tree b7fc62d5a7c5059040a39b55d7ab9e9d6bab497b
parent 2ec189313ef0a07735684caebd1ba8b8ebca456f
author Brad Fitzpatrick <bradfitz@golang.org> 1570048635 +0000
committer Brad Fitzpatrick <bradfitz@golang.org> 1570122688 +0000

http2: fix memory leak in random write scheduler

In certain shutdown cases (from the client and/or server), the http2
Server can Push stream-specific frames on closed streams. This caused
memory leaks in the random write scheduler.

As a conservative fix for backporting, just clear the map element
whenever its queue value is empty. The map entry is re-created as
needed anyway. This isn't perfectly ideal (it adds a map+delete and
free queue put+get) in the case where a stream is open & actively
writing, but it's an easy fix for now. A future CL can optimize all
this code. It looks like there are some other good optimization
opportunities in related code anyway. But I'd rather that happen on
master and not be done in a backported change.

Fixes golang/go#33812

Change-Id: I21508ba2ebc361e8b8532d0d1cebf882e82c473c
Reviewed-on: https://go-review.googlesource.com/c/net/+/198462
Reviewed-by: Bryan C. Mills <bcmills@google.com>