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igtl::ConditionVariable Class Reference

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

#include <igtlConditionVariable.h>

Inheritance diagram for igtl::ConditionVariable:
igtl::LightObject

List of all members.

Public Types

typedef SmartPointer< const SelfConstPointer
typedef SmartPointer< SelfPointer
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
 igtlNewMacro (Self)
 igtlTypeMacro (ConditionVariable, LightObject)
void Print (std::ostream &os) 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 ()
 ~ConditionVariable ()
virtual void PrintSelf (std::ostream &os) const
virtual void PrintHeader (std::ostream &os) const
virtual void PrintTrailer (std::ostream &os) const

Protected Attributes

volatile int m_ReferenceCount
SimpleFastMutexLock m_ReferenceCountLock

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 IGTL 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 84 of file igtlConditionVariable.h.


Member Typedef Documentation

Reimplemented from igtl::LightObject.

Definition at line 91 of file igtlConditionVariable.h.

Reimplemented from igtl::LightObject.

Definition at line 90 of file igtlConditionVariable.h.

Standard class typedefs.

Reimplemented from igtl::LightObject.

Definition at line 88 of file igtlConditionVariable.h.


Constructor & Destructor Documentation

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

Member Function Documentation

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

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

void igtl::ConditionVariable::Broadcast ( )

Signal that the condition is true and release all waiting threads

virtual Pointer igtl::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 igtl::Object.

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

Delete an igtl 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* igtl::LightObject::GetNameOfClass ( ) const [inline, virtual, inherited]

Return the name of this class as a string. Used by the object factory (implemented in New()) to instantiate objects of a named type. Also used for debugging and other output information.

Definition at line 86 of file igtlLightObject.h.

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

Gets the reference count on this object.

Definition at line 112 of file igtlLightObject.h.

igtl::ConditionVariable::igtlNewMacro ( Self  )

Method for creation through the object factory.

igtl::ConditionVariable::igtlTypeMacro ( ConditionVariable  ,
LightObject   
)

Run-time type information (and related methods).

static Pointer igtl::LightObject::New ( ) [static, inherited]

Method for creation through the object factory.

Reimplemented in igtl::Object.

void igtl::LightObject::Print ( std::ostream &  os) const [inherited]

Cause the object to print itself out.

virtual void igtl::LightObject::PrintHeader ( std::ostream &  os) const [protected, virtual, inherited]

Methods invoked by 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 igtl::LightObject::PrintSelf ( std::ostream &  os) const [protected, virtual, inherited]

Methods invoked by 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.

Reimplemented in igtl::ClientSocket, igtl::FastMutexLock, igtl::MultiThreader, igtl::MutexLock, igtl::Object, igtl::ObjectFactoryBase, igtl::ServerSocket, igtl::Socket, and igtl::TimeStamp.

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

Methods invoked by 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 igtl::LightObject::Register ( ) const [virtual, inherited]

Increase the reference count (mark as used by another object).

Reimplemented in igtl::Object.

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

Sets the reference count on this object. This is a dangerous method, use it with care.

Reimplemented in igtl::Object.

void igtl::ConditionVariable::Signal ( )

Signal that the condition is true and release one waiting thread

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

Decrease the reference count (release by another object).

Reimplemented in igtl::Object.

void igtl::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.


Member Data Documentation

volatile int igtl::LightObject::m_ReferenceCount [mutable, protected, inherited]

Number of uses of this object by other objects.

Definition at line 133 of file igtlLightObject.h.

Mutex lock to protect modification to the reference count

Definition at line 136 of file igtlLightObject.h.


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

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