120 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			120 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*
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 * Copyright (c) 2018 MariaDB Corporation Ab
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 *
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 * Use of this software is governed by the Business Source License included
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 * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
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 *
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 * Change Date: 2024-11-16
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 *
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 * On the date above, in accordance with the Business Source License, use
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 * of this software will be governed by version 2 or later of the General
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 * Public License.
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 */
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#pragma once
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/**
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 * @file include/maxscale/poll.hh - The public poll interface
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 */
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#include <maxscale/ccdefs.hh>
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#include <maxscale/buffer.hh>
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#include <maxscale/dcb.hh>
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MXS_BEGIN_DECLS
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/**
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 * A statistic identifier that can be returned by poll_get_stat
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 */
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typedef enum
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{
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    POLL_STAT_READ,
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    POLL_STAT_WRITE,
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    POLL_STAT_ERROR,
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    POLL_STAT_HANGUP,
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    POLL_STAT_ACCEPT,
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    POLL_STAT_EVQ_AVG,
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    POLL_STAT_EVQ_MAX,
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    POLL_STAT_MAX_QTIME,
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    POLL_STAT_MAX_EXECTIME
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} POLL_STAT;
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/*
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 * Return a particular statistics value.
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 *
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 * @param stat  What to return.
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 *
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 * @return The value.
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 */
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int64_t poll_get_stat(POLL_STAT stat);
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/*
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 * Insert a fake hangup event for a DCB into the polling queue.
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 *
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 * This is used when a monitor detects that a server is not responding.
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 *
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 * @param dcb   DCB to emulate an EPOLLOUT event for
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 */
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void poll_fake_hangup_event(DCB* dcb);
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/*
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 * Insert a fake write completion event for a DCB into the polling
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 * queue.
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 *
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 * This is used to trigger transmission activity on another DCB from
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 * within the event processing routine of a DCB. or to allow a DCB
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 * to defer some further output processing, to allow for other DCBs
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 * to receive a slice of the processing time. Fake events are added
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 * to the tail of the event queue, in the same way that real events
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 * are, so maintain the "fairness" of processing.
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 *
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 * @param dcb   DCB to emulate an EPOLLOUT event for
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 */
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void poll_fake_write_event(DCB* dcb);
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/*
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 * Insert a fake read completion event for a DCB into the polling
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 * queue.
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 *
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 * This is used to trigger transmission activity on another DCB from
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 * within the event processing routine of a DCB. or to allow a DCB
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 * to defer some further input processing, to allow for other DCBs
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 * to receive a slice of the processing time. Fake events are added
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 * to the tail of the event queue, in the same way that real events
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 * are, so maintain the "fairness" of processing.
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 *
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 * @param dcb   DCB to emulate an EPOLLIN event for
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 */
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void poll_fake_read_event(DCB* dcb);
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/**
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 * Add a DCB to the set of descriptors within the polling
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 * environment.
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 *
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 * @param dcb   The descriptor to add to the poll
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 * @return      -1 on error or 0 on success
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 */
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int poll_add_dcb(DCB*);
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/**
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 * Remove a descriptor from the set of descriptors within the
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 * polling environment.
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 *
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 * @param dcb   The descriptor to remove
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 * @return      -1 on error or 0 on success; actually always 0
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 */
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int poll_remove_dcb(DCB*);
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/**
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 * Add given GWBUF to DCB's readqueue and add a pending EPOLLIN event for DCB.
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 * The event pretends that there is something to read for the DCB. Actually
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 * the incoming data is stored in the DCB's readqueue where it is read.
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 *
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 * @param dcb   DCB where the event and data are added
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 * @param buf   GWBUF including the data
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 *
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 */
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void poll_add_epollin_event_to_dcb(DCB* dcb, GWBUF* buf);
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MXS_END_DECLS
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