[thirdparty/glibc.git] / mach / msgserver.c

/* Copyright (C) 1993, 1994, 1995, 1996, 2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

/* Based on CMU's mach_msg_server.c revision 2.4 of 91/05/14, and thus
   under the following copyright.  Rewritten by Roland McGrath (FSF)
   93/12/06 to use stack space instead of malloc, and to handle
   large messages with MACH_RCV_LARGE.  */

/*
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 * HISTORY
 * $Log$
 * Revision 1.6  2001/04/09 21:23:38  roland
 * 2001-04-07  Roland McGrath  <roland@frob.com>
 *
 * 	* mach/msgserver.c (__mach_msg_server_timeout): Add an assert.
 *
 * Revision 1.5  1996/12/20 01:32:35  drepper
 * Update from main archive 961219
 *
 * Revision 1.5  1996/12/19 20:23:45  drepper
 * Spelling corrections.
 *
 * Revision 1.4  1996/01/29 15:44:23  roland
 * Declare DEMUX arg with prototype.
 *
 * Revision 1.3  1995/01/21  15:00:57  roland
 * Converted to use weak aliases with macros from libc-symbols.h.
 *
 * Revision 1.2  1994/10/10  07:20:14  roland
 * Increase default MAX_SIZE to two pages.
 *
 * Revision 1.1  1993/12/06  23:25:25  roland
 * entered into RCS
 *
 * Revision 2.4  91/05/14  17:53:22  mrt
 * 	Correcting copyright
 *
 * Revision 2.3  91/02/14  14:17:47  mrt
 * 	Added new Mach copyright
 * 	[91/02/13  12:44:20  mrt]
 *
 * Revision 2.2  90/08/06  17:23:58  rpd
 * 	Created.
 *
 */


#include <mach.h>
#include <mach/mig_errors.h>
#include <stdlib.h>		/* For malloc and free.  */
#include <assert.h>

mach_msg_return_t
__mach_msg_server_timeout (boolean_t (*demux) (mach_msg_header_t *request,
					       mach_msg_header_t *reply),
			   mach_msg_size_t max_size,
			   mach_port_t rcv_name,
			   mach_msg_option_t option,
			   mach_msg_timeout_t timeout)
{
  register mig_reply_header_t *request, *reply;
  register mach_msg_return_t mr;

  if (max_size == 0)
    {
      option |= MACH_RCV_LARGE;
      max_size = 2 * __vm_page_size; /* Generic.  Good? XXX */
    }

  request = __alloca (max_size);
  reply = __alloca (max_size);

  while (1)
    {
    get_request:
      mr = __mach_msg (&request->Head, MACH_RCV_MSG|option,
		       0, max_size, rcv_name,
		       timeout, MACH_PORT_NULL);
      while (mr == MACH_MSG_SUCCESS)
	{
	  /* We have a request message.
	     Pass it to DEMUX for processing.  */

	  (void) (*demux) (&request->Head, &reply->Head);
	  assert (reply->Head.msgh_size <= max_size);

	  switch (reply->RetCode)
	    {
	    case KERN_SUCCESS:
	      /* Hunky dory.  */
	      break;

	    case MIG_NO_REPLY:
	      /* The server function wanted no reply sent.
		 Loop for another request.  */
	      goto get_request;

	    default:
	      /* Some error; destroy the request message to release any
		 port rights or VM it holds.  Don't destroy the reply port
		 right, so we can send an error message.  */
	      request->Head.msgh_remote_port = MACH_PORT_NULL;
	      __mach_msg_destroy (&request->Head);
	      break;
	    }

	  if (reply->Head.msgh_remote_port == MACH_PORT_NULL)
	    {
	      /* No reply port, so destroy the reply.  */
	      if (reply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)
		__mach_msg_destroy (&reply->Head);
	      goto get_request;
	    }

	  /* Send the reply and the get next request.  */

	  {
	    /* Swap the request and reply buffers.  mach_msg will read the
	       reply message from the buffer we pass and write the new
	       request message to the same buffer.  */
	    void *tmp = request;
	    request = reply;
	    reply = tmp;
	  }

	  mr = __mach_msg (&request->Head,
			   MACH_SEND_MSG|MACH_RCV_MSG|option,
			   request->Head.msgh_size, max_size, rcv_name,
			   timeout, MACH_PORT_NULL);
	}

