PSyncPoint Class Reference

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

#include <syncpoint.h>

Inheritance diagram for PSyncPoint:

Collaboration diagram for PSyncPoint:

Public Member Functions
	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...
virtual void	Signal ()
	Signal that the synchronisation object is available. More...
Public Member Functions inherited from PSync
	PSync ()
Public Member Functions inherited from PObject
unsigned	GetTraceContextIdentifier () const
	Get PTRACE context identifier. More...
void	SetTraceContextIdentifier (unsigned id)
void	GetTraceContextIdentifier (PObject &obj)
void	GetTraceContextIdentifier (PObject *obj)
void	SetTraceContextIdentifier (const PObject &obj)
void	SetTraceContextIdentifier (const PObject *obj)
virtual	~PObject ()
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 const char *	GetClass (unsigned ancestor=0) const
	Get the current dynamic type of the object instance. More...
PBoolean	IsClass (const char *cls) const
virtual PBoolean	InternalIsDescendant (const char *clsName) const
	Determine if the dynamic type of the current instance is a descendent of the specified class. More...
__inline const PObject *	PTraceObjectInstance () const
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...

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 const char *	Class ()
	Get the name of the class as a C string. More...
static __inline const PObject *	PTraceObjectInstance (const char *)
static __inline const PObject *	PTraceObjectInstance (const PObject *obj)
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...
Protected Attributes inherited from PObject
unsigned	m_traceContextIdentifier
Friends inherited from PObject

Detailed Description

This class defines a thread synchronisation object.

This form of semaphore is used to indicate an event has occurred. A thread may block on the sync point and wait until another thread signals that it may continue. eg:

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

    ... thread 2
    do_something_else();
    sync.Signal();    // At this point thread 1 wake up and does something.
    do_yet_more();

Note that events are boolean in nature. If "thread one" is not waiting on the event, multiple calls to Signal() are ignored, thread one will only exit the Wait() call a single time once it gets there. Similarly, if multiple threads are waiting on the event, only one thread will be released. As you cannot know which thread will be released this mode of use is not recommended.

Constructor & Destructor Documentation

PSyncPoint::PSyncPoint

(

)

Create a new sync point.

PSyncPoint::PSyncPoint

(

const PSyncPoint &

)

Member Function Documentation

virtual void PSyncPoint::Signal ( )

virtual

Signal that the synchronisation object is available.

Implements PSync.

Reimplemented in PSyncPointAck.

virtual void PSyncPoint::Wait ( )

virtual

Block until the synchronisation object is available.

Implements PSync.

virtual PBoolean PSyncPoint::Wait ( const PTimeInterval &  timeout )

virtual

Block, for a time, until the synchronisation object is available.

Returns

true if lock is acquired, false if timed out

Implements PSync.

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

• syncpoint.h