C++ DB_ENV::set_isalive方法代码示例

/*
 * Creates a database environment handle
 *
 * ARGUMENTS:
 *      path            Pathname of the database directory.  Shall not be NULL.
 *                      The client can free it upon return.
 *      dbEnv           Pointer to a pointer to the database environment.  Shall
 *                      not be NULL.  "*dbEnv" is set upon successful return.
 * RETURNS:
 *      0               Success.  "*dbEnv" is set.
 *      ENOMEM          System error.  "log_start()" called.
 *      EIO             Backend database error.  "log_start()" called.
 */
static RegStatus
createEnvHandle(
    const char* const   path,
    DB_ENV** const      dbEnv)
{
    RegStatus   status;
    DB_ENV*     env;

    assert(NULL != path);

    log_clear();

    if (status = db_env_create(&env, 0)) {
        log_serror("Couldn't create environment handle for database: %s",
                   db_strerror(status));
        status = ENOMEM;
    }
    else {
        env->set_errcall(env, logDbError);

        if (status = env->set_isalive(env, is_alive)) {
            log_add("Couldn't register \"is_alive()\" function for "
                    "database \"%s\"", path);
            status = EIO;
        }
        else {
            static const unsigned      threadCount = 256;

            if (status = env->set_thread_count(env, threadCount)) {
                log_add("Couldn't set thread count to %u for database \"%s\"",
                        threadCount, path);
                status = EIO;
            }
            else {
                *dbEnv = env;
            }
        }

        if (status)
            (void)env->close(env, 0);
    }                                   /* "env" allocated */

    return status;
}

static int db_init(rpmdb rdb, const char * dbhome)
{
    DB_ENV *dbenv = NULL;
    int rc, xx;
    int retry_open = 2;
    int lockfd = -1;
    struct dbConfig_s * cfg = &rdb->cfg;
    /* This is our setup, thou shall not have other setups before us */
    uint32_t eflags = (DB_CREATE|DB_INIT_MPOOL|DB_INIT_CDB);

    if (rdb->db_dbenv != NULL) {
	rdb->db_opens++;
	return 0;
    } else {
	/* On first call, set backend description to something... */
	free(rdb->db_descr);
	rasprintf(&rdb->db_descr, "db%u", DB_VERSION_MAJOR);
    }

    /*
     * Both verify and rebuild are rather special, if for different reasons:
     * On rebuild we dont want to be affected by eg paniced environment, and
     * CDB only slows things down there. Verify is a quirky beast unlike
     * anything else in BDB, and does not like shared env or CDB.
     */
    if (rdb->db_flags & (RPMDB_FLAG_VERIFYONLY|RPMDB_FLAG_REBUILD)) {
	eflags |= DB_PRIVATE;
	eflags &= ~DB_INIT_CDB;
    }

    rc = db_env_create(&dbenv, 0);
    rc = dbapi_err(rdb, "db_env_create", rc, _debug);
    if (dbenv == NULL || rc)
	goto errxit;

    dbenv->set_alloc(dbenv, rmalloc, rrealloc, NULL);
    dbenv->set_errcall(dbenv, NULL);
    dbenv->set_errpfx(dbenv, _errpfx);
    dbenv->set_msgcall(dbenv, warnlog);

    /* 
     * These enable automatic stale lock removal. 
     * thread_count 8 is some kind of "magic minimum" value...
     */
    dbenv->set_thread_count(dbenv, 8);
    dbenv->set_isalive(dbenv, isalive);

    dbenv->set_verbose(dbenv, DB_VERB_DEADLOCK,
	    (cfg->db_verbose & DB_VERB_DEADLOCK));
    dbenv->set_verbose(dbenv, DB_VERB_RECOVERY,
	    (cfg->db_verbose & DB_VERB_RECOVERY));
    dbenv->set_verbose(dbenv, DB_VERB_WAITSFOR,
	    (cfg->db_verbose & DB_VERB_WAITSFOR));

    if (cfg->db_mmapsize) {
	xx = dbenv->set_mp_mmapsize(dbenv, cfg->db_mmapsize);
	xx = dbapi_err(rdb, "dbenv->set_mp_mmapsize", xx, _debug);
    }

    if (cfg->db_cachesize) {
	xx = dbenv->set_cachesize(dbenv, 0, cfg->db_cachesize, 0);
	xx = dbapi_err(rdb, "dbenv->set_cachesize", xx, _debug);
    }

    /*
     * Serialize shared environment open (and clock) via fcntl() lock.
     * Otherwise we can end up calling dbenv->failchk() while another
     * process is joining the environment, leading to transient
     * DB_RUNRECOVER errors. Also prevents races wrt removing the
     * environment (eg chrooted operation). Silently fall back to
     * private environment on failure to allow non-privileged queries
     * to "work", broken as it might be.
     */
    if (!(eflags & DB_PRIVATE)) {
	lockfd = serialize_env(dbhome);
	if (lockfd < 0) {
	    eflags |= DB_PRIVATE;
	    retry_open--;
	    rpmlog(RPMLOG_DEBUG, "serialize failed, using private dbenv\n");
	}
    }

