1 /* Copyright (c) 2018-2021. 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 #include <simgrid/s4u/Semaphore.hpp>
7 #include <simgrid/semaphore.h>
9 #include "src/kernel/activity/SemaphoreImpl.hpp"
10 #include "src/kernel/actor/SimcallObserver.hpp"
15 SemaphorePtr Semaphore::create(unsigned int initial_capacity)
17 auto* sem = new kernel::activity::SemaphoreImpl(initial_capacity);
18 return SemaphorePtr(&sem->sem(), false);
21 void Semaphore::acquire()
23 kernel::actor::ActorImpl* issuer = kernel::actor::ActorImpl::self();
24 kernel::actor::SemAcquireSimcall observer{issuer, pimpl_};
25 kernel::actor::simcall_blocking([&observer] { observer.get_sem()->acquire(observer.get_issuer(), -1.0); }, &observer);
28 bool Semaphore::acquire_timeout(double timeout)
30 kernel::actor::ActorImpl* issuer = kernel::actor::ActorImpl::self();
31 kernel::actor::SemAcquireSimcall observer{issuer, pimpl_, timeout};
32 return kernel::actor::simcall_blocking(
33 [&observer] { observer.get_sem()->acquire(observer.get_issuer(), observer.get_timeout()); }, &observer);
36 void Semaphore::release()
38 kernel::actor::simcall([this] { pimpl_->release(); });
41 int Semaphore::get_capacity() const
43 return kernel::actor::simcall([this] { return pimpl_->get_capacity(); });
46 bool Semaphore::would_block() const
48 return kernel::actor::simcall([this] { return pimpl_->would_block(); });
51 /* refcounting of the intrusive_ptr is delegated to the implementation object */
52 void intrusive_ptr_add_ref(const Semaphore* sem)
58 void intrusive_ptr_release(const Semaphore* sem)
65 } // namespace simgrid
67 /* **************************** Public C interface *************************** */
68 /** @brief creates a semaphore object of the given initial capacity */
69 sg_sem_t sg_sem_init(int initial_value)
71 return simgrid::s4u::Semaphore::create(initial_value).detach();
74 /** @brief locks on a semaphore object */
75 void sg_sem_acquire(sg_sem_t sem)
80 /** @brief locks on a semaphore object up until the provided timeout expires */
81 int sg_sem_acquire_timeout(sg_sem_t sem, double timeout)
83 return sem->acquire_timeout(timeout);
86 /** @brief releases the semaphore object */
87 void sg_sem_release(sg_sem_t sem)
92 int sg_sem_get_capacity(const_sg_sem_t sem)
94 return sem->get_capacity();
97 void sg_sem_destroy(const_sg_sem_t sem)
99 intrusive_ptr_release(sem);
102 /** @brief returns a boolean indicating if this semaphore would block at this very specific time
104 * Note that the returned value may be wrong right after the function call, when you try to use it...
105 * But that's a classical semaphore issue, and SimGrid's semaphore are not different to usual ones here.
107 int sg_sem_would_block(const_sg_sem_t sem)
109 return sem->would_block();