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vtkThreadedCallbackQueue Class Reference

simple threaded callback queue More...

#include <vtkThreadedCallbackQueue.h>

Inheritance diagram for vtkThreadedCallbackQueue:
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Collaboration diagram for vtkThreadedCallbackQueue:
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Classes

class  vtkSharedFuture
 A vtkSharedFuture is an object returned by the methods Push and PushDependent. More...
 
class  vtkSharedFutureBase
 vtkSharedFutureBase is the base block to store, run, get the returned value of the tasks that are pushed in the queue. More...
 

Public Types

typedef vtkObject Superclass
 
using SharedFutureBasePointer = vtkSmartPointer< vtkSharedFutureBase >
 
template<class ReturnT >
using SharedFuturePointer = vtkSmartPointer< vtkSharedFuture< ReturnT > >
 

Public Member Functions

virtual vtkTypeBool IsA (const char *type)
 Return 1 if this class is the same type of (or a subclass of) the named class. More...
 
vtkThreadedCallbackQueueNewInstance () const
 
void PrintSelf (ostream &os, vtkIndent indent) override
 Methods invoked by print to print information about the object including superclasses. More...
 
 vtkThreadedCallbackQueue ()
 
 ~vtkThreadedCallbackQueue () override
 Any remaining function that was not executed yet will be executed in this destructor. More...
 
template<class FT , class... ArgsT>
SharedFuturePointer< InvokeResult< FT > > Push (FT &&f, ArgsT &&... args)
 Pushes a function f to be passed args... More...
 
template<class SharedFutureContainerT , class FT , class... ArgsT>
SharedFuturePointer< InvokeResult< FT > > PushDependent (SharedFutureContainerT &&priorSharedFutures, FT &&f, ArgsT &&... args)
 This method behaves the same way Push does, with the addition of a container of futures. More...
 
template<class SharedFutureContainerT >
void Wait (SharedFutureContainerT &&priorSharedFuture)
 This method blocks the current thread until all the tasks associated with each shared future inside priorSharedFuture has terminated. More...
 
void SetNumberOfThreads (int numberOfThreads)
 Sets the number of threads. More...
 
int GetNumberOfThreads () const
 Returns the number of allocated threads. More...
 
template<class ReturnT >
vtkSharedFuture< ReturnT >::ReturnLValueRef Get (SharedFuturePointer< ReturnT > &future)
 Get the returned value from the task associated with the input future. More...
 
template<class ReturnT >
vtkSharedFuture< ReturnT >::ReturnConstLValueRef Get (const SharedFuturePointer< ReturnT > &future)
 Get the returned value from the task associated with the input future. More...
 
- Public Member Functions inherited from vtkObject
 vtkBaseTypeMacro (vtkObject, vtkObjectBase)
 
virtual void DebugOn ()
 Turn debugging output on. More...
 
virtual void DebugOff ()
 Turn debugging output off. More...
 
bool GetDebug ()
 Get the value of the debug flag. More...
 
void SetDebug (bool debugFlag)
 Set the value of the debug flag. More...
 
virtual void Modified ()
 Update the modification time for this object. More...
 
virtual vtkMTimeType GetMTime ()
 Return this object's modified time. More...
 
void RemoveObserver (unsigned long tag)
 
void RemoveObservers (unsigned long event)
 
void RemoveObservers (const char *event)
 
void RemoveAllObservers ()
 
vtkTypeBool HasObserver (unsigned long event)
 
vtkTypeBool HasObserver (const char *event)
 
vtkTypeBool InvokeEvent (unsigned long event)
 
vtkTypeBool InvokeEvent (const char *event)
 
std::string GetObjectDescription () const override
 The object description printed in messages and PrintSelf output. More...
 
unsigned long AddObserver (unsigned long event, vtkCommand *, float priority=0.0f)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
unsigned long AddObserver (const char *event, vtkCommand *, float priority=0.0f)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
vtkCommandGetCommand (unsigned long tag)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
void RemoveObserver (vtkCommand *)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
void RemoveObservers (unsigned long event, vtkCommand *)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
void RemoveObservers (const char *event, vtkCommand *)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
vtkTypeBool HasObserver (unsigned long event, vtkCommand *)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
vtkTypeBool HasObserver (const char *event, vtkCommand *)
 Allow people to add/remove/invoke observers (callbacks) to any VTK object. More...
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, void(T::*callback)(), float priority=0.0f)
 Overloads to AddObserver that allow developers to add class member functions as callbacks for events. More...
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, void(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
 Overloads to AddObserver that allow developers to add class member functions as callbacks for events. More...
 
