platform_bionic/libc/bionic/fork.cpp
Elliott Hughes 36d6188f8c Clean up forking and cloning.
The kernel now maintains the pthread_internal_t::tid field for us,
and __clone was only used in one place so let's inline it so we don't
have to leave such a dangerous function lying around. Also rename
files to match their content and remove some useless #includes.

Change-Id: I24299fb4a940e394de75f864ee36fdabbd9438f9
2013-11-19 14:08:54 -08:00

57 lines
2.3 KiB
C++

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <unistd.h>
#include <sys/syscall.h>
#include "private/libc_logging.h"
#include "pthread_internal.h"
int fork() {
// POSIX mandates that the timers of a fork child process be
// disarmed, but not destroyed. To avoid a race condition, we're
// going to stop all timers now, and only re-start them in case
// of error, or in the parent process
__timer_table_start_stop(1);
__bionic_atfork_run_prepare();
pthread_internal_t* self = __get_thread();
int flags = CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | SIGCHLD;
#if defined(__x86_64__) // sys_clone's last two arguments are flipped on x86-64.
int result = syscall(__NR_clone, flags, NULL, NULL, &(self->tid), NULL);
#else
int result = syscall(__NR_clone, flags, NULL, NULL, NULL, &(self->tid));
#endif
if (result == 0) {
__bionic_atfork_run_child();
} else {
__timer_table_start_stop(0);
__bionic_atfork_run_parent();
}
return result;
}