Bug 52725 - Frequent CSC hangs when invoked on xamarin-android builder
Summary: Frequent CSC hangs when invoked on xamarin-android builder
Alias: None
Product: Runtime
Classification: Mono
Component: General ()
Version: master
Hardware: PC Mac OS
: --- normal
Target Milestone: ---
Assignee: Zoltan Varga
Depends on:
Reported: 2017-02-23 22:31 UTC by Andi McClure
Modified: 2017-03-07 17:10 UTC (History)
4 users (show)

Tags: 2017-02
Is this bug a regression?: ---
Last known good build:

crash stack (237.16 KB, text/plain)
2017-02-23 22:31 UTC, Andi McClure

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Description Andi McClure 2017-02-23 22:31:43 UTC
Created attachment 19936 [details]
crash stack

When the xamarin-android builder runs with the 2017-02 toolchain, on maybe 1 out of every 2 build attempts, at least one csc invocation hangs permanently. This problem does not reproduce on my development laptop.

Marek thinks this is linked to bugzilla #52258, however, that was a crash, and I'm confused what the status of #52258 is anyway.

The hang looks to me like a managed deadlock. If we halt the affected process, it seems to be inside managed threads and doing work.

For example, here is one set of managed stacks obtained with kill -QUIT:


For another, here's the results of a kill -ABORT from a different run, plus my results of attaching with LLDB:

[see attachment]
Comment 1 Zoltan Varga 2017-03-02 22:24:17 UTC
_Hopefully_ fixed by:
Comment 2 Zoltan Varga 2017-03-07 17:10:12 UTC
Should be fixed.