source: mainline/uspace/srv/net/tcp/ncsim.c@ 4802dd7

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 4802dd7 was 88a6819, checked in by Jiri Svoboda <jiri@…>, 13 years ago

Use fibrils instead of threads for background work in TCP.

  • Property mode set to 100644
File size: 4.4 KB
RevLine 
[8218b6b]1/*
2 * Copyright (c) 2011 Jiri Svoboda
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup tcp
30 * @{
31 */
32
33/**
34 * @file Network condition simulator
35 *
36 * Simulate network conditions for testing the reliability implementation:
37 * - variable latency
38 * - frame drop
39 */
40
41#include <adt/list.h>
42#include <async.h>
43#include <errno.h>
44#include <io/log.h>
45#include <stdlib.h>
[88a6819]46#include <fibril.h>
[8218b6b]47#include "conn.h"
48#include "ncsim.h"
49#include "rqueue.h"
[7cf7ded]50#include "segment.h"
[8218b6b]51#include "tcp_type.h"
52
53static list_t sim_queue;
54static fibril_mutex_t sim_queue_lock;
55static fibril_condvar_t sim_queue_cv;
56
57/** Initialize segment receive queue. */
58void tcp_ncsim_init(void)
59{
60 list_initialize(&sim_queue);
61 fibril_mutex_initialize(&sim_queue_lock);
62 fibril_condvar_initialize(&sim_queue_cv);
63}
64
65/** Bounce segment through simulator into receive queue.
66 *
67 * @param sp Socket pair, oriented for transmission
68 * @param seg Segment
69 */
70void tcp_ncsim_bounce_seg(tcp_sockpair_t *sp, tcp_segment_t *seg)
71{
72 tcp_squeue_entry_t *sqe;
73 tcp_squeue_entry_t *old_qe;
74 link_t *link;
75
[7cf7ded]76 log_msg(LVL_DEBUG, "tcp_ncsim_bounce_seg()");
77 tcp_rqueue_bounce_seg(sp, seg);
78 return;
79
80 if (0 /*random() % 4 == 3*/) {
81 /* Drop segment */
82 log_msg(LVL_ERROR, "NCSim dropping segment");
83 tcp_segment_delete(seg);
84 return;
85 }
[8218b6b]86
87 sqe = calloc(1, sizeof(tcp_squeue_entry_t));
88 if (sqe == NULL) {
89 log_msg(LVL_ERROR, "Failed allocating SQE.");
90 return;
91 }
92
93 sqe->delay = random() % (1000 * 1000);
94 sqe->sp = *sp;
95 sqe->seg = seg;
96
97 fibril_mutex_lock(&sim_queue_lock);
98
99 link = list_first(&sim_queue);
100 while (link != NULL && sqe->delay > 0) {
101 old_qe = list_get_instance(link, tcp_squeue_entry_t, link);
102 if (sqe->delay < old_qe->delay)
103 break;
104
105 sqe->delay -= old_qe->delay;
106
107 link = link->next;
108 if (link == &sim_queue.head)
109 link = NULL;
110 }
111
112 if (link != NULL)
113 list_insert_after(&sqe->link, link);
114 else
115 list_append(&sqe->link, &sim_queue);
116
117 fibril_condvar_broadcast(&sim_queue_cv);
118 fibril_mutex_unlock(&sim_queue_lock);
119}
120
[88a6819]121/** Network condition simulator handler fibril. */
122static int tcp_ncsim_fibril(void *arg)
[8218b6b]123{
124 link_t *link;
125 tcp_squeue_entry_t *sqe;
126 int rc;
127
[88a6819]128 log_msg(LVL_DEBUG, "tcp_ncsim_fibril()");
[8218b6b]129
130
131 while (true) {
132 fibril_mutex_lock(&sim_queue_lock);
133
134 while (list_empty(&sim_queue))
135 fibril_condvar_wait(&sim_queue_cv, &sim_queue_lock);
136
137 do {
138 link = list_first(&sim_queue);
139 sqe = list_get_instance(link, tcp_squeue_entry_t, link);
140
141 log_msg(LVL_DEBUG, "NCSim - Sleep");
142 rc = fibril_condvar_wait_timeout(&sim_queue_cv,
143 &sim_queue_lock, sqe->delay);
144 } while (rc != ETIMEOUT);
145
146 list_remove(link);
147 fibril_mutex_unlock(&sim_queue_lock);
148
149 log_msg(LVL_DEBUG, "NCSim - End Sleep");
150 tcp_rqueue_bounce_seg(&sqe->sp, sqe->seg);
151 free(sqe);
152 }
[88a6819]153
154 /* Not reached */
155 return 0;
[8218b6b]156}
157
[88a6819]158/** Start simulator handler fibril. */
159void tcp_ncsim_fibril_start(void)
[8218b6b]160{
[88a6819]161 fid_t fid;
[8218b6b]162
[88a6819]163 log_msg(LVL_DEBUG, "tcp_ncsim_fibril_start()");
[8218b6b]164
[88a6819]165 fid = fibril_create(tcp_ncsim_fibril, NULL);
166 if (fid == 0) {
167 log_msg(LVL_ERROR, "Failed creating ncsim fibril.");
[8218b6b]168 return;
169 }
[88a6819]170
171 fibril_add_ready(fid);
[8218b6b]172}
173
174/**
175 * @}
176 */
Note: See TracBrowser for help on using the repository browser.