CreateThread Procedure

Creates a thread.

Syntax

[ hThread = ] CreateThread ( proc [, lParameter] [,bSuspended] [,lId] )

The CreateThread procedure syntax has the following parts:

Name	Type	Description
lHandle	AHandle	Handle to the thread.
proc	Val Procedure	Thread procedure. See Comments.
lParameter	Val Long	Specifies a single 32-bit parameter value passed to the thread.
bSuspended	Val Bool	A Boolean expression specifying whether the thread is to be suspended after it is created.
hThreaad	Var Long	Handle for the thread. 0 if error occurred and the thread creation failed.

Where

bSuspended can have one of the following values:

Value	Description
True	The thread is to be suspended.
False *	The thread is running.

Comments

The CreateThread function creates a thread to run in parallel to the caller thread, all run in the same process sharing the same address space. The procedure passed get execute in parallel to the caller thread.

The caller can use for WaitForSingleObject() internal function to wait until the thread exit.

The procedure (proc) must have the following prototype:

ThreadProcedure(lParameter : Val Long): Void

The called thread will end when the ThreadProcedure returns (using return statement or reached to the end of the procedure), or by calling ExitThread() internal function.

Example

The following example creates a thread that reads data:

hThread=CreateThread(ReadThreadProc, 10)
if hThread=0 then
TestStatus=FAIL
exittest
endif

! wait until the thread is over or 2000 ms
if WaitForSingleObject(hThread, 2000)<>aWaitObject0 ! should be done by now
TestStatus=FAIL
endif

The following shows an example for the thread procedure (ReadThreadProc):

Procedure ReadThreadProc (lBytes): Void
------------------------------------------------------------------------

lBytes: Val Long

{

while ReadAppendByte(m_sBuffer)>0

continue

if len(m_sBuffer)>lBytes

return ! exit the thread

endif

endwhile

! no more data exit the thread

}

Procedure ReadAppendByte (): Long

!------------------------------------------------------------------------

{

! read lBytesRead

if ChecckStatus()<0

ExitThread() ! end the thread