1 /* Copyright (c) 2007-2021. 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 "src/kernel/activity/ConditionVariableImpl.hpp"
7 #include "simgrid/Exception.hpp"
8 #include "src/kernel/activity/MutexImpl.hpp"
9 #include "src/kernel/activity/SynchroRaw.hpp"
11 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_condition, simix_synchro, "Condition variables");
13 /********************************* Condition **********************************/
15 /** @brief Handle a condition waiting simcall without timeouts */
16 void simcall_HANDLER_cond_wait(smx_simcall_t simcall, smx_cond_t cond, smx_mutex_t mutex)
18 cond->wait(mutex, -1, simcall->issuer_);
21 /** @brief Handle a condition waiting simcall with timeouts */
22 void simcall_HANDLER_cond_wait_timeout(smx_simcall_t simcall, smx_cond_t cond, smx_mutex_t mutex, double timeout)
24 simcall_cond_wait_timeout__set__result(simcall, 0); // default result, will be set to 1 on timeout
25 cond->wait(mutex, timeout, simcall->issuer_);
33 * @brief Signalizes a condition.
35 * Signalizes a condition and wakes up a sleeping process.
36 * If there are no process sleeping, no action is done.
38 void ConditionVariableImpl::signal()
40 XBT_DEBUG("Signal condition %p", this);
42 /* If there are processes waiting for the condition choose one and try
43 to make it acquire the mutex */
44 if (not sleeping_.empty()) {
45 auto& proc = sleeping_.front();
46 sleeping_.pop_front();
48 /* Destroy waiter's synchronization */
49 proc.waiting_synchro_ = nullptr;
51 /* Now transform the cond wait simcall into a mutex lock one */
52 smx_simcall_t simcall = &proc.simcall_;
53 MutexImpl* simcall_mutex;
54 if (simcall->call_ == simix::Simcall::COND_WAIT)
55 simcall_mutex = simcall_cond_wait__get__mutex(simcall);
57 simcall_mutex = simcall_cond_wait_timeout__get__mutex(simcall);
58 simcall->call_ = simix::Simcall::MUTEX_LOCK;
60 simcall_mutex->lock(simcall->issuer_);
66 * @brief Broadcasts a condition.
68 * Signal ALL processes waiting on a condition.
69 * If there are no process waiting, no action is done.
71 void ConditionVariableImpl::broadcast()
73 XBT_DEBUG("Broadcast condition %p", this);
75 /* Signal the condition until nobody is waiting on it */
76 while (not sleeping_.empty())
80 void ConditionVariableImpl::wait(smx_mutex_t mutex, double timeout, actor::ActorImpl* issuer)
82 XBT_DEBUG("Wait condition %p", this);
84 /* If there is a mutex unlock it */
85 if (mutex != nullptr) {
86 xbt_assert(mutex->get_owner() == issuer,
87 "Actor %s cannot wait on ConditionVariable %p since it does not own the provided mutex %p",
88 issuer->get_cname(), this, mutex);
90 mutex->unlock(issuer);
93 RawImplPtr synchro(new RawImpl());
94 synchro->set_host(issuer->get_host()).set_timeout(timeout).start();
95 synchro->register_simcall(&issuer->simcall_);
96 sleeping_.push_back(*issuer);
99 // boost::intrusive_ptr<ConditionVariableImpl> support:
100 void intrusive_ptr_add_ref(simgrid::kernel::activity::ConditionVariableImpl* cond)
102 cond->refcount_.fetch_add(1, std::memory_order_relaxed);
105 void intrusive_ptr_release(simgrid::kernel::activity::ConditionVariableImpl* cond)
107 if (cond->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
108 std::atomic_thread_fence(std::memory_order_acquire);
109 xbt_assert(cond->sleeping_.empty(), "Cannot destroy conditional since someone is still using it");
113 } // namespace activity
114 } // namespace kernel
115 } // namespace simgrid