CmtScheduleThreadPoolFunction

int CmtScheduleThreadPoolFunction (CmtThreadPoolHandle poolHandle, CmtThreadFunctionPtr threadFunction, void *threadFunctionData, CmtThreadFunctionID *threadFunctionID);

Purpose

Notifies a thread pool that you want to execute a function in a thread from the pool.

If an idle thread exists in the thread pool, it is used to execute the function. If no idle threads exist, and the maximum number of threads for the thread pool has not been reached, the pool creates a new thread and executes the function in it. If the maximum number of threads has been reached and no idle threads exist, the pool executes the function when a thread becomes available. Functions waiting to execute in this manner are assigned threads in the order in which they were scheduled.

If you do not pass NULL for the threadFunctionID parameter, you must call CmtReleaseThreadPoolFunctionID to free the Thread Function ID.

Note   If you want to perform some operation in a timer callback that executes in its own thread, you can use the cvi/toolslib/toolbox/asynctmr.fp instrument driver. This timer uses its own thread to execute the timer callback and does not require you to create a thread or explicitly schedule a function in another thread.

Parameters

Input
Name	Type	Description
poolHandle	CmtThreadPoolHandle	The handle you obtained from CmtNewThreadPool to identify the thread pool. Pass DEFAULT_THREAD_POOL_HANDLE to specify the default thread pool. (RT) Do not use the default thread pool in RT applications. Default thread pool threads continue running after RTMain exits. This behavior can cause the real-time target to become unstable. Instead, create a new thread pool and discard the thread pool before you exit RTMain.
threadFunction	CmtThreadFunctionPtr	The function to schedule for execution. The function must have the following prototype: int CVICALLBACK ThreadFunction (void *functionData); Upon entry to the Thread Function, the functionData parameter contains the value you passed in the Thread Function Data parameter of this function. You can call, from any thread, CmtGetThreadPoolFunctionAttribute with the ATTR_TP_FUNCTION_RETURN_VALUE attribute to obtain the return value from the Thread Function.
threadFunctionData	void *	The value that you want the thread pool to pass to the Thread Function as the function data parameter. Do not pass the address of a local variable or any other variable that might not be valid when the function is executed.
Output
Name	Type	Description
threadFunctionID	CmtThreadFunctionID	Returns a unique ID that you can use to identify the Thread Function. You can use this ID to get various attributes of the Thread Function, including the return value of the Thread Function. You can also pass the ID to the CmtWaitForThreadPoolFunctionCompletion or CmtWaitForThreadPoolFunctionCompletionEx functions if you want to wait for the Thread Function to finish executing. Note  This ID is not the same ID returned by CmtGetCurrentThreadID. Pass NULL if you do not want the threadFunctionID. If you do not pass NULL for this parameter, you must call CmtReleaseThreadPoolFunctionID to free the threadFunctionID.

Return Value

Additional Information

Library: Utility Library

Include file: utility.h

LabWindows/CVI compatibility: LabWindows/CVI 5.5 and later