Adding upstream version 2:20.4+dfsg.upstream/2%20.4+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 54 insertions, 0 deletions

diff --git a/xbmc/threads/SharedSection.h b/xbmc/threads/SharedSection.h
new file mode 100644
index 0000000..dce371d
--- /dev/null
+++ b/xbmc/threads/SharedSection.h
@@ -0,0 +1,54 @@
+/*
+ *  Copyright (C) 2005-2018 Team Kodi
+ *  This file is part of Kodi - https://kodi.tv
+ *
+ *  SPDX-License-Identifier: GPL-2.0-or-later
+ *  See LICENSES/README.md for more information.
+ */
+
+#pragma once
+
+#include "threads/Condition.h"
+
+#include <mutex>
+#include <shared_mutex>
+
+/**
+ * A CSharedSection is a mutex that satisfies the Shared Lockable concept (see Lockables.h).
+ */
+class CSharedSection
+{
+  CCriticalSection sec;
+  XbmcThreads::ConditionVariable actualCv;
+
+  unsigned int sharedCount = 0;
+
+public:
+  inline CSharedSection() = default;
+
+  inline void lock()
+  {
+    std::unique_lock<CCriticalSection> l(sec);
+    while (sharedCount)
+      actualCv.wait(l, [this]() { return sharedCount == 0; });
+    sec.lock();
+  }
+  inline bool try_lock() { return (sec.try_lock() ? ((sharedCount == 0) ? true : (sec.unlock(), false)) : false); }
+  inline void unlock() { sec.unlock(); }
+
+  inline void lock_shared()
+  {
+    std::unique_lock<CCriticalSection> l(sec);
+    sharedCount++;
+  }
+  inline bool try_lock_shared() { return (sec.try_lock() ? sharedCount++, sec.unlock(), true : false); }
+  inline void unlock_shared()
+  {
+    std::unique_lock<CCriticalSection> l(sec);
+    sharedCount--;
+    if (!sharedCount)
+    {
+      actualCv.notifyAll();
+    }
+  }
+};