Fix race condition in time barriers #49
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tanneberger
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May 23, 2023
cmnrd
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This pulls in lf-lang/reactor-cpp#49 to fix #1746
cmnrd
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This pulls in lf-lang/reactor-cpp#49 to fix #1746
cmnrd
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This pulls in lf-lang/reactor-cpp#49 to fix #1746
cmnrd
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May 24, 2023
This pulls in lf-lang/reactor-cpp#49 to fix #1746
cmnrd
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This pulls in lf-lang/reactor-cpp#49 to fix #1746
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There was a race condition in the main synchronization primitive that we use to coordinate enclaves. Our code used two separate locks, one for protecting the variable holding the last released tag and another one for receiving updates from the scheduler. However, we can only use one of the locks when calling
waiton our condition variable. This creates a race between updating the wait condition (i.e. releasing a tag) and actually starting the wait under the second lock (Here is an explanation, see "An atomic predicate") This PR refactors the time barriers, such that the global scheduler lock is also used to protect our localreleased_tag_variable.This adresses lf-lang/lingua-franca#1746