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
  29 #ifdef MACH_MSG_OVERWRITE
  30 /* In variants with this feature, the actual system call is
  31    __mach_msg_overwrite_trap.  */
  32 mach_msg_return_t
  33 __mach_msg_trap (mach_msg_header_t *msg,
  34                  mach_msg_option_t option,
  35                  mach_msg_size_t send_size,
  36                  mach_msg_size_t rcv_size,
  37                  mach_port_t rcv_name,
  38                  mach_msg_timeout_t timeout,
  39                  mach_port_t notify)
  40 {
  41   return __mach_msg_overwrite_trap (msg, option, send_size,
  42                                     rcv_size, rcv_name, timeout, notify,
  43                                     MACH_MSG_NULL, 0);
  44 }
  45 weak_alias (__mach_msg_trap, mach_msg_trap)
  46
  47 /* See comments below in __mach_msg.  */
  48 mach_msg_return_t
  49 __mach_msg_overwrite (mach_msg_header_t *msg,
  50                       mach_msg_option_t option,
  51                       mach_msg_size_t send_size,
  52                       mach_msg_size_t rcv_size,
  53                       mach_port_t rcv_name,
  54                       mach_msg_timeout_t timeout,
  55                       mach_port_t notify,
  56                       mach_msg_header_t *rcv_msg,
  57                       mach_msg_size_t rcv_msg_size)
  58
  59 {
  60   mach_msg_return_t ret;
  61
  62   /* Consider the following cases:
  63      1. Errors in pseudo-receive (eg, MACH_SEND_INTERRUPTED
  64      plus special bits).
  65      2. Use of MACH_SEND_INTERRUPT/MACH_RCV_INTERRUPT options.
  66      3. RPC calls with interruptions in one/both halves.
  67   */
  68
  69   ret = __mach_msg_overwrite_trap (msg, option, send_size,
  70                                    rcv_size, rcv_name, timeout, notify,
  71                                    rcv_msg, rcv_msg_size);
  72   if (ret == MACH_MSG_SUCCESS)
  73     return MACH_MSG_SUCCESS;
  74
  75   if (!(option & MACH_SEND_INTERRUPT))
  76     while (ret == MACH_SEND_INTERRUPTED)
  77       ret = __mach_msg_overwrite_trap (msg, option, send_size,
  78                                        rcv_size, rcv_name, timeout, notify,
  79                                        rcv_msg, rcv_msg_size);
  80
  81   if (!(option & MACH_RCV_INTERRUPT))
  82     while (ret == MACH_RCV_INTERRUPTED)
  83       ret = __mach_msg_overwrite_trap (msg, option & ~MACH_SEND_MSG,
  84                                        0, rcv_size, rcv_name, timeout, notify,
  85                                        rcv_msg, rcv_msg_size);
  86
  87   return ret;
  88 }
  89 weak_alias (__mach_msg_overwrite, mach_msg_overwrite)
  90 #endif
  91
  92 mach_msg_return_t
  93 __mach_msg (mach_msg_header_t *msg,
  94             mach_msg_option_t option,
  95             mach_msg_size_t send_size,
  96             mach_msg_size_t rcv_size,
  97             mach_port_t rcv_name,
  98             mach_msg_timeout_t timeout,
  99             mach_port_t notify)
 100 {
 101   mach_msg_return_t ret;
 102
 103   /* Consider the following cases:
 104      1. Errors in pseudo-receive (eg, MACH_SEND_INTERRUPTED
 105      plus special bits).
 106      2. Use of MACH_SEND_INTERRUPT/MACH_RCV_INTERRUPT options.
 107      3. RPC calls with interruptions in one/both halves.
 108      */
 109
 110   ret = __mach_msg_trap (msg, option, send_size,
 111                          rcv_size, rcv_name, timeout, notify);
 112   if (ret == MACH_MSG_SUCCESS)
 113     return MACH_MSG_SUCCESS;
 114
 115   if (!(option & MACH_SEND_INTERRUPT))
 116     while (ret == MACH_SEND_INTERRUPTED)
 117       ret = __mach_msg_trap (msg, option, send_size,
 118                              rcv_size, rcv_name, timeout, notify);
 119
 120   if (!(option & MACH_RCV_INTERRUPT))
 121     while (ret == MACH_RCV_INTERRUPTED)
 122       ret = __mach_msg_trap (msg, option & ~MACH_SEND_MSG,
 123                              0, rcv_size, rcv_name, timeout, notify);
 124
 125   return ret;
 126 }
 127 weak_alias (__mach_msg, mach_msg)
 128
 129 mach_msg_return_t
 130 __mach_msg_send (mach_msg_header_t *msg)
 131 {
 132   return __mach_msg (msg, MACH_SEND_MSG,
 133                      msg->msgh_size, 0, MACH_PORT_NULL,
 134                      MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
 135 }
 136 weak_alias (__mach_msg_send, mach_msg_send)
 137
 138 mach_msg_return_t
 139 __mach_msg_receive (mach_msg_header_t *msg)
 140 {
 141   return __mach_msg (msg, MACH_RCV_MSG,
 142                      0, msg->msgh_size, msg->msgh_local_port,
 143                      MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
 144 }
 145 weak_alias (__mach_msg_receive, mach_msg_receive)