1638284 - We still have unlabeled JS threads

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P2)

Description

[David Teller [:Yoric] - still alive but not very active]

While investigating bug 1630898, I found out that we do not label all JS threads.

We should fix this :)

Comment 1

[David Teller [:Yoric] - still alive but not very active]

Attachment: Making anonymous JS threads visible

To make these threads visible:

• apply the attached patch;
• open "about:processes";
• look for "??? JS".

Comment 2

[Florian Quèze [:florian]]

Applying the patch from comment 1 on my local build, I saw one "??? JS" thread on the parent process and one per content process.

I then added a printf in SetName and a printf for the address of f the main function of the thread. In the output in the terminal, I looked for lines printing an address not followed by lines printing a name.

That gave me an address I could print in lldb:

(lldb) p (void (*)(void))0x111e0b940
(void (*)()) $1 = 0x0000000111e0b940 (XUL`MachExceptionHandlerThread() at WasmSignalHandlers.cpp:880)

So here is the JS main function that doesn't set a thread name.

Comment 3

[Florian Quèze [:florian]]

Attachment: Bug 1638284 - Name the MachExceptionHandler thread started from WasmSignalHandlers.cpp, r=sfink.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b5d91064e430
Name the MachExceptionHandler thread started from WasmSignalHandlers.cpp, r=lth.

Comment 5

[Dorel Luca [:dluca]]

https://hg.mozilla.org/mozilla-central/rev/b5d91064e430