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rw_mutex

rw_mutex#

[mutex.rw_mutex]

A rw_mutex is a class that models ReaderWriterMutex requirement using an adaptive approach, it guarantees that the thread that cannot acquire the lock spins before blocking. The rw_mutex class satisfies all of the shared mutex requirements described in the [thread.sharedmutex.requirements] section of the ISO C++ standard. The rw_mutex class is an unfair reader-writer lock with a writer preference.

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

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

            rw_mutex(const rw_mutex&) = delete;
            rw_mutex& operator=(const rw_mutex&) = delete;

            class scoped_lock;

            // exclusive ownership
            void lock();
            bool try_lock();
            void unlock();

            // shared ownership
            void lock_shared();
            bool try_lock_shared();
            void unlock_shared();

            static constexpr bool is_rw_mutex = true;
            static constexpr bool is_recursive_mutex = false;
            static constexpr bool is_fair_mutex = false;
        };
    }
}

Member classes#

class scoped_lock#

The corresponding scoped-lock class. See ReaderWriterMutex requirement.

Member functions#

rw_mutex()#

Constructs an unlocked rw_mutex.

~rw_mutex()#

Destroys an unlocked rw_mutex.

void lock()#

Acquires a lock. It uses an adaptive logic for waiting, thus it is blocked after a certain time of busy waiting.

bool try_lock()#

Tries to acquire a lock (non-blocking) on write. Returns true if succeeded; false otherwise.

void unlock()#

Releases the write lock held by the current thread.

void lock_shared()#

Acquires a lock on read. It uses an adaptive logic for waiting, thus it is blocked after a certain time of busy waiting.

bool try_lock_shared()#

Tries to acquire the lock (non-blocking) on read. Returns true if succeeded; false otherwise.

void unlock_shared()#

Releases the read lock held by the current thread.

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