The aio_suspend() function shall suspend the calling thread until at least one of the asynchronous I/O operations referenced by the list argument has completed, until a signal interrupts the function, or, if timeout is not NULL, until the time interval specified by timeout has passed. The application may determine which AIO completed by scanning operations using aio_error() and aio_return(). aio_supend() shall return zero after one or more AIO operations have completed. If any of the aiocb structures in the list correspond to a completed AIO, the aio_suspend() shall return without suspending. The list array may contain NULL pointers which are ignored. On a timeout exit, aio_suspend shall return with an error. If the monotonic clock option is supported, the clock that shall be used to measure this time interval shall be CLOCK_MONOTONIC clock. aio_suspend() shall return the value -1 and set errno to indicate error if it returns before at least one AIO operation have completed. aio_suspend() shall fail if: [EAGAIN] No AIO indicated in the list completed before timeout aio_suspend() shall fail if: [EINTR] A signal interrupted aio_suspend().