From 615a91f3fe5e0a557700d81ed713bfa8d4ef76a7 Mon Sep 17 00:00:00 2001
From: TUNQRT <bauerovakar@gmail.com>
Date: Thu, 13 Mar 2025 17:35:23 +0100
Subject: [PATCH] thread pool

---
 task_queue.h      |   0
 triangulation.cpp | 177 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 177 insertions(+)
 delete mode 100644 task_queue.h

diff --git a/task_queue.h b/task_queue.h
deleted file mode 100644
index e69de29..0000000
diff --git a/triangulation.cpp b/triangulation.cpp
index e69de29..0d064ec 100644
--- a/triangulation.cpp
+++ b/triangulation.cpp
@@ -0,0 +1,177 @@
+#include <thread>
+#include <chrono>
+#include <ctime>
+#include <cstdlib>
+#include <iostream>
+#include <mutex>
+#include <vector>
+#include <queue>
+#include <atomic>
+#include <condition_variable>
+
+#ifndef libpoly092986127876181939u43295237
+#define libpoly092986127876181939u43295237
+
+extern void test(void); // prints to stdout to test linking
+
+#include <vector>
+#include <memory>
+
+struct LP_Point {
+    double x, y;
+};
+
+struct LP_Polygon {
+    std::vector< LP_Point > points;
+    LP_Polygon(std::vector< LP_Point >&& p) : points(p) {}
+};
+
+struct LP_Task : public std::enable_shared_from_this< LP_Task > {
+    LP_Polygon p;
+    double minimal_triangulation;
+};
+
+using LP_Task_p = std::shared_ptr< LP_Task >;
+
+extern LP_Task_p pickup_task(); //je thread safe, nebo si to musím ošéfit?
+extern bool submit_task(LP_Task_p&&);
+extern void print_stats();
+
+#endif // libpoly092986127876181939u43295237
+
+//############################################################ GLOBALS
+
+std::condition_variable can_pop;
+std::condition_variable can_push;
+
+std::atomic_uint32_t active_producents;
+std::atomic_uint32_t active_consuments;
+std::atomic_bool tasks_incoming;
+
+//############################# MODIFY HERE
+
+constexpr unsigned NUM_PRODUCENTS = 20;
+constexpr unsigned NUM_WORKERS = 20;
+
+//############################################################ COMMON STRUCTURES
+
+class Task {
+private:
+    LP_Task_p task;
+    bool ready_for_submit;
+
+public:
+    Task() = delete;
+    Task(const Task&) = delete;
+    Task(Task&& t): task(t.task), ready_for_submit(t.ready_for_submit){
+        t.task.reset();
+    }
+    Task(LP_Task_p&& tp): task(tp), ready_for_submit(false){}
+    void triangulate();
+};
+
+class Queue{
+    std::queue<Task> q;
+    std::mutex q_l;
+    const size_t MAX_LENGHT = 100'000;
+    
+public:
+
+    void push(Task&& t){
+        std::unique_lock<std::mutex> pushlock(q_l);
+        can_push.wait(pushlock, [this]{ return (q.size() < MAX_LENGHT); });
+
+
+        q.push(std::move(t));
+        pushlock.unlock();
+        can_pop.notify_one();
+    }
+
+    Task pop(){
+        std::unique_lock<std::mutex> poplock(q_l);
+        can_pop.wait(poplock, [this]{ return !is_empty(); });
+        
+        Task t(std::move(q.front()));
+        q.pop();
+        poplock.unlock();
+        can_push.notify_one();
+        return t;
+    }
+
+    bool is_empty( ){
+        return q.empty();
+    }
+};
+
+using task_queue_ptr = std::shared_ptr<Queue>;
+
+//############################################################ PRODUCE THREAD
+
+class Producent{
+private:
+    task_queue_ptr task_queue;
+public:
+    Producent(task_queue_ptr tq): task_queue(tq){ active_producents++; }
+    Producent(const Producent&) = delete;
+    ~Producent(){ active_producents--; }
+
+    Task get_task(){
+        LP_Task_p tp = pickup_task(); //might need to be locked - ask Ondra
+        return Task(std::move(tp));
+    }
+
+    void fill_queue(){
+        while(tasks_incoming){
+            task_queue->push(get_task());
+        }
+    }
+};
+
+void produce_thread(task_queue_ptr task_queue){
+    Producent p(task_queue);
+    p.fill_queue();
+}
+
+//############################################################ WORKER THREAD
+
+class Consument {
+private:
+    task_queue_ptr task_queue;
+public:
+    Consument(task_queue_ptr tq): task_queue(tq){ active_consuments++; }
+    Consument(const Consument&) = delete;
+    ~Consument() { active_consuments--; }
+
+    Task get_task(){ // might be redundant
+        return task_queue->pop();
+    }
+
+    void work(){
+        while(active_producents || ! task_queue->is_empty()){
+            Task t = get_task();
+            t.triangulate();
+        }
+    }
+};
+
+void consume_thread(task_queue_ptr task_queue){
+    Consument c(task_queue);
+}
+
+//############################################################ MAIN
+
+int main(){
+    active_producents = 0;
+    Queue q;
+    task_queue_ptr queue_ptr(&q);
+    std::vector<std::thread> threads;
+
+    for(unsigned int i = 0; i < NUM_PRODUCENTS; i++){
+        threads.emplace_back(produce_thread, queue_ptr);
+    }
+
+    std::this_thread::sleep_for(std::chrono::seconds(5));
+    for(auto& t : threads){
+        t.join();
+    }
+}
\ No newline at end of file