On Wed, Oct 31, 2012 at 03:45:20PM -0200, Luiz Capitulino wrote:
> It's implemented by opening the serial port in "non-blocking" mode
> and using the GSourceFuncs API in the following way:
>
> o prepare(): issue a read request. If something has been read, it's
> stored in rs->buf and rs->pending will store the number
> of bytes read. If there wasn't any bytes available, we
> set the timeout to 500 ms and return
>
> o check(): returns true if prepare() was able to read anything,
> otherwise return false
>
> o finalize(): does nothing
>
> At dispatch() time we simply copy the bytes read to the buffer passed
> to ga_channel_read().
>
> Signed-off-by: Luiz Capitulino <lcapitul...@redhat.com>
> ---
> qga/channel-win32.c | 87
> +++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 87 insertions(+)
>
> diff --git a/qga/channel-win32.c b/qga/channel-win32.c
> index c173270..887fe5f 100644
> --- a/qga/channel-win32.c
> +++ b/qga/channel-win32.c
> @@ -179,6 +179,46 @@ static gboolean ga_channel_dispatch_ov(GSource *source,
> GSourceFunc unused,
> return success;
> }
>
> +static gboolean ga_channel_prepare(GSource *source, gint *timeout_ms)
> +{
> + GAWatch *watch = (GAWatch *)source;
> + GAChannel *c = (GAChannel *)watch->channel;
> + GAChannelReadState *rs = &c->rstate;
> + DWORD count_read = 0;
> + bool success;
> +
> + success = ReadFile(c->handle, rs->buf, rs->buf_size, &count_read, NULL);
> + if (success) {
> + if (count_read == 0) {
> + *timeout_ms = 500;
> + return false;
> + }
> + rs->pending = count_read;
> + return true;
> + }
> +
> + return false;
> +}
> +
> +static gboolean ga_channel_check(GSource *source)
> +{
> + GAWatch *watch = (GAWatch *)source;
> + GAChannel *c = (GAChannel *)watch->channel;
> + GAChannelReadState *rs = &c->rstate;
> +
> + return !!rs->pending;
> +}
> +
> +static gboolean ga_channel_dispatch(GSource *source, GSourceFunc unused,
> + gpointer user_data)
> +{
> + GAWatch *watch = (GAWatch *)source;
> + GAChannel *c = (GAChannel *)watch->channel;
> +
> + g_assert(c->cb);
> + return c->cb(0, c->user_data);
> +}
> +
> static void ga_channel_finalize_ov(GSource *source)
> {
> g_debug("finalize");
> @@ -203,6 +243,30 @@ static GSource *ga_channel_create_watch_ov(GAChannel *c)
> return source;
> }
>
> +static void ga_channel_finalize(GSource *source)
> +{
> + g_debug("finalize");
> +}
> +
> +GSourceFuncs ga_channel_watch_funcs = {
> + ga_channel_prepare,
> + ga_channel_check,
> + ga_channel_dispatch,
> + ga_channel_finalize
> +};
> +
> +static GSource *ga_channel_create_watch(GAChannel *c)
> +{
> + GSource *source = g_source_new(&ga_channel_watch_funcs, sizeof(GAWatch));
> + GAWatch *watch = (GAWatch *)source;
> +
> + watch->channel = c;
> + watch->pollfd.fd = -1;
> + g_source_add_poll(source, &watch->pollfd);
> +
> + return source;
> +}
> +
> GIOStatus ga_channel_read(GAChannel *c, char *buf, size_t size, gsize *count)
> {
> GAChannelReadState *rs = &c->rstate;
> @@ -225,6 +289,12 @@ GIOStatus ga_channel_read(GAChannel *c, char *buf,
> size_t size, gsize *count)
> status = G_IO_STATUS_AGAIN;
> }
> break;
> + case GA_CHANNEL_ISA_SERIAL:
> + memcpy(buf, rs->buf, rs->pending);
Do we really want to ignore size? Seems like we can overrun their buffer
if it's smaller than ours. You can use rs->start to track the number of
bytes theyve read so far and offset from that in prepare()
> + *count = rs->pending;
> + rs->pending = 0;
> + status = G_IO_STATUS_NORMAL;
> + break;
> default:
> abort(); /* impossible */
> }
> @@ -303,6 +373,7 @@ GAChannel *ga_channel_new(GAChannelMethod method, const
> gchar *path,
> {
> GAChannel *c = g_malloc0(sizeof(GAChannel));
> SECURITY_ATTRIBUTES sec_attrs;
> + COMMTIMEOUTS timeouts;
>
> switch (method) {
> case GA_CHANNEL_VIRTIO_SERIAL:
> @@ -322,6 +393,22 @@ GAChannel *ga_channel_new(GAChannelMethod method, const
> gchar *path,
>
> c->source = ga_channel_create_watch_ov(c);
> break;
> + case GA_CHANNEL_ISA_SERIAL:
> + if (!ga_channel_open(c, path, 0)) {
> + g_critical("error opening channel (path: %s)", path);
> + goto out_err;
> + }
> +
> + /* non-blocking I/O */
> + memset(&timeouts, 0, sizeof(timeouts));
> + timeouts.ReadIntervalTimeout = MAXDWORD;
> + if (!SetCommTimeouts(c->handle, &timeouts)) {
> + CloseHandle(c->handle);
> + goto out_err;
> + }
> +
> + c->source = ga_channel_create_watch(c);
> + break;
> default:
> g_critical("unsupported communication method");
> goto out_err;
> --
> 1.7.12.315.g682ce8b
>
>
