Commit 347952ffe0039369ff4e7c94c4e27e7333ba8ecb
2009-11-27T15:20:43
Revise the locking API: deprecate the old locking callbacks and add trylock. Previously, there was no good way to request different kinds of lock (say, read/write vs writeonly or recursive vs nonrecursive), or for a lock function to signal failure (which would be important for a trylock mode). This patch revises the lock API to be a bit more useful. The older lock calls are still supported for now. We also add a debugging mode to catch common errors in using the locking APIs.