juce::ScopedTryReadLock Class Reference

Automatically locks and unlocks a ReadWriteLock object. More...

#include <juce_ScopedReadLock.h>

Collaboration diagram for juce::ScopedTryReadLock:

Public Member Functions
	ScopedTryReadLock (ReadWriteLock &lockIn)
	Creates a ScopedTryReadLock and calls ReadWriteLock::tryEnterRead() as soon as it is created.
	ScopedTryReadLock (ReadWriteLock &lockIn, bool acquireLockOnInitialisation) noexcept
	Creates a ScopedTryReadLock.
	~ScopedTryReadLock () noexcept
	Destructor.
bool	isLocked () const noexcept
	Returns true if the mutex was successfully locked.
bool	retryLock () noexcept
	Retry gaining the lock by calling tryEnter on the underlying lock.

Private Attributes
ReadWriteLock &	lock
bool	lockWasSuccessful

Detailed Description

Automatically locks and unlocks a ReadWriteLock object.

Use one of these as a local variable to control access to a ReadWriteLock.

e.g.

ReadWriteLock myLock;
 
for (;;)
{
    const ScopedTryReadLock myScopedTryLock (myLock);
 
    // Unlike using a ScopedReadLock, this may fail to actually get the lock, so you
    // should test this with the isLocked() method before doing your thread-unsafe
    // action.
 
    if (myScopedTryLock.isLocked())
    {
        ...do some stuff...
    }
    else
    {
        ..our attempt at locking failed because a write lock has already been issued..
    }
 
    // myLock gets unlocked here (if it was locked).
}

See also

ReadWriteLock, ScopedTryWriteLock

@tags{Core}

Constructor & Destructor Documentation

ScopedTryReadLock() [1/2]

juce::ScopedTryReadLock::ScopedTryReadLock ( ReadWriteLock &  lockIn )

inlineexplicit

Creates a ScopedTryReadLock and calls ReadWriteLock::tryEnterRead() as soon as it is created.

When the ScopedTryReadLock object is destructed, the ReadWriteLock will be unlocked (if it was successfully acquired).

Make sure this object is created and destructed by the same thread, otherwise there are no guarantees what will happen! Best just to use it as a local stack object, rather than creating one with the new() operator.

ScopedTryReadLock() [2/2]

juce::ScopedTryReadLock::ScopedTryReadLock ( ReadWriteLock &  lockIn, bool  acquireLockOnInitialisation  )

inlinenoexcept

Creates a ScopedTryReadLock.

If acquireLockOnInitialisation is true then as soon as it is created, this will call ReadWriteLock::tryEnterRead(), and when the ScopedTryReadLock object is destructed, the ReadWriteLock will be unlocked (if it was successfully acquired).

Make sure this object is created and destructed by the same thread, otherwise there are no guarantees what will happen! Best just to use it as a local stack object, rather than creating one with the new() operator.

~ScopedTryReadLock()

juce::ScopedTryReadLock::~ScopedTryReadLock ( )

inlinenoexcept

Destructor.

The ReadWriteLock's exitRead() method will be called when the destructor is called.

Make sure this object is created and destructed by the same thread, otherwise there are no guarantees what will happen!

Member Function Documentation

isLocked()

bool juce::ScopedTryReadLock::isLocked ( ) const

inlinenoexcept

Returns true if the mutex was successfully locked.

retryLock()

bool juce::ScopedTryReadLock::retryLock ( )

inlinenoexcept

Retry gaining the lock by calling tryEnter on the underlying lock.

Member Data Documentation

lock

ReadWriteLock& juce::ScopedTryReadLock::lock

private

lockWasSuccessful

bool juce::ScopedTryReadLock::lockWasSuccessful

private

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The documentation for this class was generated from the following file:

• juce_ScopedReadLock.h