      /* A message error occurred.  */

      switch (mr)
	{
	case MACH_RCV_TOO_LARGE:
	  /* The request message is larger than MAX_SIZE, and has not
	     been dequeued.  The message header has the actual size of
	     the message.  We recurse here in hopes that the compiler
	     will optimize the tail-call and allocate some more stack
	     space instead of way too much.  */
	  return __mach_msg_server_timeout (demux, request->Head.msgh_size,
					    rcv_name, option, timeout);

	case MACH_SEND_INVALID_DEST:
	  /* The reply can't be delivered, so destroy it.  This error
	     indicates only that the requester went away, so we
	     continue and get the next request.  */
	  __mach_msg_destroy (&request->Head);
	  break;

	default:
	  /* Some other form of lossage; return to caller.  */
	  return mr;
	}
    }
}
weak_alias (__mach_msg_server_timeout, mach_msg_server_timeout)

mach_msg_return_t
__mach_msg_server (demux, max_size, rcv_name)
     boolean_t (*demux) (mach_msg_header_t *in, mach_msg_header_t *out);
     mach_msg_size_t max_size;
     mach_port_t rcv_name;
{
  return __mach_msg_server_timeout (demux, max_size, rcv_name,
				    MACH_MSG_OPTION_NONE,
				    MACH_MSG_TIMEOUT_NONE);
}
weak_alias (__mach_msg_server, mach_msg_server)
Commit	Line	Data
6c2a1e81	1	/* Copyright (C) 1993, 1994, 1995, 1996, 2001 Free Software Foundation, Inc.
6d52618b	2	This file is part of the GNU C Library.
28f540f4	3
6d52618b UD	4	The GNU C Library is free software; you can redistribute it and/or
	5	modify it under the terms of the GNU Library General Public License as
	6	published by the Free Software Foundation; either version 2 of the
	7	License, or (at your option) any later version.
28f540f4	8
6d52618b UD	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	Library General Public License for more details.
28f540f4	13
6d52618b UD	14	You should have received a copy of the GNU Library General Public
	15	License along with the GNU C Library; see the file COPYING.LIB. If not,
	16	write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	17	Boston, MA 02111-1307, USA. */
28f540f4 RM	18
	19	/* Based on CMU's mach_msg_server.c revision 2.4 of 91/05/14, and thus
	20	under the following copyright. Rewritten by Roland McGrath (FSF)
	21	93/12/06 to use stack space instead of malloc, and to handle
	22	large messages with MACH_RCV_LARGE. */
	23
19c3f208	24	/*
28f540f4 RM	25	* Mach Operating System
	26	* Copyright (c) 1991,1990 Carnegie Mellon University
	27	* All Rights Reserved.
19c3f208	28	*
28f540f4 RM	29	* Permission to use, copy, modify and distribute this software and its
	30	* documentation is hereby granted, provided that both the copyright
	31	* notice and this permission notice appear in all copies of the
	32	* software, derivative works or modified versions, and any portions
	33	* thereof, and that both notices appear in supporting documentation.
19c3f208	34	*
28f540f4 RM	35	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	36	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	37	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
19c3f208	38	*
28f540f4	39	* Carnegie Mellon requests users of this software to return to
19c3f208	40	*
28f540f4 RM	41	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	42	* School of Computer Science
	43	* Carnegie Mellon University
	44	* Pittsburgh PA 15213-3890
19c3f208	45	*
28f540f4 RM	46	* any improvements or extensions that they make and grant Carnegie Mellon
	47	* the rights to redistribute these changes.
	48	*/
	49	/*
	50	* HISTORY
	51	* $Log$
6c2a1e81 RM	52	* Revision 1.6 2001/04/09 21:23:38 roland
	53	* 2001-04-07 Roland McGrath <roland@frob.com>
	54	*
	55	* * mach/msgserver.c (__mach_msg_server_timeout): Add an assert.
	56	*
6d52618b UD	57	* Revision 1.5 1996/12/20 01:32:35 drepper
	58	* Update from main archive 961219
	59	*
	60	* Revision 1.5 1996/12/19 20:23:45 drepper
	61	* Spelling corrections.
	62	*
19c3f208 RM	63	* Revision 1.4 1996/01/29 15:44:23 roland
	64	* Declare DEMUX arg with prototype.
	65	*
	66	* Revision 1.3 1995/01/21 15:00:57 roland
28f540f4 RM	67	* Converted to use weak aliases with macros from libc-symbols.h.
	68	*
	69	* Revision 1.2 1994/10/10 07:20:14 roland
