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/*
* Copyright (c) 2001-2002 The Trustees of Indiana University.
* All rights reserved.
* Copyright (c) 1998-2001 University of Notre Dame.
* All rights reserved.
* Copyright (c) 1994-1998 The Ohio State University.
* All rights reserved.
*
* This file is part of the LAM/MPI software package. For license
* information, see the LICENSE file in the top level directory of the
* LAM/MPI source distribution.
*
* $HEADER$
*
* $Id: krecv.c,v 6.5 2002/10/29 02:11:39 brbarret Exp $
*
* Function: - kernel message receive
*/
#include <errno.h>
#include <kio.h>
#include <kreq.h>
#include <portable.h>
#include <terror.h>
#include <typical.h>
/*
* external variables
*/
extern struct kio_t _kio; /* kernel I/O block */
/*
* external functions
*/
extern int _cipc_krecvback(); /* ITB/OTB msg recv */
extern int _cipc_krecvfront(); /* ITB/OTB msg recv */
extern void _ksig_follow(); /* check signals */
/*
* krecv
*
* Function: - receives a message from another process
* - retries kernel request after signal interruption
* or transfer timeout
* Accepts: - kernel message descriptor ptr
* Returns: - 0 or ERROR
*/
int
krecv(struct kmsg *pkmsg)
{
int4 r;
/*
* Loop through possible signal interruptions.
*/
do {
if (krecvfront(pkmsg) < 0) {
return(LAMERROR);
}
r = krecvback(pkmsg);
} while ((r > 0) && ((r & _kio.ki_sigretry) == r));
if (r > 0) {
errno = EINTR;
return(LAMERROR);
} else if (r < 0) {
return(LAMERROR);
}
return(0);
}
/*
* krecvfront
*
* Function: - request portion of kernel message receive
* Accepts: - kernel message descriptor ptr
* Returns: - kernel-client socket descriptor or ERROR
*/
int
krecvfront(struct kmsg *pkmsg)
{
struct kreq req; /* kernel request */
/*
* Formulate the KQRECV request.
*/
LAM_ZERO_ME(req);
req.kq_req = KQRECV;
req.kq_index = _kio.ki_index;
req.kq_msg.k_event = pkmsg->k_event;
req.kq_msg.k_type = pkmsg->k_type;
req.kq_msg.k_flags = pkmsg->k_flags;
req.kq_msg.k_length = pkmsg->k_length;
req.kq_msg.k_msg = pkmsg->k_msg;
return(_cipc_krecvfront(&req));
}
/*
* krecvback
*
* Function: - reply portion of kernel message receive
* Accepts: - kernel message descriptor ptr
* Returns: - signal if request was interrupted
* - 0 or ERROR or signal
*/
int4
krecvback(struct kmsg *pkmsg)
{
struct kreq req; /* kernel request */
struct kreply reply; /* kernel reply */
req.kq_msg.k_flags = pkmsg->k_flags;
req.kq_msg.k_msg = pkmsg->k_msg;
if (_cipc_krecvback(&req, &reply)) {
return(LAMERROR);
}
if (pkmsg->k_flags & KTRACE) {
_kio.ki_blktime += reply.kr_blktime;
}
if (reply.kr_signal) {
_kio.ki_signal |= reply.kr_signal;
_ksig_follow();
if (reply.kr_reply == EINTR) {
errno = EINTR;
return(reply.kr_signal);
}
}
if (reply.kr_reply) {
errno = reply.kr_reply;
return(LAMERROR);
}
pkmsg->k_type = reply.kr_type;
pkmsg->k_length = reply.kr_length;
return(0);
}
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