System::Threading::ThreadPool class

ThreadPool class

Thread pool API allowing it pushing jobs into queue to be read by pool of worker threads. This is a static type with no instance services. You should never create instances of it by any means.

class ThreadPool : public System::Object

Methods

Method	Description
static GetAvailableThreads(int&, int&)	Gets number of available threads.
static GetInstance()	RTTI information.
static GetMaxThreads(int&, int&)	Gets maximal number of concurrent threads.
static GetMinThreads(int&, int&)	Gets minimal number of threads being created by pool.
static JoinAllThreads()	Joins all owned threads. Waits infinitely.
operator=(const ThreadPool&)	No copying.
static QueueUserWorkItem(WaitCallback)	Puts work item into queue which is present with callback with no parameter.
static QueueUserWorkItem(WaitCallback, const System::SharedPtr<System::Object>&)	Puts work item into queue which is present with callback with no parameter.
static SetMaxThreads(int, int)	Sets number of threads owned by pool.
static SetMinThreads(int, int)	Sets minimal number of threads owned by pool.
ThreadPool(const ThreadPool&)	No copying.

Remarks

#include "system/threading/thread_pool.h"
#include "system/threading/thread.h"
#include "system/object.h"
#include "system/smart_ptr.h"
#include <iostream>
#include <mutex>
#include <string>
#include <thread>

const std::string &BooleanToString(bool value)
{
  static const std::string True = "True";
  static const std::string False = "False";

  return value ? True : False;
}

int main()
{
  using namespace System::Threading;
  std::mutex m;

  const auto threadsCount = std::thread::hardware_concurrency();

  for (unsigned int i = 0; i < threadsCount; ++i)
  {
    ThreadPool::QueueUserWorkItem([&m](System::SharedPtr<System::Object> object) -> void {
      auto thread = Thread::get_CurrentThread();
      m.lock();
      std::cout << "Background: " << BooleanToString(thread->get_IsBackground()) <<
        ", Thread pool: " << BooleanToString(thread->get_IsThreadPoolThread()) <<
        ", Thread ID: " << thread->get_ManagedThreadId() << std::endl;
      m.unlock();
    });
  }

  ThreadPool::JoinAllThreads();

  return 0;
}
/*
This code example produces the following output:
Background: True, Thread pool: True, Thread ID: 1
Background: True, Thread pool: True, Thread ID: 3
Background: True, Thread pool: True, Thread ID: 5
Background: True, Thread pool: True, Thread ID: 6
Background: True, Thread pool: True, Thread ID: 9
Background: True, Thread pool: True, Thread ID: 1
Background: True, Thread pool: True, Thread ID: 7
Background: True, Thread pool: True, Thread ID: 2
Background: True, Thread pool: True, Thread ID: 4
Background: True, Thread pool: True, Thread ID: 3
Background: True, Thread pool: True, Thread ID: 12
Background: True, Thread pool: True, Thread ID: 8
Background: True, Thread pool: True, Thread ID: 5
Background: True, Thread pool: True, Thread ID: 6
Background: True, Thread pool: True, Thread ID: 16
Background: True, Thread pool: True, Thread ID: 11
*/

See Also

• Class Object
• Namespace System::Threading
• Library Aspose.PDF for C++