-/* Copyright (c) 2006-2018. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2006-2022. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
#define SIMGRID_S4U_SEMAPHORE_HPP
#include <simgrid/forward.h>
-#include <simgrid/simix.h>
namespace simgrid {
namespace s4u {
/** @brief A classical semaphore, but blocking in the simulation world
- * @ingroup s4u_api
*
+ * @beginrst
* It is strictly impossible to use a real semaphore, such as
- * <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_init.html">sem_init</a>,
+ * `sem_init <http://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_init.html>`_,
* because it would block the whole simulation.
* Instead, you should use the present class, that offers a very similar interface.
*
- * As for any S4U object, Semaphores are using the @ref s4u_raii "RAII idiom" for memory management.
- * Use #create() to get a simgrid::s4u::SemaphorePtr to a newly created semaphore
- * and only manipulate simgrid::s4u::SemaphorePtr.
+ * An example is available in Section :ref:`s4u_ex_IPC`.
+ *
+ * As for any S4U object, you can use the :ref:`RAII idiom <s4u_raii>` for memory management of semaphores.
+ * Use :cpp:func:`create() <simgrid::s4u::Mutex::create()>` to get a :cpp:type:`simgrid::s4u::SemaphorePtr` to a newly
+ * created semaphore, that will get automatically freed when the variable goes out of scope.
+ * @endrst
*
*/
class XBT_PUBLIC Semaphore {
- smx_sem_t sem_;
- std::atomic_int_fast32_t refcount_{0};
+#ifndef DOXYGEN
+ friend kernel::activity::SemaphoreImpl;
+ friend void kernel::activity::intrusive_ptr_release(kernel::activity::SemaphoreImpl* sem);
+#endif
- explicit Semaphore(unsigned int initial_capacity);
- ~Semaphore();
+ kernel::activity::SemaphoreImpl* const pimpl_;
- friend void intrusive_ptr_add_ref(Semaphore* sem);
- friend void intrusive_ptr_release(Semaphore* sem);
+ friend void intrusive_ptr_add_ref(const Semaphore* sem);
+ friend void intrusive_ptr_release(const Semaphore* sem);
-public:
- // No copy:
- /** You cannot create a new semaphore by copying an existing one. Use SemaphorePtr instead */
- Semaphore(Semaphore const&) = delete;
- /** You cannot create a new semaphore by value assignment either. Use SemaphorePtr instead */
- Semaphore& operator=(Semaphore const&) = delete;
+ explicit Semaphore(kernel::activity::SemaphoreImpl* sem) : pimpl_(sem) {}
+ ~Semaphore() = default;
+#ifndef DOXYGEN
+ Semaphore(Semaphore const&) = delete; // No copy constructor. Use SemaphorePtr instead
+ Semaphore& operator=(Semaphore const&) = delete; // No direct assignment either. Use SemaphorePtr instead
+#endif
+public:
/** Constructs a new semaphore */
static SemaphorePtr create(unsigned int initial_capacity);
void acquire();
+ bool acquire_timeout(double timeout);
void release();
+ int get_capacity() const;
+ bool would_block() const;
};
-}} // namespace simgrid::s4u
+} // namespace s4u
+} // namespace simgrid
#endif /* SIMGRID_S4U_SEMAPHORE_HPP */