1522318 - Add a way to wait to debug child processes' native code

Status: RESOLVED FIXED

(GeckoView Graveyard :: Sandboxing, enhancement, P3)

Description

[[ex-Mozilla] Agi Sferro | :agi]

We need a way to wait for the debugger for child processes, similar to MOZ_DEBUG_CHILD_PROCESS for desktop.

Comment 1

[Nick Alexander :nalexander [he/him]]

agi: snorp pointed you at try MOZ_DEBUG_CHILD_PROCESS=1 and MOZ_DEBUG_CHILD_PAUSE=10. Can you test, capture this somewhere (in the GeckoView wiki -- I don't know anywhere better), and if you're satisfied close this ticket?

If it's easy we could support this in mach run while we're trying to improve that functionality: Bug 1521996.

Comment 2

[Chris Peterson [:cpeterson]]

P3. This is necessary for debugging content process crashes on startup.

Comment 3

[[ex-Mozilla] Agi Sferro | :agi]

OK looks like MOZ_DEBUG_CHILD_PAUSE works somewhat, but we can do better. I think we should add a flag similar to MOZ_DEBUG_CHILD_PROCESS that makes us wait for the debugger (right now the code just continues) something like MOZ_DEBUG_WAIT_FOR_JAVA_DEBUGGER.

Comment 4

[Nick Alexander :nalexander [he/him]]

Attachment: Bug 1522318 - Wait for Java debugger when MOZ_DEBUG_{CHILD_}WAIT_FOR_JAVA_DEBUGGER. r?esawin

Set MOZ_DEBUG_WAIT_FOR_JAVA_DEBUGGER=1 in the environment to make the
main (Gecko) process wait for a Java debugger to connect. This is a
superset of Android Studio's built-in debugging support so it won't be
particularly useful, but perhaps some folks want to use a different
jdwp debugger.

Set MOZ_DEBUG_CHILD_WAIT_FOR_JAVA_DEBUGGER=filter in the environment
to make child processes wait for a Java debugger to connect. This is
not easy in Android Studio.

Valid filter values are:

• "1" to make all child processes (:tab, :media, etc) wait
• "suffix" to make any child process with a process name with suffix "suffix" wait

N.b.: the empty string "" is a suffix of all process names and thus
MOZ_DEBUG_CHILD_WAIT_FOR_JAVA_DEBUGGER= makes all child processes wait.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1afc68022e2b
Wait for Java debugger when MOZ_DEBUG_{CHILD_}WAIT_FOR_JAVA_DEBUGGER. r=esawin

Comment 6

[Nick Alexander :nalexander [he/him]]

For folks following along at home, documentation is here: https://mozilla.github.io/geckoview/tutorials/native-debugging.html#attaching-debuggers-to-content-and-other-child-processes.

Comment 7

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/1afc68022e2b

Comment 8

[Chris Peterson [:cpeterson]]

Moving content process bugs to the new GeckoView::Sandboxing component.