pgPool.cpp

#include "pgPool.h"

PGPool::PGPool()
{
  createPool();
}

void PGPool::createPool()
{
  std::lock_guard<std::mutex> locker_( m_mutex );

  for (auto i=0; i < POOL_SIZE; i++) {
    m_pool.emplace(std::make_shared<pqxx::lazyconnection>());
  }
}

std::shared_ptr<pqxx::lazyconnection> PGPool::connection()
{
  std::unique_lock<std::mutex> lock_(m_mutex);

  // if pool is empty, then wait until it notifies back
  while (m_pool.empty()) {
    m_condition.wait(lock_);
  }

  // get new connection in queue
  auto conn_ = m_pool.front();
  // immediately pop as we will use it now
  m_pool.pop();

  return conn_;
}

void PGPool::freeConnection(std::shared_ptr<pqxx::lazyconnection> conn_)
{
  std::unique_lock<std::mutex> lock_(m_mutex);

  // push a new connection into a pool
  m_pool.push(conn_);

  // unlock mutex
  lock_.unlock();

  // notify one of thread that is waiting
  m_condition.notify_one();
}