platform_bionic/libc/bionic/getpid.cpp
Josh Gao f6e5b58260 Introduce api to track fd ownership in libc.
Add two functions to allow objects that own a file descriptor to
enforce that only they can close their file descriptor.

Use them in FILE* and DIR*.

Bug: http://b/110100358
Test: bionic_unit_tests
Test: aosp/master boots without errors
Test: treehugger
Change-Id: Iecd6e8b26c62217271e0822dc3d2d7888b091a45
2018-07-19 14:28:54 -07:00

55 lines
2 KiB
C++

/*
* Copyright (C) 2014 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 "pthread_internal.h"
extern "C" pid_t __getpid();
pid_t __get_cached_pid() {
pthread_internal_t* self = __get_thread();
if (__predict_true(self)) {
pid_t cached_pid;
if (__predict_true(self->get_cached_pid(&cached_pid))) {
return cached_pid;
}
}
return 0;
}
pid_t getpid() {
pid_t cached_pid = __get_cached_pid();
if (__predict_true(cached_pid != 0)) {
return cached_pid;
}
// We're still in the dynamic linker or we're in the middle of forking, so ask the kernel.
// We don't know whether it's safe to update the cached value, so don't try.
return __getpid();
}