[/

(C) Copyright 2012 Vicente J. Botet Escriba.

Distributed under the Boost Software License, Version 1.0.

(See accompanying file LICENSE_1_0.txt or copy at

http://www.boost.org/LICENSE_1_0.txt).

]

[section:tutorial Tutorial]

[@http://web.archive.org/web/20140531071228/http://home.roadrunner.com/~hinnant/mutexes/locking.html Handling mutexes in C++] is an excellent tutorial. You need just replace std and ting by boost.

[@http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2406.html Mutex, Lock, Condition Variable Rationale] adds rationale for the design decisions made for mutexes, locks and condition variables.

In addition to the C++11 standard locks, Boost.Thread provides other locks and some utilities that help the user to make their code thread-safe.

[include internal_locking.qbk]

[include external_locking.qbk]

[section:with Executing Around a Function]

In particular, the library provides a way to lock around the execution of a function.

template <class Lockable, class Function, class... Args>

auto with_lock_guard(

Lockable& m,

Function&& func,

Args&&... args

) -> decltype(func(boost::forward<Args>(args)...)) {

boost::lock_guard<Lockable> lock(m);

return func(boost::forward<Args>(args)...);

}

that can be used with regular functions:

int func(int, int&);

//...

boost::mutex m;

int a;

int result = boost::with_lock_guard(m, func, 1, boost::ref(a));

with boost::bind:

int result = boost::with_lock_guard(

m, boost::bind(func, 2, boost::ref(a))

);

or with lambda expression:

int a;

int result = boost::with_lock_guard(

m,

[&a](int x) {

// this scope is protected by mutex m

a = 3;

return x + 4;

},

5

);

[endsect] [/ With]

[endsect] [/ Tutorial]