Asynchronous I/O Behavior

Asynchronous I/O operations do not always execute in the sequence in which the operations are queued to the kernel. Asynchronous operations do not necessarily return to the caller in the sequence in which the operations were performed.

If a single buffer is specified for a rapid sequence of calls to aioread(3AIO), the buffer's state is uncertain. The uncertainty of the buffer's state is from the time the first call is made to the time the last result is signaled to the caller.

An individual aio_result_t structure can be used for only one asynchronous operation. The operation can be a read or a write operation.

Real-time Files

SunOS provides no facilities to ensure that files are allocated as physically contiguous.

For regular files, the read(2) and write(2) operations are always buffered. An application can use mmap(2) and msync(3C) to effect direct I/O transfers between secondary storage and process memory.