CMsgThread Class

Microsoft DirectShow 9.0

CMsgThread Class

The CMsgThread class is a worker-thread class that queues requests to the queuing thread for completion asynchronously. To use this class, derive your class from it and override the CMsgThread::ThreadMessageProc member function. The ThreadMessageProc member function carries out each request. Your client functions and the ThreadMessageProc member function must share a common definition of the parameters in the CMsg object.

A negotiated mechanism tells the worker thread to exit. Typically, this will be one value of the CMsg class's uMsg message code.

It is a good idea to send this message from the destructor of your derived class, and call the CMsgThread::WaitForThreadExit member function before completing the destruction of the derived class.

Protected Data Members

m_hSem	Indicates a handle used for signaling.
m_Lock	Protects access to lists.
m_lWaiting	Indicates waiting for a free thread.
m_ThreadQueue	Overrides the CMsgThread::GetThreadMsg member function and blocks on things other than this queue.

Member Functions

CMsgThread	Constructs a CMsgThread object.
CreateThread	Creates a thread.
GetThreadHandle	Retrieves the thread handle.
GetThreadID	Retrieves the identifier of the thread.
GetThreadPriority	Retrieves the current thread priority.
PutThreadMsg	Queues a request for execution by the worker thread.
ResumeThread	Continues the operation of the worker thread.
SetThreadPriority	Sets the priority of the thread to a new value.
SuspendThread	Suspends the operation of a running thread.
WaitForThreadExit	Blocks until the thread has exited after a call to the CMsgThread::SuspendThread member function.

Overridable Member Functions

GetThreadMsg	Retrieves a queued CMsg object containing a request.
OnThreadInit	Provides initialization on a thread.
ThreadMessageProc	Processes requests. This is a pure virtual member function.