1 /* Copyright (c) 2018-2019. 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 "src/msg/msg_private.hpp"
9 #include "simgrid/forward.h"
10 #include "simgrid/s4u/Semaphore.hpp"
11 #include "src/kernel/activity/SemaphoreImpl.hpp"
16 Semaphore::Semaphore(unsigned int initial_capacity)
18 sem_ = kernel::actor::simcall([initial_capacity] { return new kernel::activity::SemaphoreImpl(initial_capacity); });
21 Semaphore::~Semaphore()
23 if (sem_ != nullptr) {
24 xbt_assert(sem_->sleeping_.empty(), "Cannot destroy semaphore since someone is still using it");
29 SemaphorePtr Semaphore::create(unsigned int initial_capacity)
31 return SemaphorePtr(new Semaphore(initial_capacity));
34 void Semaphore::acquire()
36 simcall_sem_acquire(sem_);
39 int Semaphore::acquire_timeout(double timeout)
41 return simcall_sem_acquire_timeout(sem_, timeout);
44 void Semaphore::release()
46 kernel::actor::simcall([this] { sem_->release(); });
49 int Semaphore::get_capacity()
51 return kernel::actor::simcall([this] { return sem_->get_capacity(); });
54 int Semaphore::would_block()
56 return kernel::actor::simcall([this] { return sem_->would_block(); });
59 void intrusive_ptr_add_ref(Semaphore* sem)
62 sem->refcount_.fetch_add(1, std::memory_order_relaxed);
65 void intrusive_ptr_release(Semaphore* sem)
68 if (sem->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
69 std::atomic_thread_fence(std::memory_order_acquire);
75 } // namespace simgrid
77 /* **************************** Public C interface *************************** */
78 /** @brief creates a semaphore object of the given initial capacity */
79 sg_sem_t sg_sem_init(int initial_value)
81 return new simgrid::s4u::Semaphore(initial_value);
84 /** @brief locks on a semaphore object */
85 void sg_sem_acquire(sg_sem_t sem)
90 /** @brief locks on a semaphore object up until the provided timeout expires */
91 int sg_sem_acquire_timeout(sg_sem_t sem, double timeout)
93 return sem->acquire_timeout(timeout);
96 /** @brief releases the semaphore object */
97 void sg_sem_release(sg_sem_t sem)
102 int sg_sem_get_capacity(sg_sem_t sem)
104 return sem->get_capacity();
107 void sg_sem_destroy(sg_sem_t sem)
112 /** @brief returns a boolean indicating if this semaphore would block at this very specific time
114 * Note that the returned value may be wrong right after the function call, when you try to use it...
115 * But that's a classical semaphore issue, and SimGrid's semaphore are not different to usual ones here.
117 int sg_sem_would_block(sg_sem_t sem)
119 return sem->would_block();