1/* 2 * Copyright (c) 2008 The Hewlett-Packard Development Company 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Nathan Binkert 29 */ 30 31#ifndef __BASE_ATOMICIO_HH__ 32#define __BASE_ATOMICIO_HH__ 33 34#include <unistd.h> 35 36// These functions keep reading/writing, if possible, until all data 37// has been transferred. Basically, try again when there's no error, 38// but there is data left also retry on EINTR. 39// This function blocks until it is done. 40 41ssize_t atomic_read(int fd, void *s, size_t n); 42ssize_t atomic_write(int fd, const void *s, size_t n); 43 44/** 45 * Statically allocate a string and write it to a file descriptor. 46 * 47 * @warning The return value will from atomic_write will be ignored 48 * which means that errors will be ignored. This is normally fine as 49 * this macro is intended to be used in fatal signal handlers where 50 * error handling might not be feasible. 51 */ 52#define STATIC_MSG(fd, m) \ 53 do { \ 54 static const char msg[] = m; \ 55 atomic_write(fd, msg, sizeof(msg) - 1); \ 56 } while (0) 57 58/** 59 * Statically allocate a string and write it to STDERR. 60 * 61 * @warning The return value will from atomic_write will be ignored 62 * which means that errors will be ignored. This is normally fine as 63 * this macro is intended to be used in fatal signal handlers where 64 * error handling might not be feasible. 65 */ 66#define STATIC_ERR(m) STATIC_MSG(STDERR_FILENO, m) 67 68#endif // __BASE_ATOMICIO_HH__ 69