2009-09-25 Gonzalo Paniagua Javier <gonzalo@novell.com>

2009-09-25 Gonzalo Paniagua Javier <gonzalo@novell.com>

	* threadpool.c:
	* class-internals.h:
	* mono-perfcounters-def.h:
	* mono-perfcounters.c:
	-There is a list of idle threads
	-Each of those idle threads wait on their own WaitHandle instead
	of all of them using the same semaphore. When a new work item is
	added, the job is assigned directly to an idle thread or a newly
	created one if possible and then the handle for that thread is
	signaled. Compare that to the current approach where all the
	threads in the pool compete to dequeue a job from the same
	queue.
	-New struct ThreadPool that brings together the bunch of static
	variable for each threadpool (IO and regular).
	-New performance counters: # of items added and its rate per
	threadpool. The rate will be used later, perhaps together with
	other perf. counters, to decide when idle threads should exit.

svn path=/trunk/mono/; revision=142667