guy_breaking_chains_watching_sunrise.png

.clangd

@@ -0,0 +1,2 @@
+CompileFlags:
+  Add: [-std=c++23]

README.md

@@ -11,7 +11,7 @@ And also my first serious C++ project.
 - [X] Serialisation and saving
 - [X] FUCKING NETWORKING (probably minimal RESP)
 - [X] Proper startup/shutdown w/ load & save
-- [ ] Multithreading
+- [X] Multithreading
 - [ ] More types
-- [ ] Async
+- [X] Async
 - [ ] Backflip off the Rio-Antirrio bridge

main.cpp

@@ -1,4 +1,7 @@
-#include <asm-generic/socket.h>
+#include <boost/asio/detached.hpp>
+#include <boost/asio/executor_work_guard.hpp>
+#include <boost/asio/io_context.hpp>
+#include <boost/asio/use_awaitable.hpp>
 #include <vector>
 #include <string>
 #include <iostream>
@@ -12,6 +15,7 @@
 #include <unistd.h>
 #include <cstdlib>
 #include <thread>
+#include <boost/asio.hpp>
 
 using Db = std::vector<std::vector<std::string>>;
 Db database;
@@ -63,18 +67,18 @@ std::vector<std::string> parse_resp_request(char* request) {
   return split_request;
 }
 
-void safe_exit(int signum) {
+namespace asio = boost::asio;
-  std::cout << "[W] Exiting..." << std::endl;
+using asio::ip::tcp;
-  save_database("db.json");
+using asio::use_awaitable;
-  exit(signum);
+boost::asio::io_context io_context;
-}
 
-void handle_client(int client_socket) {
+asio::awaitable<void> handle_client(tcp::socket client_socket) {
-    while (true) {
+    char buffer[4096];
-      char buffer[4096];
+
-      int bytes_received = recv(client_socket, buffer, 4096, 0);
+    try {
+      while (true) {
+        std::size_t bytes_received = co_await client_socket.async_read_some(asio::buffer(buffer), use_awaitable);
   
-      if (bytes_received > 0) {
         buffer[bytes_received] = '\0';
         std::vector<std::string> parsed = parse_resp_request(buffer);
 
@@ -84,97 +88,100 @@ void handle_client(int client_socket) {
           for (const auto& inner_vec: database) { // Iterate through DB and find the required item
             if (!inner_vec.empty() && inner_vec[0] == parsed[1]) {
               int length = inner_vec[1].length();
-              std::string return_string = std::format("${}\r\n{}\r\n", length, inner_vec[1]); // Serialise to RESP
+                std::string return_string = std::format("${}\r\n{}\r\n", length, inner_vec[1]); // Serialise to RESP
-              std::cout << "[d] Sending: " << return_string << std::endl;
+                std::cout << "[d] Sending: " << return_string << std::endl;
-              send(client_socket, return_string.data(), return_string.length(), 0);
+                co_await asio::async_write(client_socket, asio::buffer(return_string.data(), return_string.length()), use_awaitable);
-              found = true;
+                found = true;
-            }
+              }
-          }
-
-          if (!found) {
-            send(client_socket, "$-1\r\n", strlen("$-1\r\n"), 0); // Not found
-          }
-        } else if (parsed[0] == "SET") {
-          bool found = false; // Avoids SEGFAULT
-                              
-          for (auto& inner_vec: database) {
-            if (!inner_vec.empty() && inner_vec[0] == parsed[1]) {
-              inner_vec[1] = parsed[2];
-              send(client_socket, "+OK\r\n", strlen("+OK\r\n"), 0);
-              found = true;
             }
     
