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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2001-2004
* Sleepycat Software. All rights reserved.
*
* $Id: ex_rq_client.c,v 1.39 2004/01/28 03:36:03 bostic Exp $
*/
#include <sys/types.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <db.h>
#include "ex_repquote.h"
static void *check_loop __P((void *));
static void *display_loop __P((void *));
static int print_stocks __P((DBC *));
typedef struct {
const char *progname;
DB_ENV *dbenv;
} disploop_args;
typedef struct {
DB_ENV *dbenv;
machtab_t *machtab;
const char *progname;
} checkloop_args;
int
doclient(dbenv, progname, machtab)
DB_ENV *dbenv;
const char *progname;
machtab_t *machtab;
{
checkloop_args cargs;
disploop_args dargs;
thread check_thr, disp_thr;
void *cstatus, *dstatus;
int rval, s;
rval = EXIT_SUCCESS;
s = -1;
memset(&dargs, 0, sizeof(dargs));
dargs.progname = progname;
dargs.dbenv = dbenv;
if (thread_create(&disp_thr, NULL, display_loop, (void *)&dargs)) {
dbenv->err(dbenv, errno, "display_loop thread creation failed");
goto err;
}
cargs.dbenv = dbenv;
cargs.machtab = machtab;
cargs.progname = progname;
if (thread_create(&check_thr, NULL, check_loop, (void *)&cargs)) {
dbenv->err(dbenv, errno, "check_thread pthread_create failed");
goto err;
}
if (thread_join(disp_thr, &dstatus) ||
thread_join(check_thr, &cstatus)) {
dbenv->err(dbenv, errno, "pthread_join failed");
goto err;
}
if (0) {
err: rval = EXIT_FAILURE;
}
return (rval);
}
/*
* Our only job is to check that the master is valid and if it's not
* for an extended period, to trigger an election. We do two phases.
* If we do not have a master, first we send out a request for a master
* to identify itself (that would be a call to rep_start). If that fails,
* we trigger an election.
*/
static void *
check_loop(args)
void *args;
{
DB_ENV *dbenv;
DBT dbt;
const char *progname;
checkloop_args *cargs;
int count, n, pri;
machtab_t *machtab;
u_int32_t timeout;
cargs = (checkloop_args *)args;
dbenv = cargs->dbenv;
machtab = cargs->machtab;
progname = cargs->progname;
#define IDLE_INTERVAL 1
count = 0;
while (master_eid == DB_EID_INVALID) {
/*
* Call either rep_start or rep_elect depending on if
* count is 0 or 1.
*/
if (count == 0) {
memset(&dbt, 0, sizeof(dbt));
dbt.data = myaddr;
dbt.size = strlen(myaddr) + 1;
(void)dbenv->rep_start(dbenv, &dbt, DB_REP_CLIENT);
count = 1;
} else {
machtab_parm(machtab, &n, &pri, &timeout);
if (dbenv->rep_elect(dbenv,
n, (n/2+1), pri, timeout, &master_eid, 0) == 0)
break;
count = 0;
}
sleep(IDLE_INTERVAL);
}
/* Check if I won the election. */
if (master_eid == SELF_EID &&
dbenv->rep_start(dbenv, NULL, DB_REP_MASTER) == 0)
(void)domaster(dbenv, progname);
return ((void *)EXIT_SUCCESS);
}
static void *
display_loop(args)
void *args;
{
DB *dbp;
DB_ENV *dbenv;
DBC *dbc;
const char *progname;
disploop_args *dargs;
int ret, rval, t_ret;
dargs = (disploop_args *)args;
progname = dargs->progname;
dbenv = dargs->dbenv;
dbc = NULL;
dbp = NULL;
ret = 0;
retry: for (;;) {
/* If we become master, shut this loop off. */
if (master_eid == SELF_EID)
break;
if (dbp == NULL) {
if ((ret = db_create(&dbp, dbenv, 0)) != 0) {
dbenv->err(dbenv, ret, "db_create");
return ((void *)EXIT_FAILURE);
}
if ((ret = dbp->open(dbp, NULL,
DATABASE, NULL, DB_BTREE, DB_RDONLY, 0)) != 0) {
if (ret == ENOENT) {
printf(
"No stock database yet available.\n");
if ((ret = dbp->close(dbp, 0)) != 0) {
dbenv->err(dbenv,
ret, "DB->close");
goto err;
}
dbp = NULL;
sleep(SLEEPTIME);
continue;
}
dbenv->err(dbenv, ret, "DB->open");
goto err;
}
}
if ((ret = dbp->cursor(dbp, NULL, &dbc, 0)) != 0)
dbenv->err(dbenv, ret, "DB->cursor");
else {
if ((ret = print_stocks(dbc)) != 0)
dbenv->err(dbenv, ret,
"database traversal failed");
if ((t_ret = dbc->c_close(dbc)) != 0) {
dbenv->err(dbenv, ret, "DBC->c_close");
if (ret == 0)
ret = t_ret;
}
}
if (ret == DB_REP_HANDLE_DEAD) {
dbp = NULL;
continue;
} else if (ret != 0)
goto err;
dbc = NULL;
sleep(SLEEPTIME);
}
err: rval = EXIT_SUCCESS;
switch (ret) {
case DB_LOCK_DEADLOCK:
if (dbc != NULL) {
(void)dbc->c_close(dbc);
dbc = NULL;
}
ret = 0;
goto retry;
case DB_REP_HANDLE_DEAD:
if (dbp != NULL) {
(void)dbp->close(dbp, DB_NOSYNC);
dbp = NULL;
}
ret = 0;
goto retry;
default:
break;
}
if (ret != 0)
rval = EXIT_FAILURE;
if (dbp != NULL && (ret = dbp->close(dbp, 0)) != 0) {
dbenv->err(dbenv, ret, "DB->close");
return ((void *)EXIT_FAILURE);
}
return ((void *)rval);
}
static int
print_stocks(dbc)
DBC *dbc;
{
DBT key, data;
#define MAXKEYSIZE 10
#define MAXDATASIZE 20
char keybuf[MAXKEYSIZE + 1], databuf[MAXDATASIZE + 1];
int ret;
u_int32_t keysize, datasize;
memset(&key, 0, sizeof(key));
memset(&data, 0, sizeof(data));
printf("\tSymbol\tPrice\n");
printf("\t======\t=====\n");
for (ret = dbc->c_get(dbc, &key, &data, DB_FIRST);
ret == 0;
ret = dbc->c_get(dbc, &key, &data, DB_NEXT)) {
keysize = key.size > MAXKEYSIZE ? MAXKEYSIZE : key.size;
memcpy(keybuf, key.data, keysize);
keybuf[keysize] = '\0';
datasize = data.size >= MAXDATASIZE ? MAXDATASIZE : data.size;
memcpy(databuf, data.data, datasize);
databuf[datasize] = '\0';
printf("\t%s\t%s\n", keybuf, databuf);
}
printf("\n");
return (ret == DB_NOTFOUND ? 0 : ret);
}
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