diff options
| author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2010-10-27 19:16:26 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-10-28 10:27:00 -0700 |
| commit | dc841e30eaea9f9f83c9ab1ee0b3ef9e5c95ce8a (patch) | |
| tree | 921458d0ea02f1478dbac9305c1925dbea8c0dd9 /include | |
| parent | fe84f4140f0d24deca8591e38926b95cfd097e62 (diff) | |
dccp: Extend CCID packet dequeueing interface
This extends the packet dequeuing interface of dccp_write_xmit() to allow
1. CCIDs to take care of timing when the next packet may be sent;
2. delayed sending (as before, with an inter-packet gap up to 65.535 seconds).
The main purpose is to take CCID-2 out of its polling mode (when it is network-
limited, it tries every millisecond to send, without interruption).
The mode of operation for (2) is as follows:
* new packet is enqueued via dccp_sendmsg() => dccp_write_xmit(),
* ccid_hc_tx_send_packet() detects that it may not send (e.g. window full),
* it signals this condition via `CCID_PACKET_WILL_DEQUEUE_LATER',
* dccp_write_xmit() returns without further action;
* after some time the wait-condition for CCID becomes true,
* that CCID schedules the tasklet,
* tasklet function calls ccid_hc_tx_send_packet() via dccp_write_xmit(),
* since the wait-condition is now true, ccid_hc_tx_packet() returns "send now",
* packet is sent, and possibly more (since dccp_write_xmit() loops).
Code reuse: the taskled function calls dccp_write_xmit(), the timer function
reduces to a wrapper around the same code.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/dccp.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 7187bd8a75f6..749f01ccd26e 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -462,7 +462,8 @@ struct dccp_ackvec; * @dccps_hc_rx_insert_options - receiver wants to add options when acking * @dccps_hc_tx_insert_options - sender wants to add options when sending * @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3) - * @dccps_xmit_timer - timer for when CCID is not ready to send + * @dccps_xmitlet - tasklet scheduled by the TX CCID to dequeue data packets + * @dccps_xmit_timer - used by the TX CCID to delay sending (rate-based pacing) * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs) */ struct dccp_sock { @@ -502,6 +503,7 @@ struct dccp_sock { __u8 dccps_hc_rx_insert_options:1; __u8 dccps_hc_tx_insert_options:1; __u8 dccps_server_timewait:1; + struct tasklet_struct dccps_xmitlet; struct timer_list dccps_xmit_timer; }; |