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author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2010-10-27 19:16:26 +0000 |
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committer | David S. Miller <davem@davemloft.net> | 2010-10-28 10:27:00 -0700 |
commit | dc841e30eaea9f9f83c9ab1ee0b3ef9e5c95ce8a (patch) | |
tree | 921458d0ea02f1478dbac9305c1925dbea8c0dd9 /net/dccp/timer.c | |
parent | fe84f4140f0d24deca8591e38926b95cfd097e62 (diff) | |
download | linux-dc841e30eaea9f9f83c9ab1ee0b3ef9e5c95ce8a.tar.bz2 |
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 'net/dccp/timer.c')
-rw-r--r-- | net/dccp/timer.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/net/dccp/timer.c b/net/dccp/timer.c index 1a9aa05d4dc4..916f9d1dab36 100644 --- a/net/dccp/timer.c +++ b/net/dccp/timer.c @@ -237,32 +237,35 @@ out: sock_put(sk); } -/* Transmit-delay timer: used by the CCIDs to delay actual send time */ -static void dccp_write_xmit_timer(unsigned long data) +/** + * dccp_write_xmitlet - Workhorse for CCID packet dequeueing interface + * See the comments above %ccid_dequeueing_decision for supported modes. + */ +static void dccp_write_xmitlet(unsigned long data) { struct sock *sk = (struct sock *)data; - struct dccp_sock *dp = dccp_sk(sk); bh_lock_sock(sk); if (sock_owned_by_user(sk)) - sk_reset_timer(sk, &dp->dccps_xmit_timer, jiffies+1); + sk_reset_timer(sk, &dccp_sk(sk)->dccps_xmit_timer, jiffies + 1); else dccp_write_xmit(sk, 0); bh_unlock_sock(sk); - sock_put(sk); } -static void dccp_init_write_xmit_timer(struct sock *sk) +static void dccp_write_xmit_timer(unsigned long data) { - struct dccp_sock *dp = dccp_sk(sk); - - setup_timer(&dp->dccps_xmit_timer, dccp_write_xmit_timer, - (unsigned long)sk); + dccp_write_xmitlet(data); + sock_put((struct sock *)data); } void dccp_init_xmit_timers(struct sock *sk) { - dccp_init_write_xmit_timer(sk); + struct dccp_sock *dp = dccp_sk(sk); + + tasklet_init(&dp->dccps_xmitlet, dccp_write_xmitlet, (unsigned long)sk); + setup_timer(&dp->dccps_xmit_timer, dccp_write_xmit_timer, + (unsigned long)sk); inet_csk_init_xmit_timers(sk, &dccp_write_timer, &dccp_delack_timer, &dccp_keepalive_timer); } |