From 45d2969dcbf5bcc9d2354a52a3611cd79acc77b6 Mon Sep 17 00:00:00 2001
From: An Tao <antao2002@gmail.com>
Date: Sat, 21 Mar 2020 21:29:33 +0800
Subject: [PATCH] Graceful shutdown (#393)

Call app().quit() to gracefully stop a drogon application.
---
 examples/simple_example/api_v1_ApiTest.h |  7 +++++
 lib/src/HttpAppFrameworkImpl.cc          |  5 +++-
 lib/src/HttpServer.cc                    |  5 +++-
 lib/src/HttpServer.h                     |  1 +
 lib/src/ListenerManager.cc               | 38 +++++++++++++++---------
 lib/src/ListenerManager.h                |  2 ++
 trantor                                  |  2 +-
 7 files changed, 43 insertions(+), 17 deletions(-)

diff --git a/examples/simple_example/api_v1_ApiTest.h b/examples/simple_example/api_v1_ApiTest.h
index a921e255..867d386f 100644
--- a/examples/simple_example/api_v1_ApiTest.h
+++ b/examples/simple_example/api_v1_ApiTest.h
@@ -31,6 +31,8 @@ class ApiTest : public drogon::HttpController<ApiTest>
     ADD_METHOD_TO(ApiTest::get2,
                   "/absolute/{}",
                   Get);  // path is /absolute/{arg1}
+    ADD_METHOD_TO(ApiTest::shutdown, "/shutdown",
+                  Get);  // path is /shutdown
     METHOD_ADD(ApiTest::jsonTest, "/json", Post);
     METHOD_ADD(ApiTest::formTest, "/form", Post);
     METHOD_ADD(ApiTest::attributesTest, "/attrs", Get);
@@ -66,6 +68,11 @@ class ApiTest : public drogon::HttpController<ApiTest>
                    std::function<void(const HttpResponsePtr &)> &&callback,
                    int p1,
                    std::string &&p2);
+    void shutdown(const HttpRequestPtr &req,
+                  std::function<void(const HttpResponsePtr &)> &&callback)
+    {
+        app().quit();
+    }
 
   public:
     ApiTest()
diff --git a/lib/src/HttpAppFrameworkImpl.cc b/lib/src/HttpAppFrameworkImpl.cc
index 3cd4f37a..e35ab713 100644
--- a/lib/src/HttpAppFrameworkImpl.cc
+++ b/lib/src/HttpAppFrameworkImpl.cc
@@ -885,7 +885,10 @@ void HttpAppFrameworkImpl::quit()
 {
     if (getLoop()->isRunning())
     {
-        getLoop()->queueInLoop([this]() { getLoop()->quit(); });
+        getLoop()->queueInLoop([this]() {
+            listenerManagerPtr_->stopListening();
+            getLoop()->quit();
+        });
     }
 }
 
diff --git a/lib/src/HttpServer.cc b/lib/src/HttpServer.cc
index 2cda5d3e..60bec4f4 100644
--- a/lib/src/HttpServer.cc
+++ b/lib/src/HttpServer.cc
@@ -139,7 +139,10 @@ void HttpServer::start()
               << server_.ipPort();
     server_.start();
 }
-
+void HttpServer::stop()
+{
+    server_.stop();
+}
 void HttpServer::onConnection(const TcpConnectionPtr &conn)
 {
     if (conn->connected())
diff --git a/lib/src/HttpServer.h b/lib/src/HttpServer.h
index 853d106f..f64f182c 100644
--- a/lib/src/HttpServer.h
+++ b/lib/src/HttpServer.h
@@ -75,6 +75,7 @@ class HttpServer : trantor::NonCopyable
         return server_.getIoLoops();
     }
     void start();
+    void stop();
 
     void enableSSL(const std::string &certPath, const std::string &keyPath)
     {
diff --git a/lib/src/ListenerManager.cc b/lib/src/ListenerManager.cc
index bf84078e..deef5da7 100644
--- a/lib/src/ListenerManager.cc
+++ b/lib/src/ListenerManager.cc
@@ -79,13 +79,12 @@ std::vector<trantor::EventLoop *> ListenerManager::createListeners(
         &syncAdvices)
 {
 #ifdef __linux__
-    std::vector<trantor::EventLoop *> ioLoops;
     for (size_t i = 0; i < threadNum; ++i)
     {
         LOG_TRACE << "thread num=" << threadNum;
         auto loopThreadPtr = std::make_shared<EventLoopThread>("DrogonIoLoop");
         listeningloopThreads_.push_back(loopThreadPtr);
-        ioLoops.push_back(loopThreadPtr->getLoop());
+        ioLoops_.push_back(loopThreadPtr->getLoop());
         for (auto const &listener : listeners_)
         {
             auto const &ip = listener.ip_;
@@ -183,9 +182,9 @@ std::vector<trantor::EventLoop *> ListenerManager::createListeners(
         serverPtr->start();
         servers_.push_back(serverPtr);
     }
-    auto ioLoops = ioLoopThreadPoolPtr_->getLoops();
+    ioLoops_ = ioLoopThreadPoolPtr_->getLoops();
 #endif
-    return ioLoops;
+    return ioLoops_;
 }
 
 void ListenerManager::startListening()
@@ -200,16 +199,6 @@ void ListenerManager::startListening()
 
 ListenerManager::~ListenerManager()
 {
-    for (size_t i = 0; i < servers_.size(); ++i)
-    {
-        std::promise<int> pro;
-        auto f = pro.get_future();
-        servers_[i]->getLoop()->runInLoop([&pro, this, i] {
-            servers_[i].reset();
-            pro.set_value(1);
-        });
-        (void)f.get();
-    }
 }
 
 trantor::EventLoop *ListenerManager::getIOLoop(size_t id) const
@@ -235,3 +224,24 @@ trantor::EventLoop *ListenerManager::getIOLoop(size_t id) const
     return ioLoopThreadPoolPtr_->getLoop(id);
 #endif
 }
+void ListenerManager::stopListening()
+{
+    for (auto &serverPtr : servers_)
+    {
+        serverPtr->stop();
+    }
+    for (auto loop : ioLoops_)
+    {
+        assert(!loop->isInLoopThread());
+        if (loop->isRunning())
+        {
+            std::promise<int> pro;
+            auto f = pro.get_future();
+            loop->queueInLoop([loop, &pro]() {
+                loop->quit();
+                pro.set_value(1);
+            });
+            (void)f.get();
+        }
+    }
+}
diff --git a/lib/src/ListenerManager.h b/lib/src/ListenerManager.h
index e737bd15..9119ec1e 100644
--- a/lib/src/ListenerManager.h
+++ b/lib/src/ListenerManager.h
@@ -47,6 +47,8 @@ class ListenerManager : public trantor::NonCopyable
     ~ListenerManager();
 
     trantor::EventLoop *getIOLoop(size_t id) const;
+    void stopListening();
+    std::vector<trantor::EventLoop *> ioLoops_;
 
   private:
     struct ListenerInfo
diff --git a/trantor b/trantor
index f38eba77..0415747a 160000
--- a/trantor
+++ b/trantor
@@ -1 +1 @@
-Subproject commit f38eba777fa91d3bc2443efe853fcb8b64afa459
+Subproject commit 0415747a7e2bbf1950d924544ff7855b1ad8da6f