Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89
Commit: 93712b24bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256
Reviewed-by: https://github.com/sideshowbarker

Libraries/LibThreading/Mutex.h

@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <andreas@ladybird.org>
+ * Copyright (c) 2021, kleines Filmröllchen <malu.bertsch@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Assertions.h>
+#include <AK/Noncopyable.h>
+#include <AK/Types.h>
+#include <pthread.h>
+
+namespace Threading {
+
+class Mutex {
+    AK_MAKE_NONCOPYABLE(Mutex);
+    AK_MAKE_NONMOVABLE(Mutex);
+    friend class ConditionVariable;
+
+public:
+    Mutex()
+        : m_lock_count(0)
+    {
+        pthread_mutexattr_t attr;
+        pthread_mutexattr_init(&attr);
+        pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+        pthread_mutex_init(&m_mutex, &attr);
+    }
+    ~Mutex()
+    {
+        VERIFY(m_lock_count == 0);
+        // FIXME: pthread_mutex_destroy() is not implemented.
+    }
+
+    void lock();
+    void unlock();
+
+private:
+    pthread_mutex_t m_mutex;
+    unsigned m_lock_count { 0 };
+};
+
+class MutexLocker {
+    AK_MAKE_NONCOPYABLE(MutexLocker);
+    AK_MAKE_NONMOVABLE(MutexLocker);
+
+public:
+    ALWAYS_INLINE explicit MutexLocker(Mutex& mutex)
+        : m_mutex(mutex)
+    {
+        lock();
+    }
+    ALWAYS_INLINE ~MutexLocker()
+    {
+        unlock();
+    }
+    ALWAYS_INLINE void unlock() { m_mutex.unlock(); }
+    ALWAYS_INLINE void lock() { m_mutex.lock(); }
+
+private:
+    Mutex& m_mutex;
+};
+
+ALWAYS_INLINE void Mutex::lock()
+{
+    pthread_mutex_lock(&m_mutex);
+    m_lock_count++;
+}
+
+ALWAYS_INLINE void Mutex::unlock()
+{
+    VERIFY(m_lock_count > 0);
+    // FIXME: We need to protect the lock count with the mutex itself.
+    // This may be bad because we're not *technically* unlocked yet,
+    // but we're not handling any errors from pthread_mutex_unlock anyways.
+    m_lock_count--;
+    pthread_mutex_unlock(&m_mutex);
+}
+
+}