template<class U , class T >
unsigned long AddObserver (unsigned long event, U observer, bool(T::*callback)(vtkObject *, unsigned long, void *), float priority=0.0f)
 Allow user to set the AbortFlagOn() with the return value of the callback method. More...
 
vtkTypeBool InvokeEvent (unsigned long event, void *callData)
 This method invokes an event and return whether the event was aborted or not. More...
 
vtkTypeBool InvokeEvent (const char *event, void *callData)
 This method invokes an event and return whether the event was aborted or not. More...
 
virtual void SetObjectName (const std::string &objectName)
 Set/get the name of this object for reporting purposes. More...
 
virtual std::string GetObjectName () const
 Set/get the name of this object for reporting purposes. More...
 
- Public Member Functions inherited from vtkObjectBase
const char * GetClassName () const
 Return the class name as a string. More...
 
virtual vtkIdType GetNumberOfGenerationsFromBase (const char *name)
 Given the name of a base class of this class type, return the distance of inheritance between this class type and the named class (how many generations of inheritance are there between this class and the named class). More...
 
virtual void Delete ()
 Delete a VTK object. More...
 
virtual void FastDelete ()
 Delete a reference to this object. More...
 
void InitializeObjectBase ()
 
void Print (ostream &os)
 Print an object to an ostream. More...
 
void Register (vtkObjectBase *o)
 Increase the reference count (mark as used by another object). More...
 
virtual void UnRegister (vtkObjectBase *o)
 Decrease the reference count (release by another object). More...
 
int GetReferenceCount ()
 Return the current reference count of this object. More...
 
void SetReferenceCount (int)
 Sets the reference count. More...
 
bool GetIsInMemkind () const
 A local state flag that remembers whether this object lives in the normal or extended memory space. More...
 
virtual void PrintHeader (ostream &os, vtkIndent indent)
 Methods invoked by print to print information about the object including superclasses. More...
 
virtual void PrintTrailer (ostream &os, vtkIndent indent)
 Methods invoked by print to print information about the object including superclasses. More...
 
virtual bool UsesGarbageCollector () const
 Indicate whether the class uses vtkGarbageCollector or not. More...
 

Static Public Member Functions

static vtkThreadedCallbackQueueNew ()
 
static vtkTypeBool IsTypeOf (const char *type)
 
static vtkThreadedCallbackQueueSafeDownCast (vtkObjectBase *o)
 
- Static Public Member Functions inherited from vtkObject
static vtkObjectNew ()
 Create an object with Debug turned off, modified time initialized to zero, and reference counting on. More...
 
static void BreakOnError ()
 This method is called when vtkErrorMacro executes. More...
 
static void SetGlobalWarningDisplay (vtkTypeBool val)
 This is a global flag that controls whether any debug, warning or error messages are displayed. More...
 
static void GlobalWarningDisplayOn ()
 This is a global flag that controls whether any debug, warning or error messages are displayed. More...
 
static void GlobalWarningDisplayOff ()
 This is a global flag that controls whether any debug, warning or error messages are displayed. More...
 
static vtkTypeBool GetGlobalWarningDisplay ()
 This is a global flag that controls whether any debug, warning or error messages are displayed. More...
 
- Static Public Member Functions inherited from vtkObjectBase
static vtkTypeBool IsTypeOf (const char *name)
 Return 1 if this class type is the same type of (or a subclass of) the named class. More...
 
static vtkIdType GetNumberOfGenerationsFromBaseType (const char *name)
 Given a the name of a base class of this class type, return the distance of inheritance between this class type and the named class (how many generations of inheritance are there between this class and the named class). More...
 
static vtkObjectBaseNew ()
 Create an object with Debug turned off, modified time initialized to zero, and reference counting on. More...
 
static void SetMemkindDirectory (const char *directoryname)
 The name of a directory, ideally mounted -o dax, to memory map an extended memory space within. More...
 
static bool GetUsingMemkind ()
 A global state flag that controls whether vtkObjects are constructed in the usual way (the default) or within the extended memory space. More...
 

Protected Member Functions

virtual vtkObjectBaseNewInstanceInternal () const
 
- Protected Member Functions inherited from vtkObject
 vtkObject ()
 
 ~vtkObject () override
 
void RegisterInternal (vtkObjectBase *, vtkTypeBool check) override
 
void UnRegisterInternal (vtkObjectBase *, vtkTypeBool check) override
 
void InternalGrabFocus (vtkCommand *mouseEvents, vtkCommand *keypressEvents=nullptr)
 These methods allow a command to exclusively grab all events. More...
 
void InternalReleaseFocus ()
 These methods allow a command to exclusively grab all events. More...
 
