SIGEV_KEVENT       42 os/unix/ngx_aio_read.c         rev->aiocb.aio_sigevent.sigev_notify = SIGEV_KEVENT;
SIGEV_KEVENT       39 os/unix/ngx_aio_write.c         wev->aiocb.aio_sigevent.sigev_notify = SIGEV_KEVENT;
SIGEV_KEVENT      100 os/unix/ngx_file_aio_read.c     aio->aiocb.aio_sigevent.sigev_notify = SIGEV_KEVENT;