Missing BZ number.
[glibc.git] / mach / msgserver.c
blob9478ae1914adf01d11dc325c3380ebf1fdec2335
1 /* Copyright (C) 1993,94,95,96,2001,02 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
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 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17 02111-1307 USA. */
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. */
25 * Mach Operating System
26 * Copyright (c) 1991,1990 Carnegie Mellon University
27 * All Rights Reserved.
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.
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.
39 * Carnegie Mellon requests users of this software to return to
41 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
42 * School of Computer Science
43 * Carnegie Mellon University
44 * Pittsburgh PA 15213-3890
46 * any improvements or extensions that they make and grant Carnegie Mellon
47 * the rights to redistribute these changes.
50 * (pre-GNU) HISTORY
52 * Revision 2.4 91/05/14 17:53:22 mrt
53 * Correcting copyright
55 * Revision 2.3 91/02/14 14:17:47 mrt
56 * Added new Mach copyright
57 * [91/02/13 12:44:20 mrt]
59 * Revision 2.2 90/08/06 17:23:58 rpd
60 * Created.
65 #include <mach.h>
66 #include <mach/mig_errors.h>
67 #include <stdlib.h> /* For malloc and free. */
68 #include <assert.h>
70 #ifdef NDR_CHAR_ASCII /* OSF Mach flavors have different names. */
71 # define mig_reply_header_t mig_reply_error_t
72 #endif
74 mach_msg_return_t
75 __mach_msg_server_timeout (boolean_t (*demux) (mach_msg_header_t *request,
76 mach_msg_header_t *reply),
77 mach_msg_size_t max_size,
78 mach_port_t rcv_name,
79 mach_msg_option_t option,
80 mach_msg_timeout_t timeout)
82 register mig_reply_header_t *request, *reply;
83 register mach_msg_return_t mr;
85 if (max_size == 0)
87 #ifdef MACH_RCV_LARGE
88 option |= MACH_RCV_LARGE;
89 max_size = 2 * __vm_page_size; /* Generic. Good? XXX */
90 #else
91 max_size = 4 * __vm_page_size; /* XXX */
92 #endif
95 request = __alloca (max_size);
96 reply = __alloca (max_size);
98 while (1)
100 get_request:
101 mr = __mach_msg (&request->Head, MACH_RCV_MSG|option,
102 0, max_size, rcv_name,
103 timeout, MACH_PORT_NULL);
104 while (mr == MACH_MSG_SUCCESS)
106 /* We have a request message.
107 Pass it to DEMUX for processing. */
109 (void) (*demux) (&request->Head, &reply->Head);
110 assert (reply->Head.msgh_size <= max_size);
112 switch (reply->RetCode)
114 case KERN_SUCCESS:
115 /* Hunky dory. */
116 break;
118 case MIG_NO_REPLY:
119 /* The server function wanted no reply sent.
120 Loop for another request. */
121 goto get_request;
123 default:
124 /* Some error; destroy the request message to release any
125 port rights or VM it holds. Don't destroy the reply port
126 right, so we can send an error message. */
127 request->Head.msgh_remote_port = MACH_PORT_NULL;
128 __mach_msg_destroy (&request->Head);
129 break;
132 if (reply->Head.msgh_remote_port == MACH_PORT_NULL)
134 /* No reply port, so destroy the reply. */
135 if (reply->Head.msgh_bits & MACH_MSGH_BITS_COMPLEX)
136 __mach_msg_destroy (&reply->Head);
137 goto get_request;
140 /* Send the reply and the get next request. */
143 /* Swap the request and reply buffers. mach_msg will read the
144 reply message from the buffer we pass and write the new
145 request message to the same buffer. */
146 void *tmp = request;
147 request = reply;
148 reply = tmp;
151 mr = __mach_msg (&request->Head,
152 MACH_SEND_MSG|MACH_RCV_MSG|option,
153 request->Head.msgh_size, max_size, rcv_name,
154 timeout, MACH_PORT_NULL);
157 /* A message error occurred. */
159 switch (mr)
161 case MACH_RCV_TOO_LARGE:
162 #ifdef MACH_RCV_LARGE
163 /* The request message is larger than MAX_SIZE, and has not
164 been dequeued. The message header has the actual size of
165 the message. We recurse here in hopes that the compiler
166 will optimize the tail-call and allocate some more stack
167 space instead of way too much. */
168 return __mach_msg_server_timeout (demux, request->Head.msgh_size,
169 rcv_name, option, timeout);
170 #else
171 /* XXX the kernel has destroyed the msg */
172 break;
173 #endif
175 case MACH_SEND_INVALID_DEST:
176 /* The reply can't be delivered, so destroy it. This error
177 indicates only that the requester went away, so we
178 continue and get the next request. */
179 __mach_msg_destroy (&request->Head);
180 break;
182 default:
183 /* Some other form of lossage; return to caller. */
184 return mr;
188 weak_alias (__mach_msg_server_timeout, mach_msg_server_timeout)
190 mach_msg_return_t
191 __mach_msg_server (demux, max_size, rcv_name)
192 boolean_t (*demux) (mach_msg_header_t *in, mach_msg_header_t *out);
193 mach_msg_size_t max_size;
194 mach_port_t rcv_name;
196 return __mach_msg_server_timeout (demux, max_size, rcv_name,
197 MACH_MSG_OPTION_NONE,
198 MACH_MSG_TIMEOUT_NONE);
200 weak_alias (__mach_msg_server, mach_msg_server)