/src/crow/include/crow/http_server.h

Source (jump to first uncovered line)
#pragma once

#ifdef CROW_USE_BOOST
#include <boost/asio.hpp>
#ifdef CROW_ENABLE_SSL
#include <boost/asio/ssl.hpp>
#endif
#else
#ifndef ASIO_STANDALONE
#define ASIO_STANDALONE
#endif
#include <asio.hpp>
#ifdef CROW_ENABLE_SSL
#include <asio/ssl.hpp>
#endif
#endif

#include <atomic>
#include <chrono>
#include <cstdint>
#include <future>
#include <memory>
#include <vector>

#include "crow/version.h"
#include "crow/http_connection.h"
#include "crow/logging.h"
#include "crow/task_timer.h"


namespace crow // NOTE: Already documented in "crow/app.h"
{
#ifdef CROW_USE_BOOST
    namespace asio = boost::asio;
    using error_code = boost::system::error_code;
#else
    using error_code = asio::error_code;
#endif
    using tcp = asio::ip::tcp;

    template<typename Handler, typename Adaptor = SocketAdaptor, typename... Middlewares>
    class Server
    {
    public:
      Server(Handler* handler,
             const tcp::endpoint& endpoint,
             std::string server_name = std::string("Crow/") + VERSION,
             std::tuple<Middlewares...>* middlewares = nullptr,
             uint16_t concurrency = 1,
             uint8_t timeout = 5,
             typename Adaptor::context* adaptor_ctx = nullptr):
          acceptor_(io_context_,endpoint),
          signals_(io_context_),
          tick_timer_(io_context_),
          handler_(handler),
          concurrency_(concurrency),
          timeout_(timeout),
          server_name_(server_name),
          task_queue_length_pool_(concurrency_ - 1),
          middlewares_(middlewares),
          adaptor_ctx_(adaptor_ctx)
        {}

        void set_tick_function(std::chrono::milliseconds d, std::function<void()> f)
        {
            tick_interval_ = d;
            tick_function_ = f;
        }

        void on_tick()
        {
            tick_function_();
            tick_timer_.expires_after(std::chrono::milliseconds(tick_interval_.count()));
            tick_timer_.async_wait([this](const error_code& ec) {
                if (ec)
                    return;
                on_tick();
            });
        }

        void run()
        {
            uint16_t worker_thread_count = concurrency_ - 1;
            for (int i = 0; i < worker_thread_count; i++)
                io_context_pool_.emplace_back(new asio::io_context());
            get_cached_date_str_pool_.resize(worker_thread_count);
            task_timer_pool_.resize(worker_thread_count);

            std::vector<std::future<void>> v;
            std::atomic<int> init_count(0);
            for (uint16_t i = 0; i < worker_thread_count; i++)
                v.push_back(
                  std::async(
                    std::launch::async, [this, i, &init_count] {
                        // thread local date string get function
                        auto last = std::chrono::steady_clock::now();

                        std::string date_str;
                        auto update_date_str = [&] {
                            auto last_time_t = time(0);
                            tm my_tm;

#if defined(_MSC_VER) || defined(__MINGW32__)
                            gmtime_s(&my_tm, &last_time_t);
#else
                            gmtime_r(&last_time_t, &my_tm);
#endif
                            date_str.resize(100);
                            size_t date_str_sz = strftime(&date_str[0], 99, "%a, %d %b %Y %H:%M:%S GMT", &my_tm);
                            date_str.resize(date_str_sz);
                        };
                        update_date_str();
                        get_cached_date_str_pool_[i] = [&]() -> std::string {
                            if (std::chrono::steady_clock::now() - last >= std::chrono::seconds(1))
                            {
                                last = std::chrono::steady_clock::now();
                                update_date_str();
                            }
                            return date_str;
                        };

                        // initializing task timers
                        detail::task_timer task_timer(*io_context_pool_[i]);
                        task_timer.set_default_timeout(timeout_);
                        task_timer_pool_[i] = &task_timer;
                        task_queue_length_pool_[i] = 0;

