db_server_cxxutil.cpp

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 2000-2005
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: db_server_cxxutil.cpp,v 12.2 2005/06/16 20:23:40 bostic Exp $
 */

#include "db_config.h"

#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>

#if TIME_WITH_SYS_TIME
#include <sys/time.h>
#include <time.h>
#else
#if HAVE_SYS_TIME_H
#include <sys/time.h>
#else
#include <time.h>
#endif
#endif

#include <rpc/rpc.h>

#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#endif

#include "db_server.h"

#include "db_int.h"
#include "db_cxx.h"
#include "dbinc_auto/clib_ext.h"

extern "C" {
#include "dbinc/db_server_int.h"
#include "dbinc_auto/rpc_server_ext.h"
#include "dbinc_auto/common_ext.h"

extern int __dbsrv_main  __P((void));
}

static int add_home __P((char *));
static int add_passwd __P((char *));
static int env_recover __P((char *));
static void __dbclear_child __P((ct_entry *));

static LIST_HEAD(cthead, ct_entry) __dbsrv_head;
static LIST_HEAD(homehead, home_entry) __dbsrv_home;
static long __dbsrv_defto = DB_SERVER_TIMEOUT;
static long __dbsrv_maxto = DB_SERVER_MAXTIMEOUT;
static long __dbsrv_idleto = DB_SERVER_IDLETIMEOUT;
static char *logfile = NULL;
static char *prog;

static void usage __P((char *));
static void version_check __P((void));

int __dbsrv_verbose = 0;

int
main(
        int argc,
        char **argv)
{
        extern char *optarg;
        CLIENT *cl;
        int ch, ret;
        char *passwd;

        prog = argv[0];

        version_check();

        /*
         * Check whether another server is running or not.  There
         * is a race condition where two servers could be racing to
         * register with the portmapper.  The goal of this check is to
         * forbid running additional servers (like those started from
         * the test suite) if the user is already running one.
         *
         * XXX
         * This does not solve nor prevent two servers from being
         * started at the same time and running recovery at the same
         * time on the same environments.
         */
        if ((cl = clnt_create("localhost",
            DB_RPC_SERVERPROG, DB_RPC_SERVERVERS, "tcp")) != NULL) {
                fprintf(stderr,
                    "%s: Berkeley DB RPC server already running.\n", prog);
                clnt_destroy(cl);
                return (EXIT_FAILURE);
        }

        LIST_INIT(&__dbsrv_home);
        while ((ch = getopt(argc, argv, "h:I:L:P:t:T:Vv")) != EOF)
                switch (ch) {
                case 'h':
                        (void)add_home(optarg);
                        break;
                case 'I':
                        if (__db_getlong(NULL, prog,
                            optarg, 1, LONG_MAX, &__dbsrv_idleto))
                                return (EXIT_FAILURE);
                        break;
                case 'L':
                        logfile = optarg;
                        break;
                case 'P':
                        passwd = strdup(optarg);
                        memset(optarg, 0, strlen(optarg));
                        if (passwd == NULL) {
                                fprintf(stderr, "%s: strdup: %s\n",
                                    prog, strerror(errno));
                                return (EXIT_FAILURE);
                        }
                        if ((ret = add_passwd(passwd)) != 0) {
                                fprintf(stderr, "%s: strdup: %s\n",
                                    prog, strerror(ret));
                                return (EXIT_FAILURE);
                        }
                        break;
                case 't':
                        if (__db_getlong(NULL, prog,
                            optarg, 1, LONG_MAX, &__dbsrv_defto))
                                return (EXIT_FAILURE);
                        break;
                case 'T':
                        if (__db_getlong(NULL, prog,
                            optarg, 1, LONG_MAX, &__dbsrv_maxto))
                                return (EXIT_FAILURE);
                        break;
                case 'V':
                        printf("%s\n", db_version(NULL, NULL, NULL));
                        return (EXIT_SUCCESS);
                case 'v':
                        __dbsrv_verbose = 1;
                        break;
                default:
                        usage(prog);
                }
        /*
         * Check default timeout against maximum timeout
         */
        if (__dbsrv_defto > __dbsrv_maxto)
                __dbsrv_defto = __dbsrv_maxto;

