    // Copyright (C) 2008  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.

    #include <sstream>
    #include <string>
    #include <cstdlib>
    #include <ctime>
    #include <dlib/misc_api.h>
    #include <dlib/threads.h>
    #include <dlib/any.h>

    #include "tester.h"

    namespace
    {
        using namespace test;
        using namespace dlib;
        using namespace std;

        logger dlog("test.thread_pool");

        struct some_struct : noncopyable
        {
            float val;
        };

        int global_var = 0;

        struct add_functor
        {
            add_functor() { var = 1;}
            add_functor(int v):var(v) {}

            template <typename T, typename U, typename V>
            void operator()(T a, U b, V& res)
            {
                dlib::sleep(20);
                res = a + b;
            }

            void set_global_var() { global_var = 9; }
            void set_global_var_const() const { global_var = 9; }

            void set_global_var_arg1(int val) { global_var = val; }
            void set_global_var_const_arg1(int val) const { global_var = val; }
            void set_global_var_arg2(int val, int val2) { global_var = val+val2; }
            void set_global_var_const_arg2(int val, int val2) const { global_var = val+val2; }

            void operator()()
            {
                global_var = 9;
            }

            // use an any just so that if this object goes out of scope
            // then var will get all messed up.
            any var;
            void operator()(int& a) { dlib::sleep(100); a = var.get<int>(); }
            void operator()(int& a, int& b) { dlib::sleep(100); a = var.get<int>(); b = 2; }
            void operator()(int& a, int& b, int& c) { dlib::sleep(100); a = var.get<int>(); b = 2; c = 3; }
            void operator()(int& a, int& b, int& c, int& d) { dlib::sleep(100); a = var.get<int>(); b = 2; c = 3; d = 4; }
        };

        void set_global_var() {  global_var = 9; }

        void gset_struct_to_zero (some_struct& a) { a.val = 0; }
        void gset_to_zero (int& a) { a = 0; }
        void gincrement (int& a) { ++a; }
        void gadd (int a, const int& b, int& res) { dlib::sleep(20); res = a + b; }
        void gadd1(int& a, int& res) { res += a; }
        void gadd2 (int c, int a, const int& b, int& res) { dlib::sleep(20); res = a + b + c; }

        class thread_pool_tester : public tester
        {
        public:
            thread_pool_tester (
            ) :
                tester ("test_thread_pool",
                        "Runs tests on the thread_pool component.")
            {}

            void perform_test (
            )
            {
                add_functor f;
                for (int num_threads= 0; num_threads < 4; ++num_threads)
                {
                    future<int> a, b, c, res, d;
                    thread_pool tp(num_threads);
                    print_spinner();

                    future<some_struct> obj;

                    for (int i = 0; i < 4; ++i)
                    {
                        a = 1;
                        b = 2;
                        c = 3;
                        res = 4;

                        DLIB_TEST(a==a);
                        DLIB_TEST(a!=b);
                        DLIB_TEST(a==1);

                        tp.add_task(gset_to_zero, a);
                        tp.add_task(gset_to_zero, b);
                        tp.add_task(*this, &thread_pool_tester::set_to_zero, c);
                        tp.add_task(gset_to_zero, res);
                        DLIB_TEST(a == 0);
                        DLIB_TEST(b == 0);
                        DLIB_TEST(c == 0);
                        DLIB_TEST(res == 0);

                        tp.add_task(gincrement, a);
                        tp.add_task(*this, &thread_pool_tester::increment, b);
                        tp.add_task(*this, &thread_pool_tester::increment, c);
                        tp.add_task(gincrement, res);

                        DLIB_TEST(a == 1);
                        DLIB_TEST(b == 1);
                        DLIB_TEST(c == 1);
                        DLIB_TEST(res == 1);

                        tp.add_task(&gincrement, a);
                        tp.add_task(*this, &thread_pool_tester::increment, b);
                        tp.add_task(*this, &thread_pool_tester::increment, c);
                        tp.add_task(&gincrement, res);
                        tp.add_task(gincrement, a);
                        tp.add_task(*this, &thread_pool_tester::increment, b);
                        tp.add_task(*this, &thread_pool_tester::increment, c);
                        tp.add_task(gincrement, res);

                        DLIB_TEST(a == 3);
                        DLIB_TEST(b == 3);
                        DLIB_TEST(c == 3);
                        DLIB_TEST(res == 3);

                        tp.add_task(*this, &thread_pool_tester::increment, c);
                        tp.add_task(gincrement, res);
                        DLIB_TEST(c == 4);
                        DLIB_TEST(res == 4);

                        tp.add_task(gadd, a, b, res);
                        DLIB_TEST(res == a+b);
                        DLIB_TEST(res == 6);
                        a = 3;
                        b = 4;
                        res = 99;
                        DLIB_TEST(res == 99);
                        tp.add_task(*this, &thread_pool_tester::add, a, b, res);
                        DLIB_TEST(res == a+b);
                        DLIB_TEST(res == 7);

                        a = 1;
                        b = 2;
                        c = 3;
                        res = 88;
                        DLIB_TEST(res == 88);
                        DLIB_TEST(a == 1);
                        DLIB_TEST(b == 2);
                        DLIB_TEST(c == 3);

                        tp.add_task(gadd2, a, b, c, res);
                        DLIB_TEST(res == 6);
                        DLIB_TEST(a == 1);
                        DLIB_TEST(b == 2);
                        DLIB_TEST(c == 3);

