From a76dabb12734154177a78033324b40365e7c6f21 Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Wed, 21 Jul 2021 14:46:48 +0200
Subject: Fix freeze on search reset in manga combined plugin. Fix
 multithreading issues in AsyncTask

---
 include/AsyncTask.hpp | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

(limited to 'include/AsyncTask.hpp')

diff --git a/include/AsyncTask.hpp b/include/AsyncTask.hpp
index 6148923..45b3397 100644
--- a/include/AsyncTask.hpp
+++ b/include/AsyncTask.hpp
@@ -3,6 +3,7 @@
 #include "Program.hpp"
 #include <thread>
 #include <future>
+#include <mutex>
 
 namespace QuickMedia {
     template <class T, class... Args>
@@ -13,6 +14,7 @@ namespace QuickMedia {
         AsyncTask() = default;
 
         AsyncTask(CallbackFunc callback_func, Args&&... args) {
+            std::lock_guard<std::mutex> lock(mutex);
             std::promise<T> promise;
             future = promise.get_future();
             thread = std::thread(&AsyncTask::thread_handler, this, std::move(promise), std::move(callback_func), std::forward<Args>(args)...);
@@ -20,12 +22,14 @@ namespace QuickMedia {
 
         AsyncTask(AsyncTask &&other) {
             cancel();
+            std::lock_guard<std::mutex> lock(mutex);
             thread = std::move(other.thread);
             future = std::move(other.future);
         }
 
         AsyncTask& operator=(AsyncTask &&other) {
             cancel();
+            std::lock_guard<std::mutex> lock(mutex);
             thread = std::move(other.thread);
             future = std::move(other.future);
             return *this;
@@ -36,22 +40,40 @@ namespace QuickMedia {
         }
 
         bool valid() {
+            std::lock_guard<std::mutex> lock(mutex);
             return future.valid();
         }
 
         bool ready() {
+            std::lock_guard<std::mutex> lock(mutex);
             return future.valid() && future.wait_for(std::chrono::seconds(0)) == std::future_status::ready;
         }
 
         T get() {
-            thread.join();
-            return future.get();
+            std::lock_guard<std::mutex> lock(mutex);
+            if constexpr(std::is_same<T, void>::value) {
+                if(thread.joinable()) {
+                    thread.join();
+                    future.get();
+                }
+            } else {
+                T result;
+                if(thread.joinable()) {
+                    thread.join();
+                    result = std::move(future.get());
+                }
+                return result;
+            }
         }
 
         void cancel() {
-            if(valid()) {
+            std::lock_guard<std::mutex> lock(mutex);
+            if(future.valid()) {
                 program_kill_in_thread(thread.get_id());
-                get();
+                if(thread.joinable()) {
+                    thread.join();
+                    future.get();
+                }
             }
         }
     private:
@@ -66,5 +88,6 @@ namespace QuickMedia {
     private:
         std::thread thread;
         std::future<T> future;
+        std::mutex mutex;
     };
 }
\ No newline at end of file
-- 
cgit v1.2.3