Fix problem with single producer - single consumer queue: previous test was not…

Fix problem with single producer - single consumer queue: previous test was not suitable for this case, modified in order to account for spsc

linearizability_tester/main.cc

-/* 
+/*
  * Main script that applies the linearizability tester on embb data structures.
  */
 
@@ -17,7 +17,24 @@
 #include <embb/containers/lock_free_mpmc_queue.h>
 #include <embb/containers/wait_free_spsc_queue.h>
 
-// Each thread executes quasi randomly operations (TryEqneueu, TryDequeue)
+// Class that provides unique ids for threads.
+class id_creator {
+ public:
+   id_creator() : id(0) {};
+
+   void next_id(size_t &cur_id){
+     std::lock_guard<std::mutex> lock(mut);
+     cur_id = id;
+     id ++;
+   }
+ private:
+   size_t id;
+
+   std::mutex  mut;
+
+};
+
+// Each thread executes quasi randomly operations (TryEnqueue, TryDequeue)
 // on the concurrent data structure and construct the history.
 template<std::size_t N, class S>
 static void embb_worker_stack(
@@ -64,39 +81,83 @@ template<std::size_t N, class S>
 static void embb_worker_queue(
   const WorkerConfiguration& worker_configuration,
   ConcurrentLog<state::Queue<N>>& concurrent_log,
-  S& concurrent_queue)
+  S& concurrent_queue,
+  id_creator* creator,
+  bool mpmc)
 {
+
   std::random_device rd;
   std::mt19937 gen(rd());
   std::uniform_int_distribution<> value_dist('\0', worker_configuration.max_value);
   std::uniform_int_distribution<> percentage_dist(0, 100);
 
-  bool ret;
+  // my_id is used only in the case of single producer, single consumer.
+  // my_id == 0 : producer thread, my_id == 1 : consumer thread
+  size_t my_id;
+  creator->next_id(my_id);
 
+  bool ret;
   char value;
   unsigned percentage;
   EntryPtr<state::Queue<N>> call_entry_ptr;
-  for (unsigned number_of_ops{ 0U };
-  number_of_ops < worker_configuration.number_of_ops;
-    ++number_of_ops)
-  {
-    value = value_dist(rd);
-    percentage = percentage_dist(rd);
-    // Note: this threshold affects considerably the running time of the test
-    // increasing threshold -> increasing running time
-    if (percentage < 20)
+  if (mpmc){
+    for (unsigned number_of_ops{ 0U };
+    number_of_ops < worker_configuration.number_of_ops;
+      ++number_of_ops)
     {
-      call_entry_ptr = concurrent_log.push_back(state::Queue<N>::make_try_enqueue_call(value));
-      ret = concurrent_queue.TryEnqueue(value);
-      concurrent_log.push_back(call_entry_ptr, state::Queue<N>::make_try_enqueue_ret(ret));
+      value = value_dist(rd);
+      percentage = percentage_dist(rd);
+      // Note: this threshold affects considerably the running time of the test
+      // increasing threshold -> increasing running time
+      if (percentage < 20)
+      {
+        call_entry_ptr = concurrent_log.push_back(state::Queue<N>::make_try_enqueue_call(value));
+        ret = concurrent_queue.TryEnqueue(value);
+        concurrent_log.push_back(call_entry_ptr, state::Queue<N>::make_try_enqueue_ret(ret));
+      }
+      else
+      {
+        call_entry_ptr = concurrent_log.push_back(state::Queue<N>::make_try_dequeue_call());
+        ret = concurrent_queue.TryDequeue(value);
+        concurrent_log.push_back(call_entry_ptr, state::Queue<N>::make_try_dequeue_ret(ret, value));
+      }
     }
-    else
-    {
-      call_entry_ptr = concurrent_log.push_back(state::Queue<N>::make_try_dequeue_call());
-      ret = concurrent_queue.TryDequeue(value);
-      concurrent_log.push_back(call_entry_ptr, state::Queue<N>::make_try_dequeue_ret(ret, value));
+  }
+  // single produced - single consumer case. Note that the final number of operations
+  // is not known, because threads do not enqueue/dequeue at each iteration
+  else {
+    if(my_id == 0){
+        // multiplying by 2 the number of operations because
+        // the thread will not make an operation at teach iteration
+        for (unsigned number_of_ops{ 0U };
+        number_of_ops < worker_configuration.number_of_ops * 2;
+          ++number_of_ops)
+        {
+          percentage = percentage_dist(rd);
+          value = value_dist(rd);
+          if (percentage<20){
+            call_entry_ptr = concurrent_log.push_back(state::Queue<N>::make_try_enqueue_call(value));
+            ret = concurrent_queue.TryEnqueue(value);
+            concurrent_log.push_back(call_entry_ptr, state::Queue<N>::make_try_enqueue_ret(ret));
+          }
+
+        }
+    }
+    else if(my_id == 1){
+        for (unsigned number_of_ops{ 0U };
+        number_of_ops < worker_configuration.number_of_ops * 2;
+          ++number_of_ops)
+        {
+          percentage = percentage_dist(rd);
+          if (percentage>80){
+            call_entry_ptr = concurrent_log.push_back(state::Queue<N>::make_try_dequeue_call());
+            ret = concurrent_queue.TryDequeue(value);
+            concurrent_log.push_back(call_entry_ptr, state::Queue<N>::make_try_dequeue_ret(ret, value));
+          }
+        }
     }
   }
+
 }
 
