Kea: isc::asiolink::IoServiceThreadPool Class Reference

| Kea 3.2.0-git

isc::asiolink::IoServiceThreadPool Class Reference

Implements a pausable pool of IOService driven threads. More...

`#include <io_service_thread_pool.h>`

## Public Types
enum class | State { STOPPED , RUNNING , PAUSED }
| Describes the possible operational state of the thread pool. More...

## Public Member Functions
| IoServiceThreadPool (asiolink::IOServicePtr io_service, size_t pool_size, bool defer_start=false)
| Constructor.
| ~IoServiceThreadPool ()
| Destructor.
void | checkPausePermissions ()
| Check current thread permissions to transition to the new PAUSED state.
asiolink::IOServicePtr | getIOService () const
| Fetches the IOService that drives the pool.
uint16_t | getPoolSize () const
| Fetches the maximum size of the thread pool.
uint16_t | getThreadCount () const
| Fetches the number of threads in the pool.
bool | isPaused ()
| Check if the thread pool is paused.
bool | isRunning ()
| Check if the thread pool is running.
bool | isStopped ()
| Check if the thread pool is stopped.
void | pause ()
| Transitions the pool from RUNNING to PAUSED.
void | run ()
| Transitions the pool from STOPPED or PAUSED to RUNNING.
void | stop ()
| Transitions the pool from RUNNING or PAUSED to STOPPED.

## Detailed Description

Implements a pausable pool of IOService driven threads.

Definition at line 24 of file io_service_thread_pool.h.

## Member Enumeration Documentation

## ◆ State

enum class isc::asiolink::IoServiceThreadPool::State
| strong

Describes the possible operational state of the thread pool.

Enumerator
STOPPED |
RUNNING | Pool is not operational.
PAUSED | Pool is populated with running threads.

Definition at line 27 of file io_service_thread_pool.h.

## Constructor & Destructor Documentation

## ◆ IoServiceThreadPool()

IoServiceThreadPool::IoServiceThreadPool | ( | asiolink::IOServicePtr | io_service,
|  | size_t | pool_size,
|  | bool | defer_start = false )

Constructor.

Parameters

  io_service | IOService that will drive the pool's IO. If empty, it create its own instance.
  pool_size | Maximum number of threads in the pool. Currently the number of threads is fixed at this value.
  defer_start | If true, creation of the threads is deferred until a subsequent call to run(). In this case the pool's operational state post construction is STOPPED. If false, the constructor will invoke run() to transition the pool into the RUNNING state.

Definition at line 30 of file io_service_thread_pool.cc.

References isc_throw, and run().

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## ◆ ~IoServiceThreadPool()

IoServiceThreadPool::~IoServiceThreadPool | ( |  | ) |

Destructor.

Ensures the thread pool is stopped prior to destruction.

Definition at line 54 of file io_service_thread_pool.cc.

References stop().

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## Member Function Documentation

## ◆ checkPausePermissions()

void IoServiceThreadPool::checkPausePermissions | ( |  | ) |

Check current thread permissions to transition to the new PAUSED state.

This function throws MultiThreadingInvalidOperation if the calling thread is one of the worker threads. This would prevent a dead-lock if the calling thread would try to perform a thread pool state transition to PAUSED state.

Exceptions

  MultiThreadingInvalidOperation | if the state transition is done on any of the worker threads.

Definition at line 106 of file io_service_thread_pool.cc.

References PAUSED.

## ◆ getIOService()

IOServicePtr IoServiceThreadPool::getIOService | ( |  | ) | const

Fetches the IOService that drives the pool.

Returns
  the pointer to the IOService.

Definition at line 283 of file io_service_thread_pool.cc.

## ◆ getPoolSize()

uint16_t IoServiceThreadPool::getPoolSize | ( |  | ) | const

Fetches the maximum size of the thread pool.

Returns
  the maximum size of the thread pool.

Definition at line 288 of file io_service_thread_pool.cc.

## ◆ getThreadCount()

uint16_t IoServiceThreadPool::getThreadCount | ( |  | ) | const

Fetches the number of threads in the pool.

Returns
  the number of running threads.

Definition at line 293 of file io_service_thread_pool.cc.

## ◆ isPaused()

bool isc::asiolink::IoServiceThreadPool::isPaused | ( |  | ) |
| inline

Check if the thread pool is paused.

Returns
  True if the thread pool is paused, false otherwise.

Definition at line 84 of file io_service_thread_pool.h.

References PAUSED.

## ◆ isRunning()

bool isc::asiolink::IoServiceThreadPool::isRunning | ( |  | ) |
| inline

Check if the thread pool is running.

Returns
  True if the thread pool is running, false otherwise.

Definition at line 77 of file io_service_thread_pool.h.

References RUNNING.

## ◆ isStopped()

bool isc::asiolink::IoServiceThreadPool::isStopped | ( |  | ) |
| inline

Check if the thread pool is stopped.

Returns
  True if the thread pool is stopped, false otherwise.

Definition at line 91 of file io_service_thread_pool.h.

References STOPPED.

## ◆ pause()

void IoServiceThreadPool::pause | ( |  | ) |

Transitions the pool from RUNNING to PAUSED.

Pool threads suspend event processing and pause until they are released to either resume running or stop. Has no effect if the pool is already in the PAUSED or STOPPED state.

Definition at line 64 of file io_service_thread_pool.cc.

References PAUSED.

## ◆ run()

void IoServiceThreadPool::run | ( |  | ) |

Transitions the pool from STOPPED or PAUSED to RUNNING.

When called from the STOPPED state, the pool threads are created and begin processing events. When called from the PAUSED state, the pool threads are released from PAUSED and resume processing events. Has no effect if the pool is already in the RUNNING state.

Definition at line 59 of file io_service_thread_pool.cc.

References RUNNING.

Referenced by IoServiceThreadPool().

## ◆ stop()

void IoServiceThreadPool::stop | ( |  | ) |

Transitions the pool from RUNNING or PAUSED to STOPPED.

Stops thread event processing and then destroys the pool's threads Has no effect if the pool is already in the STOPPED state.

Definition at line 69 of file io_service_thread_pool.cc.

References STOPPED.

Referenced by ~IoServiceThreadPool().

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

- io_service_thread_pool.h
- io_service_thread_pool.cc