                        init_count++;
                        while (1)
                        {
                            try
                            {
                                if (io_context_pool_[i]->run() == 0)
                                {
                                    // when io_service.run returns 0, there are no more works to do.
                                    break;
                                }
                            }
                            catch (std::exception& e)
                            {
                                CROW_LOG_ERROR << "Worker Crash: An uncaught exception occurred: " << e.what();
                            }
                        }
                    }));

            if (tick_function_ && tick_interval_.count() > 0)
            {
                tick_timer_.expires_after(std::chrono::milliseconds(tick_interval_.count()));
                tick_timer_.async_wait(
                  [this](const error_code& ec) {
                      if (ec)
                          return;
                      on_tick();
                  });
            }

            handler_->port(acceptor_.local_endpoint().port());


            CROW_LOG_INFO << server_name_
                          << " server is running at " << (handler_->ssl_used() ? "https://" : "http://")
                          << acceptor_.local_endpoint().address() << ":" << acceptor_.local_endpoint().port() << " using " << concurrency_ << " threads";
            CROW_LOG_INFO << "Call `app.loglevel(crow::LogLevel::Warning)` to hide Info level logs.";

            signals_.async_wait(
              [&](const error_code& /*error*/, int /*signal_number*/) {
                  stop();
              });

            while (worker_thread_count != init_count)
                std::this_thread::yield();

            do_accept();

            std::thread(
              [this] {
                  notify_start();
                  io_context_.run();
                  CROW_LOG_INFO << "Exiting.";
              })
              .join();
        }

        void stop()
        {
            shutting_down_ = true; // Prevent the acceptor from taking new connections
            for (auto& io_context : io_context_pool_)
            {
                if (io_context != nullptr)
                {
                    CROW_LOG_INFO << "Closing IO service " << &io_context;
                    io_context->stop(); // Close all io_services (and HTTP connections)
                }
            }

            CROW_LOG_INFO << "Closing main IO service (" << &io_context_ << ')';
            io_context_.stop(); // Close main io_service
        }

        uint16_t port() const {
            return acceptor_.local_endpoint().port();
        }

        /// Wait until the server has properly started or until timeout
        std::cv_status wait_for_start(std::chrono::steady_clock::time_point wait_until)
        {
            std::unique_lock<std::mutex> lock(start_mutex_);
            
            std::cv_status status = std::cv_status::no_timeout;
            while (!server_started_ && ( status==std::cv_status::no_timeout ))
                status = cv_started_.wait_until(lock,wait_until);
            return status;
        }

        void signal_clear()
        {
            signals_.clear();
        }

        void signal_add(int signal_number)
        {
            signals_.add(signal_number);
        }

    private:
        uint16_t pick_io_context_idx()
        {
            uint16_t min_queue_idx = 0;

            // TODO improve load balancing
            // size_t is used here to avoid the security issue https://codeql.github.com/codeql-query-help/cpp/cpp-comparison-with-wider-type/
            // even though the max value of this can be only uint16_t as concurrency is uint16_t.
            for (size_t i = 1; i < task_queue_length_pool_.size() && task_queue_length_pool_[min_queue_idx] > 0; i++)
            // No need to check other io_services if the current one has no tasks
            {
                if (task_queue_length_pool_[i] < task_queue_length_pool_[min_queue_idx])
                    min_queue_idx = i;
            }
            return min_queue_idx;
        }

        void do_accept()
        {
            if (!shutting_down_)
            {
                uint16_t context_idx = pick_io_context_idx();
                asio::io_context& ic = *io_context_pool_[context_idx];
                task_queue_length_pool_[context_idx]++;
                CROW_LOG_DEBUG << &ic << " {" << context_idx << "} queue length: " << task_queue_length_pool_[context_idx];

                auto p = std::make_shared<Connection<Adaptor, Handler, Middlewares...>>(
                  ic, handler_, server_name_, middlewares_,
                  get_cached_date_str_pool_[context_idx], *task_timer_pool_[context_idx], adaptor_ctx_, task_queue_length_pool_[context_idx]);

                acceptor_.async_accept(
                  p->socket(),
                  [this, p, &ic, context_idx](error_code ec) {
                      if (!ec)
                      {
                          asio::post(ic,
                            [p] {
                                p->start();
                            });
                      }
                      else
                      {
                          task_queue_length_pool_[context_idx]--;
                          CROW_LOG_DEBUG << &ic << " {" << context_idx << "} queue length: " << task_queue_length_pool_[context_idx];
                      }
                      do_accept();
                  });
            }
        }

