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## Class named_recursive_mutex

boost::interprocess::named_recursive_mutex

## Synopsis

    // In header: <boost/interprocess/sync/named_recursive_mutex.hpp>

    class named_recursive_mutex {
    public:

      // public member functions
      named_recursive_mutex(create_only_t, const char *,
                            const permissions & = permissions());
      named_recursive_mutex(open_or_create_t, const char *,
                            const permissions & = permissions());
      named_recursive_mutex(open_only_t, const char *);
      named_recursive_mutex(create_only_t, const wchar_t *,
                            const permissions & = permissions());
      named_recursive_mutex(open_or_create_t, const wchar_t *,
                            const permissions & = permissions());
      named_recursive_mutex(open_only_t, const wchar_t *);
      ~named_recursive_mutex();
      void unlock();
      void lock();
      bool try_lock();
      template<typename TimePoint> bool timed_lock(const TimePoint &);
      template<typename TimePoint> bool try_lock_until(const TimePoint &);
      template<typename Duration> bool try_lock_for(const Duration &);

      // public static functions
      static bool remove(const char *);
      static bool remove(const wchar_t *);
    };

## Description

A recursive mutex with a global name, so it can be found from different processes. This mutex can't be placed in shared memory, and each process should have it's own named_recursive_mutex.

### `named_recursive_mutex` public member functions

1.     named_recursive_mutex(create_only_t, const char * name,
                             const permissions & perm = permissions());

   Creates a global recursive_mutex with a name. If the recursive_mutex can't be created throws interprocess_exception

2.     named_recursive_mutex(open_or_create_t, const char * name,
                             const permissions & perm = permissions());

   Opens or creates a global recursive_mutex with a name. If the recursive_mutex is created, this call is equivalent to named_recursive_mutex(create_only_t, ... ) If the recursive_mutex is already created, this call is equivalent named_recursive_mutex(open_only_t, ... ) Does not throw

3.     named_recursive_mutex(open_only_t, const char * name);

   Opens a global recursive_mutex with a name if that recursive_mutex is previously created. If it is not previously created this function throws interprocess_exception.

4.     named_recursive_mutex(create_only_t, const wchar_t * name,
                             const permissions & perm = permissions());

   Creates a global recursive_mutex with a name. If the recursive_mutex can't be created throws interprocess_exception

   Note: This function is only available on operating systems with native wchar_t APIs (e.g. Windows).

5.     named_recursive_mutex(open_or_create_t, const wchar_t * name,
                             const permissions & perm = permissions());

   Opens or creates a global recursive_mutex with a name. If the recursive_mutex is created, this call is equivalent to named_recursive_mutex(create_only_t, ... ) If the recursive_mutex is already created, this call is equivalent named_recursive_mutex(open_only_t, ... ) Does not throw

   Note: This function is only available on operating systems with native wchar_t APIs (e.g. Windows).

6.     named_recursive_mutex(open_only_t, const wchar_t * name);

   Opens a global recursive_mutex with a name if that recursive_mutex is previously created. If it is not previously created this function throws interprocess_exception.

   Note: This function is only available on operating systems with native wchar_t APIs (e.g. Windows).

7.     ~named_recursive_mutex();

   Destroys *this and indicates that the calling process is finished using the resource. The destructor function will deallocate any system resources allocated by the system for use by this process for this resource. The resource can still be opened again calling the open constructor overload. To erase the resource from the system use remove().

8.     void unlock();

   Unlocks a previously locked named_recursive_mutex.

9.     void lock();

   Locks named_recursive_mutex, sleeps when named_recursive_mutex is already locked. Throws interprocess_exception if a severe error is found.

   Note: A program shall not deadlock if the thread that has ownership calls this function.

10.     bool try_lock();

    Tries to lock the named_recursive_mutex, returns false when named_recursive_mutex is already locked, returns true when success. Throws interprocess_exception if a severe error is found.

    Note: A program shall not deadlock if the thread that has ownership calls this function.

11.     template<typename TimePoint> bool timed_lock(const TimePoint & abs_time);

    Tries to lock the named_recursive_mutex until time abs_time, Returns false when timeout expires, returns true when locks. Throws interprocess_exception if a severe error is found

    Note: A program shall not deadlock if the thread that has ownership calls this function.

12.     template<typename TimePoint> bool try_lock_until(const TimePoint & abs_time);

    Same as `timed_lock`, but this function is modeled after the standard library interface.

13.     template<typename Duration> bool try_lock_for(const Duration & dur);

    Same as `timed_lock`, but this function is modeled after the standard library interface.

### `named_recursive_mutex` public static functions

1.     static bool remove(const char * name);

   Erases a named recursive mutex from the system

2.     static bool remove(const wchar_t * name);

   Erases a named recursive mutex from the system

   Note: This function is only available on operating systems with native wchar_t APIs (e.g. Windows).