Botan::Thread_Pool Class Reference

#include <thread_pool.h>

Public Member Functions
Thread_Pool &	operator= (const Thread_Pool &)=delete
Thread_Pool &	operator= (Thread_Pool &&)=delete
void	queue_thunk (std::function< void()>)
template<class F , class... Args>
auto	run (F &&f, Args &&... args) -> std::future< typename std::result_of< F(Args...)>::type >
void	shutdown ()
	Thread_Pool (size_t pool_size=0)
	Thread_Pool (const Thread_Pool &)=delete
	Thread_Pool (Thread_Pool &&)=delete
size_t	worker_count () const
	~Thread_Pool ()

Static Public Member Functions
static Thread_Pool &	global_instance ()

Detailed Description

Definition at line 24 of file thread_pool.h.

Constructor & Destructor Documentation

Thread_Pool() [1/3]

Botan::Thread_Pool::Thread_Pool

(

size_t

pool_size = 0

)

Initialize a thread pool with some number of threads

Parameters

pool_size

number of threads in the pool, if 0 then some default value is chosen

Definition at line 21 of file thread_pool.cpp.

References Botan::OS::get_cpu_available().

   {
   if(pool_size == 0)
      {
      pool_size = OS::get_cpu_available();

      /*
      * For large machines don't create too many threads, unless
      * explicitly asked to by the caller.
      */
      if(pool_size > 16)
         pool_size = 16;
      }

   if(pool_size <= 1)
      pool_size = 2;

   m_shutdown = false;

   for(size_t i = 0; i != pool_size; ++i)
      {
      m_workers.push_back(std::thread(&Thread_Pool::worker_thread, this));
      }
   }

~Thread_Pool()

Botan::Thread_Pool::~Thread_Pool ( )

inline

Definition at line 39 of file thread_pool.h.

{ shutdown(); }

Thread_Pool() [2/3]

Botan::Thread_Pool::Thread_Pool ( const Thread_Pool &  )

delete

Thread_Pool() [3/3]

Botan::Thread_Pool::Thread_Pool ( Thread_Pool &&  )

delete

Member Function Documentation

global_instance()

Thread_Pool & Botan::Thread_Pool::global_instance ( )

static

Return an instance to a shared thread pool

Definition at line 15 of file thread_pool.cpp.

References Botan::OS::read_env_variable_sz().

Referenced by Botan::XMSS_PrivateKey::tree_hash().

   {
   static Thread_Pool g_thread_pool(OS::read_env_variable_sz("BOTAN_THREAD_POOL_SIZE"));
   return g_thread_pool;
   }

operator=() [1/2]

Thread_Pool& Botan::Thread_Pool::operator= ( const Thread_Pool &  )

delete

operator=() [2/2]

Thread_Pool& Botan::Thread_Pool::operator= ( Thread_Pool &&  )

delete

queue_thunk()

void Botan::Thread_Pool::queue_thunk

(

std::function< void()>

fn

)

Definition at line 66 of file thread_pool.cpp.

   {
   std::unique_lock<std::mutex> lock(m_mutex);

   if(m_shutdown)
      throw Invalid_State("Cannot add work after thread pool has shut down");

   m_tasks.push_back(fn);
   m_more_tasks.notify_one();
   }

run()

template<class F , class... Args>

auto Botan::Thread_Pool::run ( F &&  f, Args &&...  args  ) -> std::future<typename std::result_of<F(Args...)>::type>

inline

Definition at line 57 of file thread_pool.h.

References type.

Referenced by Botan::XMSS_PrivateKey::tree_hash().

         {
         typedef typename std::result_of<F(Args...)>::type return_type;

         auto future_work = std::bind(std::forward<F>(f), std::forward<Args>(args)...);
         auto task = std::make_shared<std::packaged_task<return_type ()>>(future_work);
         auto future_result = task->get_future();
         queue_thunk([task]() { (*task)(); });
         return future_result;
         }

shutdown()

void Botan::Thread_Pool::shutdown

(

)

Definition at line 46 of file thread_pool.cpp.

   {
      {
      std::unique_lock<std::mutex> lock(m_mutex);

      if(m_shutdown == true)
         return;

      m_shutdown = true;

      m_more_tasks.notify_all();
      }

   for(auto&& thread : m_workers)
      {
      thread.join();
      }
   m_workers.clear();
   }

worker_count()

size_t Botan::Thread_Pool::worker_count ( ) const

inline

Definition at line 43 of file thread_pool.h.

Referenced by Botan::XMSS_PrivateKey::tree_hash().

{ return m_workers.size(); }

---

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

• src/lib/utils/thread_utils/thread_pool.h
• src/lib/utils/thread_utils/thread_pool.cpp