tests/lib/test_heavy_thread.c

   1 /*
   2  * $Id: heavy-thread.c,v 1.2 2005/04/25 16:42:24 paul Exp $
   3  *
   4  * This file is part of Quagga.
   5  *
   6  * Quagga is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * Quagga is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /* This programme shows the effects of 'heavy' long-running functions
  22  * on the cooperative threading model, as demonstrated by heavy.c, and how
  23  * they can be mitigated using a background thread.
  24  *
  25  * Run it with a config file containing 'password whatever', telnet to it
  26  * (it defaults to port 4000) and enter the 'clear foo string' command.
  27  * then type whatever and observe that, unlike heavy.c, the vty interface
  28  * remains responsive.
  29  */
  30 #include <zebra.h>
  31 #include <math.h>
  32
  33 #include "thread.h"
  34 #include "vty.h"
  35 #include "command.h"
  36 #include "memory.h"
  37 #include "log.h"
  38
  39 #include "tests.h"
  40
  41 extern struct thread_master *master;
  42
  43 enum { ITERS_FIRST = 0,
  44        ITERS_ERR = 100,
  45        ITERS_LATER = 400,
  46        ITERS_PRINT = 10,
  47        ITERS_MAX = 1000,
  48 };
  49
  50 struct work_state {
  51         struct vty *vty;
  52         char *str;
  53         int i;
  54 };
  55
  56 static void slow_func(struct vty *vty, const char *str, const int i)
  57 {
  58         double x = 1;
  59         int j;
  60
  61         for (j = 0; j < 300; j++)
  62                 x += sin(x) * j;
  63
  64         if ((i % ITERS_LATER) == 0)
  65                 printf("%s: %d, temporary error, save this somehow and do it later..\n",
  66                        __func__, i);
  67
  68         if ((i % ITERS_ERR) == 0)
  69                 printf("%s: hard error\n", __func__);
  70
  71         if ((i % ITERS_PRINT) == 0)
  72                 printf("%s did %d, x = %g\n", str, i, x);
  73 }
  74
  75 static int clear_something(struct thread *thread)
  76 {
  77         struct work_state *ws = THREAD_ARG(thread);
  78
  79         /* this could be like iterating through 150k of route_table
  80          * or worse, iterating through a list of peers, to bgp_stop them with
  81          * each having 150k route tables to process...
  82          */
  83         while (ws->i < ITERS_MAX) {
  84                 slow_func(ws->vty, ws->str, ws->i);
  85                 ws->i++;
  86                 if (thread_should_yield(thread)) {
  87                         thread_add_timer_msec(master, clear_something, ws, 0,
  88                                               NULL);
  89                         return 0;
  90                 }
  91         }
  92
  93         /* All done! */
  94         XFREE(MTYPE_TMP, ws->str);
  95         XFREE(MTYPE_TMP, ws);
  96         return 0;
  97 }
  98
  99 DEFUN (clear_foo,
 100        clear_foo_cmd,
 101        "clear foo LINE...",
 102        "clear command\n"
 103        "arbitrary string\n")
 104 {
 105         char *str;
 106         struct work_state *ws;
 107
 108         if (!argc) {
 109                 vty_out(vty, "%% string argument required\n");
 110                 return CMD_WARNING;
 111         }
 112
 113         str = argv_concat(argv, argc, 0);
 114
 115         if ((ws = XMALLOC(MTYPE_TMP, sizeof(*ws))) == NULL) {
 116                 zlog_err("%s: unable to allocate work_state", __func__);
 117                 return CMD_WARNING;
 118         }
 119
 120         if (!(ws->str = XSTRDUP(MTYPE_TMP, str))) {
 121                 zlog_err("%s: unable to xstrdup", __func__);
 122                 XFREE(MTYPE_TMP, ws);
 123                 return CMD_WARNING;
 124         }
 125
 126         ws->vty = vty;
 127         ws->i = ITERS_FIRST;
 128
 129         thread_add_timer_msec(master, clear_something, ws, 0, NULL);
 130
 131         return CMD_SUCCESS;
 132 }
 133
 134 void test_init()
 135 {
 136         install_element(VIEW_NODE, &clear_foo_cmd);
 137 }