 // Creates the history and apply the tester on it
@@ -117,7 +178,7 @@ static void embb_experiment_stack()
   char value;
   assert(concurrent_stack.TryPush(5));
   assert(concurrent_stack.TryPop(value));
-  
+
   // create history
   start_threads(number_of_threads, embb_worker_stack<N, S>, std::cref(worker_configuration),
     std::ref(concurrent_log), std::ref(concurrent_stack));
@@ -148,7 +209,7 @@ static void embb_experiment_stack()
 
 // Creates the history and apply the tester on it
 template <class S>
-static void embb_experiment_queue()
+static void embb_experiment_queue(bool mpmc)
 {
   constexpr std::chrono::hours max_duration{ 1 };
   constexpr std::size_t N = 560000U;
@@ -165,12 +226,14 @@ static void embb_experiment_queue()
   char value;
   assert(concurrent_queue.TryEnqueue(5));
   assert(concurrent_queue.TryDequeue(value));
+  id_creator* creator = new id_creator();
 
   // create history
-  start_threads(number_of_threads, embb_worker_queue<N, S>, std::cref(worker_configuration),
-    std::ref(concurrent_log), std::ref(concurrent_queue));
+  start_threads(number_of_threads,  embb_worker_queue<N, S>,  std::cref(worker_configuration),
+    std::ref(concurrent_log), std::ref(concurrent_queue), std::cref(creator),std::cref(mpmc));
+  delete creator;
   const std::size_t number_of_entries{ concurrent_log.number_of_entries() };
-  const LogInfo<state::Queue<N>> log_info{ concurrent_log.info() };
+  const LogInfo<state::Queue<N>> log_info{ concurrent_log.info()};
 
   auto start = std::chrono::system_clock::now();
   auto end = std::chrono::system_clock::now();
@@ -194,20 +257,19 @@ static void embb_experiment_queue()
 
 
 int main()
-{  
+{
 
   // Test functions and structures in linearizability_tester.h and sequential_data_structures.h
   run_tests();
   embb::base::Thread::SetThreadsMaxCount(255);
-  
+
   std::cout << "Linearizability test on LockFreeMPMCQueue" << std::endl;
-  embb_experiment_queue<embb::containers::LockFreeMPMCQueue<char>>();
+  embb_experiment_queue<embb::containers::LockFreeMPMCQueue<char>>(true);
 
   std::cout << "Linearizability test on WaitFreeSPSCQueue" << std::endl;
-  embb_experiment_queue<embb::containers::WaitFreeSPSCQueue<char>>();
+  embb_experiment_queue<embb::containers::WaitFreeSPSCQueue<char>>(false);
 
   std::cout << "Linearizability test on LockFreeStack" << std::endl;
   embb_experiment_stack<embb::containers::LockFreeStack<char>>();
   return 0;
 }
-