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/* $OpenBSD: atomicio.c,v 1.4 2012/12/04 02:24:47 deraadt 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 <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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} |