std::recursive_mutex

C++

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Technical Specifications

Thread support library

Threads
thread (C++11)
hardware_destructive_interference_sizehardware_constructive_interference_size (C++17)(C++17)
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get_id (C++11) yield (C++11)	sleep_for (C++11) sleep_until (C++11)
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mutex (C++11) recursive_mutex (C++11) shared_mutex (C++17)	timed_mutex (C++11) recursive_timed_mutex (C++11) shared_timed_mutex (C++14)
Generic lock management
lock_guard (C++11) scoped_lock (C++17) unique_lock (C++11) shared_lock (C++14) defer_lock_ttry_to_lock_tadopt_lock_t (C++11)(C++11)(C++11)	lock (C++11) try_lock (C++11) defer_locktry_to_lockadopt_lock (C++11)(C++11)(C++11) once_flag (C++11) call_once (C++11)
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condition_variable (C++11)
condition_variable_any (C++11)
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promise (C++11) future (C++11) shared_future (C++11) packaged_task (C++11) async (C++11)	launch (C++11) future_status (C++11) future_error (C++11) future_category (C++11) future_errc (C++11)

std::recursive_mutex

Member functions

recursive_mutex::recursive_mutex

recursive_mutex::~recursive_mutex

Locking

recursive_mutex::lock

recursive_mutex::try_lock

recursive_mutex::unlock

Native handle

recursive_mutex::native_handle

Defined in header <mutex>
class recursive_mutex;		(since C++11)

The recursive_mutex class is a synchronization primitive that can be used to protect shared data from being simultaneously accessed by multiple threads.

recursive_mutex offers exclusive, recursive ownership semantics:

• A calling thread owns a recursive_mutex for a period of time that starts when it successfully calls either lock or try_lock. During this period, the thread may make additional calls to lock or try_lock. The period of ownership ends when the thread makes a matching number of calls to unlock.
• When a thread owns a recursive_mutex, all other threads will block (for calls to lock) or receive a false return value (for try_lock) if they attempt to claim ownership of the recursive_mutex.
• The maximum number of times that a recursive_mutex may be locked is unspecified, but after that number is reached, calls to lock will throw std::system_error and calls to try_lock will return false.

The behavior of a program is undefined if a recursive_mutex is destroyed while still owned by some thread. The recursive_mutex class satisfies all requirements of Mutex and StandardLayoutType.

Member types

Member type	Definition
native_handle_type(optional)	implementation-defined

Member functions

(constructor)	constructs the mutex (public member function)
(destructor)	destroys the mutex (public member function)
operator= [deleted]	not copy-assignable (public member function)
Locking
lock	locks the mutex, blocks if the mutex is not available (public member function)
try_lock	tries to lock the mutex, returns if the mutex is not available (public member function)
unlock	unlocks the mutex (public member function)
Native handle
native_handle	returns the underlying implementation-defined native handle object (public member function)