Fix #516, Use absolute timeout for timedlock calls #518
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Describe the contribution
The pthread API defines the timeout parameter for the pthread_mutex_timedlock call as an absolute value based on CLOCK_REALTIME.
This introduces a wrapper function to calculate the absolute timeout for this.
Fixes #516
Testing performed
Build and execute CFE, sanity check CFE operation, and run all unit tests.
Coverage is not affected because there is no coverage test for POSIX.
Expected behavior changes
The timed lock in binary semaphores should now correctly wait for up to 2 seconds for the lock to become available before failing. The net effect of passing a relative timeout in place of an absolute one meant that the code would not wait, basically turning into a "trylock" instead.
System(s) tested on
Ubuntu 20.04
Additional context
Unfortunately this wasn't previously noticed during testing because it requires getting two tasks to operate on the same binary sem at exactly the same time, which is difficult to replicate.
Contributor Info - All information REQUIRED for consideration of pull request
Joseph Hickey, Vantage Systems, Inc.