1 /* Copyright (c) 2006-2023. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 #ifndef SIMGRID_S4U_MUTEX_HPP
7 #define SIMGRID_S4U_MUTEX_HPP
9 #include "simgrid/s4u/Actor.hpp"
10 #include <simgrid/forward.h>
11 #include <xbt/asserts.h>
13 namespace simgrid::s4u {
15 /** @brief A classical mutex, but blocking in the simulation world.
17 * S4U mutexes are not recursive. If an actor tries to lock the same object twice, it deadlocks with itself.
20 * It is strictly impossible to use a real mutex, such as
21 * `std::mutex <http://en.cppreference.com/w/cpp/thread/mutex>`_
22 * or `pthread_mutex_t <http://pubs.opengroup.org/onlinepubs/007908775/xsh/pthread_mutex_lock.html>`_,
23 * because it would block the whole simulation.
24 * Instead, you should use the present class, that is a drop-in replacement of these mechanisms.
26 * An example is available in Section :ref:`s4u_ex_IPC`.
28 * As for any S4U object, you can use the :ref:`RAII idiom <s4u_raii>` for memory management of Mutexes.
29 * Use :cpp:func:`create() <simgrid::s4u::Mutex::create()>` to get a :cpp:type:`simgrid::s4u::MutexPtr` to a newly
30 * created mutex, and only manipulate :cpp:type:`simgrid::s4u::MutexPtr`.
33 class XBT_PUBLIC Mutex {
35 friend ConditionVariable;
36 friend kernel::activity::MutexImpl;
37 friend XBT_PUBLIC void kernel::activity::intrusive_ptr_release(kernel::activity::MutexImpl* mutex);
40 kernel::activity::MutexImpl* const pimpl_;
42 friend XBT_PUBLIC void intrusive_ptr_add_ref(const Mutex* mutex);
43 friend XBT_PUBLIC void intrusive_ptr_release(const Mutex* mutex);
45 explicit Mutex(kernel::activity::MutexImpl* mutex) : pimpl_(mutex) {}
48 Mutex(Mutex const&) = delete; // No copy constructor; Use MutexPtr instead
49 Mutex& operator=(Mutex const&) = delete; // No direct assignment either. Use MutexPtr instead
53 /** \static Constructs a new mutex */
54 static MutexPtr create(bool recursive = false);
63 } // namespace simgrid::s4u
65 #endif /* SIMGRID_S4U_MUTEX_HPP */