    /*
     * Actually open the environment. Fall back to private environment
     * if we dont have permission to join/create shared environment or
     * system doesn't support it..
     */
    while (retry_open) {
	char *fstr = prDbiOpenFlags(eflags, 1);
	rpmlog(RPMLOG_DEBUG, "opening  db environment %s %s\n", dbhome, fstr);
	free(fstr);

	rc = (dbenv->open)(dbenv, dbhome, eflags, rdb->db_perms);
	if ((rc == EACCES || rc == EROFS) || (rc == EINVAL && errno == rc)) {
	    eflags |= DB_PRIVATE;
	    retry_open--;
	} else {
	    retry_open = 0;
	}
    }
//.........这里部分代码省略.........

static int db_init(dbiIndex dbi, const char * dbhome,
		const char * dbfile,
		const char * dbsubfile,
		DB_ENV ** dbenvp)
{
    rpmdb rpmdb = dbi->dbi_rpmdb;
    DB_ENV *dbenv = NULL;
    int eflags;
    int rc;

    if (dbenvp == NULL)
	return 1;

    /* XXX HACK */
    if (rpmdb->db_errfile == NULL)
	rpmdb->db_errfile = stderr;

    eflags = (dbi->dbi_oeflags | dbi->dbi_eflags);
    if (eflags & DB_JOINENV) eflags &= DB_JOINENV;

    if (dbfile) {
	char *dbiflags = prDbiOpenFlags(eflags, 1);
	rpmlog(RPMLOG_DEBUG, "opening  db environment %s/%s %s\n",
		dbhome, dbfile, dbiflags);
	free(dbiflags);
    }

    /* XXX Can't do RPC w/o host. */
    if (dbi->dbi_host == NULL)
	dbi->dbi_ecflags &= ~DB_CLIENT;

    /* XXX Set a default shm_key. */
    if ((dbi->dbi_eflags & DB_SYSTEM_MEM) && dbi->dbi_shmkey == 0) {
#if defined(HAVE_FTOK)
	dbi->dbi_shmkey = ftok(dbhome, 0);
#else
	dbi->dbi_shmkey = 0x44631380;
#endif
    }

    rc = db_env_create(&dbenv, dbi->dbi_ecflags);
    rc = cvtdberr(dbi, "db_env_create", rc, _debug);
    if (dbenv == NULL || rc)
	goto errxit;

  { int xx;

 /* 4.1: dbenv->set_app_dispatch(???) */
 /* 4.1: dbenv->set_alloc(???) */
 /* 4.1: dbenv->set_data_dir(???) */
 /* 4.1: dbenv->set_encrypt(???) */

    dbenv->set_errcall(dbenv, (void *) rpmdb->db_errcall);
    dbenv->set_errfile(dbenv, rpmdb->db_errfile);
    dbenv->set_errpfx(dbenv, rpmdb->db_errpfx);

 /* 4.1: dbenv->set_feedback(???) */
 /* 4.1: dbenv->set_flags(???) */

 /* dbenv->set_paniccall(???) */

#if (DB_VERSION_MAJOR >= 4 && DB_VERSION_MINOR >= 5)
    /* 
     * These enable automatic stale lock removal. 
     * thread_count 8 is some kind of "magic minimum" value...
     */
    dbenv->set_thread_count(dbenv, 8);
    dbenv->set_isalive(dbenv, db3isalive);
#endif

    if ((dbi->dbi_ecflags & DB_CLIENT) && dbi->dbi_host) {
	const char * home;
	int retry = 0;

	if ((home = strrchr(dbhome, '/')) != NULL)
	    dbhome = ++home;

	while (retry++ < 5) {
	    xx = dbenv->set_rpc_server(dbenv, NULL, dbi->dbi_host,
		dbi->dbi_cl_timeout, dbi->dbi_sv_timeout, 0);
	    xx = cvtdberr(dbi, "dbenv->set_server", xx, _debug);
	    if (!xx)
		break;
	    (void) sleep(15);
	}
    } else {
#if !(DB_VERSION_MAJOR == 4 && DB_VERSION_MINOR >= 3)
	xx = dbenv->set_verbose(dbenv, DB_VERB_CHKPOINT,
		(dbi->dbi_verbose & DB_VERB_CHKPOINT));
#endif
	xx = dbenv->set_verbose(dbenv, DB_VERB_DEADLOCK,
		(dbi->dbi_verbose & DB_VERB_DEADLOCK));
	xx = dbenv->set_verbose(dbenv, DB_VERB_RECOVERY,
		(dbi->dbi_verbose & DB_VERB_RECOVERY));
	xx = dbenv->set_verbose(dbenv, DB_VERB_WAITSFOR,
		(dbi->dbi_verbose & DB_VERB_WAITSFOR));

	if (dbi->dbi_mmapsize) {
	    xx = dbenv->set_mp_mmapsize(dbenv, dbi->dbi_mmapsize);
	    xx = cvtdberr(dbi, "dbenv->set_mp_mmapsize", xx, _debug);
//.........这里部分代码省略.........