HP-UX

NAME

viDiscardEvents − Discards all pending occurrences of the specifed event types

SYNOPSIS

viDiscardEvents(ViSession vi, ViEventType eventType,
ViUInt16 mechanism);

Description

 
This function discards all pending occurrences of the specified event types for the mechanisms specified in a given session. The information about all the event occurrences which have not yet been handled is discarded.  This function is useful to remove event occurrences that an application no longer needs.
 

Parameters

vi An input parameter. Unique logical identifier to a session. 
 

eventType An input parameter. Logical event identifier. (See the following tables.) 
 

mechanism An input parameter.  Specifies the mechanisms for which the events are to be discarded.  VI_QUEUE is specified for the queuing mechanism and VI_SUSPEND_HNDLR is specified for the pending events in the callback mechanism.  It is possible to specify both mechanisms simultaneously by specifying VI_ALL_MECH. (See the following table.) 
 

Special Values for eventType

VI_ALL_ENABLED_EVENTS Discard events of every type that is enabled. 
 
The following events can be enabled:
 

VI_EVENT_SERVICE_REQ Notification that a device is requesting service. 
 

VI_EVENT_VXI_SIGP Notification that a VXI signal or VXI interrupt has been received from a device. 
 

VI_EVENT_TRIG Notification that a hardware trigger was received from a device. 
 
 

Special Values for mechanism Parameter

VI_QUEUE Discard the specified event(s) from the waiting queue. 
 

VI_SUSPEND_HNDLR Discard the specified event(s) from the callback queue. 
 

VI_ALL_MECH Discard the specified event(s) from all mechanisms. 
 
NOTE Some combinations of VTL-defined values for different parameters of this function are also supported.
 
 

Return Values

 
This is the functional return status.  It returns either a completion code or an error code as follows.
 
 

VI_SUCCESS Event queue flushed successfully. 
 

VI_SUCCESS_QUEUE_EMPTY Operation completed successfully, but queue was empty. 
 

VI_ERROR_INV_SESSION VI_ERROR_INV_OBJECT The given session or object reference is invalid (both are the same value). 
 

VI_ERROR_INV_EVENT Specified event type is not supported by the resource. 
 

VI_ERROR_INV_MECH Invalid mechanism specified. 
 
 

See Also

 
viEnableEvent, viWaitOnEvent, viInstallHandler
 

AUTHOR

viDiscardEvents was developed by HP
 

Hewlett-Packard Comapny  —  September 29, 1999