        /*
         * Check default timeout against idle timeout
         * It would be bad to timeout environments sooner than txns.
         */
        if (__dbsrv_defto > __dbsrv_idleto)
                fprintf(stderr,
            "%s: WARNING: Idle timeout %ld is less than resource timeout %ld\n",
                    prog, __dbsrv_idleto, __dbsrv_defto);

        LIST_INIT(&__dbsrv_head);

        /*
         * If a client crashes during an RPC, our reply to it
         * generates a SIGPIPE.  Ignore SIGPIPE so we don't exit unnecessarily.
         */
#ifdef SIGPIPE
        signal(SIGPIPE, SIG_IGN);
#endif

        if (logfile != NULL && __db_util_logset("berkeley_db_svc", logfile))
                return (EXIT_FAILURE);

        /*
         * Now that we are ready to start, run recovery on all the
         * environments specified.
         */
        if (env_recover(prog) != 0)
                return (EXIT_FAILURE);

        /*
         * We've done our setup, now call the generated server loop
         */
        if (__dbsrv_verbose)
                printf("%s:  Ready to receive requests\n", prog);
        __dbsrv_main();

        /* NOTREACHED */
        abort();
}

static void
usage(char *prog)
{
        fprintf(stderr, "usage: %s %s\n\t%s\n", prog,
            "[-Vv] [-h home] [-P passwd]",
            "[-I idletimeout] [-L logfile] [-t def_timeout] [-T maxtimeout]");
        exit(EXIT_FAILURE);
}

static void
version_check()
{
        int v_major, v_minor, v_patch;

        /* Make sure we're loaded with the right version of the DB library. */
        (void)db_version(&v_major, &v_minor, &v_patch);
        if (v_major != DB_VERSION_MAJOR ||
            v_minor != DB_VERSION_MINOR || v_patch != DB_VERSION_PATCH) {
                fprintf(stderr,
        "%s: version %d.%d.%d doesn't match library version %d.%d.%d\n",
                    prog, DB_VERSION_MAJOR, DB_VERSION_MINOR,
                    DB_VERSION_PATCH, v_major, v_minor, v_patch);
                exit(EXIT_FAILURE);
        }
}

extern "C" void
__dbsrv_settimeout(
        ct_entry *ctp,
        u_int32_t to)
{
        if (to > (u_int32_t)__dbsrv_maxto)
                ctp->ct_timeout = __dbsrv_maxto;
        else if (to <= 0)
                ctp->ct_timeout = __dbsrv_defto;
        else
                ctp->ct_timeout = to;
}

extern "C" void
__dbsrv_timeout(int force)
{
        static long to_hint = -1;
        time_t t;
        long to;
        ct_entry *ctp, *nextctp;

        if ((t = time(NULL)) == -1)
                return;

        /*
         * Check hint.  If hint is further in the future
         * than now, no work to do.
         */
        if (!force && to_hint > 0 && t < to_hint)
                return;
        to_hint = -1;
        /*
         * Timeout transactions or cursors holding DB resources.
         * Do this before timing out envs to properly release resources.
         *
         * !!!
         * We can just loop through this list looking for cursors and txns.
         * We do not need to verify txn and cursor relationships at this
         * point because we maintain the list in LIFO order *and* we
         * maintain activity in the ultimate txn parent of any cursor
         * so either everything in a txn is timing out, or nothing.
         * So, since we are LIFO, we will correctly close/abort all the
         * appropriate handles, in the correct order.
         */
        for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL; ctp = nextctp) {
                nextctp = LIST_NEXT(ctp, entries);
                switch (ctp->ct_type) {
                case CT_TXN:
                        to = *(ctp->ct_activep) + ctp->ct_timeout;
                        /* TIMEOUT */
                        if (to < t) {
                                if (__dbsrv_verbose)
                                        printf("Timing out txn id %ld\n",
                                            ctp->ct_id);
                                (void)((DbTxn *)ctp->ct_anyp)->abort();
                                __dbdel_ctp(ctp);
                                /*
                                 * If we timed out an txn, we may have closed
                                 * all sorts of ctp's.
                                 * So start over with a guaranteed good ctp.
                                 */
                                nextctp = LIST_FIRST(&__dbsrv_head);
                        } else if ((to_hint > 0 && to_hint > to) ||
                            to_hint == -1)
                                to_hint = to;
                        break;
                case CT_CURSOR:
                case (CT_JOINCUR | CT_CURSOR):
                        to = *(ctp->ct_activep) + ctp->ct_timeout;
                        /* TIMEOUT */
                        if (to < t) {
                                if (__dbsrv_verbose)
                                        printf("Timing out cursor %ld\n",
                                            ctp->ct_id);
                                (void)__dbc_close_int(ctp);
                                /*
                                 * Start over with a guaranteed good ctp.
                                 */
                                nextctp = LIST_FIRST(&__dbsrv_head);
                        } else if ((to_hint > 0 && to_hint > to) ||
                            to_hint == -1)
                                to_hint = to;
                        break;
                default:
                        break;
                }
        }
        /*
         * Timeout idle handles.
         * If we are forcing a timeout, we'll close all env handles.
         */
        for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL; ctp = nextctp) {
                nextctp = LIST_NEXT(ctp, entries);
                if (ctp->ct_type != CT_ENV)
                        continue;
                to = *(ctp->ct_activep) + ctp->ct_idle;
                /* TIMEOUT */
                if (to < t || force) {
                        if (__dbsrv_verbose)
                                printf("Timing out env id %ld\n", ctp->ct_id);
                        (void)__env_close_int(ctp->ct_id, 0, 1);
                        /*
                         * If we timed out an env, we may have closed
                         * all sorts of ctp's (maybe even all of them.
                         * So start over with a guaranteed good ctp.
                         */
                        nextctp = LIST_FIRST(&__dbsrv_head);
                }
        }
}

/*
 * RECURSIVE FUNCTION.  We need to clear/free any number of levels of nested
 * layers.
 */
static void
__dbclear_child(ct_entry *parent)
{
        ct_entry *ctp, *nextctp;

        for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL;
            ctp = nextctp) {
                nextctp = LIST_NEXT(ctp, entries);
                if (ctp->ct_type == 0)
                        continue;
                if (ctp->ct_parent == parent) {
                        __dbclear_child(ctp);
                        /*
                         * Need to do this here because le_next may
                         * have changed with the recursive call and we
                         * don't want to point to a removed entry.
                         */
                        nextctp = LIST_NEXT(ctp, entries);
                        __dbclear_ctp(ctp);
                }
        }
}

extern "C" void
__dbclear_ctp(ct_entry *ctp)
{
        LIST_REMOVE(ctp, entries);
        __os_free(NULL, ctp);
}

extern "C" void
__dbdel_ctp(ct_entry *parent)
{
        __dbclear_child(parent);
        __dbclear_ctp(parent);
}

extern "C" ct_entry *
new_ct_ent(int *errp)
{
        time_t t;
        ct_entry *ctp, *octp;
        int ret;

        if ((ret = __os_malloc(NULL, sizeof(ct_entry), &ctp)) != 0) {
                *errp = ret;
                return (NULL);
        }
        memset(ctp, 0, sizeof(ct_entry));
        /*
         * Get the time as ID.  We may service more than one request per
         * second however.  If we are, then increment id value until we
         * find an unused one.  We insert entries in LRU fashion at the
         * head of the list.  So, if the first entry doesn't match, then
         * we know for certain that we can use our entry.
         */
        if ((t = time(NULL)) == -1) {
                *errp = __os_get_errno();
                __os_free(NULL, ctp);
                return (NULL);
        }
        octp = LIST_FIRST(&__dbsrv_head);
        if (octp != NULL && octp->ct_id >= t)
                t = octp->ct_id + 1;
        ctp->ct_id = t;
        ctp->ct_idle = __dbsrv_idleto;
        ctp->ct_activep = &ctp->ct_active;
        ctp->ct_origp = NULL;
        ctp->ct_refcount = 1;

        LIST_INSERT_HEAD(&__dbsrv_head, ctp, entries);
        return (ctp);
}

extern "C" ct_entry *
get_tableent(long id)
{
        ct_entry *ctp;

        for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL;
            ctp = LIST_NEXT(ctp, entries))
                if (ctp->ct_id == id)
                        return (ctp);
        return (NULL);
}

extern "C" ct_entry *
__dbsrv_sharedb(ct_entry *db_ctp,
    const char *name, const char *subdb, DBTYPE type, u_int32_t flags)
{
        ct_entry *ctp;

        /*
         * Check if we can share a db handle.  Criteria for sharing are:
         * If any of the non-sharable flags are set, we cannot share.
         * Must be a db ctp, obviously.
         * Must share the same env parent.
         * Must be the same type, or current one DB_UNKNOWN.
         * Must be same byteorder, or current one must not care.
         * All flags must match.
         * Must be same name, but don't share in-memory databases.
         * Must be same subdb name.
         */
        if (flags & DB_SERVER_DBNOSHARE)
                return (NULL);
        for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL;
            ctp = LIST_NEXT(ctp, entries)) {
                /*
                 * Skip ourselves.
                 */
                if (ctp == db_ctp)
                        continue;
                if (ctp->ct_type != CT_DB)
                        continue;
                if (ctp->ct_envparent != db_ctp->ct_envparent)
                        continue;
                if (type != DB_UNKNOWN && ctp->ct_dbdp.type != type)
                        continue;
                if (ctp->ct_dbdp.dbflags != LF_ISSET(DB_SERVER_DBFLAGS))
                        continue;
                if (db_ctp->ct_dbdp.setflags != 0 &&
                    ctp->ct_dbdp.setflags != db_ctp->ct_dbdp.setflags)
                        continue;
                if (name == NULL || ctp->ct_dbdp.db == NULL ||
                    strcmp(name, ctp->ct_dbdp.db) != 0)
                        continue;
                if (subdb != ctp->ct_dbdp.subdb &&
                    (subdb == NULL || ctp->ct_dbdp.subdb == NULL ||
                    strcmp(subdb, ctp->ct_dbdp.subdb) != 0))
                        continue;
                /*
                 * If we get here, then we match.
                 */
                ctp->ct_refcount++;
                return (ctp);
        }

        return (NULL);
}

extern "C" ct_entry *
__dbsrv_shareenv(ct_entry *env_ctp, home_entry *home, u_int32_t flags)
{
        ct_entry *ctp;

        /*
         * Check if we can share an env.  Criteria for sharing are:
         * Must be an env ctp, obviously.
         * Must share the same home env.
         * All flags must match.
         */
        for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL;
            ctp = LIST_NEXT(ctp, entries)) {
                /*
                 * Skip ourselves.
                 */
                if (ctp == env_ctp)
                        continue;
                if (ctp->ct_type != CT_ENV)
                        continue;
                if (ctp->ct_envdp.home != home)
                        continue;
                if (ctp->ct_envdp.envflags != flags)
                        continue;
                if (ctp->ct_envdp.onflags != env_ctp->ct_envdp.onflags)
                        continue;
                if (ctp->ct_envdp.offflags != env_ctp->ct_envdp.offflags)
                        continue;
                /*
                 * If we get here, then we match.  The only thing left to
                 * check is the timeout.  Since the server timeout set by
                 * the client is a hint, for sharing we'll give them the
                 * benefit of the doubt and grant them the longer timeout.
                 */
                if (ctp->ct_timeout < env_ctp->ct_timeout)
                        ctp->ct_timeout = env_ctp->ct_timeout;
                ctp->ct_refcount++;
                return (ctp);
        }

