.. SPDX-FileCopyrightText: 2019-2021 Intel Corporation .. .. SPDX-License-Identifier: CC-BY-4.0

========== spin_mutex

[mutex.spin_mutex]

A spin_mutex is a class that models the :doc:Mutex requirement <../named_requirements/mutexes/mutex> using a spin lock. The spin_mutex class satisfies all requirements of mutex type from the [thread.mutex.requirements] ISO C++ section. The spin_mutex class is not fair or recursive.

.. code:: cpp

// Defined in header <oneapi/tbb/spin_mutex.h>

namespace oneapi {
namespace tbb {
    class spin_mutex {
    public:
        spin_mutex() noexcept;
        ~spin_mutex();

        spin_mutex(const spin_mutex&) = delete;
        spin_mutex& operator=(const spin_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;
    };
} // namespace tbb
} // namespace oneapi

Member classes

.. namespace:: oneapi::tbb::spin_mutex

.. cpp:class:: scoped_lock

Corresponding ``scoped_lock`` class. See the :doc:`Mutex requirement <../named_requirements/mutexes/mutex>`.

Member functions

.. cpp:function:: spin_mutex()

Constructs ``spin_mutex`` with unlocked state.

.. cpp:function:: ~spin_mutex()

Destroys an unlocked ``spin_mutex``.

.. cpp:function:: void lock()

Acquires a lock. Spins if the lock is taken.

.. cpp:function:: bool try_lock()

Attempts to acquire a lock (non-blocking). Returns **true** if lock is acquired; **false**, otherwise.

.. cpp:function:: void unlock()

Releases a lock held by a current thread.