libsyscall/mach/mig_reply_port.c

   1 /*
   2  * Copyright (c) 2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <mach/mach.h>
  30 #include <mach/mach_init.h>
  31 #include <sys/cdefs.h>
  32 #include "tsd.h"
  33
  34 __XNU_PRIVATE_EXTERN mach_port_t _task_reply_port = MACH_PORT_NULL;
  35
  36 static inline mach_port_t
  37 _mig_get_reply_port()
  38 {
  39         return _os_tsd_get_direct(__TSD_MIG_REPLY);
  40 }
  41
  42 static inline void
  43 _mig_set_reply_port(mach_port_t port)
  44 {
  45         _os_tsd_set_direct(__TSD_MIG_REPLY, port);
  46 }
  47
  48 /*
  49  * Called by mig interface code whenever a reply port is needed.
  50  * Tracing is masked during this call; otherwise, a call to printf()
  51  * can result in a call to malloc() which eventually reenters
  52  * mig_get_reply_port() and deadlocks.
  53  */
  54 mach_port_t
  55 mig_get_reply_port(void)
  56 {
  57         mach_port_t port = _mig_get_reply_port();
  58         if (port == MACH_PORT_NULL) {
  59                 port = mach_reply_port();
  60                 _mig_set_reply_port(port);
  61         }
  62         return port;
  63 }
  64
  65 /*
  66  * Called by mig interface code after a timeout on the reply port.
  67  * May also be called by user. The new mig calls with port passed in.
  68  */
  69 void
  70 mig_dealloc_reply_port(mach_port_t migport)
  71 {
  72         mach_port_t port = _mig_get_reply_port();
  73         if (port != MACH_PORT_NULL && port != _task_reply_port) {
  74                 _mig_set_reply_port(_task_reply_port);
  75                 (void) mach_port_mod_refs(mach_task_self(), port, MACH_PORT_RIGHT_RECEIVE, -1);
  76                 if (migport != port) {
  77                         (void) mach_port_deallocate(mach_task_self(), migport);
  78                 }
  79                 _mig_set_reply_port(MACH_PORT_NULL);
  80         }
  81 }
  82
  83 /*************************************************************
  84  *  Called by mig interfaces after each RPC.
  85  *  Could be called by user.
  86  ***********************************************************/
  87
  88 void
  89 mig_put_reply_port(mach_port_t reply_port __unused)
  90 {
  91 }