to dispatch input m, but has not yet begun to do so. Thus, any subsequent page execution events (profiling, debugger pauses, etc) are caused by m being dispatched.

Attachments
WIP 0a (1.76 KB, patch) 2014-09-26 16:47 PDT, Brian Burg	no flags	Details Formatted Diff Diff
WIP 0b (876 bytes, patch) 2014-09-26 16:48 PDT, Brian Burg	no flags	Details Formatted Diff Diff
WIP 0c (2.07 KB, patch) 2014-09-26 16:48 PDT, Brian Burg	no flags	Details Formatted Diff Diff
Patch (6.97 KB, patch) 2014-09-26 17:48 PDT, Brian Burg	no flags	Details Formatted Diff Diff
Show Obsolete (3) View All Add attachment proposed patch, testcase, etc.