        /// Notify anything using `wait_for_start()` to proceed
        void notify_start()
        {
            std::unique_lock<std::mutex> lock(start_mutex_);
            server_started_ = true;
            cv_started_.notify_all();
        }

    private:
        std::vector<std::unique_ptr<asio::io_context>> io_context_pool_;
        asio::io_context io_context_;
        std::vector<detail::task_timer*> task_timer_pool_;
        std::vector<std::function<std::string()>> get_cached_date_str_pool_;
        tcp::acceptor acceptor_;
        bool shutting_down_ = false;
        bool server_started_{false};
        std::condition_variable cv_started_;
        std::mutex start_mutex_;
        asio::signal_set signals_;

        asio::basic_waitable_timer<std::chrono::high_resolution_clock> tick_timer_;

        Handler* handler_;
        uint16_t concurrency_{2};
        std::uint8_t timeout_;
        std::string server_name_;
        std::vector<std::atomic<unsigned int>> task_queue_length_pool_;

        std::chrono::milliseconds tick_interval_;
        std::function<void()> tick_function_;

        std::tuple<Middlewares...>* middlewares_;

        typename Adaptor::context* adaptor_ctx_;
    };
} // namespace crow

Coverage Report

Created: 2025-01-24 06:22

Line	Count	Source (jump to first uncovered line)
1		#pragma once
2
3		#ifdef CROW_USE_BOOST
4		#include <boost/asio.hpp>
5		#ifdef CROW_ENABLE_SSL
6		#include <boost/asio/ssl.hpp>
7		#endif
8		#else
9		#ifndef ASIO_STANDALONE
10		#define ASIO_STANDALONE
11		#endif
12		#include <asio.hpp>
13		#ifdef CROW_ENABLE_SSL
14		#include <asio/ssl.hpp>
15		#endif
16		#endif
17
18		#include <atomic>
19		#include <chrono>
20		#include <cstdint>
21		#include <future>
22		#include <memory>
23		#include <vector>
24
25		#include "crow/version.h"
26		#include "crow/http_connection.h"
27		#include "crow/logging.h"
28		#include "crow/task_timer.h"
29
30
31		namespace crow // NOTE: Already documented in "crow/app.h"
32		{
33		#ifdef CROW_USE_BOOST
34		namespace asio = boost::asio;
35		using error_code = boost::system::error_code;
36		#else
37		using error_code = asio::error_code;
38		#endif
39		using tcp = asio::ip::tcp;
40
41		template<typename Handler, typename Adaptor = SocketAdaptor, typename... Middlewares>
42		class Server
43		{
44		public:
45		Server(Handler* handler,
46		const tcp::endpoint& endpoint,
47		std::string server_name = std::string("Crow/") + VERSION,
48		std::tuple<Middlewares...>* middlewares = nullptr,
49		uint16_t concurrency = 1,
50		uint8_t timeout = 5,
51		typename Adaptor::context* adaptor_ctx = nullptr):
52	0	acceptor_(io_context_,endpoint),
53	0	signals_(io_context_),
54	0	tick_timer_(io_context_),
55	0	handler_(handler),
56	0	concurrency_(concurrency),
57	0	timeout_(timeout),
58	0	server_name_(server_name),
59	0	task_queue_length_pool_(concurrency_ - 1),
60	0	middlewares_(middlewares),
61	0	adaptor_ctx_(adaptor_ctx)
62	0	{}
63
64		void set_tick_function(std::chrono::milliseconds d, std::function<void()> f)
65	0	{
66	0	tick_interval_ = d;
67	0	tick_function_ = f;
68	0	}
69
70		void on_tick()
71	0	{
72	0	tick_function_();
73	0	tick_timer_.expires_after(std::chrono::milliseconds(tick_interval_.count()));
74	0	tick_timer_.async_wait([this](const error_code& ec) {
75	0	if (ec)
76	0	return;
77	0	on_tick();
78	0	});
79	0	}
80
81		void run()
82	0	{
83	0	uint16_t worker_thread_count = concurrency_ - 1;
84	0	for (int i = 0; i < worker_thread_count; i++)
