Fix #8860: [Win32] Crashlog window wasn't reliably shown for crashes. #8861
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TrueBrain
reviewed
Mar 13, 2021
src/crashlog.h
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| @@ -114,6 +114,12 @@ class CrashLog { | |||
| */ | |||
| static void InitialiseCrashLog(); | |||
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| /** | |||
| * Initialiser in case a newly started thread has to be prepared for the crash log. | |||
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this is a weird sentence .. initialiser in case a thread has to be prepared .. feels really vague :D Can't you make it more absolute in what it does / when it has to be called?
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I just copied the language from the comment for InitialiseCrashLog directly above, but you are right that it reads a bit strange.
…rashes not on the main thread.
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TrueBrain
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Mar 13, 2021
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Motivation / Problem
If a crash occurs on a different thread to the main thread, the crashlog window wasn't reliably shown on windows.
Description
Crashlog on windows relies on a captured stack pointer to always have a safe stack area. We only captured the stack pointer on the main thread, which doesn't work when calling the crashlog handler from a different thread.
To solve this, we make the stack pointer a thread local var and capture it on thread init.
Limitations
@JGRennison has an alternate suggestion in #8860, which, as far as I can see, would be enough for Windows (expect ARM64). This PR implements a solution that is more general, which in the future could be used to support thread specific things also on other platforms.
Checklist for review
Some things are not automated, and forgotten often. This list is a reminder for the reviewers.