Kea 2.5.9
isc::tcp::TcpConnectionPool Class Reference

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
connectionPointer 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
connectionPointer 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
connectionPointer 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_ipThe remote IP address.
[out]total_connectionsSize 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_ipThe remote IP address.
[out]total_connectionsSize 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: