Defined in carb/thread/Mutex.h

class recursive_mutex : protected detail::BaseMutex<true>

A Carbonite implementation of std::recursive_mutex.


Windows: std::recursive_mutex uses SRWLOCK for Win 7+, CONDITION_VARIABLE for Vista and the massive CRITICAL_SECTION for pre-Vista. Due to this, the std::recursive_mutex class is about 80 bytes. Since Carbonite supports Windows 10 and later, SRWLOCK is used exclusively. This implementation is 16 bytes. This version that uses SRWLOCK is significantly faster on Windows than the portable implementation used for the linux version.


Linux: sizeof(std::recursive_mutex) is 40 bytes on GLIBC 2.27, which is based on the size of pthread_mutex_t. The Carbonite implementation of recursive_mutex is 24 bytes and at least as performant as std::recursive_mutex in the contended case.

Public Functions

recursive_mutex() noexcept = default



Unlike std::recursive_mutex, this implementation can be declared constexpr.

~recursive_mutex() = default



std::terminate() is called if recursive_mutex is locked by a thread.

inline void lock()

Locks the recursive_mutex, blocking until it becomes available.

The calling thread must call unlock() at a later time to release the lock. There must be symmetrical calls to unlock() for each call to lock() or successful call to try_lock().

inline bool try_lock()

Attempts to immediately lock the recursive_mutex.


true if the recursive_mutex was available and the lock was taken by the calling thread (unlock() must be called from the calling thread at a later time to release the lock); false if the recursive_mutex could not be locked by the calling thread. If the lock was already held by the calling thread, true is always returned.

inline void unlock()

Unlocks the recursive_mutex.


std::terminate() is called if the calling thread does not own the recursive_mutex.

inline bool is_current_thread_owner() const noexcept

Checks if the current thread owns the mutex.


This is a non-standard Carbonite extension.


true if the current thread owns the mutex; false otherwise.