Mixing synchronous and asynchronous requests
- Last Updated: October 20, 2020
- 1 minute read
- OpenEdge
- Version 13.0
- Documentation
If you attempt to execute a synchronous request on a server connection
with outstanding asynchronous requests, The client session raises the ERROR condition. You can determine if there are any
outstanding asynchronous requests for a server object by checking the value of the
ASYNC-REQUEST-COUNT attribute of the appropriate
server handle.
You can also ensure that all asynchronous requests for a given server
handle have completed execution by the way you set up your event management in the
client. Specify the PROCEDURE-COMPLETE event in the
WAIT-FOR statement for the asynchronous request
handle that corresponds to the last asynchronous request submitted before the WAIT-FOR statement is executed. For example, assume that
you submit three asynchronous requests for some server handle and that the asynchronous
request handles are returned in HANDLE variables
hdl1, hdl2, and
hdl3. To ensure that there are no outstanding
asynchronous requests before submitting a synchronous request, execute the WAIT-FOR statement specifying the PROCEDURE-COMPLETE event for hdl3.