Is there a faster kind of TMultiReadExclusiveWriteSynchronizer out there? FastCode perhaps?

Starting with Windows Vista, Microsoft added a Slim Reader/Writer lock. It performs much better than Delphi's TMultiReadExclusiveWriteSynchronizer. Unfortunately it only exists in Windows Vista and later, something which few customers actually have yet.

Presumably the concepts in use inside a Slim Reader/Writer lock could be redone in native Delphi code - but has anyone done it?

i have a situation where acquiring and releasing locks on a TMultiReadExclusiveWriteSynchronizer (even when there's no contention - a single thread), causes 100% overhead (the operation time doubles). i can run without locking, but then my class is no longer thread-safe.

Is there a faster TMultiReadExclusiveWriteSynchronizer?

Note: If i use a TCriticalSection i only suffer a 2% performance hit (although critical sections are known to be fast when the acquire succeeds, i.e. while it's single threaded and there's no contention). The downside of a CS is that i lose the "multiple readers" capability.

The Measurements

Using TMultiReadExclusiveWriteSynchronizer a sizable amount of time is spent inside BeginRead and EndRead:

i then ported the code to use Window's own SlimReaderWriter Lock (which some code rewrite, as it doesn't support recursive lock taking), and profiled the resutls: