1074770 - Add CircularBuffer class to MFBT

Status: RESOLVED WONTFIX

(Core :: MFBT, defect)

Description

[Kan-Ru Chen [:kanru] (UTC+9)]

Attachment: Basic CircularBuffer template class

Needed to implement bug 1074203. Note profiler already has a circular buffer implemented in ThreadProfile which needs to iterate the items in the buffer.

Comment 1

[Kan-Ru Chen [:kanru] (UTC+9)]

Attachment: Basic CircularBuffer template class

Still can't replace the one currently used in the profiler which has the concept of "generation" and flush(), erase() operation.

The goal is to have a drop-in replacement for circular-buffer-like structures. The first user will be the task tracer profiler. In the beginning I wanted to make it use mozilla::Array but found that the profiler is able to config the buffer size dynamically so can't use a compile time const size array type.

Comment 2

[Markus Stange [:mstange]]

Bug 1127498 removes the profiler buffer's flush() and erase() methods. They were used for the "jank-only" mode which nobody was using.

Comment 3

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Task Tracer was removed in bug 1715257, so we don't need this one for that anymore -- also the profiler itself doesn't use a fixed-size circular buffer anymore, it was not suitable for the many-processes Fission world.
If a circular buffer is needed for something else, another bug can be opened then.