PIAdapters: Eliminate InputMeasurementKeyTypes race conditions in PIOutputAdapter - #568
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As the comment previously indicated, there is a possible race condition where the backing field for
InputMeasurementKeysis updated butInputMeasurementKeyTypesis not. Comparing the length of each array is a decent way to guard against this race condition, but it makes two assumptions.InputMeasurementKeysis strictly ordered.Neither of these assumptions are guaranteed, but in practice the race condition and the violations of these assumptions are quite rare. One notable exception, however, occurs in an openPDC system with a large number of measurements. At least in one user's case, the first assumption is violated frequently after a
ReloadConfig -Databaseis issued to the service unless anORDER BYclause is added to the filter expression.This PR avoids the race condition entirely by replacing the parallel arrays with a single array of tuples.