85	0	io_context_pool_.emplace_back(new asio::io_context());
86	0	get_cached_date_str_pool_.resize(worker_thread_count);
87	0	task_timer_pool_.resize(worker_thread_count);
88
89	0	std::vector<std::future<void>> v;
90	0	std::atomic<int> init_count(0);
91	0	for (uint16_t i = 0; i < worker_thread_count; i++)
92	0	v.push_back(
93	0	std::async(
94	0	std::launch::async, [this, i, &init_count] {
95		// thread local date string get function
96	0	auto last = std::chrono::steady_clock::now();
97
98	0	std::string date_str;
99	0	auto update_date_str = [&] {
100	0	auto last_time_t = time(0);
101	0	tm my_tm;
102
103		#if defined(_MSC_VER) \|\| defined(__MINGW32__)
104		gmtime_s(&my_tm, &last_time_t);
105		#else
106	0	gmtime_r(&last_time_t, &my_tm);
107	0	#endif
108	0	date_str.resize(100);
109	0	size_t date_str_sz = strftime(&date_str[0], 99, "%a, %d %b %Y %H:%M:%S GMT", &my_tm);
110	0	date_str.resize(date_str_sz);
111	0	};
112	0	update_date_str();
113	0	get_cached_date_str_pool_[i] = [&]() -> std::string {
114	0	if (std::chrono::steady_clock::now() - last >= std::chrono::seconds(1))
115	0	{
116	0	last = std::chrono::steady_clock::now();
117	0	update_date_str();
118	0	}
119	0	return date_str;
120	0	};
121
122		// initializing task timers
123	0	detail::task_timer task_timer(*io_context_pool_[i]);
124	0	task_timer.set_default_timeout(timeout_);
125	0	task_timer_pool_[i] = &task_timer;
126	0	task_queue_length_pool_[i] = 0;
127
128	0	init_count++;
129	0	while (1)
130	0	{
131	0	try
132	0	{
133	0	if (io_context_pool_[i]->run() == 0)
134	0	{
135		// when io_service.run returns 0, there are no more works to do.
136	0	break;
137	0	}
138	0	}
139	0	catch (std::exception& e)
140	0	{
141	0	CROW_LOG_ERROR << "Worker Crash: An uncaught exception occurred: " << e.what();
142	0	}
143	0	}
144	0	}));
145
146	0	if (tick_function_ && tick_interval_.count() > 0)
147	0	{
148	0	tick_timer_.expires_after(std::chrono::milliseconds(tick_interval_.count()));
149	0	tick_timer_.async_wait(
150	0	[this](const error_code& ec) {
151	0	if (ec)
152	0	return;
153	0	on_tick();
154	0	});
155	0	}
156
157	0	handler_->port(acceptor_.local_endpoint().port());
158
159
160	0	CROW_LOG_INFO << server_name_
161	0	<< " server is running at " << (handler_->ssl_used() ? "https://" : "http://")
162	0	<< acceptor_.local_endpoint().address() << ":" << acceptor_.local_endpoint().port() << " using " << concurrency_ << " threads";
163	0	CROW_LOG_INFO << "Call `app.loglevel(crow::LogLevel::Warning)` to hide Info level logs.";
164
165	0	signals_.async_wait(
166	0	[&](const error_code& /error/, int /signal_number/) {
167	0	stop();
168	0	});
169
170	0	while (worker_thread_count != init_count)
171	0	std::this_thread::yield();
172
173	0	do_accept();
174
175	0	std::thread(
176	0	[this] {
177	0	notify_start();
178	0	io_context_.run();
179	0	CROW_LOG_INFO << "Exiting.";
180	0	})
181	0	.join();
182	0	}
183
184		void stop()
185	0	{
186	0	shutting_down_ = true; // Prevent the acceptor from taking new connections
187	0	for (auto& io_context : io_context_pool_)
188	0	{
189	0	if (io_context != nullptr)
190	0	{
191	0	CROW_LOG_INFO << "Closing IO service " << &io_context;
192	0	io_context->stop(); // Close all io_services (and HTTP connections)
193	0	}
194	0	}
195
196	0	CROW_LOG_INFO << "Closing main IO service (" << &io_context_ << ')';
197	0	io_context_.stop(); // Close main io_service
198	0	}
199
200		uint16_t port() const {
201		return acceptor_.local_endpoint().port();
202		}
203
