122 lines
4.4 KiB
C++
122 lines
4.4 KiB
C++
/*
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==============================================================================
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This file is part of the JUCE library.
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Copyright (c) 2017 - ROLI Ltd.
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JUCE is an open source library subject to commercial or open-source
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licensing.
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The code included in this file is provided under the terms of the ISC license
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http://www.isc.org/downloads/software-support-policy/isc-license. Permission
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To use, copy, modify, and/or distribute this software for any purpose with or
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without fee is hereby granted provided that the above copyright notice and
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this permission notice appear in all copies.
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JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
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EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
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DISCLAIMED.
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==============================================================================
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*/
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namespace juce
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{
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//==============================================================================
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/**
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Acts as a critical section which processes can use to block each other.
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@see CriticalSection
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@tags{Core}
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*/
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class JUCE_API InterProcessLock
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{
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public:
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//==============================================================================
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/** Creates a lock object.
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@param name a name that processes will use to identify this lock object
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*/
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explicit InterProcessLock (const String& name);
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/** Destructor.
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This will also release the lock if it's currently held by this process.
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*/
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~InterProcessLock();
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//==============================================================================
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/** Attempts to lock the critical section.
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@param timeOutMillisecs how many milliseconds to wait if the lock is already
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held by another process - a value of 0 will return
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immediately, negative values will wait forever
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@returns true if the lock could be gained within the timeout period, or
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false if the timeout expired.
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*/
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bool enter (int timeOutMillisecs = -1);
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/** Releases the lock if it's currently held by this process. */
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void exit();
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//==============================================================================
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/**
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Automatically locks and unlocks an InterProcessLock object.
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This works like a ScopedLock, but using an InterprocessLock rather than
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a CriticalSection.
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@see ScopedLock
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*/
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class ScopedLockType
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{
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public:
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//==============================================================================
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/** Creates a scoped lock.
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As soon as it is created, this will lock the InterProcessLock, and
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when the ScopedLockType object is deleted, the InterProcessLock will
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be unlocked.
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Note that since an InterprocessLock can fail due to errors, you should check
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isLocked() to make sure that the lock was successful before using it.
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Make sure this object is created and deleted by the same thread,
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otherwise there are no guarantees what will happen! Best just to use it
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as a local stack object, rather than creating one with the new() operator.
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*/
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explicit ScopedLockType (InterProcessLock& l) : ipLock (l) { lockWasSuccessful = l.enter(); }
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/** Destructor.
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The InterProcessLock will be unlocked when the destructor is called.
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Make sure this object is created and deleted by the same thread,
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otherwise there are no guarantees what will happen!
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*/
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inline ~ScopedLockType() { ipLock.exit(); }
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/** Returns true if the InterProcessLock was successfully locked. */
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bool isLocked() const noexcept { return lockWasSuccessful; }
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private:
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//==============================================================================
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InterProcessLock& ipLock;
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bool lockWasSuccessful;
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JUCE_DECLARE_NON_COPYABLE (ScopedLockType)
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};
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private:
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//==============================================================================
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class Pimpl;
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std::unique_ptr<Pimpl> pimpl;
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CriticalSection lock;
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String name;
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JUCE_DECLARE_NON_COPYABLE (InterProcessLock)
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};
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} // namespace juce
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