DtThreadSafe< T > Class Template Reference

a thread safe interface to a value. More...

Inheritance diagram for DtThreadSafe< T >:

Collaboration diagram for DtThreadSafe< T >:

Classes
class	ConstLockedProxy
	Private class that provides a locked call to the const object. More...
class	LockedProxy
	Private class that provides a locked call to the object. More...
class	SequenceLockImpl
	Private class which implements the Sequence lock. More...

Public Member Functions
	DtThreadSafe (const T &value)
	DtThreadSafe ()
	operator T () const
	Proxy type copy operator.
LockedProxy	operator-> ()
	Proxy pointer access operator.
ConstLockedProxy	operator-> () const
	Proxy pointer access operator.
DtThreadSafe< T > &	operator= (const DtThreadSafe< T > &orig)
	Locked Copy operator,.
DtThreadSafe< T > &	operator= (const T &orig)
	Locked Copy operator, from safe value.
DtScopedSequenceLock	sequenceLock ()
	Request a sequence lock, this object will maintain a lock on the object during it's life-time.

Protected Member Functions
void	lockObject ()
	Lock the external object.
void	unlockObject ()
	Unlock the external object.

Protected Attributes
T	myValue
	Value which is to be thread safe.
DtScopedLock *	myExternalLock
	The external lock which allows the sequence lock.
DtMutex	myLockMutex
	The mutex which is used to lock when created the external lock.
DtMutex	myMutex
	The mutex which is used to make the object thread safe.

Friends
class	SequenceLockImpl

Detailed Description

template<typename T>
class DtThreadSafe< T >

a thread safe interface to a value.

Which can be shared between threads. DtThreadSafe provides a safe access to T value. T is assumed to have value semantics and is copyable. DtThreadSafe provides a locked pointer to the underlying value interface.

Warning

Thread safety is only assumed for the duration a single call. Any references, pointers or proxy objects returns (for example iterators) are not thread safe.

Example: Thread safe iteration.

DtThreadSafe<std::vector<int> > aVector;
...
{
   DtScopedSequenceLock lock = aVector.sequenceLock();
   std::vector<int>::iterator start = aVector->begin();
   std::vector<int>::iterator end   = aVector->end();
   for(;start != end;++start)
   {
      //Now all access to iterator is considered thread safe due to 
      *start = 0;
   }
}

Constructor & Destructor Documentation

template<typename T>

DtThreadSafe< T >::DtThreadSafe ( const T &  value )

explicit

template<typename T>

DtThreadSafe< T >::DtThreadSafe ( )

explicit

Member Function Documentation

template<typename T>

void DtThreadSafe< T >::lockObject ( )

protected

Lock the external object.

template<typename T>

DtThreadSafe< T >::operator T

(

)

const

Proxy type copy operator.

template<typename T>

LockedProxy DtThreadSafe< T >::operator->

(

)

Proxy pointer access operator.

The locked proxy will maintain a lock for the call (typically and the line).

template<typename T>

ConstLockedProxy DtThreadSafe< T >::operator->

(

)

const

Proxy pointer access operator.

The locked proxy will maintain a lock for the call (typically and the line).

template<typename T>

DtThreadSafe<T>& DtThreadSafe< T >::operator=

(

const DtThreadSafe< T > &

orig

)

Locked Copy operator,.

template<typename T>

DtThreadSafe<T>& DtThreadSafe< T >::operator=

(

const T &

orig

)

Locked Copy operator, from safe value.

template<typename T>

DtScopedSequenceLock DtThreadSafe< T >::sequenceLock

(

)

Request a sequence lock, this object will maintain a lock on the object during it's life-time.

Note: this is fairly expensive and should be called sparingly.

template<typename T>

void DtThreadSafe< T >::unlockObject ( )

protected

Unlock the external object.

Friends And Related Function Documentation

template<typename T>

friend class SequenceLockImpl

friend

Member Data Documentation

template<typename T>

DtScopedLock* DtThreadSafe< T >::myExternalLock

protected

The external lock which allows the sequence lock.

This lock is not used unless a sequence is requested.

template<typename T>

DtMutex DtThreadSafe< T >::myLockMutex

protected

The mutex which is used to lock when created the external lock.

template<typename T>

DtMutex DtThreadSafe< T >::myMutex

mutableprotected

The mutex which is used to make the object thread safe.

template<typename T>

T DtThreadSafe< T >::myValue

protected

Value which is to be thread safe.

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

• vlThreadSafe.h