94 lines
2.6 KiB
C
94 lines
2.6 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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/***
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This file is part of systemd.
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Copyright 2013 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <pthread.h>
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#include <unistd.h>
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#include "async.h"
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#include "fd-util.h"
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#include "log.h"
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#include "util.h"
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int asynchronous_job(void* (*func)(void *p), void *arg) {
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pthread_attr_t a;
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pthread_t t;
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int r;
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/* It kinda sucks that we have to resort to threads to
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* implement an asynchronous sync(), but well, such is
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* life.
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*
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* Note that issuing this command right before exiting a
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* process will cause the process to wait for the sync() to
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* complete. This function hence is nicely asynchronous really
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* only in long running processes. */
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r = pthread_attr_init(&a);
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if (r > 0)
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return -r;
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r = pthread_attr_setdetachstate(&a, PTHREAD_CREATE_DETACHED);
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if (r > 0)
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goto finish;
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r = pthread_create(&t, &a, func, arg);
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finish:
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pthread_attr_destroy(&a);
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return -r;
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}
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static void *sync_thread(void *p) {
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sync();
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return NULL;
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}
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int asynchronous_sync(void) {
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log_debug("Spawning new thread for sync");
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return asynchronous_job(sync_thread, NULL);
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}
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static void *close_thread(void *p) {
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assert_se(close_nointr(PTR_TO_INT(p)) != -EBADF);
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return NULL;
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}
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int asynchronous_close(int fd) {
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int r;
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/* This is supposed to behave similar to safe_close(), but
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* actually invoke close() asynchronously, so that it will
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* never block. Ideally the kernel would have an API for this,
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* but it doesn't, so we work around it, and hide this as a
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* far away as we can. */
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if (fd >= 0) {
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PROTECT_ERRNO;
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r = asynchronous_job(close_thread, INT_TO_PTR(fd));
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if (r < 0)
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assert_se(close_nointr(fd) != -EBADF);
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}
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return -1;
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}
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