                        a = 1;
                        b = 2;
                        c = 3;
                        res = 88;
                        DLIB_TEST(res == 88);
                        DLIB_TEST(a == 1);
                        DLIB_TEST(b == 2);
                        DLIB_TEST(c == 3);
                        tp.add_task(*this, &thread_pool_tester::add2, a, b, c, res);
                        DLIB_TEST(res == 6);
                        DLIB_TEST(a == 1);
                        DLIB_TEST(b == 2);
                        DLIB_TEST(c == 3);

                        a = 1;
                        b = 2;
                        c = 3;
                        res = 88;
                        tp.add_task(gadd1, a, b);
                        DLIB_TEST(a == 1);
                        DLIB_TEST(b == 3);
                        a = 2;
                        tp.add_task(*this, &thread_pool_tester::add1, a, b);
                        DLIB_TEST(a == 2);
                        DLIB_TEST(b == 5);

                        val = 4;
                        uint64 id = tp.add_task(*this, &thread_pool_tester::zero_val);
                        tp.wait_for_task(id);
                        DLIB_TEST(val == 0);
                        id = tp.add_task(*this, &thread_pool_tester::accum2, 1,2);
                        tp.wait_for_all_tasks();
                        DLIB_TEST(val == 3);
                        id = tp.add_task(*this, &thread_pool_tester::accum1, 3);
                        tp.wait_for_task(id);
                        DLIB_TEST(val == 6);

                        obj.get().val = 8;
                        DLIB_TEST(obj.get().val == 8);
                        tp.add_task(gset_struct_to_zero, obj);
                        DLIB_TEST(obj.get().val == 0);
                        obj.get().val = 8;
                        DLIB_TEST(obj.get().val == 8);
                        tp.add_task(*this,&thread_pool_tester::set_struct_to_zero, obj);
                        DLIB_TEST(obj.get().val == 0);

                        a = 1;
                        b = 2;
                        res = 0;
                        tp.add_task(f, a, b, res);
                        DLIB_TEST(a == 1);
                        DLIB_TEST(b == 2);
                        DLIB_TEST(res == 3);

                        global_var = 0;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task(&set_global_var);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 9);

                        global_var = 0;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task(f);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 9);

                        global_var = 0;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task(f, &add_functor::set_global_var);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 9);

                        global_var = 0;
                        a = 4;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task(f, &add_functor::set_global_var_arg1, a);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 4);

                        global_var = 0;
                        a = 4;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task_by_value(f, &add_functor::set_global_var_arg1, a);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 4);

                        global_var = 0;
                        a = 4;
                        b = 3;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task(f, &add_functor::set_global_var_arg2, a, b);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 7);

                        global_var = 0;
                        a = 4;
                        b = 3;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task_by_value(f, &add_functor::set_global_var_arg2, a, b);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 7);

                        global_var = 0;
                        a = 4;
                        b = 3;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task(f, &add_functor::set_global_var_const_arg2, a, b);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 7);

                        global_var = 0;
                        a = 4;
                        b = 3;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task_by_value(f, &add_functor::set_global_var_const_arg2, a, b);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 7);

                        global_var = 0;
                        a = 4;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task(f, &add_functor::set_global_var_const_arg1, a);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 4);

                        global_var = 0;
                        a = 4;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task_by_value(f, &add_functor::set_global_var_const_arg1, a);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 4);

                        global_var = 0;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task_by_value(f, &add_functor::set_global_var);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 9);

                        global_var = 0;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task(f, &add_functor::set_global_var_const);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 9);

                        global_var = 0;
                        DLIB_TEST(global_var == 0);
                        id = tp.add_task_by_value(f, &add_functor::set_global_var_const);
                        tp.wait_for_task(id);
                        DLIB_TEST(global_var == 9);

                    }

                    // add this task just to to perterb the thread pool before it goes out of scope
                    tp.add_task(f, a, b, res);

                    for (int k = 0; k < 3; ++k)
                    {
                        print_spinner();
                        global_var = 0;
                        tp.add_task_by_value(add_functor());
                        tp.wait_for_all_tasks();
                        DLIB_TEST(global_var == 9);

                        a = 0; b = 0; c = 0; d = 0;
                        tp.add_task_by_value(add_functor(), a);
                        DLIB_TEST(a == 1);
                        a = 0; b = 0; c = 0; d = 0;
                        tp.add_task_by_value(add_functor(8), a, b);
                        DLIB_TEST(a == 8);
                        DLIB_TEST(b == 2);
                        a = 0; b = 0; c = 0; d = 0;
                        tp.add_task_by_value(add_functor(), a, b, c);
                        DLIB_TEST(a == 1);
                        DLIB_TEST(b == 2);
                        DLIB_TEST(c == 3);
                        a = 0; b = 0; c = 0; d = 0;
                        tp.add_task_by_value(add_functor(5), a, b, c, d);
                        DLIB_TEST(a == 5);
                        DLIB_TEST(b == 2);
                        DLIB_TEST(c == 3);
                        DLIB_TEST(d == 4);
                    }

                }
            }

            long val;
            void accum1(long a) { val += a; }
            void accum2(long a, long b) { val += a + b; }
            void zero_val() { dlib::sleep(20); val = 0; }

            void set_struct_to_zero (some_struct& a) { a.val = 0; }
            void set_to_zero (int& a) { dlib::sleep(20); a = 0; }
            void increment (int& a) const { dlib::sleep(20); ++a; }
            void add (int a, const int& b, int& res) { dlib::sleep(20); res = a + b; }
            void add1(int& a, int& res) const { res += a; }
            void add2 (int c, int a, const int& b, int& res) { res = a + b + c; }

        } a;

    }