sysdeps/mach/hurd/mig-reply.c

   1 /* Copyright (C) 1994-2016 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <mach.h>
  19 #include <hurd/threadvar.h>
  20
  21 #define GETPORT \
  22   mach_port_t *portloc = \
  23     (mach_port_t *) __hurd_threadvar_location (_HURD_THREADVAR_MIG_REPLY)
  24 #define reply_port (*(use_threadvar ? portloc : &global_reply_port))
  25
  26 static int use_threadvar;
  27 static mach_port_t global_reply_port;
  28
  29 /* These functions are called by MiG-generated code.  */
  30
  31 /* Called by MiG to get a reply port.  */
  32 mach_port_t
  33 __mig_get_reply_port (void)
  34 {
  35   GETPORT;
  36
  37   if (reply_port == MACH_PORT_NULL)
  38     reply_port = __mach_reply_port ();
  39
  40   return reply_port;
  41 }
  42 weak_alias (__mig_get_reply_port, mig_get_reply_port)
  43
  44 /* Called by MiG to deallocate the reply port.  */
  45 void
  46 __mig_dealloc_reply_port (mach_port_t arg)
  47 {
  48   mach_port_t port;
  49
  50   GETPORT;
  51
  52   port = reply_port;
  53   reply_port = MACH_PORT_NULL;  /* So the mod_refs RPC won't use it.  */
  54
  55   if (MACH_PORT_VALID (port))
  56     __mach_port_mod_refs (__mach_task_self (), port,
  57                           MACH_PORT_RIGHT_RECEIVE, -1);
  58 }
  59 weak_alias (__mig_dealloc_reply_port, mig_dealloc_reply_port)
  60
  61 /* Called by mig interfaces when done with a port.  Used to provide the
  62    same interface as needed when a custom allocator is used.  */
  63 void
  64 __mig_put_reply_port(mach_port_t port)
  65 {
  66   /* Do nothing.  */
  67 }
  68 weak_alias (__mig_put_reply_port, mig_put_reply_port)
  69
  70 /* Called at startup with STACK == NULL.  When per-thread variables are set
  71    up, this is called again with STACK set to the new stack being switched
  72    to, where per-thread variables should be set up.  */
  73 void
  74 __mig_init (void *stack)
  75 {
  76   use_threadvar = stack != 0;
  77
  78   if (use_threadvar)
  79     {
  80       /* Recycle the reply port used before multithreading was enabled.  */
  81       mach_port_t *portloc = (mach_port_t *)
  82         __hurd_threadvar_location_from_sp (_HURD_THREADVAR_MIG_REPLY, stack);
  83       *portloc = global_reply_port;
  84       global_reply_port = MACH_PORT_NULL;
  85     }
  86 }
  87 weak_alias (__mig_init, mig_init)