itk::ConditionVariable Class Reference

#include <itkConditionVariable.h>

Inheritance diagram for itk::ConditionVariable:

[legend]Collaboration diagram for itk::ConditionVariable:

[legend]List of all members.

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Detailed Description

A thread synchronization object used to suspend execution until some condition on shared data is met.

A thread calls Wait() to suspend its execution until the condition is met. Each call to Signal() from an executing thread will then cause a single waiting thread to be released. A call to Signal() means, "signal that the condition is true." Broadcast() releases all threads waiting on the condition variable.

The ITK ConditionVariable implementation is consistent with the standard definition and use of condition variables in pthreads and other common thread libraries.

IMPORTANT: A condition variable always requires an associated SimpleMutexLock object. The mutex object is used to avoid a dangerous race condition when Wait() and Signal() are called simultaneously from two different threads.

On systems using pthreads, this implementation abstract the standard calls to the pthread condition variable. On Win32 systems, there is no system provided condition variable. This class implements a condition variable using a critical section, a semphore, an event and a number of counters. The implementation is almost an extract translation of the implementation presented by Douglas C Schmidt and Irfan Pyarali in "Strategies for Implementing POSIX Condition Variables on Win32". This article can be found at http://www.cs.wustl.edu/~schmidt/win32-cv-1.html

Definition at line 67 of file itkConditionVariable.h.

Public Types
typedef SmartPointer< const Self >	ConstPointer
typedef SmartPointer< Self >	Pointer
typedef ConditionVariable	Self
typedef LightObject	Superclass
Public Member Functions
void	Broadcast ()
virtual Pointer	CreateAnother () const
virtual void	Delete ()
virtual const char *	GetNameOfClass () const
virtual int	GetReferenceCount () const
void	Print (std::ostream &os, Indent indent=0) const
virtual void	Register () const
virtual void	SetReferenceCount (int)
void	Signal ()
virtual void	UnRegister () const
void	Wait (SimpleMutexLock *mutex)
Static Public Member Functions
static void	BreakOnError ()
static Pointer	New ()
Protected Member Functions
	ConditionVariable ()
virtual void	PrintTrailer (std::ostream &os, Indent indent) const
	~ConditionVariable ()
Protected Attributes
int	m_ReferenceCount
SimpleFastMutexLock	m_ReferenceCountLock
Methods invoked by virtual Print() to print information about the object *including superclasses.Typically not called by the user(use Print()*instead) but used in the hierarchical print process to combine the *output of several classes.*/virtual void PrintSelf(std voi	PrintHeader )(std::ostream &os, Indent indent) const

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Member Typedef Documentation

typedef SmartPointer<const Self> itk::ConditionVariable::ConstPointer

Reimplemented from itk::LightObject. Definition at line 74 of file itkConditionVariable.h.

typedef SmartPointer<Self> itk::ConditionVariable::Pointer

Reimplemented from itk::LightObject. Definition at line 73 of file itkConditionVariable.h.

typedef ConditionVariable itk::ConditionVariable::Self

Standard class typedefs. Reimplemented from itk::LightObject. Definition at line 71 of file itkConditionVariable.h.

typedef LightObject itk::ConditionVariable::Superclass

Definition at line 72 of file itkConditionVariable.h.

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Constructor & Destructor Documentation

itk::ConditionVariable::ConditionVariable (   )  [protected]

itk::ConditionVariable::~ConditionVariable (   )  [protected]

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Member Function Documentation

static void itk::LightObject::BreakOnError (   )  [static, inherited]

This method is called when itkExceptionMacro executes. It allows the debugger to break on error.

void itk::ConditionVariable::Broadcast (   )

Signal that the condition is true and release all waiting threads

virtual Pointer itk::LightObject::CreateAnother (   )  const [virtual, inherited]

Create an object from an instance, potentially deferring to a factory. This method allows you to create an instance of an object that is exactly the same type as the referring object. This is useful in cases where an object has been cast back to a base class. Reimplemented in itk::Object.

virtual void itk::LightObject::Delete (   )  [virtual, inherited]

Delete an itk object. This method should always be used to delete an object when the new operator was used to create it. Using the C delete method will not work with reference counting.

virtual const char* itk::ConditionVariable::GetNameOfClass (   )  const [virtual]

Run-time type information (and related methods). Reimplemented from itk::LightObject.

virtual int itk::LightObject::GetReferenceCount (   )  const [inline, virtual, inherited]

Gets the reference count on this object. Definition at line 98 of file itkLightObject.h.

static Pointer itk::ConditionVariable::New (   )  [static]

Method for creation through the object factory. Reimplemented from itk::LightObject.

void itk::LightObject::Print (  std::ostream &  os, Indent  indent = 0 )  const [inherited]

Cause the object to print itself out.

virtual void itk::LightObject::PrintTrailer (  std::ostream &  os, Indent  indent )  const [protected, virtual, inherited]

virtual void itk::LightObject::Register (   )  const [virtual, inherited]

Increase the reference count (mark as used by another object). Reimplemented in itk::Object.

virtual void itk::LightObject::SetReferenceCount (  int   )  [virtual, inherited]

Sets the reference count on this object. This is a dangerous method, use it with care. Reimplemented in itk::Object.

void itk::ConditionVariable::Signal (   )

Signal that the condition is true and release one waiting thread

virtual void itk::LightObject::UnRegister (   )  const [virtual, inherited]

Decrease the reference count (release by another object). Reimplemented in itk::Object.

void itk::ConditionVariable::Wait (  SimpleMutexLock *  mutex  )

Suspend execution of this thread until the condition is signaled. The argument is a SimpleMutex object that must be locked prior to calling this method.

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Member Data Documentation

int itk::LightObject::m_ReferenceCount [mutable, protected, inherited]

Number of uses of this object by other objects. Definition at line 119 of file itkLightObject.h.

SimpleFastMutexLock itk::LightObject::m_ReferenceCountLock [mutable, protected, inherited]

Mutex lock to protect modification to the reference count Definition at line 122 of file itkLightObject.h.

Methods invoked by virtual Print () to print information about the object * including superclasses. Typically not called by the user (use Print() * instead) but used in the hierarchical print process to combine the * output of several classes. */ virtual void PrintSelf(std voi itk::LightObject::PrintHeader)(std::ostream &os, Indent indent) const [protected, inherited]

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

• itkConditionVariable.h

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