Problem with aio_write() function

Hello,

How to execute a call back function after aio_write() or aio_read() in Sun Solaris 5.7?

I have filled the control block struct aiocb as follows:
aio_sigevent.sigev_signo = SIGEV
aio_sigevent.sigev_notify = SIGEV_THREAD

Then I have filled the call back function in
aio_sigevent.sigev_notify_function and the argument in sigev_value.

But, this does not execute the call back function though the asynchronous write is completed in the file.

Can someone explain why this is happening & how to correct it ?

Regards,
Murali