Async read/write

Question

Hi all,
I am developing a device driver for a custom PCI card on 64 bit Sparc
Solaris 8 which is going to replace another card. We already have
applications running, so I'm supposed to give the same interface as the
original one.
The application with the original driver/card makes asynchronous
reads/writes as follows:
- open(device, O_RDWR | O_NONBLOCK)
- call write
- for (;;) {
call ioctl to get device status
break on completion or error.
- call write second time (same buffer, same size)
So, in the driver, I should implement async writes in the 'write'
entry, not 'awrite'.
I was thinking of creating an aio_req structure and calling aphysio
inside 'write', but this is not documented. Another problem in this
approach is the second call to 'write' in the application.
So my questions are:
1) How should I implement this? Create a thread and provide async
functionality inside this thread? But this doesn't make much sense to
me because there's already an async functionality provided by Solaris.
2) What could the purpose of the second 'write' call be in the user app.
Thanks in advance

Answer 1

All has been checked, and rechecked.
We now have a very strange situation:
We testen failover by manually turning of one LPAR at a time.
After this reboot, the Async I/O error seem to have gone.
That is, they haven't appeared now for two days
Why they occurred and why they don't occur anymore is not found/explained
There I'll close this thread.