             if (!found) {
-              std::vector<std::string> new_kv = { parsed[1], parsed[2] };
+              co_await asio::async_write(client_socket, asio::buffer("$-1\r\n", strlen("$-1\r\n")), use_awaitable); // Not found
-              database.push_back(new_kv);
-              send(client_socket, "+OK\r\n", strlen("+OK\r\n"), 0);
-              found = true;
             }
+          } else if (parsed[0] == "SET") {
+            bool found = false; // Avoids SEGFAULT
+                                  
+            for (auto& inner_vec: database) {
+              if (!inner_vec.empty() && inner_vec[0] == parsed[1]) {
+                inner_vec[1] = parsed[2];
+                co_await asio::async_write(client_socket, asio::buffer("+OK\r\n", strlen("+OK\r\n")), use_awaitable);
+                found = true;
+              }
+    
+              if (!found) {
+                std::vector<std::string> new_kv = { parsed[1], parsed[2] };
+                database.push_back(new_kv);
+                co_await asio::async_write(client_socket, asio::buffer("+OK\r\n", strlen("+OK\r\n")), use_awaitable);
+                found = true;
+              }
+            }
+          } else {
+            co_await asio::async_write(client_socket, asio::buffer("+OK\r\n", strlen("+OK\r\n")), use_awaitable); // Temporary catch-all (for more advanced handshake)
           }
-        } else {
-          send(client_socket, "+OK\r\n", strlen("+OK\r\n"), 0); // Temporary catch-all (for more advanced handshake)
         }
-      } else {
+      } catch (const std::exception& e) {
-        close(client_socket);
+        std::cout << "[i] Client session ened/error" << e.what() << std::endl;
-        std::cout << "[i] Client disconnected." << std::endl;
-        break;
       }
-    }
+}
+
+
+
+asio::awaitable<void> tcp_server_task(tcp::acceptor& acceptor) {
+  std::cout << "[i] Server listening on port 6379" << std::endl;
+  while (true) {
+    tcp::socket socket = co_await acceptor.async_accept(use_awaitable);
+
+    asio::co_spawn(
+        io_context,
+        handle_client(std::move(socket)),
+        asio::detached
+    );
+  }
+}
+
+asio::awaitable<void> shutdown_handler(asio::io_context& io_context, tcp::acceptor& acceptor, std::shared_ptr<asio::executor_work_guard<asio::io_context::executor_type>> work_guard) {
+  asio::signal_set signals(io_context, SIGINT, SIGTERM);
+  co_await signals.async_wait(use_awaitable);
+  std::cout << "[i] Stopping blueis server..." << std::endl;
+  acceptor.cancel();
+  acceptor.close();
+
+  work_guard->reset();
 }
 
 int main() {
-  std::cout << "[i] Starting blueis server..." << std::endl;
-
-  signal(SIGINT, safe_exit);
-
   load_database("db.json");
-  int listening_socket = socket(AF_INET, SOCK_STREAM, 0 );
+  const int N_THREADS = std::thread::hardware_concurrency();
-  if (listening_socket < 0) {
+  std::vector<std::thread> threads;
-    std::cerr << "[E] Failed to create socket." << std::endl;
+  tcp::endpoint endpoint(tcp::v4(), 6379);
-    return 1;
+  tcp::acceptor acceptor(io_context, endpoint);
+  auto work_guard = std::make_shared<asio::executor_work_guard<asio::io_context::executor_type>>(asio::make_work_guard(io_context));
+  
+  asio::co_spawn(
+      io_context,
+      tcp_server_task(acceptor),
+      asio::detached
+  );
+
+  asio::co_spawn(
+      io_context,
+      shutdown_handler(io_context, acceptor, work_guard),
+      asio::detached
+  );
+
+  for (int i = 0; i < N_THREADS - 1; i++) {
+    threads.emplace_back([&io_context] {
+      io_context.run();
+    });
   }
 
-  int optval = 1;
+  std::cout << "[i] Starting blueis server on 6379..." << std::endl;
-  if (setsockopt(listening_socket, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval)) < 0) {
+  io_context.run();
-    std::cerr << "[W] Failed to use SO_REUSEADDR. Continuing." << std::endl;
-  }
 
-  sockaddr_in server_address;
+  for (auto& t: threads) {
-  server_address.sin_family = AF_INET;
-  server_address.sin_port = htons(6379);
-  server_address.sin_addr.s_addr = INADDR_ANY;
-
-  if (bind(listening_socket, (sockaddr*)&server_address, sizeof(server_address)) < 0) {
-    std::cerr << "[E] Failed to bind to port 6379. Check for any other running redis or blueis instances." << std::endl;
-    close(listening_socket);
-    return 1;
-  }
-
-  if (listen(listening_socket, 5) < 0) {
-    std::cerr << "[E] Failed to listen on socket." << std::endl;
-    close(listening_socket);
-    return 1;
-  }
-
-  std::cout << "[i] Server listening on port 6379..." << std::endl;
-
-  sockaddr_in client_address;
-  socklen_t client_size = sizeof(client_address);
-
-  while (true) {
-    int client_socket = accept(listening_socket, (sockaddr*)&client_address, &client_size);
-    if (client_socket < 0) {
-      std::cerr << "[E] Failed to accept connection." << std::endl;
-      close(listening_socket);
-      return 1;
-    }
-    std::thread t(handle_client, client_socket); // Temporarily using the shit method of one thread per client despite the DoS potential until I can get async down.
     if (t.joinable()) {
-      t.detach();
+      t.join();
     }
-    std::cout << "[i] Client connected." << std::endl;
   }
 
-
-  return 0;
 }