* cygheap.h (cygheap_types): Add HEAP_ARCHETYPES.

(init_cheap::ctty): Change to pointer.
* dtable.h (dtable::find_archetype): Declare new function.
(dtable::add_archetype): Declare new function.
(dtable::delete_archetype): Declare new function.
(dtable::narchetypes): Declare.
(dtable::farchetypes): Declare.
(dtable::initial_archetype_size): Declare.
(dtable::dtable): Initialize new fields.
(dtable::initial_archetype_size): Declare.
* dtable.cc (dtable::find_archetype): Define new function.
(dtable::add_archetype): Define new function.
(dtable::delete_archetype): Define new function.
(dtable::initial_archetype_size): Define.
* fhandler.h (fhandler_base::archetype): Declare.
(fhandler_base::usecount): Declare.
* fhandler.cc (fhandler_base::fhandler_base): Initialize new fields.
* fhandler_console.cc (fhandler_console::get_tty_stuff): Pass NULL to third
argument of set_ctty.
* fhandler_tty.cc (fhandler_tty_slave::open): Accommodate new archetype method
to create only one instance of a tty.
(fhandler_tty_slave::close): Don't close handles unless archetype usecount is
zero.  When that happens, close archetype too.
(fhandler_tty_slave::dup): Just copy archetype.  Set use count appropriately.
Set ctty, if appropriate.
(fhandler_tty_common::dup): Remove slave considerations.
(fhandler_tty_common::set_close_on_exec): Remove cygheap->ctty considerations.
* pinfo.cc (_pinfo::set_ctty): Accommodate new archetype methods.
* pinfo.h (_pinfo::set_ctty): Make third argument explicit.
* syscalls.cc (close_all_files): Decrement controlling tty use count before
closing all handles to allow controlling tty to be closed.  Remove previous
controlling tty considerations.

winsup/cygwin/dtable.cc

@@ -163,6 +163,39 @@ dtable::stdio_init ()
     set_console_ctty ();
 }
 
+const int dtable::initial_archetype_size;
+
+fhandler_base *
+dtable::find_archetype (device& dev)
+{
+  for (unsigned i = 0; i < farchetype; i++)
+    if (archetypes[i]->get_device () == (unsigned) dev)
+      return archetypes[i];
+  return NULL;
+}
+
+fhandler_base **
+dtable::add_archetype ()
+{
+  if (farchetype++ >= narchetypes)
+    archetypes = (fhandler_base **) crealloc (archetypes, (narchetypes += initial_archetype_size) * sizeof archetypes[0]);
+  return archetypes + farchetype - 1;
+}
+
+void
+dtable::delete_archetype (fhandler_base *fh)
+{
+  for (unsigned i = 0; i < narchetypes; i++)
+    if (fh == archetypes[i])
+      {
+	if (i < --farchetype)
+	  archetypes[i] = archetypes[farchetype];
+	break;
+      }
+
+  delete fh;
+}
+
 int
 dtable::find_unused_handle (int start)
 {