aio_suspend - wait for asynchronous I/O operation or timeout
int aio_suspend(const struct aiocb * const cblist, int n, const struct timespec *timeout);
The aio_suspend() function suspends the calling process until at least one of the asynchronous I/O requests in the list cblist of length n have completed, a signal is delivered, or timeout is not NULL and the time interval it indicates has passed.
If CLOCK_MONOTONIC is supported, this clock is used to measure the timeout interval.
If this function returns after completion of one of the indicated requests, it returns 0. Otherwise it returns -1 and sets errno appropriately.
EAGAIN The call was ended by timeout, before any of the indicated operations had completed.
EINTR The call was ended by signal. (Possibly the completion signal of one of the operations we were waiting for.)
One can achieve polling by using a non-NULL timeout that specifies a zero time interval.