204		/// Wait until the server has properly started or until timeout
205		std::cv_status wait_for_start(std::chrono::steady_clock::time_point wait_until)
206		{
207		std::unique_lock<std::mutex> lock(start_mutex_);
208
209		std::cv_status status = std::cv_status::no_timeout;
210		while (!server_started_ && ( status==std::cv_status::no_timeout ))
211		status = cv_started_.wait_until(lock,wait_until);
212		return status;
213		}
214
215		void signal_clear()
216		{
217		signals_.clear();
218		}
219
220		void signal_add(int signal_number)
221	0	{
222	0	signals_.add(signal_number);
223	0	}
224
225		private:
226		uint16_t pick_io_context_idx()
227	0	{
228	0	uint16_t min_queue_idx = 0;
229
230		// TODO improve load balancing
231		// size_t is used here to avoid the security issue https://codeql.github.com/codeql-query-help/cpp/cpp-comparison-with-wider-type/
232		// even though the max value of this can be only uint16_t as concurrency is uint16_t.
233	0	for (size_t i = 1; i < task_queue_length_pool_.size() && task_queue_length_pool_[min_queue_idx] > 0; i++)
234		// No need to check other io_services if the current one has no tasks
235	0	{
236	0	if (task_queue_length_pool_[i] < task_queue_length_pool_[min_queue_idx])
237	0	min_queue_idx = i;
238	0	}
239	0	return min_queue_idx;
240	0	}
241
242		void do_accept()
243	0	{
244	0	if (!shutting_down_)
245	0	{
246	0	uint16_t context_idx = pick_io_context_idx();
247	0	asio::io_context& ic = *io_context_pool_[context_idx];
248	0	task_queue_length_pool_[context_idx]++;
249	0	CROW_LOG_DEBUG << &ic << " {" << context_idx << "} queue length: " << task_queue_length_pool_[context_idx];
250
251	0	auto p = std::make_shared<Connection<Adaptor, Handler, Middlewares...>>(
252	0	ic, handler_, server_name_, middlewares_,
253	0	get_cached_date_str_pool_[context_idx], *task_timer_pool_[context_idx], adaptor_ctx_, task_queue_length_pool_[context_idx]);
254
255	0	acceptor_.async_accept(
256	0	p->socket(),
257	0	[this, p, &ic, context_idx](error_code ec) {
258	0	if (!ec)
259	0	{
260	0	asio::post(ic,
261	0	[p] {
262	0	p->start();
263	0	});
264	0	}
265	0	else
266	0	{
267	0	task_queue_length_pool_[context_idx]--;
268	0	CROW_LOG_DEBUG << &ic << " {" << context_idx << "} queue length: " << task_queue_length_pool_[context_idx];
269	0	}
270	0	do_accept();
271	0	});
272	0	}
273	0	}
274
275		/// Notify anything using `wait_for_start()` to proceed
276		void notify_start()
277	0	{
278	0	std::unique_lock<std::mutex> lock(start_mutex_);
279	0	server_started_ = true;
280	0	cv_started_.notify_all();
281	0	}
282
283		private:
284		std::vector<std::unique_ptr<asio::io_context>> io_context_pool_;
285		asio::io_context io_context_;
286		std::vector<detail::task_timer*> task_timer_pool_;
287		std::vector<std::function<std::string()>> get_cached_date_str_pool_;
288		tcp::acceptor acceptor_;
289		bool shutting_down_ = false;
290		bool server_started_{false};
291		std::condition_variable cv_started_;
292		std::mutex start_mutex_;
293		asio::signal_set signals_;
294
295		asio::basic_waitable_timer<std::chrono::high_resolution_clock> tick_timer_;
296
297		Handler* handler_;
298		uint16_t concurrency_{2};
299		std::uint8_t timeout_;
300		std::string server_name_;
301		std::vector<std::atomic<unsigned int>> task_queue_length_pool_;
302
303		std::chrono::milliseconds tick_interval_;
304		std::function<void()> tick_function_;
305
306		std::tuple<Middlewares...>* middlewares_;
307
308		typename Adaptor::context* adaptor_ctx_;
309		};
310		} // namespace crow