Protect phase switch from race conditions #111
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Signed-off-by: Michael X. Grey <mxgrey@intrinsic.ai>
Signed-off-by: Michael X. Grey <mxgrey@intrinsic.ai>
Signed-off-by: Michael X. Grey <mxgrey@intrinsic.ai>
…sk into safer_phase_switch
Signed-off-by: Michael X. Grey <mxgrey@intrinsic.ai>
Signed-off-by: Michael X. Grey <mxgrey@intrinsic.ai>
xiyuoh
approved these changes
Mar 19, 2024
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We recently found a crash that seems to originate from the phase switching code in
rmf_task_sequence. While it's still unclear what conditions could have caused the crash, the most likely culprit would be a race condition.This PR adds a mutex that locks before any phase switching happens, which should ensure that race conditions cannot lead to a crash happening. We also add some sanity checks that run each time a phase switch is set to happen, so if anything suspicious is going on we'll identify it before a segmentation fault can happen. Unfortunately those situations cause us to abort via exception, but that is likely a better outcome than allowing undefined behavior to proceed.