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/*
* Copyright (C) 2021 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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 APPLE INC. AND ITS 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 APPLE INC. OR ITS 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 "Timeout.h"
#include <wtf/Lock.h>
#include <wtf/Noncopyable.h>
#include <wtf/Seconds.h>
#if PLATFORM(COCOA)
#include <mach/semaphore.h>
#include <wtf/MachSendRight.h>
#elif OS(WINDOWS)
#include <wtf/win/Win32Handle.h>
#elif USE(UNIX_DOMAIN_SOCKETS)
#include <wtf/unix/UnixFileDescriptor.h>
#endif
namespace IPC {
class Decoder;
class Encoder;
struct EventSignalPair;
std::optional<EventSignalPair> createEventSignalPair();
// A semaphore implementation that can be duplicated across IPC.
// The cocoa implementation of this only interrupts wait calls upon the
// remote process terminating if the Semaphore was created by the remote
// process.
// It is generally preferred to start using IPC::Event/Signal instead
// to avoid this.
class Semaphore {
WTF_MAKE_FAST_ALLOCATED;
WTF_MAKE_NONCOPYABLE(Semaphore);
public:
Semaphore();
Semaphore(Semaphore&&);
~Semaphore();
Semaphore& operator=(Semaphore&&);
void signal();
bool wait();
bool waitFor(Timeout);
#if PLATFORM(COCOA)
explicit Semaphore(MachSendRight&&);
MachSendRight createSendRight() const;
explicit operator bool() const { return m_sendRight || m_semaphore != SEMAPHORE_NULL; }
#elif OS(WINDOWS)
explicit Semaphore(Win32Handle&&);
Win32Handle win32Handle() const { return Win32Handle { m_semaphoreHandle }; }
#elif USE(UNIX_DOMAIN_SOCKETS)
explicit Semaphore(UnixFileDescriptor&&);
UnixFileDescriptor duplicateDescriptor() const;
explicit operator bool() const { return !!m_fd; }
#else
explicit operator bool() const { return true; }
#endif
private:
friend std::optional<EventSignalPair> createEventSignalPair();
void destroy();
#if PLATFORM(COCOA)
MachSendRight m_sendRight;
semaphore_t m_semaphore { SEMAPHORE_NULL };
#elif OS(WINDOWS)
Win32Handle m_semaphoreHandle;
#elif USE(UNIX_DOMAIN_SOCKETS)
UnixFileDescriptor m_fd;
#endif
};
} // namespace IPC
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