On Fri, Nov 28, 2014 at 7:47 PM, Stefan Hajnoczi <stefa...@gmail.com> wrote: > On Fri, Nov 28, 2014 at 01:55:00PM +0700, Iwan Budi Kusnanto wrote: >> I meant, does the coroutine will do yield internally when it get >> blocked on send(3)? > > No. In general, QEMU will use non-blocking file descriptors so the > blocking case does not apply. (You can't use blocking file descriptors > in an event loop without a risk of blocking the entire event loop.) > > There is qemu_co_send(), which attempts the non-blocking send(2) and > yields on EAGAIN. > > block/sheepdog.c and nbd.c both use this function. It's a little ugly > because the caller must add/remove the socket write fd handler function > so that the coroutine is re-entered when the fd becomes writable again. > > Stefan
Thanks Stefan, it really helps. -- Iwan Budi Kusnanto
