mach/msg.c

   1 /*
   2  * Mach Operating System
   3  * Copyright (c) 1991,1990,1989, 1995 Carnegie Mellon University
   4  * All Rights Reserved.
   5  *
   6  * Permission to use, copy, modify and distribute this software and its
   7  * documentation is hereby granted, provided that both the copyright
   8  * notice and this permission notice appear in all copies of the
   9  * software, derivative works or modified versions, and any portions
  10  * thereof, and that both notices appear in supporting documentation.
  11  *
  12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  15  *
  16  * Carnegie Mellon requests users of this software to return to
  17  *
  18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  19  *  School of Computer Science
  20  *  Carnegie Mellon University
  21  *  Pittsburgh PA 15213-3890
  22  *
  23  * any improvements or extensions that they make and grant Carnegie Mellon
  24  * the rights to redistribute these changes.
  25  */
  26 #include <mach/port.h>
  27 #include <mach/message.h>
  28 #include <mach.h>
  29
  30 #ifdef MACH_MSG_OVERWRITE
  31 /* In variants with this feature, the actual system call is
  32    __mach_msg_overwrite_trap.  */
  33 mach_msg_return_t
  34 __mach_msg_trap (mach_msg_header_t *msg,
  35                  mach_msg_option_t option,
  36                  mach_msg_size_t send_size,
  37                  mach_msg_size_t rcv_size,
  38                  mach_port_t rcv_name,
  39                  mach_msg_timeout_t timeout,
  40                  mach_port_t notify)
  41 {
  42   return __mach_msg_overwrite_trap (msg, option, send_size,
  43                                     rcv_size, rcv_name, timeout, notify,
  44                                     MACH_MSG_NULL, 0);
  45 }
  46 weak_alias (__mach_msg_trap, mach_msg_trap)
  47
  48 /* See comments below in __mach_msg.  */
  49 mach_msg_return_t
  50 __mach_msg_overwrite (mach_msg_header_t *msg,
  51                       mach_msg_option_t option,
  52                       mach_msg_size_t send_size,
  53                       mach_msg_size_t rcv_size,
  54                       mach_port_t rcv_name,
  55                       mach_msg_timeout_t timeout,
  56                       mach_port_t notify,
  57                       mach_msg_header_t *rcv_msg,
  58                       mach_msg_size_t rcv_msg_size)
  59
  60 {
  61   mach_msg_return_t ret;
  62
  63   /* Consider the following cases:
  64      1. Errors in pseudo-receive (eg, MACH_SEND_INTERRUPTED
  65      plus special bits).
  66      2. Use of MACH_SEND_INTERRUPT/MACH_RCV_INTERRUPT options.
  67      3. RPC calls with interruptions in one/both halves.
  68   */
  69
  70   ret = __mach_msg_overwrite_trap (msg, option, send_size,
  71                                    rcv_size, rcv_name, timeout, notify,
  72                                    rcv_msg, rcv_msg_size);
  73   if (ret == MACH_MSG_SUCCESS)
  74     return MACH_MSG_SUCCESS;
  75
  76   if (!(option & MACH_SEND_INTERRUPT))
  77     while (ret == MACH_SEND_INTERRUPTED)
  78       ret = __mach_msg_overwrite_trap (msg, option, send_size,
  79                                        rcv_size, rcv_name, timeout, notify,
  80                                        rcv_msg, rcv_msg_size);
  81
  82   if (!(option & MACH_RCV_INTERRUPT))
  83     while (ret == MACH_RCV_INTERRUPTED)
  84       ret = __mach_msg_overwrite_trap (msg, option & ~MACH_SEND_MSG,
  85                                        0, rcv_size, rcv_name, timeout, notify,
  86                                        rcv_msg, rcv_msg_size);
  87
  88   return ret;
  89 }
  90 weak_alias (__mach_msg_overwrite, mach_msg_overwrite)
  91 #endif
  92
  93 mach_msg_return_t
  94 __mach_msg (mach_msg_header_t *msg,
  95             mach_msg_option_t option,
  96             mach_msg_size_t send_size,
  97             mach_msg_size_t rcv_size,
  98             mach_port_t rcv_name,
  99             mach_msg_timeout_t timeout,
 100             mach_port_t notify)
 101 {
 102   mach_msg_return_t ret;
 103
 104   /* Consider the following cases:
 105      1. Errors in pseudo-receive (eg, MACH_SEND_INTERRUPTED
 106      plus special bits).
 107      2. Use of MACH_SEND_INTERRUPT/MACH_RCV_INTERRUPT options.
 108      3. RPC calls with interruptions in one/both halves.
 109      */
 110
 111   ret = __mach_msg_trap (msg, option, send_size,
 112                          rcv_size, rcv_name, timeout, notify);
 113   if (ret == MACH_MSG_SUCCESS)
 114     return MACH_MSG_SUCCESS;
 115
 116   if (!(option & MACH_SEND_INTERRUPT))
 117     while (ret == MACH_SEND_INTERRUPTED)
 118       ret = __mach_msg_trap (msg, option, send_size,
 119                              rcv_size, rcv_name, timeout, notify);
 120
 121   if (!(option & MACH_RCV_INTERRUPT))
 122     while (ret == MACH_RCV_INTERRUPTED)
 123       ret = __mach_msg_trap (msg, option & ~MACH_SEND_MSG,
 124                              0, rcv_size, rcv_name, timeout, notify);
 125
 126   return ret;
 127 }
 128 weak_alias (__mach_msg, mach_msg)
 129 libc_hidden_def (__mach_msg)
 130
 131 mach_msg_return_t
 132 __mach_msg_send (mach_msg_header_t *msg)
 133 {
 134   return __mach_msg (msg, MACH_SEND_MSG,
 135                      msg->msgh_size, 0, MACH_PORT_NULL,
 136                      MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
 137 }
 138 weak_alias (__mach_msg_send, mach_msg_send)
 139
 140 mach_msg_return_t
 141 __mach_msg_receive (mach_msg_header_t *msg)
 142 {
 143   return __mach_msg (msg, MACH_RCV_MSG,
 144                      0, msg->msgh_size, msg->msgh_local_port,
 145                      MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
 146 }
 147 weak_alias (__mach_msg_receive, mach_msg_receive)