| Message ID | 1404495717-4239-9-git-send-email-dgilbert@redhat.com |
|---|---|
| State | New |
| Headers | show |
Il 04/07/2014 19:41, Dr. David Alan Gilbert (git) ha scritto: > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > The return path uses a non-blocking fd so as not to block waiting > for the (possibly broken) destination to finish returning a message, > however we still want outbound data to behave in the same way and block. > > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > qemu-file.c | 39 +++++++++++++++++++++++++++++++++++---- > 1 file changed, 35 insertions(+), 4 deletions(-) > > diff --git a/qemu-file.c b/qemu-file.c > index 98a6d2a..9809428 100644 > --- a/qemu-file.c > +++ b/qemu-file.c > @@ -70,12 +70,43 @@ static ssize_t socket_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, > QEMUFileSocket *s = opaque; > ssize_t len; > ssize_t size = iov_size(iov, iovcnt); > + ssize_t offset = 0; > + int err; > > - len = iov_send(s->fd, iov, iovcnt, 0, size); > - if (len < size) { > - len = -socket_error(); > + while (size > 0) { > + len = iov_send(s->fd, iov, iovcnt, offset, size); > + > + if (len > 0) { > + size -= len; > + offset += len; > + } > + > + if (size > 0) { > + err = socket_error(); > + > + if (err != EAGAIN) { > + error_report("socket_writev_buffer: Got err=%d for (%zd/%zd)", > + err, size, len); > + /* > + * If I've already sent some but only just got the error, I > + * could return the amount validly sent so far and wait for the > + * next call to report the error, but I'd rather flag the error > + * immediately. > + */ > + return -err; > + } > + > + /* Emulate blocking */ > + GPollFD pfd; > + > + pfd.fd = s->fd; > + pfd.events = G_IO_OUT | G_IO_ERR; > + pfd.revents = 0; > + g_poll(&pfd, 1 /* 1 fd */, -1 /* no timeout */); > + } > } > - return len; > + > + return offset; > } > > static int socket_get_fd(void *opaque) > I guess the table I just asked about would help clarifying this as well. Also note that g_poll doesn't work on sockets on Windows, but I hope we can avoid it altogether. :) Paolo
diff --git a/qemu-file.c b/qemu-file.c index 98a6d2a..9809428 100644 --- a/qemu-file.c +++ b/qemu-file.c @@ -70,12 +70,43 @@ static ssize_t socket_writev_buffer(void *opaque, struct iovec *iov, int iovcnt, QEMUFileSocket *s = opaque; ssize_t len; ssize_t size = iov_size(iov, iovcnt); + ssize_t offset = 0; + int err; - len = iov_send(s->fd, iov, iovcnt, 0, size); - if (len < size) { - len = -socket_error(); + while (size > 0) { + len = iov_send(s->fd, iov, iovcnt, offset, size); + + if (len > 0) { + size -= len; + offset += len; + } + + if (size > 0) { + err = socket_error(); + + if (err != EAGAIN) { + error_report("socket_writev_buffer: Got err=%d for (%zd/%zd)", + err, size, len); + /* + * If I've already sent some but only just got the error, I + * could return the amount validly sent so far and wait for the + * next call to report the error, but I'd rather flag the error + * immediately. + */ + return -err; + } + + /* Emulate blocking */ + GPollFD pfd; + + pfd.fd = s->fd; + pfd.events = G_IO_OUT | G_IO_ERR; + pfd.revents = 0; + g_poll(&pfd, 1 /* 1 fd */, -1 /* no timeout */); + } } - return len; + + return offset; } static int socket_get_fd(void *opaque)