[Spice-devel] [PATCH spice-server 3/4] reds-stream: Introduce reds_stream_set_no_delay() helper

[Frediano Ziglio]

> 
> From: Christophe Fergeau <cfergeau at redhat.com>
> 
> The code to enable/disable on a TCP socket is duplicated in multiple
> places in the code base, this commit replaces this duplicated code with
> a helper in RedsStream.
> ---
>  server/common-graphics-channel.c | 13 ++-----------
>  server/red-channel-client.c      | 17 ++---------------
>  server/reds-stream.c             | 16 ++++++++++++++++
>  server/reds-stream.h             |  1 +
>  server/reds.c                    |  8 +-------
>  server/sound.c                   |  8 +-------
>  6 files changed, 23 insertions(+), 40 deletions(-)
> 
> diff --git a/server/common-graphics-channel.c
> b/server/common-graphics-channel.c
> index bad6e8c..a076111 100644
> --- a/server/common-graphics-channel.c
> +++ b/server/common-graphics-channel.c
> @@ -19,9 +19,6 @@
>  #endif
>  
>  #include <fcntl.h>
> -#include <sys/socket.h>
> -#include <netinet/in.h>
> -#include <netinet/tcp.h>
>  
>  #include "common-graphics-channel.h"
>  #include "dcc.h"
> @@ -117,24 +114,18 @@ int common_channel_config_socket(RedChannelClient *rcc)
>      RedClient *client = red_channel_client_get_client(rcc);
>      MainChannelClient *mcc = red_client_get_main(client);
>      RedsStream *stream = red_channel_client_get_stream(rcc);
> -    int delay_val;
>      gboolean is_low_bandwidth;
>  
>      // TODO - this should be dynamic, not one time at channel creation
>      is_low_bandwidth = main_channel_client_is_low_bandwidth(mcc);
> -    delay_val = is_low_bandwidth ? 0 : 1;
>      /* FIXME: Using Nagle's Algorithm can lead to apparent delays, depending
>       * on the delayed ack timeout on the other side.
>       * Instead of using Nagle's, we need to implement message buffering on
>       * the application level.
>       * see: http://www.stuartcheshire.org/papers/NagleDelayedAck/
>       */
> -    if (setsockopt(stream->socket, IPPROTO_TCP, TCP_NODELAY, &delay_val,
> -                   sizeof(delay_val)) == -1) {
> -        if (errno != ENOTSUP) {
> -            spice_warning("setsockopt failed, %s", strerror(errno));
> -        }
> -    }
> +    reds_stream_set_no_delay(stream, is_low_bandwidth);
> +
>      // TODO: move wide/narrow ack setting to red_channel.
>      red_channel_client_ack_set_client_window(rcc,
>          is_low_bandwidth ?
> diff --git a/server/red-channel-client.c b/server/red-channel-client.c
> index 32db186..f79edfc 100644
> --- a/server/red-channel-client.c
> +++ b/server/red-channel-client.c
> @@ -584,13 +584,7 @@ static void
> red_channel_client_send_ping(RedChannelClient *rcc)
>          }  else {
>              rcc->priv->latency_monitor.tcp_nodelay = delay_val;
>              if (!delay_val) {
> -                delay_val = 1;
> -                if (setsockopt(rcc->priv->stream->socket, IPPROTO_TCP,
> TCP_NODELAY, &delay_val,
> -                               sizeof(delay_val)) == -1) {
> -                   if (errno != ENOTSUP) {
> -                        spice_warning("setsockopt failed, %s",
> strerror(errno));
> -                    }
> -                }
> +                reds_stream_set_no_delay(rcc->priv->stream, TRUE);
>              }
>          }
>      }
> @@ -1414,14 +1408,7 @@ static void
> red_channel_client_handle_pong(RedChannelClient *rcc, SpiceMsgPing *
>  
>      /* set TCP_NODELAY=0, in case we reverted it for the test*/
>      if (!rcc->priv->latency_monitor.tcp_nodelay) {
> -        int delay_val = 0;
> -
> -        if (setsockopt(rcc->priv->stream->socket, IPPROTO_TCP, TCP_NODELAY,
> &delay_val,
> -                       sizeof(delay_val)) == -1) {
> -            if (errno != ENOTSUP) {
