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Class named_sharable_mutex

boost::interprocess::named_sharable_mutex

Synopsis

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


class named_sharable_mutex {
public:
  // construct/copy/destruct
  named_sharable_mutex(create_only_t, const char *, 
                       const permissions & = permissions());
  named_sharable_mutex(open_or_create_t, const char *, 
                       const permissions & = permissions());
  named_sharable_mutex(open_only_t, const char *);
  named_sharable_mutex(create_only_t, const wchar_t *, 
                       const permissions & = permissions());
  named_sharable_mutex(open_or_create_t, const wchar_t *, 
                       const permissions & = permissions());
  named_sharable_mutex(open_only_t, const wchar_t *);
  ~named_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();

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

Description

A sharable 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 sharable mutex.

named_sharable_mutex public construct/copy/destruct

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

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

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

    Opens or creates a global sharable mutex with a name. If the sharable mutex is created, this call is equivalent to named_sharable_mutex(create_only_t, ...) If the sharable mutex is already created, this call is equivalent to named_sharable_mutex(open_only_t, ... ).

  3. named_sharable_mutex(open_only_t open_only, const char * name);

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

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

    Creates a global sharable mutex with a name. If the sharable 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_sharable_mutex(open_or_create_t open_or_create, const wchar_t * name, 
                         const permissions & perm = permissions());

    Opens or creates a global sharable mutex with a name. If the sharable mutex is created, this call is equivalent to named_sharable_mutex(create_only_t, ...) If the sharable mutex is already created, this call is equivalent to named_sharable_mutex(open_only_t, ... ).

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

  6. named_sharable_mutex(open_only_t open_only, const wchar_t * name);

    Opens a global sharable mutex with a name if that sharable 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_sharable_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().

named_sharable_mutex public member functions

  1. void lock();

    Requires: The calling thread does not own the mutex.

    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.

    Note: A program may deadlock if the thread that has ownership calls this function. If the implementation can detect the deadlock, an exception could be thrown.

  2. bool try_lock();

    Requires: The calling thread does not own the mutex.

    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.

    Note: A program may deadlock if the thread that has ownership calls this function. If the implementation can detect the deadlock, an exception could be thrown.

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

    Requires: The calling thread does not own the mutex.

    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.

    Note: A program may deadlock if the thread that has ownership calls this function. If the implementation can detect the deadlock, an exception could be thrown.

  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();

    Requires: The calling thread does not own the mutex.

    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.

    Note: A program may deadlock if the thread that has ownership calls this function. If the implementation can detect the deadlock, an exception could be thrown

  6. bool try_lock_sharable();

    Requires: The calling thread does not own the mutex.

    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.

    Note: A program may deadlock if the thread that has ownership calls this function. If the implementation can detect the deadlock, an exception could be thrown

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

    Requires: The calling thread does not own the mutex.

    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.

    Note: A program may deadlock if the thread that has ownership calls this function. If the implementation can detect the deadlock, an exception could be thrown

  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.

named_sharable_mutex public static functions

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

    Erases a named sharable mutex from the system. Returns false on error. Never throws.

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

    Erases a named sharable mutex from the system. Returns false on error. Never throws.


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