CommandFacility.cpp

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#include "cmdlib/CommandFacility.hpp"
#include "cmdlib/Issues.hpp"
#include "logging/Logging.hpp"
 
#include <future>
#include <functional>
#include <utility>
#include <atomic>
#include <chrono>
#include <string>
 
using namespace dunedaq::cmdlib;
 
CommandFacility::~CommandFacility() 
{
  if (m_active.load()) {
    m_active.store(false);
    if(m_executor.joinable()) {
      m_executor.join();
    } 
  }
}
 
void 
CommandFacility::set_commanded(CommandedObject& commanded, std::string name) 
{
  if (m_commanded_object == nullptr) {
    m_name = name;
    m_commanded_object = &commanded;
    m_command_callback = std::bind(&CommandFacility::handle_command, this, std::placeholders::_1, std::placeholders::_2);
    m_active.store(true);
    m_executor = std::thread(&CommandFacility::executor, this);
  } else {
    ers::error(CommandFacilityInitialization(ERS_HERE, "set_commanded shall be called once."));
  }
}
 
void 
CommandFacility::execute_command(const cmdobj_t& cmd, cmd::CommandReply meta)
{
  auto execfut = std::async(std::launch::deferred, m_command_callback, std::move(cmd), std::move(meta));
  m_completion_queue.push(std::move(execfut));
}
 
void
CommandFacility::handle_command(const cmdobj_t& cmd, cmd::CommandReply meta)
{
  try {
    m_commanded_object->execute(cmd);
    meta.success = true;
    meta.result = "OK";
    meta.appname = m_name;
  } catch (const ers::Issue& ei ) {
    meta.success = false;
    meta.result = ei.what();
    meta.appname = m_name;
    ers::error(CommandExecutionFailed(ERS_HERE, "Caught ers::Issue", ei));
  } catch (const std::exception& exc) {
    meta.success = false;
    meta.result = exc.what();
    meta.appname = m_name;
    ers::error(CommandExecutionFailed(ERS_HERE, "Caught std::exception", exc));
  } catch (...) {  // NOLINT JCF Jan-27-2021 violates letter of the law but not the spirit
    meta.success = false;
    meta.result = "Caught unknown exception";
    meta.appname = m_name;
    ers::error(CommandExecutionFailed(ERS_HERE, meta.result));
  }
  completion_callback(cmd, meta);
}
 
void
CommandFacility::executor()
{
  std::future<void> fut; 
  while (m_active.load()) {
    if (m_completion_queue.empty()) {
      std::this_thread::sleep_for(std::chrono::milliseconds(10));
    } else {
      bool success = m_completion_queue.try_pop(fut);
      if (!success) {
        ers::error(CompletionQueueIssue(ERS_HERE, "Can't get from completion queue.")); 
      } else {
        fut.wait(); // trigger execution
      }  
    }
  }
}