threads/mig_support.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24  * Mach Operating System
  25  * Copyright (c) 1989 Carnegie-Mellon University
  26  * All rights reserved.  The CMU software License Agreement specifies
  27  * the terms and conditions for use and redistribution.
  28  */
  29 /*
  30  * mig_support.c  - by Mary Thompson
  31  *
  32  * Routines to set and deallocate the mig reply port for the current thread.
  33  * Called from mig-generated interfaces.
  34  */
  35 #include <mach/mach.h>
  36 #include <pthread_internals.h>
  37 #include <pthread.h>
  38
  39 #include "cthreads.h"
  40 #include "cthread_internals.h"
  41
  42 pthread_lock_t reply_port_lock;
  43 extern mach_port_t _pthread_reply_port(pthread_t);
  44 static mach_port_t _task_reply_port = MACH_PORT_NULL;
  45
  46 /*
  47  * called in new child...
  48  * clear lock to cover case where the parent had
  49  * a thread holding this lock while another thread
  50  * did the fork()
  51  */
  52 void mig_fork_child()
  53 {
  54         UNLOCK(reply_port_lock);
  55 }
  56
  57 /*
  58  * Called by mach_init with 0 before cthread_init is
  59  * called and again with 1 at the end of cthread_init.
  60  */
  61 void
  62 mig_init(init_done)
  63         int init_done;
  64 {
  65     if (init_done == 0) {
  66         LOCK_INIT(reply_port_lock);
  67         _task_reply_port = mach_reply_port();
  68     }
  69 }
  70
  71 /*
  72  * Called by mig interface code whenever a reply port is needed.
  73  * Tracing is masked during this call; otherwise, a call to printf()
  74  * can result in a call to malloc() which eventually reenters
  75  * mig_get_reply_port() and deadlocks.
  76  */
  77 mach_port_t _mig_get_reply_port()
  78 {
  79     pthread_t pself;
  80
  81     pself = pthread_self();
  82     if ((pself != (pthread_t)NULL) && (pself->sig == _PTHREAD_SIG)) {
  83         return pself->reply_port;
  84     }
  85     return MACH_PORT_NULL;
  86 }
  87
  88 void _mig_set_reply_port(mach_port_t port)
  89 {
  90     pthread_t pself;
  91     pself = pthread_self();
  92
  93     if ((pself != (pthread_t)NULL) && (pself->sig == _PTHREAD_SIG)) {
  94         pself->reply_port = port;
  95     }
  96 }