PSyncPointAck Class Reference

This class defines a thread synchronisation object. More...

#include <syncthrd.h>

Inheritance diagram for PSyncPointAck:

Collaboration diagram for PSyncPointAck:

Public Member Functions
virtual void	Signal ()
	If there are waiting (blocked) threads then unblock the first one that was blocked. More...
void	Signal (const PTimeInterval &waitTime)
void	Acknowledge ()
	This indicates that the thread that was blocked in a Wait() on this synchronisation object has completed the operation the signal was intended to initiate. More...
Public Member Functions inherited from PSyncPoint
	PSyncPoint ()
	Create a new sync point. More...
	PSyncPoint (const PSyncPoint &)
virtual void	Wait ()
	Block until the synchronisation object is available. More...
virtual PBoolean	Wait (const PTimeInterval &timeout)
	Block, for a time, until the synchronisation object is available. More...
Public Member Functions inherited from PSync
	PSync ()
virtual bool	InstrumentedWait (const PTimeInterval &timeout, const PDebugLocation &)
	As for Wait() but with location of call for instrumentation. Mostly used internally. More...
virtual void	InstrumentedSignal (const PDebugLocation &)
	As for Signal() but with location of call for instrumentation. Mostly used internally. More...
Public Member Functions inherited from PObject
__inline unsigned	GetTraceContextIdentifier () const
	Get PTRACE context identifier. More...
__inline void	SetTraceContextIdentifier (unsigned id)
__inline void	SetTraceContextIdentifier (const PObject &obj)
__inline void	SetTraceContextIdentifier (const PObject *obj)
__inline void	CopyTraceContextIdentifier (PObject &obj) const
__inline void	CopyTraceContextIdentifier (PObject *obj) const
virtual	~PObject ()
__inline const char *	GetClass () const
__inline bool	IsClass (const char *name) const
__inline const PObject *	PTraceObjectInstance () const
virtual PObject *	Clone () const
	Create a copy of the class on the heap. More...
template<class CLS >
CLS *	CloneAs () const
	As for Clone() but converts to specified type. More...
virtual PINDEX	HashFunction () const
	This function yields a hash value required by the PDictionary class. More...
virtual Comparison	Compare (const PObject &obj) const
	Compare the two objects and return their relative rank. More...
virtual Comparison	CompareObjectMemoryDirect (const PObject &obj) const
	Determine the byte wise comparison of two objects. More...
bool	operator== (const PObject &obj) const
	Compare the two objects. More...
bool	operator!= (const PObject &obj) const
	Compare the two objects. More...
bool	operator< (const PObject &obj) const
	Compare the two objects. More...
bool	operator> (const PObject &obj) const
	Compare the two objects. More...
bool	operator<= (const PObject &obj) const
	Compare the two objects. More...
bool	operator>= (const PObject &obj) const
	Compare the two objects. More...
virtual void	PrintOn (ostream &strm) const
	Output the contents of the object to the stream. More...
virtual void	ReadFrom (istream &strm)
	Input the contents of the object from the stream. More...

Protected Attributes
PSyncPoint	ack
Protected Attributes inherited from PObject
unsigned	m_traceContextIdentifier

Additional Inherited Members
Public Types inherited from PObject
enum	Comparison { LessThan = -1, EqualTo = 0, GreaterThan = 1 }
	Result of the comparison operation performed by the Compare() function. More...
Static Public Member Functions inherited from PObject
static __inline void	CopyTraceContextIdentifier (PObject &to, const PObject &from)
static __inline void	CopyTraceContextIdentifier (PObject &to, const PObject *from)
static __inline void	CopyTraceContextIdentifier (PObject *to, const PObject &from)
static __inline void	CopyTraceContextIdentifier (PObject *to, const PObject *from)
static __inline const char *	Class ()
static __inline const PObject *	PTraceObjectInstance (const char *)
static __inline const PObject *	PTraceObjectInstance (const PObject *obj)
template<typename T >
static Comparison	Compare2 (T v1, T v2)
	Compare two types, returning Comparison type. More...
static Comparison	InternalCompareObjectMemoryDirect (const PObject *obj1, const PObject *obj2, PINDEX size)
	Internal function caled from CompareObjectMemoryDirect() More...
Protected Member Functions inherited from PObject
	PObject ()
	Constructor for PObject, made protected so cannot ever create one on its own. More...

Detailed Description

This class defines a thread synchronisation object.

This may be used to send signals to a thread and await an acknowldegement that the signal was processed. This can be be used to initiate an action in another thread and wait for the action to be completed.

    ... thread one
    while (condition) {
      sync.Wait();
      do_something();
      sync.Acknowledge();
    }

    ... thread 2
    do_something_else();
    sync.Signal();    // At this point thread 1 wake up and does something.
    do_yet_more();    // However, this does not get done until Acknowledge()
is called in the other thread.

Member Function Documentation

void PSyncPointAck::Acknowledge

(

)

This indicates that the thread that was blocked in a Wait() on this synchronisation object has completed the operation the signal was intended to initiate.

This unblocks the thread that had called the Signal() function to initiate the action.

virtual void PSyncPointAck::Signal ( )

virtual

If there are waiting (blocked) threads then unblock the first one that was blocked.

If no waiting threads and the count is less than the maximum then increment the semaphore.

Unlike the PSyncPoint::Signal() this function will block until the target thread that was blocked by the Wait() function has resumed execution and called the Acknowledge() function.

The waitTime parameter is used as a maximum amount of time to wait for the achnowledgement to be returned from the other thread.

Reimplemented from PSyncPoint.

void PSyncPointAck::Signal

(

const PTimeInterval &

waitTime

)

Member Data Documentation

PSyncPoint PSyncPointAck::ack

protected

---

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

• syncthrd.h