- Protected Member Functions inherited from vtkObjectBase
 vtkObjectBase ()
 
virtual ~vtkObjectBase ()
 
virtual void ReportReferences (vtkGarbageCollector *)
 
 vtkObjectBase (const vtkObjectBase &)
 
void operator= (const vtkObjectBase &)
 

Friends

class ThreadWorker
 

Additional Inherited Members

- Static Protected Member Functions inherited from vtkObjectBase
static vtkMallocingFunction GetCurrentMallocFunction ()
 
static vtkReallocingFunction GetCurrentReallocFunction ()
 
static vtkFreeingFunction GetCurrentFreeFunction ()
 
static vtkFreeingFunction GetAlternateFreeFunction ()
 
- Protected Attributes inherited from vtkObject
bool Debug
 
vtkTimeStamp MTime
 
vtkSubjectHelper * SubjectHelper
 
std::string ObjectName
 
- Protected Attributes inherited from vtkObjectBase
std::atomic< int32_t > ReferenceCount
 
vtkWeakPointerBase ** WeakPointers
 

Detailed Description

simple threaded callback queue

This callback queue executes pushed functions and functors on threads whose purpose is to execute those functions. By default, one thread is created by this class, so it is advised to set NumberOfThreads. Upon destruction of an instance of this callback queue, remaining unexecuted threads are executed.

When a task is pushed, a vtkSharedFuture is returned. This instance can be used to get the returned value when the task is finished, and provides functionalities to synchronize the main thread with the status of its associated task.

All public methods of this class are thread safe.

Tests:
vtkThreadedCallbackQueue (Tests)

Definition at line 45 of file vtkThreadedCallbackQueue.h.

Member Typedef Documentation

◆ Superclass

Definition at line 88 of file vtkThreadedCallbackQueue.h.

◆ SharedFutureBasePointer

Definition at line 210 of file vtkThreadedCallbackQueue.h.

◆ SharedFuturePointer

Definition at line 212 of file vtkThreadedCallbackQueue.h.

Constructor & Destructor Documentation

◆ vtkThreadedCallbackQueue()

vtkThreadedCallbackQueue::vtkThreadedCallbackQueue ( )

◆ ~vtkThreadedCallbackQueue()

vtkThreadedCallbackQueue::~vtkThreadedCallbackQueue ( )
override

Any remaining function that was not executed yet will be executed in this destructor.

Member Function Documentation

◆ New()

static vtkThreadedCallbackQueue* vtkThreadedCallbackQueue::New ( )
static

◆ IsTypeOf()

static vtkTypeBool vtkThreadedCallbackQueue::IsTypeOf ( const char *  type)
static

◆ IsA()

virtual vtkTypeBool vtkThreadedCallbackQueue::IsA ( const char *  name)
virtual

Return 1 if this class is the same type of (or a subclass of) the named class.

Returns 0 otherwise. This method works in combination with vtkTypeMacro found in vtkSetGet.h.

Reimplemented from vtkObjectBase.

◆ SafeDownCast()

static vtkThreadedCallbackQueue* vtkThreadedCallbackQueue::SafeDownCast ( vtkObjectBase o)
static

◆ NewInstanceInternal()

virtual vtkObjectBase* vtkThreadedCallbackQueue::NewInstanceInternal ( ) const
protectedvirtual

◆ NewInstance()

vtkThreadedCallbackQueue* vtkThreadedCallbackQueue::NewInstance ( ) const

◆ PrintSelf()

void vtkThreadedCallbackQueue::PrintSelf ( ostream &  os,
vtkIndent  indent 
)
overridevirtual

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 from vtkObject.

◆ Push()

template<class FT , class... ArgsT>
SharedFuturePointer<InvokeResult<FT> > vtkThreadedCallbackQueue::Push ( FT &&  f,
ArgsT &&...  args 
)

Pushes a function f to be passed args...

as arguments. f will be called as soon as a running thread has the occasion to do so, in a FIFO fashion. This method returns a vtkSharedFuture, which is an object allowing to synchronize the code.

All the arguments of Push are stored persistently inside the queue. An argument passed as an lvalue reference will trigger a copy constructor call. It is thus advised, when possible, to pass rvalue references or smart pointers (vtkSmartPointer or std::shared_ptr for example)

The input function can be a pointer function, a lambda expression, a std::function a functor or a member function pointer.

