juce_CriticalSection.h File Reference

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Classes
class	CriticalSection
class	DummyCriticalSection
struct	DummyCriticalSection::ScopedLockType

Macros
#define	JUCE_CRITICALSECTION_H_INCLUDED

Typedefs
typedef CriticalSection::ScopedLockType	ScopedLock
typedef CriticalSection::ScopedUnlockType	ScopedUnlock
typedef CriticalSection::ScopedTryLockType	ScopedTryLock

Macro Definition Documentation

JUCE_CRITICALSECTION_H_INCLUDED

#define JUCE_CRITICALSECTION_H_INCLUDED

Typedef Documentation

ScopedLock

typedef CriticalSection::ScopedLockType ScopedLock

Automatically locks and unlocks a CriticalSection object.

You can use a ScopedLock as a local variable to provide RAII-based locking of a CriticalSection.

e.g.

struct MyObject
{
    CriticalSection objectLock;

    // assuming that this example function will be called by multiple threads
    void foo()
    {
        const ScopedLock myScopedLock (objectLock);

        // objectLock is now locked..

        ...do some thread-safe work here...

        // ..and objectLock gets unlocked here, as myScopedLock goes out of
        // scope at the end of the block
    }
};

See also

CriticalSection, ScopedUnlock

ScopedTryLock

typedef CriticalSection::ScopedTryLockType ScopedTryLock

Automatically tries to lock and unlock a CriticalSection object.

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

e.g.

struct MyObject
{
    CriticalSection objectLock;

    void foo()
    {
        const ScopedTryLock myScopedTryLock (objectLock);

        // Unlike using a ScopedLock, this may fail to actually get the lock, so you
        // must call the isLocked() method before making any assumptions..
        if (myScopedTryLock.isLocked())
        {
           ...safely do some work...
        }
        else
        {
            // If we get here, then our attempt at locking failed because another thread had already locked it..
        }
    }
};

See also

CriticalSection::tryEnter, ScopedLock, ScopedUnlock, ScopedReadLock

ScopedUnlock

typedef CriticalSection::ScopedUnlockType ScopedUnlock

Automatically unlocks and re-locks a CriticalSection object.

This is the reverse of a ScopedLock object - instead of locking the critical section for the lifetime of this object, it unlocks it.

Make sure you don't try to unlock critical sections that aren't actually locked!

e.g.

struct MyObject
{
    CriticalSection objectLock;

    void foo()
    {
        {
            const ScopedLock myScopedLock (objectLock);

            // objectLock is now locked..

            {
                ScopedUnlock myUnlocker (objectLock);

                // ..and now unlocked..
            }

            // ..and now locked again..
        }

        // ..and finally unlocked.
    }
};

See also

CriticalSection, ScopedLock