* dtable.cc (dtable::find_fifo): Release lock after fifo found (still racy).

* fhandler.h (fhandler_fifo::get_io_handle): New fifo-specific method.
* fhandler_fifo.cc (fhandler_fifo::close): Close output_handle only if it is
open.
(fhandler_fifo::open_not_mine): Reorganize slightly.  Don't call _pinfo methods
when the fifo is owned by me or suffer dtable lock_cs deadlock.
(fhandler_fifo::open): Call open_not_mine first, otherwise open myself
(racy).
* pinfo.cc (_pinfo::commune_recv): Duplicate fifo handles here in requesting
processes arena to avoid one potential race (of many).
(_pinfo::commune_send): Move all PICOM_FIFO code under one case statement.
* thread.cc (pthread::init_mainthread) Use existing hMainProc handle rather
than calling GetCurrentProcess.

winsup/cygwin/thread.cc

@@ -178,9 +178,8 @@ pthread::init_mainthread ()
 
   set_tls_self_pointer (thread);
   thread->thread_id = GetCurrentThreadId ();
-  if (!DuplicateHandle (GetCurrentProcess (), GetCurrentThread (),
-			GetCurrentProcess (), &thread->win32_obj_id,
-			0, FALSE, DUPLICATE_SAME_ACCESS))
+  if (!DuplicateHandle (hMainProc, GetCurrentThread (), hMainProc,
+			&thread->win32_obj_id, 0, FALSE, DUPLICATE_SAME_ACCESS))
     api_fatal ("failed to create mainthread handle");
   if (!thread->create_cancel_event ())
     api_fatal ("couldn't create cancel event for main thread");