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This is the documentation for a snapshot of the master branch, built from commit b9ab49fc70.
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Class named_upgradable_mutex

boost::interprocess::named_upgradable_mutex

Synopsis

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


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

  // public member functions
  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 &);
  void unlock();
  void lock_sharable();
  void lock_shared();
  bool try_lock_sharable();
  bool try_lock_shared();
  template<typename TimePoint> bool timed_lock_sharable(const TimePoint &);
  template<typename TimePoint> bool try_lock_shared_until(const TimePoint &);
  template<typename Duration> bool try_lock_shared_for(const Duration &);
  void unlock_sharable();
  void unlock_shared();
  void lock_upgradable();
  bool try_lock_upgradable();
  template<typename TimePoint> bool timed_lock_upgradable(const TimePoint &);
  void unlock_upgradable();
  void unlock_and_lock_upgradable();
  void unlock_and_lock_sharable();
  void unlock_upgradable_and_lock_sharable();
  void unlock_upgradable_and_lock();
  bool try_unlock_upgradable_and_lock();
  template<typename TimePoint> 
    bool timed_unlock_upgradable_and_lock(const TimePoint &);
  bool try_unlock_sharable_and_lock();
  bool try_unlock_sharable_and_lock_upgradable();

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

Description

A upgradable 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 upgradable mutex.

named_upgradable_mutex public construct/copy/destruct

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

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

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

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

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

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

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

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

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

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

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

    Opens a global upgradable mutex with a name if that upgradable 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_upgradable_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_upgradable_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, sharable or upgradable 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, sharable or upgradable 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. template<typename TimePoint> bool timed_lock(const TimePoint & 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, sharable or upgradable 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. 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.

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

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

  6. 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.

  7. 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

  8. void lock_shared();

    Same as lock_sharable but with a std-compatible interface

  9. 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

  10. bool try_lock_shared();

    Same as try_lock_sharable but with a std-compatible interface

  11. template<typename TimePoint> 
      bool timed_lock_sharable(const TimePoint & 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

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

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

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

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

  14. 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.

  15. void unlock_shared();

    Same as unlock_sharable but with a std-compatible interface

  16. void lock_upgradable();

    Requires: The calling thread does not own the mutex.

    Effects: The calling thread tries to obtain upgradable ownership of the mutex, and if another thread has exclusive or upgradable 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

  17. bool try_lock_upgradable();

    Requires: The calling thread does not own the mutex.

    Effects: The calling thread tries to acquire upgradable ownership of the mutex without waiting. If no other thread has exclusive or upgradable ownership of the mutex this succeeds. Returns: If it can acquire upgradable 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

  18. template<typename TimePoint> 
      bool timed_lock_upgradable(const TimePoint & abs_time);

    Requires: The calling thread does not own the mutex.

    Effects: The calling thread tries to acquire upgradable ownership of the mutex waiting if necessary until no other thread has exclusive or upgradable ownership of the mutex or abs_time is reached. Returns: If acquires upgradable 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

  19. void unlock_upgradable();

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

  20. void unlock_and_lock_upgradable();

    Precondition: The thread must have exclusive ownership of the mutex. Effects: The thread atomically releases exclusive ownership and acquires upgradable ownership. This operation is non-blocking. Throws: An exception derived from interprocess_exception on error.

  21. void unlock_and_lock_sharable();

    Precondition: The thread must have exclusive ownership of the mutex. Effects: The thread atomically releases exclusive ownership and acquires sharable ownership. This operation is non-blocking. Throws: An exception derived from interprocess_exception on error.

  22. void unlock_upgradable_and_lock_sharable();

    Precondition: The thread must have upgradable ownership of the mutex. Effects: The thread atomically releases upgradable ownership and acquires sharable ownership. This operation is non-blocking. Throws: An exception derived from interprocess_exception on error.

  23. void unlock_upgradable_and_lock();

    Precondition: The thread must have upgradable ownership of the mutex. Effects: The thread atomically releases upgradable ownership and acquires exclusive ownership. This operation will block until all threads with sharable ownership release it. Throws: An exception derived from interprocess_exception on error.

  24. bool try_unlock_upgradable_and_lock();

    Precondition: The thread must have upgradable ownership of the mutex. Effects: The thread atomically releases upgradable ownership and tries to acquire exclusive ownership. This operation will fail if there are threads with sharable ownership, but it will maintain upgradable ownership. Returns: If acquires exclusive ownership, returns true. Otherwise returns false. Throws: An exception derived from interprocess_exception on error.

  25. template<typename TimePoint> 
      bool timed_unlock_upgradable_and_lock(const TimePoint & abs_time);

    Precondition: The thread must have upgradable ownership of the mutex. Effects: The thread atomically releases upgradable ownership and tries to acquire exclusive ownership, waiting if necessary until abs_time. This operation will fail if there are threads with sharable ownership or timeout reaches, but it will maintain upgradable ownership. Returns: If acquires exclusive ownership, returns true. Otherwise returns false. Throws: An exception derived from interprocess_exception on error.

  26. bool try_unlock_sharable_and_lock();

    Precondition: The thread must have sharable ownership of the mutex. Effects: The thread atomically releases sharable ownership and tries to acquire exclusive ownership. This operation will fail if there are threads with sharable or upgradable ownership, but it will maintain sharable ownership. Returns: If acquires exclusive ownership, returns true. Otherwise returns false. Throws: An exception derived from interprocess_exception on error.

  27. bool try_unlock_sharable_and_lock_upgradable();

    Precondition: The thread must have sharable ownership of the mutex. Effects: The thread atomically releases sharable ownership and tries to acquire upgradable ownership. This operation will fail if there are threads with sharable or upgradable ownership, but it will maintain sharable ownership. Returns: If acquires upgradable ownership, returns true. Otherwise returns false. Throws: An exception derived from interprocess_exception on error.

named_upgradable_mutex public static functions

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

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

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

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

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


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