JUCE  v5.4.1-191-g0ab5e696f
JUCE API
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juce::GenericScopedTryLock< LockType > Class Template Reference

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

#include <juce_ScopedLock.h>

Collaboration diagram for juce::GenericScopedTryLock< LockType >:

Public Member Functions

 GenericScopedTryLock (const LockType &lock, bool acquireLockOnInitialisation=true) noexcept
 Creates a GenericScopedTryLock. More...
 
 ~GenericScopedTryLock () noexcept
 Destructor. More...
 
bool isLocked () const noexcept
 Returns true if the mutex was successfully locked. More...
 
bool retryLock () const noexcept
 Retry gaining the lock by calling tryEnter on the underlying lock. More...
 

Private Attributes

const LockType & lock_
 
bool lockWasSuccessful
 

Detailed Description

template<class LockType>
class juce::GenericScopedTryLock< LockType >

Automatically locks and unlocks a mutex object.

Use one of these as a local variable to provide RAII-based locking of a mutex.

The templated class could be a CriticalSection, SpinLock, or anything else that provides enter() and exit() methods.

e.g.

CriticalSection myCriticalSection;
for (;;)
{
const GenericScopedTryLock<CriticalSection> myScopedTryLock (myCriticalSection);
// Unlike using a ScopedLock, 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 another thread had already locked it..
}
// myCriticalSection gets unlocked here (if it was locked)
}
See also
CriticalSection::tryEnter, GenericScopedLock, GenericScopedUnlock

{Core}

Constructor & Destructor Documentation

◆ GenericScopedTryLock()

template<class LockType >
juce::GenericScopedTryLock< LockType >::GenericScopedTryLock ( const LockType &  lock,
bool  acquireLockOnInitialisation = true 
)
inlineexplicitnoexcept

Creates a GenericScopedTryLock.

If acquireLockOnInitialisation is true then as soon as this ScopedTryLock is created, it will attempt to acquire the lock with tryEnter.

You can retry acquiring the lock by calling retryLock.

When GenericScopedTryLock is deleted, the lock will be released (if the lock was successfully acquired).

Make sure this object is created and deleted 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.

See also
retryLock, isLocked

◆ ~GenericScopedTryLock()

template<class LockType >
juce::GenericScopedTryLock< LockType >::~GenericScopedTryLock ( )
inlinenoexcept

Destructor.

The mutex will be unlocked (if it had been successfully locked) when the destructor is called.

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

References juce::GenericScopedLock< LockType >::lock_.

Member Function Documentation

◆ isLocked()

template<class LockType >
bool juce::GenericScopedTryLock< LockType >::isLocked ( ) const
inlinenoexcept

Returns true if the mutex was successfully locked.

◆ retryLock()

template<class LockType >
bool juce::GenericScopedTryLock< LockType >::retryLock ( ) const
inlinenoexcept

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

References juce::GenericScopedLock< LockType >::lock_.

Member Data Documentation

◆ lock_

template<class LockType >
const LockType& juce::GenericScopedTryLock< LockType >::lock_
private

◆ lockWasSuccessful

template<class LockType >
bool juce::GenericScopedTryLock< LockType >::lockWasSuccessful
mutableprivate

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