platform_bionic/libc/private/bionic_fdtrack.h
Adam Barth 651f1fa509 Make the atomic load explicit
Technically, std::atomic does not have an operator(). Previously, this
code was relying on an implicit behavior of our C++ standard library in
order to compile. When compiling this code against a different C++
standard library, I encountered a compiler error on these lines.

This CL makes the std::atomic load() operation explicit, makes it
clearer what this code is actually doing and makes it conform better to
the C++ standard library spec rather than a particular implmentation.

Change-Id: I7f255dffc0a3d8e07c973c18e9ba4098c4b5843e
2021-01-08 01:21:52 +00:00

95 lines
4.7 KiB
C

/*
* Copyright (C) 2019 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.
*/
#pragma once
#include <sys/cdefs.h>
#include <stdatomic.h>
#include "platform/bionic/fdtrack.h"
#include "bionic/pthread_internal.h"
#include "private/bionic_tls.h"
#include "private/ErrnoRestorer.h"
extern "C" _Atomic(android_fdtrack_hook_t) __android_fdtrack_hook;
// Macro to record file descriptor creation.
// e.g.:
// int socket(int domain, int type, int protocol) {
// return FDTRACK_CREATE_NAME("socket", __socket(domain, type, protocol));
// }
#define FDTRACK_CREATE_NAME(name, fd_value) \
({ \
int __fd = (fd_value); \
if (__fd != -1 && __predict_false(__android_fdtrack_hook) && \
!__predict_false(__get_thread()->is_vforked())) { \
bionic_tls& tls = __get_bionic_tls(); \
/* fdtrack_disabled is only true during reentrant calls. */ \
if (!__predict_false(tls.fdtrack_disabled)) { \
ErrnoRestorer r; \
tls.fdtrack_disabled = true; \
android_fdtrack_event event; \
event.fd = __fd; \
event.type = ANDROID_FDTRACK_EVENT_TYPE_CREATE; \
event.data.create.function_name = name; \
atomic_load(&__android_fdtrack_hook)(&event); \
tls.fdtrack_disabled = false; \
} \
} \
__fd; \
})
// Macro to record file descriptor creation, with the current function's name.
// e.g.:
// int socket(int domain, int type, int protocol) {
// return FDTRACK_CREATE_NAME(__socket(domain, type, protocol));
// }
#define FDTRACK_CREATE(fd_value) FDTRACK_CREATE_NAME(__func__, (fd_value))
// Macro to record file descriptor closure.
// Note that this does not actually close the file descriptor.
#define FDTRACK_CLOSE(fd_value) \
({ \
int __fd = (fd_value); \
if (__fd != -1 && __predict_false(__android_fdtrack_hook) && \
!__predict_false(__get_thread()->is_vforked())) { \
bionic_tls& tls = __get_bionic_tls(); \
if (!__predict_false(tls.fdtrack_disabled)) { \
int saved_errno = errno; \
tls.fdtrack_disabled = true; \
android_fdtrack_event event; \
event.fd = __fd; \
event.type = ANDROID_FDTRACK_EVENT_TYPE_CLOSE; \
atomic_load(&__android_fdtrack_hook)(&event); \
tls.fdtrack_disabled = false; \
errno = saved_errno; \
} \
} \
__fd; \
})