70 lines
2.2 KiB
C
70 lines
2.2 KiB
C
/* $OpenBSD: atomicio.c,v 1.9 2007/09/07 14:50:44 tobias Exp $ */
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/*
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* Copyright (c) 2006 Damien Miller. All rights reserved.
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* Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
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* Copyright (c) 1995,1999 Theo de Raadt. All rights reserved.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/param.h>
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#include <errno.h>
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#include <poll.h>
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#include <unistd.h>
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#include "atomicio.h"
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/*
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* ensure all of data on socket comes through. f==read || f==vwrite
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*/
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size_t
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atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
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{
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char *s = _s;
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size_t pos = 0;
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ssize_t res;
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struct pollfd pfd;
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pfd.fd = fd;
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pfd.events = f == read ? POLLIN : POLLOUT;
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while (n > pos) {
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res = (f) (fd, s + pos, n - pos);
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switch (res) {
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case -1:
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if (errno == EINTR)
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continue;
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if (errno == EAGAIN) {
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(void)poll(&pfd, 1, -1);
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continue;
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}
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return 0;
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case 0:
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errno = EPIPE;
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return pos;
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default:
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pos += (size_t)res;
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}
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}
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return (pos);
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}
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