Core/Misc: Use std::scoped_lock instead of unique_lock where possible (and old lock_guard)

src/common/Threading/LockedQueue.h

@@ -39,14 +39,14 @@ public:
     //! Adds an item to the queue.
     void add(T const& item)
     {
-        std::lock_guard<std::mutex> lock(_lock);
+        std::scoped_lock lock(_lock);
         _queue.push_back(item);
     }
 
     //! Adds an item to the queue.
     void add(T&& item)
     {
-        std::lock_guard<std::mutex> lock(_lock);
+        std::scoped_lock lock(_lock);
         _queue.push_back(std::move(item));
     }
 
@@ -54,14 +54,14 @@ public:
     template<std::input_iterator Iterator>
     void readd(Iterator begin, Iterator end)
     {
-        std::lock_guard<std::mutex> lock(_lock);
+        std::scoped_lock lock(_lock);
         _queue.insert(_queue.begin(), begin, end);
     }
 
     //! Gets the next result in the queue, if any.
     bool next(T& result)
     {
-        std::lock_guard<std::mutex> lock(_lock);
+        std::scoped_lock lock(_lock);
         if (_queue.empty())
             return false;
 
@@ -73,7 +73,7 @@ public:
     template<class Checker>
     bool next(T& result, Checker& check)
     {
-        std::lock_guard<std::mutex> lock(_lock);
+        std::scoped_lock lock(_lock);
         if (_queue.empty())
             return false;
 
@@ -89,28 +89,28 @@ public:
     //! Cancels the queue.
     void cancel()
     {
-        std::lock_guard<std::mutex> lock(_lock);
+        std::scoped_lock lock(_lock);
         _canceled = true;
     }
 
     //! Checks if the queue is cancelled.
     bool cancelled()
     {
-        std::lock_guard<std::mutex> lock(_lock);
+        std::scoped_lock lock(_lock);
         return _canceled;
     }
 
     ///! Calls pop_front of the queue
     void pop_front()
     {
-        std::lock_guard<std::mutex> lock(_lock);
+        std::scoped_lock lock(_lock);
         _queue.pop_front();
     }
 
     ///! Checks if we're empty or not with locks held
     bool empty()
     {
-        std::lock_guard<std::mutex> lock(_lock);
+        std::scoped_lock lock(_lock);
         return _queue.empty();
     }
 };

src/common/Threading/ProducerConsumerQueue.h

@@ -18,10 +18,10 @@
 #ifndef TRINITY_PRODUCER_CONSUMER_QUEUE_H
 #define TRINITY_PRODUCER_CONSUMER_QUEUE_H
 
+#include <atomic>
 #include <condition_variable>
 #include <mutex>
 #include <queue>
-#include <atomic>
 #include <type_traits>
 
 template <typename T>
@@ -39,7 +39,7 @@ public:
 
     void Push(T const& value)
     {
-        std::lock_guard<std::mutex> lock(_queueLock);
+        std::scoped_lock lock(_queueLock);
         _queue.push(value);
 
         _condition.notify_one();
@@ -47,7 +47,7 @@ public:
 
     void Push(T&& value)
     {
-        std::lock_guard<std::mutex> lock(_queueLock);
+        std::scoped_lock lock(_queueLock);
         _queue.push(std::move(value));
 
         _condition.notify_one();
@@ -55,21 +55,21 @@ public:
 
     bool Empty() const
     {
-        std::lock_guard<std::mutex> lock(_queueLock);
+        std::scoped_lock lock(_queueLock);
 
         return _queue.empty();
     }
 
     size_t Size() const
     {
-        std::lock_guard<std::mutex> lock(_queueLock);
+        std::scoped_lock lock(_queueLock);
 
         return _queue.size();
     }
 
     bool Pop(T& value)
     {
-        std::lock_guard<std::mutex> lock(_queueLock);
+        std::scoped_lock lock(_queueLock);
 
         if (_queue.empty() || _shutdown)
             return false;
@@ -83,12 +83,9 @@ public:
 
     void WaitAndPop(T& value)
     {
-        std::unique_lock<std::mutex> lock(_queueLock);
+        std::unique_lock lock(_queueLock);
 
-        // we could be using .wait(lock, predicate) overload here but it is broken
-        // https://connect.microsoft.com/VisualStudio/feedback/details/1098841
-        while (_queue.empty() && !_shutdown)
-            _condition.wait(lock);
+        _condition.wait(lock, [&] { return !_queue.empty() || _shutdown; });
 
         if (_queue.empty() || _shutdown)
             return;
@@ -100,7 +97,7 @@ public:
 
     void Cancel()
     {
-        std::unique_lock<std::mutex> lock(_queueLock);
+        std::scoped_lock lock(_queueLock);
 
         while (!_queue.empty())
         {