Soft WDT: detect deliberate infinite loop at Postmortem #8918
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
A popular method of handling an unrecoverable state is to reboot. The SDK does this in many places by printing a cryptic debug message followed by something equivalent to
while(true){}, which compiles down toloop: j loop, creating a Soft WDT reset.This change calls attention to these deliberate WDT resets at Postmortem. In the one case that I examined closer, the SDK responded this way after an OOM event.
For SDK 3.0.5, I found this many "deliberate infinite loops":