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aio_waitcomplete – wait for the next completion of an aio request



Standard C Library (libc, -lc)


#include <aio.h>

aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout);


The aio_waitcomplete() system call waits for completion of an asynchronous I/O request. Upon completion, aio_waitcomplete() returns the result of the function and sets iocbp to point to the structure associated with the original request. If an asynchronous I/O request is completed before aio_waitcomplete() is called, it returns immediately with the completed request.

If timeout is a non-NULL pointer, it specifies a maximum interval to wait for a asynchronous I/O request to complete. If timeout is a NULL pointer, aio_waitcomplete() waits indefinitely. To effect a poll, the timeout argument should be non-NULL, pointing to a zero-valued timeval structure.

The aio_waitcomplete() system call also serves the function of aio_return(), thus aio_return() should not be called for the control block returned in iocbp.


If an asynchronous I/O request has completed, iocbp is set to point to the control block passed with the original request, and the status is returned as described in read(2), write(2), or fsync(2). On failure, aio_waitcomplete() returns -1, sets iocbp to NULL and sets errno to indicate the error condition.


The aio_waitcomplete() system call fails if:
  The specified time limit is invalid.
  The process has not yet called aio_read() or aio_write().
  A signal was delivered before the timeout expired and before any asynchronous I/O requests completed.
  The specified time limit expired before any asynchronous I/O requests completed.


aio_cancel(2), aio_error(2), aio_read(2), aio_return(2), aio_suspend(2), aio_write(2), fsync(2), read(2), write(2), aio(4)


The aio_waitcomplete() system call is a FreeBSD Ns -specific extension.


The aio_waitcomplete() system call first appeared in FreeBSD 4.0 .


The aio_waitcomplete() system call and this manual page were written by Christopher M Sedore <Mt cmsedore@maxwell.syr.edu>.

AIO_WAITCOMPLETE (2) March 21, 2016

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