From 7be0fcf4fd3e47fc3d50401753fd4086c146feeb Mon Sep 17 00:00:00 2001
From: Wiebe Cazemier <wiebe@halfgaar.net>
Date: Sun, 7 Mar 2021 15:56:40 +0100
Subject: [PATCH] Quit threads by using task queue

---
 authplugin.cpp | 11 +++++++++++
 authplugin.h   |  3 +++
 mainapp.cpp    |  7 ++++++-
 threaddata.cpp | 18 +++++++++++++++++-
 threaddata.h   |  5 ++++-
 5 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/authplugin.cpp b/authplugin.cpp
index 8ef2767..60e8e86 100644
--- a/authplugin.cpp
+++ b/authplugin.cpp
@@ -97,6 +97,9 @@ void AuthPlugin::init()
     if (settings.authPluginSerializeInit)
         lock.lock();
 
+    if (quitting)
+        return;
+
     AuthOptCompatWrap &authOpts = settings.getAuthOptsCompat();
     int result = init_v2(&pluginData, authOpts.head(), authOpts.size());
     if (result != 0)
@@ -125,6 +128,9 @@ void AuthPlugin::securityInit(bool reloading)
     if (settings.authPluginSerializeInit)
         lock.lock();
 
+    if (quitting)
+        return;
+
     AuthOptCompatWrap &authOpts = settings.getAuthOptsCompat();
     int result = security_init_v2(pluginData, authOpts.head(), authOpts.size(), reloading);
     if (result != 0)
@@ -201,6 +207,11 @@ AuthResult AuthPlugin::unPwdCheck(const std::string &username, const std::string
     return r;
 }
 
+void AuthPlugin::setQuitting()
+{
+    this->quitting = true;
+}
+
 std::string AuthResultToString(AuthResult r)
 {
     {
diff --git a/authplugin.h b/authplugin.h
index ec4039a..c90fc5f 100644
--- a/authplugin.h
+++ b/authplugin.h
@@ -63,6 +63,7 @@ class AuthPlugin
     Logger *logger = nullptr;
     bool initialized = false;
     bool wanted = false;
+    bool quitting = false;
 
     void *loadSymbol(void *handle, const char *symbol) const;
 public:
@@ -79,6 +80,8 @@ public:
     AuthResult aclCheck(const std::string &clientid, const std::string &username, const std::string &topic, AclAccess access);
     AuthResult unPwdCheck(const std::string &username, const std::string &password);
 
+    void setQuitting();
+
 };
 
 #endif // AUTHPLUGIN_H
diff --git a/mainapp.cpp b/mainapp.cpp
index 3bf3bfa..5161096 100644
--- a/mainapp.cpp
+++ b/mainapp.cpp
@@ -440,7 +440,12 @@ void MainApp::start()
 
     for(std::shared_ptr<ThreadData> &thread : threads)
     {
-        thread->quit();
+        thread->queueQuit();
+    }
+
+    for(std::shared_ptr<ThreadData> &thread : threads)
+    {
+        thread->waitForQuit();
     }
 
     for(auto pair : listenerMap)
diff --git a/threaddata.cpp b/threaddata.cpp
index bcfbcd0..e273caa 100644
--- a/threaddata.cpp
+++ b/threaddata.cpp
@@ -52,7 +52,6 @@ void ThreadData::start(thread_f f)
 void ThreadData::quit()
 {
     running = false;
-    thread.join();
 }
 
 void ThreadData::giveClient(Client_p client)
@@ -109,6 +108,23 @@ void ThreadData::queueDoKeepAliveCheck()
     wakeUpThread();
 }
 
+void ThreadData::queueQuit()
+{
+    std::lock_guard<std::mutex> locker(taskQueueMutex);
+
+    auto f = std::bind(&ThreadData::quit, this);
+    taskQueue.push_front(f);
+
+    authPlugin.setQuitting();
+
+    wakeUpThread();
+}
+
+void ThreadData::waitForQuit()
+{
+    thread.join();
+}
+
 // TODO: profile how fast hash iteration is. Perhaps having a second list/vector is beneficial?
 void ThreadData::doKeepAliveCheck()
 {
diff --git a/threaddata.h b/threaddata.h
index 2dc3321..aecd8bd 100644
--- a/threaddata.h
+++ b/threaddata.h
@@ -33,6 +33,7 @@ class ThreadData
     void reload(std::shared_ptr<Settings> settings);
     void wakeUpThread();
     void doKeepAliveCheck();
+    void quit();
 
 public:
     Settings settingsLocalCopy; // Is updated on reload, within the thread loop.
@@ -50,7 +51,7 @@ public:
     ThreadData(ThreadData &&other) = delete;
 
     void start(thread_f f);
-    void quit();
+
     void giveClient(Client_p client);
     Client_p getClient(int fd);
     void removeClient(Client_p client);
@@ -60,6 +61,8 @@ public:
     void initAuthPlugin();
     void queueReload(std::shared_ptr<Settings> settings);
     void queueDoKeepAliveCheck();
+    void queueQuit();
+    void waitForQuit();
 
 };
 
--
libgit2 0.21.4