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 along
15  * with this program; see the file COPYING; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 /* This programme shows the effects of 'heavy' long-running functions
20  * on the cooperative threading model.
21  *
22  * Run it with a config file containing 'password whatever', telnet to it
23  * (it defaults to port 4000) and enter the 'clear foo string' command.
24  * then type whatever and observe that the vty interface is unresponsive
25  * for quite a period of time, due to the clear_something command
26  * taking a very long time to complete.
27  */
28 #include <zebra.h>
29 
30 #include "thread.h"
31 #include "vty.h"
32 #include "command.h"
33 #include "memory.h"
34 #include "log.h"
35 #include "workqueue.h"
36 #include <math.h>
37 
38 #include "tests.h"
39 
40 DEFINE_MGROUP(TEST_HEAVYWQ, "heavy-wq test")
41 DEFINE_MTYPE_STATIC(TEST_HEAVYWQ, WQ_NODE, "heavy_wq_node")
42 DEFINE_MTYPE_STATIC(TEST_HEAVYWQ, WQ_NODE_STR, "heavy_wq_node->str")
43 
44 extern struct thread_master *master;
45 static struct work_queue *heavy_wq;
46 
47 struct heavy_wq_node {
48 	char *str;
49 	int i;
50 };
51 
52 enum { ITERS_FIRST = 0,
53        ITERS_ERR = 100,
54        ITERS_LATER = 400,
55        ITERS_PRINT = 10,
56        ITERS_MAX = 1000,
57 };
58 
heavy_wq_add(struct vty * vty,const char * str,int i)59 static void heavy_wq_add(struct vty *vty, const char *str, int i)
60 {
61 	struct heavy_wq_node *hn;
62 
63 	hn = XCALLOC(MTYPE_WQ_NODE, sizeof(struct heavy_wq_node));
64 
65 	hn->i = i;
66 	hn->str = XSTRDUP(MTYPE_WQ_NODE_STR, str);
67 
68 	work_queue_add(heavy_wq, hn);
69 
70 	return;
71 }
72 
slow_func_err(struct work_queue * wq,struct work_queue_item * item)73 static void slow_func_err(struct work_queue *wq, struct work_queue_item *item)
74 {
75 	printf("%s: running error function\n", __func__);
76 }
77 
slow_func_del(struct work_queue * wq,void * data)78 static void slow_func_del(struct work_queue *wq, void *data)
79 {
80 	struct heavy_wq_node *hn = data;
81 	assert(hn && hn->str);
82 	printf("%s: %s\n", __func__, hn->str);
83 	XFREE(MTYPE_WQ_NODE_STR, hn->str);
84 	XFREE(MTYPE_WQ_NODE, hn);
85 }
86 
slow_func(struct work_queue * wq,void * data)87 static wq_item_status slow_func(struct work_queue *wq, void *data)
88 {
89 	struct heavy_wq_node *hn = data;
90 	double x = 1;
91 	int j;
92 
93 	assert(hn && hn->str);
94 
95 	for (j = 0; j < 300; j++)
96 		x += sin(x) * j;
97 
98 	if ((hn->i % ITERS_LATER) == 0)
99 		return WQ_RETRY_LATER;
100 
101 	if ((hn->i % ITERS_ERR) == 0)
102 		return WQ_RETRY_NOW;
103 
104 	if ((hn->i % ITERS_PRINT) == 0)
105 		printf("%s did %d, x = %g\n", hn->str, hn->i, x);
106 
107 	return WQ_SUCCESS;
108 }
109 
clear_something(struct vty * vty,const char * str)110 static void clear_something(struct vty *vty, const char *str)
111 {
112 	int i;
113 
114 	/* this could be like iterating through 150k of route_table
115 	 * or worse, iterating through a list of peers, to bgp_stop them with
116 	 * each having 150k route tables to process...
117 	 */
118 	for (i = ITERS_FIRST; i < ITERS_MAX; i++)
119 		heavy_wq_add(vty, str, i);
120 }
121 
122 DEFUN (clear_foo,
123        clear_foo_cmd,
124        "clear foo LINE...",
125        "clear command\n"
126        "arbitrary string\n")
127 {
128 	char *str;
129 	if (!argc) {
130 		vty_out(vty, "%% string argument required\n");
131 		return CMD_WARNING;
132 	}
133 
134 	str = argv_concat(argv, argc, 0);
135 
136 	clear_something(vty, str);
137 	XFREE(MTYPE_TMP, str);
138 	return CMD_SUCCESS;
139 }
140 
heavy_wq_init(void)141 static int heavy_wq_init(void)
142 {
143 	heavy_wq = work_queue_new(master, "heavy_work_queue");
144 
145 	heavy_wq->spec.workfunc = &slow_func;
146 	heavy_wq->spec.errorfunc = &slow_func_err;
147 	heavy_wq->spec.del_item_data = &slow_func_del;
148 	heavy_wq->spec.max_retries = 3;
149 	heavy_wq->spec.hold = 1000;
150 
151 	return 0;
152 }
153 
test_init(void)154 void test_init(void)
155 {
156 	install_element(VIEW_NODE, &clear_foo_cmd);
157 	heavy_wq_init();
158 }
159