	70	* Increase default MAX_SIZE to two pages.
	71	*
	72	* Revision 1.1 1993/12/06 23:25:25 roland
	73	* entered into RCS
	74	*
	75	* Revision 2.4 91/05/14 17:53:22 mrt
	76	* Correcting copyright
19c3f208	77	*
28f540f4 RM	78	* Revision 2.3 91/02/14 14:17:47 mrt
	79	* Added new Mach copyright
	80	* [91/02/13 12:44:20 mrt]
19c3f208	81	*
28f540f4 RM	82	* Revision 2.2 90/08/06 17:23:58 rpd
28f540f4 RM	83	* Created.
19c3f208	84	*
28f540f4 RM	85	*/
	86
	87
	88	#include <mach.h>
	89	#include <mach/mig_errors.h>
	90	#include <stdlib.h> /* For malloc and free. */
6c2a1e81	91	#include <assert.h>
28f540f4 RM	92
	93	mach_msg_return_t
	94	__mach_msg_server_timeout (boolean_t (demux) (mach_msg_header_t request,
	95	mach_msg_header_t *reply),
	96	mach_msg_size_t max_size,
	97	mach_port_t rcv_name,
	98	mach_msg_option_t option,
	99	mach_msg_timeout_t timeout)
	100	{
	101	register mig_reply_header_t request, reply;
	102	register mach_msg_return_t mr;
	103
	104	if (max_size == 0)
	105	{
	106	option \|= MACH_RCV_LARGE;
	107	max_size = 2 * __vm_page_size; /* Generic. Good? XXX */
	108	}
	109
	110	request = __alloca (max_size);
	111	reply = __alloca (max_size);
	112
	113	while (1)
	114	{
	115	get_request:
	116	mr = __mach_msg (&request->Head, MACH_RCV_MSG\|option,
	117	0, max_size, rcv_name,
	118	timeout, MACH_PORT_NULL);
	119	while (mr == MACH_MSG_SUCCESS)
	120	{
	121	/* We have a request message.
	122	Pass it to DEMUX for processing. */
	123
	124	(void) (*demux) (&request->Head, &reply->Head);
6c2a1e81	125	assert (reply->Head.msgh_size <= max_size);
28f540f4 RM	126
	127	switch (reply->RetCode)
	128	{
	129	case KERN_SUCCESS:
	130	/* Hunky dory. */
	131	break;
	132
	133	case MIG_NO_REPLY:
	134	/* The server function wanted no reply sent.
	135	Loop for another request. */
	136	goto get_request;
	137
	138	default:
	139	/* Some error; destroy the request message to release any
	140	port rights or VM it holds. Don't destroy the reply port
	141	right, so we can send an error message. */
	142	request->Head.msgh_remote_port = MACH_PORT_NULL;
	143	__mach_msg_destroy (&request->Head);
	144	break;
	145	}
	146
	147	if (reply->Head.msgh_remote_port == MACH_PORT_NULL)
	148	{
	149	/* No reply port, so destroy the reply. */
	150	if (reply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)
	151	__mach_msg_destroy (&reply->Head);
	152	goto get_request;
	153	}
	154
	155	/* Send the reply and the get next request. */
	156
	157	{
	158	/* Swap the request and reply buffers. mach_msg will read the
	159	reply message from the buffer we pass and write the new
	160	request message to the same buffer. */
	161	void *tmp = request;
	162	request = reply;
	163	reply = tmp;
	164	}
	165
	166	mr = __mach_msg (&request->Head,
	167	MACH_SEND_MSG\|MACH_RCV_MSG\|option,
	168	request->Head.msgh_size, max_size, rcv_name,
	169	timeout, MACH_PORT_NULL);
	170	}
	171
	172	/* A message error occurred. */
	173
	174	switch (mr)
	175	{
	176	case MACH_RCV_TOO_LARGE:
	177	/* The request message is larger than MAX_SIZE, and has not
6d52618b	178	been dequeued. The message header has the actual size of
28f540f4 RM	179	the message. We recurse here in hopes that the compiler
	180	will optimize the tail-call and allocate some more stack
	181	space instead of way too much. */
	182	return __mach_msg_server_timeout (demux, request->Head.msgh_size,
	183	rcv_name, option, timeout);
	184
	185	case MACH_SEND_INVALID_DEST:
	186	/* The reply can't be delivered, so destroy it. This error
6d52618b	187	indicates only that the requester went away, so we
28f540f4 RM	188	continue and get the next request. */
	189	__mach_msg_destroy (&request->Head);
	190	break;
	191
	192	default:
	193	/* Some other form of lossage; return to caller. */
	194	return mr;
	195	}
	196	}
	197	}
	198	weak_alias (__mach_msg_server_timeout, mach_msg_server_timeout)
	199
	200	mach_msg_return_t
	201	__mach_msg_server (demux, max_size, rcv_name)
19c3f208	202	boolean_t (demux) (mach_msg_header_t in, mach_msg_header_t *out);
28f540f4 RM	203	mach_msg_size_t max_size;
	204	mach_port_t rcv_name;
	205	{
	206	return __mach_msg_server_timeout (demux, max_size, rcv_name,
	207	MACH_MSG_OPTION_NONE,
	208	MACH_MSG_TIMEOUT_NONE);
	209	}
	210	weak_alias (__mach_msg_server, mach_msg_server)