Unit 'exec' Package
[Overview][Constants][Types][Procedures and functions][Variables][Index] [#os4units]

CheckIO

Check status on an I/O request

Declaration

Source position: exec.pas line 1858

function CheckIO(

  IORequest: PIORequest

):PIORequest;

Arguments

IORequest

  

Pointer to an I/O request block

Function result

Nil if I/O is still in progress otherwise a pointer to the I/O Request.

Description

This function determines the current state of an I/O request and returns False if the I/O has not yet completed. This function effectively hides the internals of the I/O completion mechanism.

CheckIO() will NOT remove the returned IORequest from the reply port. This is best performed with WaitIO(). If the request has already completed, WaitIO() will return quickly. Use of the Remove() function is dangerous, since other tasks may still be adding things to your message port; a Disable() would be required.

This function should NOT be used to busy loop (looping until IO is complete). WaitIO() is provided for that purpose.

See also

DoIO

  

Perform an I/O request and wait for its finish

SendIO

  

Initiate an I/O command

WaitIO

  

Wait for completion of an I/O request

AbortIO

  

Attempt to abort an in-progress I/O request


Documentation generated on: 2021-07-30