QsoCancelOperation()--Cancel an I/O Operation

Syntax

 #include <qsoasync.h>

 int QsoCancelOperation(int socketDescriptor, unsigned long long operationId)

  Service Program Name: QSOSRV3

  Default Public Authority: *USE

  Threadsafe: Yes

The QsoCancelOperation() function is used to cancel one or more asynchronous I/O operations that are pending on the socket. Pending operations are defined as incomplete operations that have not been posted to an I/O completion port. The canceled operations will be posted to the I/O completion port with an errnoValue of ECANCELED.

If any operations that match the operation identifier are uninterruptible, then no pending operations will be cancelled. The only operation that is uninterruptible is gsk_secure_soc_startInit() when secure negotiations have already begun.

Parameters

int socketDescriptor (Input): The socket descriptor where the operation was started.
unsigned long long operationId (Input): The operation identifier that was specified in field operationId in the Qso_OverlappedIO_t structure when the operation was started.; All pending operations on the socket that match the operationId will be cancelled.

Authorities

No authorization is required.

Return Values

QsoCancelOperation() returns an integer. Possible values are:

-1 - The function did not complete because an error occurred. Inspect the errno value to determine the cause of the failure.
0 - An operation matching the operation identifier was not pending and could not be cancelled.
>0 - Successful, at least one operation was cancelled. The return value is the number of operations cancelled.

Errno Conditions

When QsoCancelOperation() fails, errno can be set to one of the following:

[EAGAIN]	At least one pending operation was uninterruptible. If there were multiple operations pending, none were cancelled.
[EBADF]	Invalid descriptor.
[ENOTSOCK]	The specified descriptor is not a socket.
[EUNKNOWN]	Unknown system state.

Error Messages

Message ID	Error Message Text
CPFA081 E	Unable to set return value or error code.
CPE3418 E	Possible APAR condition or hardware failure.
CPF9872 E	Program or service program &1 in library &2 ended. Reason code &3.

Usage Notes

When QsoCancelOperation() fails with EAGAIN for multiple pending operations, the application may retry QsoCancelOperation() and some pending operations may yet be cancelled after the uninterruptible operation has completed. Or the application may close() the socket to force all pending operations to be cancelled.

Related Information

QsoCreateIOCompletionPort()--Create I/O Completion Port
QsoDestroyIOCompletionPort()--Destroy I/O Completion Port
gsk_secure_soc_startInit()--Start Asynchronous Operation to Negotiate a Secure Session
gsk_secure_soc_startRecv--Start Asynchronous Receive Operation on a Secure Session
gsk_secure_soc_startSend--Start Asynchronous Send Operation on a Secure Session
QsoGenerateOperationId()--Get an I/O Operation ID
QsoIsOperationPending()--Check if an I/O Operation is Pending
QsoStartRecv--Start Asynchronous Receive Operation
QsoStartSend--Start Asynchronous Send Operation
QsoWaitForIOCompletion()--Wait for I/O Completion Operation

API introduced: V6R1

[ Back to top | UNIX-Type APIs | APIs by category ]