[alibaba/druid]发生致命错误时创建连接可能重复触发

错误代码如下

 protected final void handleFatalError(DruidPooledConnection conn,
                                          SQLException error,
                                          String sql) throws SQLException {
        final DruidConnectionHolder holder = conn.holder;

        if (conn.isTraceEnable()) {
            activeConnectionLock.lock();
            try {
                if (conn.isTraceEnable()) {
                    activeConnections.remove(conn);
                    conn.setTraceEnable(false);
                }
            } finally {
                activeConnectionLock.unlock();
            }
        }

        long lastErrorTimeMillis = this.lastErrorTimeMillis;
        if (lastErrorTimeMillis == 0) {
            lastErrorTimeMillis = System.currentTimeMillis();
        }

        if (sql != null && sql.length() > 1024) {
            sql = sql.substring(0, 1024);
        }

        boolean requireDiscard = false;
        final ReentrantLock lock = conn.lock;
        lock.lock();
        try {
            if ((!conn.isClosed()) && !conn.isDisable()) {
                conn.disable(error);
                requireDiscard = true;
            }

            lastFatalErrorTimeMillis = lastErrorTimeMillis;
            fatalErrorCount++;
            if (fatalErrorCount - fatalErrorCountLastShrink > onFatalErrorMaxActive) {
                onFatalError = true;
            }
            lastFatalError = error;
            lastFatalErrorSql = sql;
        } finally {
            lock.unlock();
        }

        if (onFatalError && holder != null && holder.getDataSource() != null) {
            ReentrantLock dataSourceLock = holder.getDataSource().lock;
            dataSourceLock.lock();
            try {
                emptySignal();
            } finally {
                dataSourceLock.unlock();
            }
        }

        if (requireDiscard) {
            if (holder.statementTrace != null) {
                holder.lock.lock();
                try {
                    for (Statement stmt : holder.statementTrace) {
                        JdbcUtils.close(stmt);
                    }
                } finally {
                    holder.lock.unlock();
                }
            }

            this.discardConnection(holder);
        }

        // holder.
        LOG.error("{conn-" + holder.getConnectionId() + "} discard", error);
    }