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Diffstat (limited to 'mach/msgserver.c')
| -rw-r--r-- | mach/msgserver.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/mach/msgserver.c b/mach/msgserver.c new file mode 100644 index 0000000..e0dc29b --- /dev/null +++ b/mach/msgserver.c @@ -0,0 +1,194 @@ +/* Copyright (C) 1993, 1994, 1995 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., 675 Mass Ave, +Cambridge, MA 02139, 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 1.3 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. */ + +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); + + 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 dequued. 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 requestor 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_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) |