From 7d7b51b1ea4b88c93cd918980913780a28840870 Mon Sep 17 00:00:00 2001
From: Adrien Matta <matta@lpccaen.in2p3.fr>
Date: Wed, 28 Apr 2021 11:20:07 +0200
Subject: [PATCH] * improving multithreading

---
 NPLib/CMakeLists.txt                               | 2 +-
 NPLib/Core/NPDetectorManager.cxx                   | 6 +++++-
 NPLib/Core/NPDetectorManager.h                     | 2 ++
 NPLib/TrackReconstruction/NPDCReconstructionMT.cxx | 7 +++++--
 NPLib/TrackReconstruction/NPDCReconstructionMT.h   | 2 ++
 5 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/NPLib/CMakeLists.txt b/NPLib/CMakeLists.txt
index dae59391e..89c549239 100644
--- a/NPLib/CMakeLists.txt
+++ b/NPLib/CMakeLists.txt
@@ -25,7 +25,7 @@ if(NOT DEFINED NPMULTITHREADING)
 endif()
 
 if(NPMULTITHREADING)
- set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DNPMULTITHREADING=1")
+ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}  -Wthread-safety -DNPMULTITHREADING=1")
  message("Building application with MultiThreading Support")
  else()
  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DNPMULTITHREADING=0")
diff --git a/NPLib/Core/NPDetectorManager.cxx b/NPLib/Core/NPDetectorManager.cxx
index 1c8274a71..0801bc36c 100644
--- a/NPLib/Core/NPDetectorManager.cxx
+++ b/NPLib/Core/NPDetectorManager.cxx
@@ -249,7 +249,9 @@ void NPL::DetectorManager::ReadConfigurationFile(std::string Path)   {
 void NPL::DetectorManager::BuildPhysicalEvent(){
 #if __cplusplus > 199711L && NPMULTITHREADING
     // add new job
+    m_mtx.lock();
     m_Ready.flip();
+    m_mtx.unlock();
     std::this_thread::yield();
 
   while(!IsDone()){
@@ -411,7 +413,7 @@ void NPL::DetectorManager::InitThreadPool(){
 ////////////////////////////////////////////////////////////////////////////////
 void NPL::DetectorManager::StartThread(NPL::VDetector* det,unsigned int id){ 
   // Let the main thread start 
-  std::this_thread::sleep_for(std::chrono::milliseconds(100));
+  //std::this_thread::sleep_for(std::chrono::milliseconds(100));
   while(true){
     // Do the job if possible
     if(m_Ready[id]){
@@ -425,7 +427,9 @@ void NPL::DetectorManager::StartThread(NPL::VDetector* det,unsigned int id){
        if(m_CheckSpectra)
           (det->*m_CheckSpectra)();
       }
+     m_mtx.lock();
      m_Ready[id].flip();
+     m_mtx.unlock();
      std::this_thread::yield();
    }
    else{
diff --git a/NPLib/Core/NPDetectorManager.h b/NPLib/Core/NPDetectorManager.h
index 3795d6455..07e280bcc 100644
--- a/NPLib/Core/NPDetectorManager.h
+++ b/NPLib/Core/NPDetectorManager.h
@@ -30,6 +30,7 @@
 #include <string>
 #include <map>
 #include <vector>
+#include <mutex>
 #include <iostream>
 #if __cplusplus > 199711L 
 #include <thread>
@@ -82,6 +83,7 @@ namespace NPL{
     private: // Thread Pool defined if C++11 is available
       std::vector<std::thread> m_ThreadPool;
       std::vector<bool> m_Ready;
+      std::mutex m_mtx;
       bool m_stop;
 
     public: // Init the Thread Pool
diff --git a/NPLib/TrackReconstruction/NPDCReconstructionMT.cxx b/NPLib/TrackReconstruction/NPDCReconstructionMT.cxx
index 769af9518..89cdc2f16 100644
--- a/NPLib/TrackReconstruction/NPDCReconstructionMT.cxx
+++ b/NPLib/TrackReconstruction/NPDCReconstructionMT.cxx
@@ -27,7 +27,6 @@
 #include "TGraph.h"
 #include "TVector3.h"
 #include "TROOT.h"
-
 using namespace std;
 using namespace NPL;
 
@@ -222,13 +221,15 @@ void DCReconstructionMT::StartThread(unsigned int id){
   // each threads needs its own or the minisation is not thread safe 
   ROOT::Math::Functor* func= new ROOT::Math::Functor(this,&NPL::DCReconstructionMT::SumD,3); 
   //Create the minimiser (deleted by the thread)
+  m_mtx.lock();
   ROOT::Math::Minimizer* mini=ROOT::Math::Factory::CreateMinimizer("Minuit2", "Migrad"); 
+  m_mtx.unlock();
 
   mini->SetFunction(*func);
   mini->SetPrintLevel(0);
 
   // Let the main thread start
-  std::this_thread::sleep_for(std::chrono::milliseconds(500));
+  //std::this_thread::sleep_for(std::chrono::milliseconds(500));
   while(true){
     // Do the job if possible
     if(m_Ready[id]){
@@ -254,7 +255,9 @@ void DCReconstructionMT::StartThread(unsigned int id){
       m_X100[uid]=(100-m_b[uid])/m_a[uid];
       m_minimum[uid] = mini->MinValue();
       // notify main thread job is done
+      m_mtx.lock();// make sure no other thread is reading/writing to the map
       m_Ready[id].flip();
+      m_mtx.unlock();
       // Let other thread move up in the queu
       std::this_thread::yield();
     }
diff --git a/NPLib/TrackReconstruction/NPDCReconstructionMT.h b/NPLib/TrackReconstruction/NPDCReconstructionMT.h
index 8931b942f..29af99a16 100644
--- a/NPLib/TrackReconstruction/NPDCReconstructionMT.h
+++ b/NPLib/TrackReconstruction/NPDCReconstructionMT.h
@@ -40,6 +40,7 @@
 #include <map>
 #include <vector>
 #include <thread>
+#include <mutex>
 class TVector3;
 class TGraph;
 namespace NPL{
@@ -98,6 +99,7 @@ namespace NPL{
       std::vector<std::thread> m_ThreadPool;
       std::vector<bool> m_Ready;
       bool m_stop;
+      std::mutex m_mtx;
 
     public: // Init the Thread Pool
 
-- 
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