Lock Contention when calling ToString from multiple threads
alitas opened this issue · comments
The default ToString method on a lot of the NodaTime classes utilize PatternBclSupport which in turn tries to read cached fields from NodaFormatInfo. However, since the reads share the same lock, this causes lock contention whenever multiple threads try to serialize dates.
As noted in #1756, one attractive option is to make sure that any NodaFormatInfo which is for a read-only culture (so likely to be reused) is eagerly initialized, so we don't need the lock.
I've started a draft implementation of that - but run into an issue where initializing the patterns relies on initializing DateTimeZone, which in turn uses (indirectly) NodaFormatInfo.InvariantCulture in FixedDateTimeZone.MakeId.
We've had type initialization problems like this before - I want to take another pass at isolating the "core" aspects from anything textual, when it comes to type initialization. I'm not sure how I can test that, but I can at least inspect the code manually and flag up anything I find.
Basically, I still think this is a good way to proceed (and some early tests with hacks to avoid the MakeId issue show promising performance results) but it'll take a little while.