Pool of active TCP connections. More...

#include <tcp_connection_pool.h>

Public Member Functions
void	shutdown (const TcpConnectionPtr &connection)
	Removes a connection from the pool and shutdown it.

void	start (const TcpConnectionPtr &connection)
	Start new connection.

void	stop (const TcpConnectionPtr &connection)
	Removes a connection from the pool and stops it.

void	stopAll ()
	Stops all connections and removes them from the pool.

size_t	usedByRemoteIp (const asiolink::IOAddress &remote_ip, size_t &total_connections)
	Returns the number of connections using a given remote IP address.

Static Public Attributes
static std::atomic< uint64_t >	rejected_counter_
	Class/static rejected (by the accept filter) connection counter.

static std::atomic< uint64_t >	started_counter_
	Class/static started (i.e. added to pool) connection counter.

static std::atomic< uint64_t >	stopped_counter_
	Class/static stopped (i.e. removed from pool) connection counter.

Protected Member Functions
void	stopAllInternal ()
	Stops all connections and removes them from the pool.

size_t	usedByRemoteIpInternal (const asiolink::IOAddress &remote_ip, size_t &total_connections)
	Returns the number of connections using a given remote IP address.

Protected Attributes
TcpConnectionList	connections_
	Set of connections.

std::mutex	mutex_
	Mutex to protect the internal state.

Detailed Description

Pool of active TCP connections.

The TCP server is designed to handle many connections simultaneously. The communication between the client and the server may take long time and the server must be able to react on other events while the communication with the clients is in progress. Thus, the server must track active connections and gracefully close them when needed. An obvious case when the connections must be terminated by the server is when the shutdown signal is received.

This object is a simple container for the server connections which provides means to terminate them on request.

Definition at line 33 of file tcp_connection_pool.h.

Member Function Documentation

◆ shutdown()

void isc::tcp::TcpConnectionPool::shutdown ( const TcpConnectionPtr & connection )

Removes a connection from the pool and shutdown it.

Shutdown is specific to TLS and is a first part of graceful close (note it is NOT the same as TCP shutdown system call).

Note: if the TLS connection stalls e.g. the peer does not try I/O on it the connection has to be explicitly stopped.

Parameters

connection Pointer to the connection.

Definition at line 60 of file tcp_connection_pool.cc.

References connections_, isc::util::MultiThreadingMgr::instance(), mutex_, and stopped_counter_.

Referenced by isc::tcp::TcpConnection::shutdownConnection().

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◆ start()

void isc::tcp::TcpConnectionPool::start ( const TcpConnectionPtr & connection )

Start new connection.

The connection is inserted to the pool and the TcpConnection::asyncAccept is invoked.

Parameters

connection Pointer to the new connection.

Definition at line 28 of file tcp_connection_pool.cc.

References connections_, isc::util::MultiThreadingMgr::instance(), mutex_, and started_counter_.

Referenced by isc::tcp::TcpListener::accept().

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◆ stop()

void isc::tcp::TcpConnectionPool::stop ( const TcpConnectionPtr & connection )

Removes a connection from the pool and stops it.

Parameters

connection Pointer to the connection.

Definition at line 42 of file tcp_connection_pool.cc.

References connections_, isc::util::MultiThreadingMgr::instance(), mutex_, and stopped_counter_.

Referenced by isc::tcp::TcpConnection::stopThisConnection().

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◆ stopAll()

void isc::tcp::TcpConnectionPool::stopAll ( )

Stops all connections and removes them from the pool.

Note: This function is not thread-safe so should be called when the thread pool is stopped.

Definition at line 78 of file tcp_connection_pool.cc.

References isc::util::MultiThreadingMgr::instance(), mutex_, and stopAllInternal().

Referenced by isc::tcp::TcpListener::stop().

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◆ stopAllInternal()

void isc::tcp::TcpConnectionPool::stopAllInternal ( )

protected

Stops all connections and removes them from the pool.

Must be called from with a thread-safe context.

Definition at line 88 of file tcp_connection_pool.cc.

References connections_, and stopped_counter_.

Referenced by stopAll().

◆ usedByRemoteIp()

size_t isc::tcp::TcpConnectionPool::usedByRemoteIp	(	const asiolink::IOAddress &	remote_ip,
		size_t &	total_connections
	)

Returns the number of connections using a given remote IP address.

Used to limit the number of connections when accepting a new one.

Parameters

	remote_ip	The remote IP address.
[out]	total_connections	Size of the connection pool.

Returns: The number of connections using a given remote IP address.

Definition at line 99 of file tcp_connection_pool.cc.

References isc::util::MultiThreadingMgr::instance(), mutex_, and usedByRemoteIpInternal().

Referenced by isc::tcp::TcpListener::usedByRemoteIp().

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◆ usedByRemoteIpInternal()

size_t isc::tcp::TcpConnectionPool::usedByRemoteIpInternal	(	const asiolink::IOAddress &	remote_ip,
		size_t &	total_connections
	)

protected

Returns the number of connections using a given remote IP address.

Used to limit the number of connections when accepting a new one. Must be called from with a thread-safe context.

Parameters

	remote_ip	The remote IP address.
[out]	total_connections	Size of the connection pool.

Returns: The number of connections using a given remote IP address.

Definition at line 110 of file tcp_connection_pool.cc.

References connections_, and isc::tcp::TcpConnection::NO_ENDPOINT().

Referenced by usedByRemoteIp().

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Member Data Documentation

◆ connections_

TcpConnectionList isc::tcp::TcpConnectionPool::connections_

protected

Set of connections.

Definition at line 104 of file tcp_connection_pool.h.

Referenced by shutdown(), start(), stop(), stopAllInternal(), and usedByRemoteIpInternal().

◆ mutex_

std::mutex isc::tcp::TcpConnectionPool::mutex_

protected

Mutex to protect the internal state.

Definition at line 107 of file tcp_connection_pool.h.

Referenced by shutdown(), start(), stop(), stopAll(), and usedByRemoteIp().

◆ rejected_counter_

std::atomic< uint64_t > isc::tcp::TcpConnectionPool::rejected_counter_

static

Class/static rejected (by the accept filter) connection counter.

Definition at line 83 of file tcp_connection_pool.h.

Referenced by isc::tcp::TcpConnection::acceptorCallback().

◆ started_counter_

std::atomic< uint64_t > isc::tcp::TcpConnectionPool::started_counter_

static

Class/static started (i.e. added to pool) connection counter.

Definition at line 77 of file tcp_connection_pool.h.

Referenced by start().

◆ stopped_counter_

std::atomic< uint64_t > isc::tcp::TcpConnectionPool::stopped_counter_

static

Class/static stopped (i.e. removed from pool) connection counter.

Definition at line 80 of file tcp_connection_pool.h.

Referenced by shutdown(), stop(), and stopAllInternal().

The documentation for this class was generated from the following files:

Public Member Functions

Static Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

◆ shutdown()

◆ start()

◆ stop()

◆ stopAll()

◆ stopAllInternal()

◆ usedByRemoteIp()

◆ usedByRemoteIpInternal()

Member Data Documentation

◆ connections_

◆ mutex_

◆ rejected_counter_

◆ started_counter_

◆ stopped_counter_