This key allows a snapshot view of the number of pending client-application RX messages.

	Note
	As packet reception might occur during calls to this config operation, the information returned may already be stale. If the thread reading this count is the only thread reading messages then this value can be viewed as the minimum number of messages pending. i.e. the client-application should always be able to read the returned number of messages.

A client-application using select() to do a non-busy wait for a message should not normally need to worry about the number of pending messages. This config key support is provided to correspond with the functionality described by the CCB protocol documentation.

This option allows, where provided by the underlying hardware interface port driver, sets of statistics to be monitored. The <cyg/io/ccb_port.h> header file defines the cyg_ccb_devio_stats_t structure used to hold RX and TX information for a specific device driver. This config key functionality uses the <cyg/io/ccb.h> header file defined cyg_ccb_io_stats_t structure to step through the available interface statistics.

The initial cyg_ccb_io_stats_t.priv_ctx field should be initialised to NULL, and then this key config call repeated until the common CCB support returns cyg_ccb_io_stats_t.priv_ctx == NULL (indicating no more data). As per the following pseudocode example:

cyg_ccb_io_stats_t stats;
cyg_bool moredata = true;

stats.priv_ctx = NULL; // start

do {
  int res = cyg_fs_fgetinfo(pcapp->fd,CYG_IO_GET_CONFIG_CCB_STATISTICS,&stats,sizeof(stats));
  if (res < 0) {
    diag_printf("FAIL:<Get statistics error %d \"%s\">\n",res,strerror(errno));
    moredata = false;
  }
  if (moredata) {
    moredata = (stats.priv_ctx != NULL);
    if (moredata) {
      diag_printf("Device \"%s\" : RX pkts=%u (bytes=%llu) dropped=%u : TX pkts=%u (bytes=%llu) retrans=%u failed=%u>n",
                  stats.dname,
                  stats.dstats.rx_pkts,
                  stats.dstats.rx_bytes,
                  stats.dstats.rx_pkts_dropped,
                  stats.dstats.tx_pkts,
                  stats.dstats.tx_bytes,
                  stats.dstats.tx_pkts_retrans,
                  stats.dstats.tx_pkts_failed);
    }
  }
} while (moredata);

When using a cyg_io_handle_t reference to the common CCB layer then the example above would use the corresponding cyg_io interface:

  Cyg_ErrNo res = cyg_io_get_config(pcapp->handle,CYG_IO_GET_CONFIG_CCB_STATISTICS,&stats,&slen);