pool.py 文件源码

def _putconn(self, conn, key=None, close=False):
        """Put away a connection."""
        if self.closed:
            raise PoolError("connection pool is closed")
        if key is None:
            key = self._rused.get(id(conn))

        if not key:
            raise PoolError("trying to put unkeyed connection")

        if len(self._pool) < self.minconn and not close:
            # Return the connection into a consistent state before putting
            # it back into the pool
            if not conn.closed:
                status = conn.get_transaction_status()
                if status == _ext.TRANSACTION_STATUS_UNKNOWN:
                    # server connection lost
                    conn.close()
                elif status != _ext.TRANSACTION_STATUS_IDLE:
                    # connection in error or in transaction
                    conn.rollback()
                    self._pool.append(conn)
                else:
                    # regular idle connection
                    self._pool.append(conn)
            # If the connection is closed, we just discard it.
        else:
            conn.close()

        # here we check for the presence of key because it can happen that a
        # thread tries to put back a connection after a call to close
        if not self.closed or key in self._used:
            del self._used[key]
            del self._rused[id(conn)]