Files
mpd/src/thread/Id.hxx
Max Kellermann 96707c0426 Merge tag 'v0.22.7'
release v0.22.7
2021-05-19 18:43:19 +02:00

110 lines
2.8 KiB
C++

/*
* Copyright 2013-2021 Max Kellermann <max.kellermann@gmail.com>
*
* 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
* FOUNDATION 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.
*/
#ifndef THREAD_ID_HXX
#define THREAD_ID_HXX
#include "util/Compiler.h"
#ifdef _WIN32
#include <processthreadsapi.h>
#else
#include <pthread.h>
#endif
/**
* A low-level identification for a thread. Designed to work with
* existing threads, such as the main thread. Mostly useful for
* debugging code.
*/
class ThreadId {
#ifdef _WIN32
DWORD id;
#else
pthread_t id;
#endif
public:
/**
* No initialisation.
*/
ThreadId() noexcept = default;
#ifdef _WIN32
constexpr ThreadId(DWORD _id) noexcept:id(_id) {}
#else
constexpr ThreadId(pthread_t _id) noexcept:id(_id) {}
#endif
static constexpr ThreadId Null() noexcept {
#ifdef _WIN32
return 0;
#else
return pthread_t();
#endif
}
gcc_pure
bool IsNull() const noexcept {
return *this == Null();
}
/**
* Return the current thread's id .
*/
gcc_pure
static const ThreadId GetCurrent() noexcept {
#ifdef _WIN32
return ::GetCurrentThreadId();
#else
return pthread_self();
#endif
}
gcc_pure
bool operator==(const ThreadId &other) const noexcept {
/* note: not using pthread_equal() because that
function "is undefined if either thread ID is not
valid so we can't safely use it on
default-constructed values" (comment from
libstdc++) - and if both libstdc++ and libc++ get
away with this, we can do it as well */
return id == other.id;
}
/**
* Check if this thread is the current thread.
*/
bool IsInside() const noexcept {
return *this == GetCurrent();
}
};
#endif