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/*
* $Id: heavy-thread.c,v 1.2 2005/04/25 16:42:24 paul Exp $
*
* This file is part of Quagga.
*
* Quagga is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* Quagga is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Quagga; see the file COPYING. If not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
/* This programme shows the effects of 'heavy' long-running functions
* on the cooperative threading model, as demonstrated by heavy.c, and how
* they can be mitigated using a background thread.
*
* Run it with a config file containing 'password whatever', telnet to it
* (it defaults to port 4000) and enter the 'clear foo string' command.
* then type whatever and observe that, unlike heavy.c, the vty interface
* remains responsive.
*/
#include <zebra.h>
#include <math.h>
#include "thread.h"
#include "vty.h"
#include "command.h"
#include "memory.h"
#include "log.h"
extern struct thread_master *master;
enum
{
ITERS_FIRST = 0,
ITERS_ERR = 100,
ITERS_LATER = 400,
ITERS_PRINT = 10,
ITERS_MAX = 1000,
};
struct work_state {
struct vty *vty;
char *str;
int i;
};
static void
slow_func (struct vty *vty, const char *str, const int i)
{
double x = 1;
int j;
for (j = 0; j < 300; j++)
x += sin(x)*j;
if ((i % ITERS_LATER) == 0)
printf ("%s: %d, temporary error, save this somehow and do it later..\n",
__func__, i);
if ((i % ITERS_ERR) == 0)
printf ("%s: hard error\n", __func__);
if ((i % ITERS_PRINT) == 0)
printf ("%s did %d, x = %g\n", str, i, x);
}
static int
clear_something (struct thread *thread)
{
struct work_state *ws = THREAD_ARG(thread);
/* this could be like iterating through 150k of route_table
* or worse, iterating through a list of peers, to bgp_stop them with
* each having 150k route tables to process...
*/
while (ws->i < ITERS_MAX)
{
slow_func(ws->vty, ws->str, ws->i);
ws->i++;
if (thread_should_yield(thread))
{
thread_add_background(master, clear_something, ws, 0);
return 0;
}
}
/* All done! */
XFREE (MTYPE_TMP, ws->str);
XFREE (MTYPE_TMP, ws);
return 0;
}
DEFUN (clear_foo,
clear_foo_cmd,
"clear foo .LINE",
"clear command\n"
"arbitrary string\n")
{
char *str;
struct work_state *ws;
if (!argc)
{
vty_out (vty, "%% string argument required%s", VTY_NEWLINE);
return CMD_WARNING;
}
str = argv_concat (argv, argc, 0);
if ((ws = XMALLOC(MTYPE_TMP, sizeof(*ws))) == NULL)
{
zlog_err ("%s: unable to allocate work_state", __func__);
return CMD_WARNING;
}
if (!(ws->str = XSTRDUP (MTYPE_TMP, str)))
{
zlog_err ("%s: unable to xstrdup", __func__);
XFREE (MTYPE_TMP, ws);
return CMD_WARNING;
}
ws->vty = vty;
ws->i = ITERS_FIRST;
thread_add_background(master, clear_something, ws, 0);
return CMD_SUCCESS;
}
void
test_init()
{
install_element (VIEW_NODE, &clear_foo_cmd);
}
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