        return (NULL);
}

extern "C" void
__dbsrv_active(ct_entry *ctp)
{
        time_t t;
        ct_entry *envctp;

        if (ctp == NULL)
                return;
        if ((t = time(NULL)) == -1)
                return;
        *(ctp->ct_activep) = t;
        if ((envctp = ctp->ct_envparent) == NULL)
                return;
        *(envctp->ct_activep) = t;
        return;
}

extern "C" int
__db_close_int(long id, u_int32_t flags)
{
        Db *dbp;
        int ret;
        ct_entry *ctp;

        ret = 0;
        ctp = get_tableent(id);
        if (ctp == NULL)
                return (DB_NOSERVER_ID);
        DB_ASSERT(ctp->ct_type == CT_DB);
        if (__dbsrv_verbose && ctp->ct_refcount != 1)
                printf("Deref'ing dbp id %ld, refcount %d\n",
                    id, ctp->ct_refcount);
        if (--ctp->ct_refcount != 0)
                return (ret);
        dbp = ctp->ct_dbp;
        if (__dbsrv_verbose)
                printf("Closing dbp id %ld\n", id);

        ret = dbp->close(flags);
        __dbdel_ctp(ctp);
        return (ret);
}

extern "C" int
__dbc_close_int(ct_entry *dbc_ctp)
{
        Dbc *dbc;
        int ret;
        ct_entry *ctp;

        dbc = (Dbc *)dbc_ctp->ct_anyp;

        ret = dbc->close();
        /*
         * If this cursor is a join cursor then we need to fix up the
         * cursors that it was joined from so that they are independent again.
         */
        if (dbc_ctp->ct_type & CT_JOINCUR)
                for (ctp = LIST_FIRST(&__dbsrv_head); ctp != NULL;
                    ctp = LIST_NEXT(ctp, entries)) {
                        /*
                         * Test if it is a join cursor, and if it is part
                         * of this one.
                         */
                        if ((ctp->ct_type & CT_JOIN) &&
                            ctp->ct_activep == &dbc_ctp->ct_active) {
                                ctp->ct_type &= ~CT_JOIN;
                                ctp->ct_activep = ctp->ct_origp;
                                __dbsrv_active(ctp);
                        }
                }
        __dbclear_ctp(dbc_ctp);
        return (ret);

}

extern "C" int
__env_close_int(long id, u_int32_t flags, int force)
{
        DbEnv *dbenv;
        int ret;
        ct_entry *ctp, *dbctp, *nextctp;

        ret = 0;
        ctp = get_tableent(id);
        if (ctp == NULL)
                return (DB_NOSERVER_ID);
        DB_ASSERT(ctp->ct_type == CT_ENV);
        if (__dbsrv_verbose && ctp->ct_refcount != 1)
                printf("Deref'ing env id %ld, refcount %d\n",
                    id, ctp->ct_refcount);
        /*
         * If we are timing out, we need to force the close, no matter
         * what the refcount.
         */
        if (--ctp->ct_refcount != 0 && !force)
                return (ret);
        dbenv = ctp->ct_envp;
        if (__dbsrv_verbose)
                printf("Closing env id %ld\n", id);

        /*
         * If we're timing out an env, we want to close all of its
         * database handles as well.  All of the txns and cursors
         * must have been timed out prior to timing out the env.
         */
        if (force)
                for (dbctp = LIST_FIRST(&__dbsrv_head);
                    dbctp != NULL; dbctp = nextctp) {
                        nextctp = LIST_NEXT(dbctp, entries);
                        if (dbctp->ct_type != CT_DB)
                                continue;
                        if (dbctp->ct_envparent != ctp)
                                continue;
                        /*
                         * We found a DB handle that is part of this
                         * environment.  Close it.
                         */
                        __db_close_int(dbctp->ct_id, 0);
                        /*
                         * If we timed out a dbp, we may have removed
                         * multiple ctp entries.  Start over with a
                         * guaranteed good ctp.
                         */
                        nextctp = LIST_FIRST(&__dbsrv_head);
                }

