please dont rip this site Prev Next

CancelIo info  Overview  Group

The CancelIo function cancels all pending input and output (I/O) operations that were issued by the calling thread for the specified file handle. The function does not cancel I/O operations issued for the file handle by other threads.

BOOL CancelIo(

    HANDLE hFile

// file handle for which to cancel I/O



Handle to a file. The function cancels all pending I/O operations for this file handle.

Return Values

If the function succeeds, the return value is nonzero All pending I/O operations issued by the calling thread for the file handle were successfully canceled.

If the function fails, the return value is zero. To get extended error information, call GetLastError.


If there are any I/O operations in progress for the specified file handle, and they were issued by the calling thread, the CancelIo function cancels them.

Note that the I/O operations must have been issued as overlapped I/O. If they were not, the I/O operations would not have returned to allow the thread to call the CancelIo function. Calling the CancelIo function with a file handle that was not opened with FILE_FLAG_OVERLAPPED does nothing.

All I/O operations that are canceled will complete with the error ERROR_OPERATION_ABORTED. All completion notifications for the I/O operations will occur normally.

See Also

CreateFile, DeviceIoControl, LockFileEx, ReadDirectoryChangesW, ReadFile, ReadFileEx, WriteFile, WriteFileEx


file: /Techref/os/win/api/win32/func/src/f04_5.htm, 2KB, , updated: 2001/6/26 10:35, local time: 2024/7/15 05:15,

 ©2024 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?
Please DO link to this page! Digg it! / MAKE!

<A HREF=""> CancelIo</A>

After you find an appropriate page, you are invited to your to this massmind site! (posts will be visible only to you before review) Just type a nice message (short messages are blocked as spam) in the box and press the Post button. (HTML welcomed, but not the <A tag: Instead, use the link box to link to another page. A tutorial is available Members can login to post directly, become page editors, and be credited for their posts.

Link? Put it here: 
if you want a response, please enter your email address: 
Attn spammers: All posts are reviewed before being made visible to anyone other than the poster.
Did you find what you needed?


Welcome to!


Welcome to!