.. SPDX-FileCopyrightText: 2021 Intel Corporation .. .. SPDX-License-Identifier: CC-BY-4.0 ===== mutex ===== **[mutex.mutex]** A ``mutex`` is a class that models :doc:`Mutex requirement <../named_requirements/mutexes/mutex>` using an adaptive approach, it guarantees that the thread that cannot acquire the lock spins before blocking. The ``mutex`` class satisfies all of the mutex requirements described in the [thread.mutex.requirements] section of the ISO C++ standard. The ``mutex`` class is not fair or recursive. .. code:: cpp // Defined in header namespace oneapi { namespace tbb { class mutex { public: mutex() noexcept; ~mutex(); mutex(const mutex&) = delete; mutex& operator=(const mutex&) = delete; class scoped_lock; void lock(); bool try_lock(); void unlock(); static constexpr bool is_rw_mutex = false; static constexpr bool is_recursive_mutex = false; static constexpr bool is_fair_mutex = false; }; } } Member classes -------------- .. namespace:: oneapi::tbb::mutex .. cpp:class:: scoped_lock The corresponding ``scoped_lock`` class. See :doc:`Mutex requirement <../named_requirements/mutexes/mutex>`. Member functions ---------------- .. cpp:function:: mutex() Constructs a ``mutex`` with the unlocked state. -------------------------------------------------- .. cpp:function:: ~mutex() Destroys an unlocked ``mutex``. -------------------------------------------------- .. cpp:function:: void lock() Acquires a lock. It uses an adaptive logic for waiting, thus it is blocked after a certain time of busy waiting. -------------------------------------------------- .. cpp:function:: bool try_lock() Tries to acquire a lock (non-blocking). Returns **true** if succeeded; **false** otherwise. -------------------------------------------------- .. cpp:function:: void unlock() Releases the lock held by a current thread.