1734970 - Hang from await fetch + StreamListenerTee intended to capture HTTP response body

Status: RESOLVED INVALID

(Core :: Networking, defect)

Description

[Alex Vincent [:WeirdAl]]

Attachment: fetch+streamlistenertee_hang.tar.bz2

I was trying to write a JavaScript XPCOM component to extract the HTTP request headers and body, and HTTP response headers and body, as a prototype for something more advanced - and to help me write documentation for the same in bug 1734764.

Alas, I hit a hang extracting the HTTP response body when a StreamListenerTee my component created was listening to an await fetch request to getpocket.cdn.mozilla.net .

I'm attaching the source code I'd drawn up to go in mozilla-central/extensions/http-experiments . So adding it to a build for testing purposes is simply ac_add_options --enable-extensions=default,http-experiments.

Interestingly enough, the stack trace illustrating the hang has no JavaScript frames on it. Since this is a clean build of mozilla-central with only the added JS component, I'm at a bit of a loss. That stack trace is coming in another attachment.

I'm filing for two reasons. One, JS causing a hang is bad. Two, I'm fully willing to admit I might not be doing this The Right Way and would appreciate directions. (I still haven't really figured out how to deal with multi-process Firefox yet.)

I'm not sure this is in the right bug component.

Comment 1

[Alex Vincent [:WeirdAl]]

Attachment: ddd-stacktrace.txt

Comment 2

[Alex Vincent [:WeirdAl]]

I figured it out. I didn't have nearly enough segments in my pipe.