From 76cf10dab7a36653a159f0e87c46a13df494474f Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Mon, 5 May 2014 21:18:34 +0200 Subject: build-sys: move async.[ch] to src/shared So that we can use it at multiple places. --- src/shared/async.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ src/shared/async.h | 27 ++++++++++++++++ 2 files changed, 121 insertions(+) create mode 100644 src/shared/async.c create mode 100644 src/shared/async.h (limited to 'src/shared') diff --git a/src/shared/async.c b/src/shared/async.c new file mode 100644 index 0000000000..3876deda70 --- /dev/null +++ b/src/shared/async.c @@ -0,0 +1,94 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2013 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see . +***/ + +#include +#include + +#include "async.h" +#include "log.h" +#include "util.h" + +int asynchronous_job(void* (*func)(void *p), void *arg) { + pthread_attr_t a; + pthread_t t; + int r; + + /* It kinda sucks that we have to resort to threads to + * implement an asynchronous sync(), but well, such is + * life. + * + * Note that issuing this command right before exiting a + * process will cause the process to wait for the sync() to + * complete. This function hence is nicely asynchronous really + * only in long running processes. */ + + r = pthread_attr_init(&a); + if (r != 0) + return -r; + + r = pthread_attr_setdetachstate(&a, PTHREAD_CREATE_DETACHED); + if (r != 0) { + r = -r; + goto finish; + } + + r = pthread_create(&t, &a, func, arg); + if (r != 0) { + r = -r; + goto finish; + } + +finish: + pthread_attr_destroy(&a); + return r; +} + +static void *sync_thread(void *p) { + sync(); + return NULL; +} + +int asynchronous_sync(void) { + log_debug("Spawning new thread for sync"); + + return asynchronous_job(sync_thread, NULL); +} + +static void *close_thread(void *p) { + safe_close(PTR_TO_INT(p)); + return NULL; +} + +int asynchronous_close(int fd) { + int r; + + /* This is supposed to behave similar to safe_close(), but + * actually invoke close() asynchronously, so that it will + * never block. Ideally the kernel would have an API for this, + * but it doesn't, so we work around it, and hide this as a + * far away as we can. */ + + r = asynchronous_job(close_thread, INT_TO_PTR(fd)); + if (r < 0) + safe_close(fd); + + return -1; +} diff --git a/src/shared/async.h b/src/shared/async.h new file mode 100644 index 0000000000..7f1ef79532 --- /dev/null +++ b/src/shared/async.h @@ -0,0 +1,27 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + This file is part of systemd. + + Copyright 2013 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see . +***/ + +int asynchronous_job(void* (*func)(void *p), void *arg); + +int asynchronous_sync(void); +int asynchronous_close(int fd); -- cgit v1.2.3-54-g00ecf