// SPDX-License-Identifier: GPL-2.0-only
|
/* Timeout API for single-threaded programs that use blocking
|
* syscalls (read/write/send/recv/connect/accept).
|
*
|
* Copyright (C) 2017 Red Hat, Inc.
|
*
|
* Author: Stefan Hajnoczi <stefanha@redhat.com>
|
*/
|
|
/* Use the following pattern:
|
*
|
* timeout_begin(TIMEOUT);
|
* do {
|
* ret = accept(...);
|
* timeout_check("accept");
|
* } while (ret < 0 && ret == EINTR);
|
* timeout_end();
|
*/
|
|
#include <stdlib.h>
|
#include <stdbool.h>
|
#include <unistd.h>
|
#include <stdio.h>
|
#include "timeout.h"
|
|
static volatile bool timeout;
|
|
/* SIGALRM handler function. Do not use sleep(2), alarm(2), or
|
* setitimer(2) while using this API - they may interfere with each
|
* other.
|
*/
|
void sigalrm(int signo)
|
{
|
timeout = true;
|
}
|
|
/* Start a timeout. Call timeout_check() to verify that the timeout hasn't
|
* expired. timeout_end() must be called to stop the timeout. Timeouts cannot
|
* be nested.
|
*/
|
void timeout_begin(unsigned int seconds)
|
{
|
alarm(seconds);
|
}
|
|
/* Exit with an error message if the timeout has expired */
|
void timeout_check(const char *operation)
|
{
|
if (timeout) {
|
fprintf(stderr, "%s timed out\n", operation);
|
exit(EXIT_FAILURE);
|
}
|
}
|
|
/* Stop a timeout */
|
void timeout_end(void)
|
{
|
alarm(0);
|
timeout = false;
|
}
|
