Make app().run() method callable on a non-main thread (#457)

lib/inc/drogon/HttpAppFramework.h

@@ -73,8 +73,8 @@ class HttpAppFramework : public trantor::NonCopyable
     /**
      * Calling this method starts the IO event loops and the main loop of the
      * application;
-     * This method MUST be called in the main thread.
-     * This method blocks the main thread until the main event loop exits.
+     * This method can be called in the main thread or any other thread.
+     * This method blocks the current thread until the main event loop exits.
      */
     virtual void run() = 0;
 
@@ -85,7 +85,8 @@ class HttpAppFramework : public trantor::NonCopyable
     /**
      * Calling this method results in stopping all network IO in the
      * framework and interrupting the blocking of the run() method. Usually,
-     * after calling this method, the application exits.
+     * after calling this method, the application exits (when the run() method
+     * is called in the main thread).
      *
      * @note
      * This method can be called in any thread and anywhere.
@@ -1081,10 +1082,11 @@ class HttpAppFramework : public trantor::NonCopyable
      * @brief Get the Current Thread Index whose range is [0, the total number
      * of IO threads]
      *
-     * @return size_t If the current thread is the main thread, the number of
-     * the IO threads is returned. If the current thread is a network IO thread,
-     * the index of it in the range [0, the number of IO threads) is returned.
-     * otherwise the maximum value of type size_t is returned.
+     * @return size_t If the current thread is the main EventLoop thread (in
+     * which the app().run() is called), the number of the IO threads is
+     * returned. If the current thread is a network IO thread, the index of it
+     * in the range [0, the number of IO threads) is returned. otherwise the
+     * maximum value of type size_t is returned.
      *
      * @note Basically this method is used for storing thread-related various in
      * an array and users can use indexes returned by this method to access

lib/src/HttpAppFrameworkImpl.cc

@@ -365,7 +365,10 @@ HttpAppFramework &HttpAppFrameworkImpl::setSSLFiles(const std::string &certPath,
 
 void HttpAppFrameworkImpl::run()
 {
-    //
+    if (!getLoop()->isInLoopThread())
+    {
+        getLoop()->moveToCurrentThread();
+    }
     LOG_TRACE << "Start to run...";
     trantor::AsyncFileLogger asyncFileLogger;
     // Create dirs for cache files

lib/src/HttpRequestParser.cc

@@ -329,7 +329,7 @@ bool HttpRequestParser::parseRequest(MsgBuffer *buf)
     return ok;
 }
 
-void HttpRequestParser::pushRquestToPipelining(const HttpRequestPtr &req)
+void HttpRequestParser::pushRequestToPipelining(const HttpRequestPtr &req)
 {
 #ifndef NDEBUG
     auto conn = conn_.lock();

lib/src/HttpRequestParser.h

@@ -72,7 +72,7 @@ class HttpRequestParser : public trantor::NonCopyable,
         websockConnPtr_ = conn;
     }
     // to support request pipelining(rfc2616-8.1.2.2)
-    void pushRquestToPipelining(const HttpRequestPtr &req);
+    void pushRequestToPipelining(const HttpRequestPtr &req);
     HttpRequestPtr getFirstRequest() const;
     std::pair<HttpResponsePtr, bool> getFirstResponse() const;
     void popFirstRequest();

lib/src/HttpServer.cc

@@ -326,7 +326,7 @@ void HttpServer::onRequests(
         bool syncFlag = false;
         if (!requestParser->emptyPipelining())
         {
-            requestParser->pushRquestToPipelining(req);
+            requestParser->pushRequestToPipelining(req);
             syncFlag = true;
         }
         if (!syncAdvices_.empty())
@@ -477,7 +477,7 @@ void HttpServer::onRequests(
             });
         if (syncFlag == false)
         {
-            requestParser->pushRquestToPipelining(req);
+            requestParser->pushRequestToPipelining(req);
         }
     }
     *loopFlagPtr = false;

lib/tests/CMakeLists.txt

@@ -9,6 +9,7 @@ add_executable(http_full_date_test HttpFullDateTest.cc)
 add_executable(gzip_test GzipTest.cc)
 add_executable(url_codec_test UrlCodecTest.cc)
 add_executable(main_loop_test MainLoopTest.cc)
+add_executable(main_loop_test2 MainLoopTest2.cc)
 
 set(test_targets
     cache_map_test
@@ -19,7 +20,8 @@ set(test_targets
     http_full_date_test
     gzip_test
     url_codec_test
-    main_loop_test)
+    main_loop_test
+    main_loop_test2)
 
 set_property(TARGET ${test_targets}
              PROPERTY CXX_STANDARD ${DROGON_CXX_STANDARD})

lib/tests/MainLoopTest2.cc

@@ -0,0 +1,21 @@
+#include <drogon/drogon.h>
+#include <thread>
+#include <chrono>
+
+/**
+ * @brief This test program tests to call the app().run() in another thread.
+ *
+ */
+int main()
+{
+    std::thread([]() {
+        drogon::app().getLoop()->runEvery(1, []() {
+            std::cout << "!" << std::endl;
+        });
+    }).detach();
+
+    std::thread l([]() { drogon::app().run(); });
+    std::this_thread::sleep_for(std::chrono::seconds(1));
+    trantor::EventLoop loop;
+    l.join();
+}

trantor

@@ -1 +1 @@
-Subproject commit 880ca0acbe89c91b557b93c711dd9624e922c209
+Subproject commit 55232baacebb77036babfeb8c652420032241b01