[Spice-devel] [PATCH spice-server v2 1/2] test-stream-device: Better Qemu emulation for data reading

[Frediano Ziglio]

ping series

> 
> Qemu does not trigger a new data read if we don't read all data in
> the buffer.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  server/stream-device.c            |  9 ++++++++
>  server/tests/test-stream-device.c | 43
>  +++++++++++++++++++++++++++++++++++++--
>  2 files changed, 50 insertions(+), 2 deletions(-)
> 
> Changes since v1:
> - avoid an inifinite loop, test added.
> 
> diff --git a/server/stream-device.c b/server/stream-device.c
> index 4eaa959b..897fc665 100644
> --- a/server/stream-device.c
> +++ b/server/stream-device.c
> @@ -123,6 +123,15 @@ stream_device_read_msg_from_dev(RedCharDevice *self,
> SpiceCharDeviceInstance *si
>          dev->hdr_pos = 0;
>      }
>  
> +    if (handled || dev->has_error) {
> +        // Qemu put the device on blocking state if we don't read all data
> +        // so schedule another read.
> +        // We arrive here if we processed that entire message or we
> +        // got an error, try to read another message or discard the
> +        // wrong data
> +        red_char_device_wakeup(self);
> +    }
> +
>      return NULL;
>  }
>  
> diff --git a/server/tests/test-stream-device.c
> b/server/tests/test-stream-device.c
> index 656bf56b..85c7ab1a 100644
> --- a/server/tests/test-stream-device.c
> +++ b/server/tests/test-stream-device.c
> @@ -23,6 +23,7 @@
>  #include <string.h>
>  #include <stdlib.h>
>  #include <stdio.h>
> +#include <unistd.h>
>  
>  #include <spice/protocol.h>
>  #include <spice/stream-device.h>
> @@ -68,8 +69,12 @@ static int vmc_read(SPICE_GNUC_UNUSED
> SpiceCharDeviceInstance *sin,
>      pos += ret;
>      // kick off next message read
>      // currently Qemu kicks the device so we need to do it manually
> -    // here
> -    spice_server_char_device_wakeup(&vmc_instance);
> +    // here. If not all data are read the device goes into blocking
> +    // state and we get the wake only when we read from the device
> +    // again
> +    if (pos >= *message_sizes_curr) {
> +        spice_server_char_device_wakeup(&vmc_instance);
> +    }
>      return ret;
>  }
>  
> @@ -177,11 +182,45 @@ static void test_stream_device(void)
>      basic_event_loop_destroy();
>  }
>  
> +static void test_stream_device_unfinished(void)
> +{
> +    uint8_t *p = message;
> +    SpiceCoreInterface *core = basic_event_loop_init();
> +    Test *test = test_new(core);
> +
> +    pos = 0;
> +    message_sizes_curr = message_sizes;
> +    message_sizes_end = message_sizes;
> +
> +    // this long and not finished message should not cause an inifinite loop
> +    p = add_stream_hdr(p, STREAM_TYPE_DATA, 100000);
> +    *message_sizes_end = p - message;
> +    ++message_sizes_end;
> +
> +    vmc_instance.base.sif = &vmc_interface.base;
> +    spice_server_add_interface(test->server, &vmc_instance.base);
> +
> +    // we need to open the device and kick the start
> +    // the alarm is to avoid program to stuck
> +    alarm(5);
> +    spice_server_port_event(&vmc_instance, SPICE_PORT_EVENT_OPENED);
> +    spice_server_char_device_wakeup(&vmc_instance);
> +    alarm(0);
> +
> +    // we should read all data
> +    g_assert(message_sizes_curr - message_sizes == 1);
> +
> +    test_destroy(test);
> +    basic_event_loop_destroy();
> +}
> +
> +
>  int main(int argc, char *argv[])
>  {
>      g_test_init(&argc, &argv, NULL);
>  
>      g_test_add_func("/server/stream-device", test_stream_device);
> +    g_test_add_func("/server/stream-device-unfinished",
> test_stream_device_unfinished);
>  
>      return g_test_run();
>  }