        ret = dbenv->close(flags);
        __dbdel_ctp(ctp);
        return (ret);
}

static int
add_home(char *home)
{
        home_entry *hp, *homep;
        int ret;

        if ((ret = __os_malloc(NULL, sizeof(home_entry), &hp)) != 0)
                return (ret);
        if ((ret = __os_malloc(NULL, strlen(home)+1, &hp->home)) != 0)
                return (ret);
        memcpy(hp->home, home, strlen(home)+1);
        hp->dir = home;
        hp->passwd = NULL;
        /*
         * This loop is to remove any trailing path separators,
         * to assure hp->name points to the last component.
         */
        hp->name = __db_rpath(home);
        if (hp->name != NULL) {
                *(hp->name) = '\0';
                hp->name++;
        } else
                hp->name = home;
        while (*(hp->name) == '\0') {
                hp->name = __db_rpath(home);
                *(hp->name) = '\0';
                hp->name++;
        }
        /*
         * Now we have successfully added it.  Make sure there are no
         * identical names.
         */
        for (homep = LIST_FIRST(&__dbsrv_home); homep != NULL;
            homep = LIST_NEXT(homep, entries))
                if (strcmp(homep->name, hp->name) == 0) {
                        printf("Already added home name %s, at directory %s\n",
                            hp->name, homep->dir);
                        return (-1);
                }
        LIST_INSERT_HEAD(&__dbsrv_home, hp, entries);
        if (__dbsrv_verbose)
                printf("Added home %s in dir %s\n", hp->name, hp->dir);
        return (0);
}

static int
add_passwd(char *passwd)
{
        home_entry *hp;

        /*
         * We add the passwd to the last given home dir.  If there
         * isn't a home dir, or the most recent one already has a
         * passwd, then there is a user error.
         */
        hp = LIST_FIRST(&__dbsrv_home);
        if (hp == NULL || hp->passwd != NULL)
                return (EINVAL);
        /*
         * We've already strdup'ed the passwd above, so we don't need
         * to malloc new space, just point to it.
         */
        hp->passwd = passwd;
        return (0);
}

extern "C" home_entry *
get_fullhome(char *name)
{
        home_entry *hp;

        if (name == NULL)
                return (NULL);

        for (hp = LIST_FIRST(&__dbsrv_home); hp != NULL;
            hp = LIST_NEXT(hp, entries))
                if (strcmp(name, hp->name) == 0)
                        return (hp);
        return (NULL);
}

static int
env_recover(char *progname)
{
        DbEnv *dbenv;
        home_entry *hp;
        u_int32_t flags;
        int exitval, ret;

        for (hp = LIST_FIRST(&__dbsrv_home); hp != NULL;
            hp = LIST_NEXT(hp, entries)) {
                exitval = 0;
                dbenv = new DbEnv(DB_CXX_NO_EXCEPTIONS);
                if (__dbsrv_verbose == 1)
                        (void)dbenv->set_verbose(DB_VERB_RECOVERY, 1);
                dbenv->set_errfile(stderr);
                dbenv->set_errpfx(progname);
                if (hp->passwd != NULL)
                        (void)dbenv->set_encrypt(hp->passwd, DB_ENCRYPT_AES);

                /*
                 * Initialize the env with DB_RECOVER.  That is all we
                 * have to do to run recovery.
                 */
                if (__dbsrv_verbose)
                        printf("Running recovery on %s\n", hp->home);
                flags = DB_CREATE | DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL |
                    DB_INIT_TXN | DB_USE_ENVIRON | DB_RECOVER;
                if ((ret = dbenv->open(hp->home, flags, 0)) != 0) {
                        dbenv->err(ret, "DbEnv->open");
                        goto error;
                }

                if (0) {
error:                  exitval = 1;
                }
                if ((ret = dbenv->close(0)) != 0) {
                        exitval = 1;
                        fprintf(stderr, "%s: dbenv->close: %s\n",
                            progname, db_strerror(ret));
                }
                if (exitval)
                        return (exitval);
        }
        return (0);
}

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