1/*
2 * This file is part of Quagga.
3 *
4 * Quagga is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the
6 * Free Software Foundation; either version 2, or (at your option) any
7 * later version.
8 *
9 * Quagga is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with Quagga; see the file COPYING.  If not, write to the Free
16 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
17 * 02111-1307, USA.
18 */
19
20/* This programme shows the effects of 'heavy' long-running functions
21 * on the cooperative threading model.
22 *
23 * Run it with a config file containing 'password whatever', telnet to it
24 * (it defaults to port 4000) and enter the 'clear foo string' command.
25 * then type whatever and observe that the vty interface is unresponsive
26 * for quite a period of time, due to the clear_something command
27 * taking a very long time to complete.
28 */
29#include <zebra.h>
30
31#include "thread.h"
32#include "vty.h"
33#include "command.h"
34#include "memory.h"
35#include "log.h"
36#include "workqueue.h"
37#include <math.h>
38
39extern struct thread_master *master;
40static struct work_queue *heavy_wq;
41
42struct heavy_wq_node
43{
44  char *str;
45  int i;
46};
47
48enum
49{
50  ITERS_FIRST = 0,
51  ITERS_ERR = 100,
52  ITERS_LATER = 400,
53  ITERS_PRINT = 10,
54  ITERS_MAX = 1000,
55};
56
57static void
58heavy_wq_add (struct vty *vty, const char *str, int i)
59{
60  struct heavy_wq_node *hn;
61
62  if ((hn = XCALLOC (MTYPE_PREFIX_LIST, sizeof(struct heavy_wq_node))) == NULL)
63    {
64      zlog_err ("%s: unable to allocate hn", __func__);
65      return;
66    }
67
68  hn->i = i;
69  if (!(hn->str = XSTRDUP (MTYPE_PREFIX_LIST_STR, str)))
70    {
71      zlog_err ("%s: unable to xstrdup", __func__);
72      XFREE (MTYPE_PREFIX_LIST, hn);
73      return;
74    }
75
76  work_queue_add (heavy_wq, hn);
77
78  return;
79}
80
81static void
82slow_func_err (struct work_queue *wq, struct work_queue_item *item)
83{
84  printf ("%s: running error function\n", __func__);
85}
86
87static void
88slow_func_del (struct work_queue *wq, void *data)
89{
90  struct heavy_wq_node *hn = data;
91  assert (hn && hn->str);
92  printf ("%s: %s\n", __func__, hn->str);
93  XFREE (MTYPE_PREFIX_LIST_STR, hn->str);
94  hn->str = NULL;
95  XFREE(MTYPE_PREFIX_LIST, hn);
96}
97
98static wq_item_status
99slow_func (struct work_queue *wq, void *data)
100{
101  struct heavy_wq_node *hn = data;
102  double x = 1;
103  int j;
104
105  assert (hn && hn->str);
106
107  for (j = 0; j < 300; j++)
108    x += sin(x)*j;
109
110  if ((hn->i % ITERS_LATER) == 0)
111    return WQ_RETRY_LATER;
112
113  if ((hn->i % ITERS_ERR) == 0)
114    return WQ_RETRY_NOW;
115
116  if ((hn->i % ITERS_PRINT) == 0)
117    printf ("%s did %d, x = %g\n", hn->str, hn->i, x);
118
119  return WQ_SUCCESS;
120}
121
122static void
123clear_something (struct vty *vty, const char *str)
124{
125  int i;
126
127  /* this could be like iterating through 150k of route_table
128   * or worse, iterating through a list of peers, to bgp_stop them with
129   * each having 150k route tables to process...
130   */
131  for (i = ITERS_FIRST; i < ITERS_MAX; i++)
132    heavy_wq_add (vty, str, i);
133}
134
135DEFUN (clear_foo,
136       clear_foo_cmd,
137       "clear foo .LINE",
138       "clear command\n"
139       "arbitrary string\n")
140{
141  char *str;
142  if (!argc)
143    {
144      vty_out (vty, "%% string argument required%s", VTY_NEWLINE);
145      return CMD_WARNING;
146    }
147
148  str = argv_concat (argv, argc, 0);
149
150  clear_something (vty, str);
151  XFREE (MTYPE_TMP, str);
152  return CMD_SUCCESS;
153}
154
155static int
156heavy_wq_init ()
157{
158  if (! (heavy_wq = work_queue_new (master, "heavy_work_queue")))
159    {
160      zlog_err ("%s: could not get new work queue!", __func__);
161      return -1;
162    }
163
164  heavy_wq->spec.workfunc = &slow_func;
165  heavy_wq->spec.errorfunc = &slow_func_err;
166  heavy_wq->spec.del_item_data = &slow_func_del;
167  heavy_wq->spec.max_retries = 3;
168  heavy_wq->spec.hold = 1000;
169
170  return 0;
171}
172
173void
174test_init()
175{
176  install_element (VIEW_NODE, &clear_foo_cmd);
177  heavy_wq_init();
178}
179