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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879// 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 <time.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. * * If you need to sleep, please use timeout_sleep() provided by this API. */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;}
/* Sleep in a timeout section. * * nanosleep(2) can be used with this API since POSIX.1 explicitly * specifies that it does not interact with signals. */int timeout_usleep(useconds_t usec){ struct timespec ts = { .tv_sec = usec / 1000000, .tv_nsec = (usec % 1000000) * 1000, };
return nanosleep(&ts, NULL);}