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## Class interprocess_sharable_mutex

boost::interprocess::interprocess_sharable_mutex

## Synopsis

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

    class interprocess_sharable_mutex {
    public:
      // construct/copy/destruct
      interprocess_sharable_mutex(const interprocess_sharable_mutex &);
      interprocess_sharable_mutex();
      interprocess_sharable_mutex & operator=(const interprocess_sharable_mutex &);
      ~interprocess_sharable_mutex();

      // public member functions
      void lock();
      bool try_lock();
      bool timed_lock(const boost::posix_time::ptime &);
      void unlock();
      void lock_sharable();
      bool try_lock_sharable();
      bool timed_lock_sharable(const boost::posix_time::ptime &);
      void unlock_sharable();
    };

## Description

Wraps a interprocess_sharable_mutex that can be placed in shared memory and can be shared between processes. Allows timed lock tries

### `interprocess_sharable_mutex` public construct/copy/destruct

1.     interprocess_sharable_mutex(const interprocess_sharable_mutex &);

2.     interprocess_sharable_mutex();

   Constructs the sharable lock. Throws `interprocess_exception` on error.

3.     interprocess_sharable_mutex & operator=(const interprocess_sharable_mutex &);

4.     ~interprocess_sharable_mutex();

   Destroys the sharable lock. Does not throw.

### `interprocess_sharable_mutex` public member functions

1.     void lock();

   Effects: The calling thread tries to obtain exclusive ownership of the mutex, and if another thread has exclusive or sharable ownership of the mutex, it waits until it can obtain the ownership. Throws: `interprocess_exception` on error.

2.     bool try_lock();

   Effects: The calling thread tries to acquire exclusive ownership of the mutex without waiting. If no other thread has exclusive or sharable ownership of the mutex this succeeds. Returns: If it can acquire exclusive ownership immediately returns true. If it has to wait, returns false. Throws: `interprocess_exception` on error.

3.     bool timed_lock(const boost::posix_time::ptime & abs_time);

   Effects: The calling thread tries to acquire exclusive ownership of the mutex waiting if necessary until no other thread has exclusive or sharable ownership of the mutex or abs_time is reached. Returns: If acquires exclusive ownership, returns true. Otherwise returns false. Throws: `interprocess_exception` on error.

4.     void unlock();

   Precondition: The thread must have exclusive ownership of the mutex. Effects: The calling thread releases the exclusive ownership of the mutex. Throws: An exception derived from `interprocess_exception` on error.

5.     void lock_sharable();

   Effects: The calling thread tries to obtain sharable ownership of the mutex, and if another thread has exclusive ownership of the mutex, waits until it can obtain the ownership. Throws: `interprocess_exception` on error.

6.     bool try_lock_sharable();

   Effects: The calling thread tries to acquire sharable ownership of the mutex without waiting. If no other thread has exclusive ownership of the mutex this succeeds. Returns: If it can acquire sharable ownership immediately returns true. If it has to wait, returns false. Throws: `interprocess_exception` on error.

7.     bool timed_lock_sharable(const boost::posix_time::ptime & abs_time);

   Effects: The calling thread tries to acquire sharable ownership of the mutex waiting if necessary until no other thread has exclusive ownership of the mutex or abs_time is reached. Returns: If acquires sharable ownership, returns true. Otherwise returns false. Throws: `interprocess_exception` on error.

8.     void unlock_sharable();

   Precondition: The thread must have sharable ownership of the mutex. Effects: The calling thread releases the sharable ownership of the mutex. Throws: An exception derived from `interprocess_exception` on error.