> -                spice_warning("setsockopt failed, %s", strerror(errno));
> -            }
> -        }
> +        reds_stream_set_no_delay(rcc->priv->stream, FALSE);
>      }
>  
>      /*
> diff --git a/server/reds-stream.c b/server/reds-stream.c
> index d0dadb9..f1952cc 100644
> --- a/server/reds-stream.c
> +++ b/server/reds-stream.c
> @@ -21,6 +21,7 @@
>  
>  #include <errno.h>
>  #include <netdb.h>
> +#include <netinet/tcp.h>
>  #include <unistd.h>
>  #include <sys/socket.h>
>  #include <fcntl.h>
> @@ -256,6 +257,21 @@ int reds_stream_is_plain_unix(const RedsStream *s)
>  
>  }
>  
> +bool reds_stream_set_no_delay(RedsStream *stream, bool no_delay)
> +{
> +    int delay_val = no_delay;
> +
> +    if (setsockopt(stream->socket, IPPROTO_TCP, TCP_NODELAY,
> +                   &delay_val, sizeof(delay_val)) != 0) {
> +        if (errno != ENOTSUP && errno != ENOPROTOOPT) {
> +            spice_printerr("setsockopt failed, %s", strerror(errno));
> +            return FALSE;
> +        }
> +    }
> +
> +    return TRUE;
> +}
> +
>  int reds_stream_send_msgfd(RedsStream *stream, int fd)
>  {
>      struct msghdr msgh = { 0, };
> diff --git a/server/reds-stream.h b/server/reds-stream.h
> index a8d1736..c76014b 100644
> --- a/server/reds-stream.h
> +++ b/server/reds-stream.h
> @@ -74,6 +74,7 @@ int reds_stream_enable_ssl(RedsStream *stream, SSL_CTX
> *ctx);
>  void reds_stream_set_info_flag(RedsStream *stream, unsigned int flag);
>  int reds_stream_get_family(const RedsStream *stream);
>  int reds_stream_is_plain_unix(const RedsStream *stream);
> +bool reds_stream_set_no_delay(RedsStream *stream, bool no_delay);
>  int reds_stream_send_msgfd(RedsStream *stream, int fd);
>  
>  typedef enum {
> diff --git a/server/reds.c b/server/reds.c
> index 39a7a31..a245f90 100644
> --- a/server/reds.c
> +++ b/server/reds.c
> @@ -2387,7 +2387,6 @@ static bool reds_init_keepalive(int socket)
>  static RedLinkInfo *reds_init_client_connection(RedsState *reds, int socket)
>  {
>      RedLinkInfo *link;
> -    int delay_val = 1;
>      int flags;
>  
>      if ((flags = fcntl(socket, F_GETFL)) == -1) {
> @@ -2400,17 +2399,12 @@ static RedLinkInfo
> *reds_init_client_connection(RedsState *reds, int socket)
>          goto error;
>      }
>  
> -    if (setsockopt(socket, IPPROTO_TCP, TCP_NODELAY, &delay_val,
> sizeof(delay_val)) == -1) {
> -        if (errno != ENOTSUP) {
> -            spice_warning("setsockopt failed, %s", strerror(errno));
> -        }
> -    }
> -
>      reds_init_keepalive(socket);
>  
>      link = spice_new0(RedLinkInfo, 1);
>      link->reds = reds;
>      link->stream = reds_stream_new(reds, socket);
> +    reds_stream_set_no_delay(link->stream, TRUE);
>  
>      /* gather info + send event */
>  
> diff --git a/server/sound.c b/server/sound.c
> index e83a547..0c92480 100644
> --- a/server/sound.c
> +++ b/server/sound.c
> @@ -739,7 +739,6 @@ static void record_channel_send_item(RedChannelClient
> *rcc, G_GNUC_UNUSED RedPip
>  
>  static int snd_channel_config_socket(RedChannelClient *rcc)
>  {
> -    int delay_val;
>  #ifdef SO_PRIORITY
>      int priority;
>  #endif
> @@ -765,12 +764,7 @@ static int snd_channel_config_socket(RedChannelClient
> *rcc)
>          }
>      }
>  
> -    delay_val = main_channel_client_is_low_bandwidth(mcc) ? 0 : 1;
> -    if (setsockopt(stream->socket, IPPROTO_TCP, TCP_NODELAY, &delay_val,
> sizeof(delay_val)) == -1) {
> -        if (errno != ENOTSUP) {
> -            spice_printerr("setsockopt failed, %s", strerror(errno));
> -        }
> -    }
> +    reds_stream_set_no_delay(stream,
> main_channel_client_is_low_bandwidth(mcc));
>  
>      return TRUE;
>  }

Patch is good however the use of bool is inconsistent.
Although I _much_ prefer bool/true/false we decided for gboolean/TRUE/FALSE.

Frediano