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¶
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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.
Acquires a lock on read. It uses an adaptive logic for waiting, thus it is blocked after a certain time of busy waiting.
Tries to acquire the lock (non-blocking) on read. Returns true if succeeded; false otherwise.
Releases the read lock held by the current thread.