2002-07-07  Conrad Scott  <conrad.scott@dsl.pipex.com>

	* debug.cc (class lock_debug): Make a class, rather than a struct.
	Fix problem where explicit use of the lock_debug::unlock method
	released the muto twice.
	(lock_debug::acquired): New field.
	(lock_debug::lock_debug): Set acquired only if the muto is
	actually acquired.
	(lock_debug::unlock): Only release the muto if it is still
	acquired by this object.
	(setclexec_pid): Disable until such time as the protected handle
	list is inherited by child processes.
	(add_handle): Unlock the lock_debug muto before using
	system_printf.
	(mark_closed): Ditto.
	(debug_fixup_after_fork): Use lock_debug, tho' it's probably
	unnecessary.