There are many places in the code base where we ignore the return value of fcntl() when getting/setting file descriptior flags. This patch introduces a convenience function that allows setting or clearing file descriptor flags and will also log an error on failure for later analysis. Change-Id: I8b81901e1b1bd537ca632567cdb408931c6eded7
158 lines
3.2 KiB
C
158 lines
3.2 KiB
C
/*
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* Asterisk -- An open source telephony toolkit.
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*
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* Copyright (C) 2017, Sean Bright
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*
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* Sean Bright <sean.bright@gmail.com>
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*
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* See http://www.asterisk.org for more information about
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* the Asterisk project. Please do not directly contact
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* any of the maintainers of this project for assistance;
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* the project provides a web site, mailing lists and IRC
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* channels for your use.
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License Version 2. See the LICENSE file
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* at the top of the source tree.
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*/
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/*! \file
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*
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* \brief Alert Pipe API
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*
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* \author Sean Bright
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*/
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#include "asterisk.h"
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#include <unistd.h>
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#include <fcntl.h>
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#ifdef HAVE_EVENTFD
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# include <sys/eventfd.h>
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#endif
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#include "asterisk/alertpipe.h"
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#include "asterisk/logger.h"
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int ast_alertpipe_init(int alert_pipe[2])
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{
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#ifdef HAVE_EVENTFD
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int fd = eventfd(0, EFD_NONBLOCK | EFD_SEMAPHORE);
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if (fd > -1) {
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alert_pipe[0] = alert_pipe[1] = fd;
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return 0;
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}
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ast_log(LOG_WARNING, "Failed to create alert pipe with eventfd(), falling back to pipe(): %s\n",
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strerror(errno));
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ast_alertpipe_clear(alert_pipe);
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#endif
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if (pipe(alert_pipe)) {
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ast_log(LOG_WARNING, "Failed to create alert pipe: %s\n", strerror(errno));
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return -1;
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} else {
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if (ast_fd_set_flags(alert_pipe[0], O_NONBLOCK)
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|| ast_fd_set_flags(alert_pipe[1], O_NONBLOCK)) {
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ast_alertpipe_close(alert_pipe);
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return -1;
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}
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}
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return 0;
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}
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void ast_alertpipe_close(int alert_pipe[2])
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{
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#ifdef HAVE_EVENTFD
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if (alert_pipe[0] == alert_pipe[1]) {
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if (alert_pipe[0] > -1) {
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close(alert_pipe[0]);
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ast_alertpipe_clear(alert_pipe);
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}
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return;
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}
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#endif
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if (alert_pipe[0] > -1) {
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close(alert_pipe[0]);
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}
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if (alert_pipe[1] > -1) {
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close(alert_pipe[1]);
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}
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ast_alertpipe_clear(alert_pipe);
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}
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ast_alert_status_t ast_alertpipe_read(int alert_pipe[2])
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{
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uint64_t tmp;
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if (!ast_alertpipe_readable(alert_pipe)) {
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return AST_ALERT_NOT_READABLE;
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}
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if (read(alert_pipe[0], &tmp, sizeof(tmp)) < 0) {
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if (errno != EINTR && errno != EAGAIN) {
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ast_log(LOG_WARNING, "read() failed: %s\n", strerror(errno));
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return AST_ALERT_READ_FAIL;
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}
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}
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return AST_ALERT_READ_SUCCESS;
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}
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ssize_t ast_alertpipe_write(int alert_pipe[2])
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{
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uint64_t tmp = 1;
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if (!ast_alertpipe_writable(alert_pipe)) {
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errno = EBADF;
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return 0;
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}
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/* preset errno in case returned size does not match */
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errno = EPIPE;
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return write(alert_pipe[1], &tmp, sizeof(tmp)) != sizeof(tmp);
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}
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ast_alert_status_t ast_alertpipe_flush(int alert_pipe[2])
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{
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int bytes_read;
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uint64_t tmp[16];
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if (!ast_alertpipe_readable(alert_pipe)) {
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return AST_ALERT_NOT_READABLE;
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}
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/* Read the alertpipe until it is exhausted. */
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for (;;) {
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bytes_read = read(alert_pipe[0], tmp, sizeof(tmp));
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if (bytes_read < 0) {
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if (errno == EINTR) {
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continue;
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}
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if (errno == EAGAIN || errno == EWOULDBLOCK) {
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/*
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* Would block so nothing left to read.
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* This is the normal loop exit.
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*/
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break;
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}
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ast_log(LOG_WARNING, "read() failed flushing alertpipe: %s\n",
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strerror(errno));
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return AST_ALERT_READ_FAIL;
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}
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if (!bytes_read) {
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/* Read nothing so we are done */
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break;
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}
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}
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return AST_ALERT_READ_SUCCESS;
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}
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