From c522a3634e0cd20804b1e3216caedd5e15cbee19 Mon Sep 17 00:00:00 2001
From: Felix Morgner <felix.morgner@ost.ch>
Date: Mon, 29 Dec 2025 12:01:04 +0100
Subject: kstd/mutex: implement lock_guard

---
 libs/kstd/include/kstd/mutex | 61 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/libs/kstd/include/kstd/mutex b/libs/kstd/include/kstd/mutex
index ae91970..7795558 100644
--- a/libs/kstd/include/kstd/mutex
+++ b/libs/kstd/include/kstd/mutex
@@ -38,6 +38,67 @@ namespace kstd
     std::atomic_flag m_locked{};
   };
 
+  //! A tag type to specify that a given @p lockable wrapper should adopt ownership of the @p lockable.
+  struct adopt_lock_t
+  {
+    explicit adopt_lock_t() = default;
+  } constexpr inline adopt_lock{};
+
+  //! A tag type to specify that a given @p lockable wrapper should defer locking the @p lockable.
+  struct defer_lock_t
+  {
+    explicit defer_lock_t() = default;
+  } constexpr inline defer_lock{};
+
+  //! A tag type to specify that a given @p lockable wrapper should attempt to lock the @p lockable.
+  struct try_to_lock_t
+  {
+    explicit try_to_lock_t() = default;
+  } constexpr inline try_to_lock{};
+
+  //! An RAII wrapper for a single @p lockable like a kstd::mutex.
+  template<typename MutexType>
+  struct lock_guard
+  {
+    using mutex_type = MutexType;
+
+    //! Construct a new lock_guard and immediately lock the given mutex.
+    //!
+    //! @note This function will block until the mutex was successfully locked.
+    //! @param mutex The mutex to lock.
+    [[gnu::section(".stl_text")]]
+    lock_guard(MutexType & mutex) noexcept
+        : m_mutex(mutex)
+    {
+      m_mutex.lock();
+    }
+
+    //! Construct a new lock_guard and take ownership of the given mutex.
+    //!
+    //! @note The behavior is undefined if the mutex is not owned by the current thread.
+    //! @param mutex The mutex to take ownership of.
+    [[gnu::section(".stl_text")]]
+    lock_guard(MutexType & mutex, adopt_lock_t) noexcept
+        : m_mutex(mutex)
+    {}
+
+    //! Destroy this lock_guard and release the owned mutex.
+    [[gnu::section(".stl_text")]]
+    ~lock_guard()
+    {
+      m_mutex.unlock();
+    }
+
+    lock_guard(lock_guard const &) noexcept = delete;
+    lock_guard(lock_guard &&) noexcept = delete;
+
+    auto operator=(lock_guard const &) noexcept -> lock_guard & = delete;
+    auto operator=(lock_guard &&) noexcept -> lock_guard & = delete;
+
+  private:
+    mutex_type & m_mutex;
+  };
+
 }  // namespace kstd
 
 #endif
\ No newline at end of file
-- 
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