fixed threadpool

threading/pool.hpp

@@ -3,77 +3,53 @@
 
 #include <mutex>
 #include <atomic>
-#include <condition_variable>
 #include <future>
+#include <queue>
+#include <condition_variable>
 
-#include "data_structures/queue/slqueue.hpp"
-#include "threading/sync/lockable.hpp"
-#include "worker.hpp"
-#include "data_structures/queue/slqueue.hpp"
+#include "sync/lockable.hpp"
 
 class Pool : Lockable<std::mutex>
 {
     using task_t = std::function<void()>;
-
 public:
-    Pool(size_t n = std::thread::hardware_concurrency())
-        : alive(true)
+    Pool(size_t n = std::thread::hardware_concurrency()) : alive(true)
     {
-        start(n);
+        threads.reserve(n);
+
+        for(size_t i = 0; i < n; ++i)
+            threads.emplace_back([this]()->void { loop(); });
     }
+
+    Pool(Pool&) = delete;
+    Pool(Pool&&) = delete;
     
     ~Pool()
     {
         alive.store(false, std::memory_order_release);
         cond.notify_all();
 
-        for(auto& worker : workers)
-            worker.join();
-    }
-
-    size_t size()
-    {
-        return workers.size();
+        for(auto& thread : threads)
+            thread.join();
     }
 
     template <class F, class... Args>
-    void execute(F&& f, Args&&... args)
+    void run(F&& f, Args&&... args)
     {
         {
-            auto guard = acquire();
-            tasks.emplace([f, args...]() { f(args...);  });
+            auto lock = acquire();
+
+            tasks.emplace([&f, &args...]() {
+                f(std::forward<Args>(args)...);
+            });
         }
 
         cond.notify_one();
     }
 
-    template <class F, class... Args>
-    auto execute_with_result(F&& f, Args&&... args)
-        -> std::future<typename std::result_of<F(Args...)>::type>
-    {
-        using ret_t = typename std::result_of<F(Args...)>::type;
-
-        auto task = std::make_shared<std::packaged_task<ret_t()>>
-            (std::bind(f, args...));
-
-        auto result = task->get_future();
-
-        {
-            auto guard = acquire();
-            tasks.emplace([task]() { (*task)();  });
-        }
-
-        cond.notify_one();
-        return result;
-    }
-
 private:
-    Pool(const Pool&) = delete;
-    Pool(Pool&&) = delete;
-
-    std::vector<Worker<task_t>> workers;
-    spinlock::Queue<task_t> tasks;
-
+    std::vector<std::thread> threads;
+    std::queue<task_t> tasks;
     std::atomic<bool> alive;
 
     std::mutex mutex;
@@ -81,29 +57,27 @@ private:
 
     void loop()
     {
-        task_t task;
-
         while(true)
         {
-            while(tasks.pop(task))
-               task(); 
+            task_t task;
 
-            auto guard = acquire();
+            {
+                auto lock = acquire();
 
-            cond.wait(guard, [this] {
-                return !this->alive || !this->tasks.empty();
-            });
+                cond.wait(lock, [this] {
+                    return !this->alive || !this->tasks.empty();
+                });
 
-            if(!alive && tasks.empty())
-                return;
+                if(!alive && tasks.empty())
+                    return;
+
+                task = std::move(tasks.front());
+                tasks.pop();
+            }
+
+            task();
         }
     }
-
-    void start(size_t n)
-    {
-        for(size_t i = 0; i < n; ++i)
-            workers.emplace_back([this]()->void { this->loop(); });
-    }
 };
 
 #endif

threading/sync/spinlock.hpp

@@ -10,8 +10,6 @@ public:
 
     void lock()
     {
-        // TODO add asm_pause and counter first before sleeping
-        // might be faster, but test this and see
         while(lock_flag.test_and_set(std::memory_order_acquire))
             usleep(250);
     }

threading/test.cpp

@@ -4,16 +4,17 @@
 
 int main(void)
 {
-    std::cout << "hardware_concurrency " << std::thread::hardware_concurrency() << std::endl;
-
-    auto size = 2048;
+    auto size = 7;
     auto N = 1000000;
 
     Pool pool(size);
 
     for(int i = 0; i < N; ++i)
-        pool.execute([size](int) {
-            std::this_thread::sleep_for(std::chrono::milliseconds(5));
+        pool.run([](int) {
+            int sum = 0;
+
+            for(int i = 0; i < 2000; ++i)
+                sum += i % 7;
         }, i);
 
     return 0;

threading/worker.hpp

@@ -1,22 +0,0 @@
-#ifndef MEMGRAPH_THREADING_WORKER_HPP
-#define MEMGRAPH_THREADING_WORKER_HPP
-
-#include <thread>
-
-template <class F, class... Args>
-class Worker
-{
-public:
-    Worker(F&& f, Args&&... args)
-        : thread(f, args...) {}
-
-    void join()
-    {
-        thread.join();
-    }
-
-private:
-    std::thread thread;
-};
-
-#endif