ASYNC_COMPLETION

This type is a callback function implemented by TAPI and supplied to the service provider as a parameter to TSPI_providerInit. The service provider calls this function to report the completion of a line or phone procedure that it executes asynchronously.

ASYNC_COMPLETION Completion_Proc;
void(
  CALLBACK* Completion_Proc)(  
  DRV_REQUESTID dwRequestID,  
  LONG lResult                
);

Parameters

dwRequestID

The identifier passed in the original request that the service provider executed asynchronously.

lResult

The outcome of the operation. This can be zero to indicate success or a negative number to indicate an error. The possible specific error values that can result from a function are the same for asynchronous or synchronous execution.

Return Values

No return value.

Remarks

The call state when calling this function can be any state.

This procedure is supplied by TAPI at the time a service provider is initialized with the TSPI_providerInit function. Some of the TSPI procedures that operate on line, call, and phone devices specify asynchronous operation. These procedures include a dwRequestID parameter to identify the request. When such a procedure is called, the service provider can return a negative number for an error if one is detected immediately, or the positive dwRequestID if the operation continues asynchronously. The service provider must report completion exactly once for each request it executes asynchronously. It does so by calling this procedure. The service provider is not permitted to call this procedure or the LINEEVENT or PHONEEVENT procedure again until this procedure returns.

The service provider is permitted to call the ASYNC_COMPLETION function before it returns from the first request. TAPI guarantees not to call the service provider from within the ASYNC_COMPLETION context except where noted.

This does not have any direct correspondence at the TAPI level because at that level asynchronous function completions are reported as a message passed through the same callback interface that is used for spontaneous event messages. At the TSPI level, spontaneous events are reported through the LINEEVENT and PHONEEVENT callback procedures.

Requirements

  Windows NT/2000: Requires Windows NT 4.0 SP3 or later.
  Windows 95/98: Requires Windows 95 or later.
  Version: Requires TAPI 2.0 or later.
  Header: Declared in Tspi.h.

See Also

LINEEVENT, PHONEEVENT, TSPI_providerInit