If f is a functor, its copy constructor will be invoked if it is passed as an lvalue reference. Consequently, if the functor is somewhat heavy, it is advised to pass it as an rvalue reference or to wrap inside a smart pointer (std::unique_ptr for example).

If f is a member function pointer, an instance of its host class needs to be provided in the second parameter. Similar to the functor case, it is advised in order to avoid calling the copy constructor to pass it as an rvalue reference or to wrap it inside a smart pointer.

Below is a short example showing off different possible insertions to this queue:

struct S {
void operator()(int) {}
void f() {}
void f_const() {}
};
void f(S&&, const S&) {}
int x;
S s;
// Pushing a lambda expression.
queue->Push([]{});
// Pushing a function pointer
// Note that the copy constructor is called for s
queue->Push(&f, s, S());
// Pushing a functor.
queue->Push(S(), x);
// Pushing a functor wrapped inside a smart pointer.
queue->Push(std::unique_ptr<S>(new S()), x);
// Pushing a member function pointer.
// Don't forget to pass an instance of the host class.
queue->Push(&S::f, S());
// Pushing a const member function pointer.
// This time, we wrap the instance of the host class inside a smart pointer.
queue->Push(&S::f_const, std::unique_ptr<S>(new S()));
Allocate and hold a VTK object.
Definition: vtkNew.h:160
Warning
DO NOT capture lvalue references in a lambda expression pushed into the queue unless you can ensure that the function will be executed in the same scope where the input lives. If not, such captures may be destroyed before the lambda is invoked by the queue.

◆ PushDependent()

template<class SharedFutureContainerT , class FT , class... ArgsT>
SharedFuturePointer<InvokeResult<FT> > vtkThreadedCallbackQueue::PushDependent ( SharedFutureContainerT &&  priorSharedFutures,
FT &&  f,
ArgsT &&...  args 
)

This method behaves the same way Push does, with the addition of a container of futures.

The function to be pushed will not be executed until the functions associated with the input futures have terminated.

The container of futures must have forward iterator (presence of a begin() and end() member function).

◆ Wait()

template<class SharedFutureContainerT >
void vtkThreadedCallbackQueue::Wait ( SharedFutureContainerT &&  priorSharedFuture)

This method blocks the current thread until all the tasks associated with each shared future inside priorSharedFuture has terminated.

It is in general more efficient to call this function than to call Wait on each future individually because if any task associated with priorSharedFuture is allowed to run (i.e. it is not depending on any other future) and is currently waiting in queue, this function will actually run it.

The current thread is blocked at most once by this function.

SharedFutureContainerT must have a forward iterator (presence of a begin() and end() member function).

◆ Get() [1/2]

template<class ReturnT >
vtkSharedFuture<ReturnT>::ReturnLValueRef vtkThreadedCallbackQueue::Get ( SharedFuturePointer< ReturnT > &  future)

Get the returned value from the task associated with the input future.

It effectlively calls Wait. If the task has not started yet upon the call of this function, then the current thread will run the task itself.

This function returns void if ReturnT is void. It returns ReturnT& or const ReturnT& otherwise.

◆ Get() [2/2]

template<class ReturnT >
vtkSharedFuture<ReturnT>::ReturnConstLValueRef vtkThreadedCallbackQueue::Get ( const SharedFuturePointer< ReturnT > &  future)

Get the returned value from the task associated with the input future.

It effectlively calls Wait. If the task has not started yet upon the call of this function, then the current thread will run the task itself.

This function returns void if ReturnT is void. It returns ReturnT& or const ReturnT& otherwise.

◆ SetNumberOfThreads()

void vtkThreadedCallbackQueue::SetNumberOfThreads ( int  numberOfThreads)

Sets the number of threads.

The running state of the queue is not impacted by this method.

This method is executed by the Controller on a different thread, so this method may terminate before the threads were allocated. Nevertheless, this method is thread-safe. Other calls to SetNumberOfThreads() will be queued by the Controller, which executes all received command serially in the background.

◆ GetNumberOfThreads()

int vtkThreadedCallbackQueue::GetNumberOfThreads ( ) const
inline

Returns the number of allocated threads.

Note that this method doesn't give any information on whether threads are running or not.

Note
SetNumberOfThreads(int) runs in the background. So the number of threads of this queue might change asynchronously as those commands are executed.

Definition at line 340 of file vtkThreadedCallbackQueue.h.

Friends And Related Function Documentation

◆ ThreadWorker

friend class ThreadWorker
friend

Definition at line 359 of file vtkThreadedCallbackQueue.h.


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