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## Class mutex

boost::mutex —

The mutex class is a model of the Mutex concept.

## Synopsis

    class mutex : private boost::noncopyable   // Exposition only
    {
    public:
      // types
      typedef implementation-defined scoped_lock;

      // construct/copy/destruct
      mutex();
      ~mutex();
    };

## Description

The mutex class is a model of the Mutex concept. It should be used to synchronize access to shared resources using Unspecified locking mechanics.

For classes that model related mutex concepts, see try_mutex and timed_mutex.

For Recursive locking mechanics, see recursive_mutex, recursive_try_mutex, and recursive_timed_mutex.

The mutex class supplies the following typedef, which models the specified locking strategy:

Lock Name | Lock Concept
--- | ---
scoped_lock | ScopedLock

The mutex class uses an Unspecified locking strategy, so attempts to recursively lock a mutex object or attempts to unlock one by threads that don't own a lock on it result in undefined behavior. This strategy allows implementations to be as efficient as possible on any given platform. It is, however, recommended that implementations include debugging support to detect misuse when `NDEBUG` is not defined.

Like all mutex models in Boost.Thread, mutex leaves the scheduling policy as Unspecified. Programmers should make no assumptions about the order in which waiting threads acquire a lock.

### `mutex` construct/copy/destruct

1.     mutex();

   Effects: | Constructs a mutex object.
   Postconditions: | `*this` is in an unlocked state.

2.     ~mutex();

   Effects: | Destroys a mutex object.
   Requires: | `*this` is in an unlocked state.
   Notes: | Danger: Destruction of a locked mutex is a serious programming error resulting in undefined behavior such as a program crash.

| Copyright © 2001-2003 William E. Kempf