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"
10 #include "src/mc/checker/SimcallObserver.hpp"
12 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_condition, simix_synchro, "Condition variables");
14 /********************************* Condition **********************************/
16 /** @brief Handle a condition waiting simcall with timeouts */
17 void simcall_HANDLER_cond_wait_timeout(smx_simcall_t simcall, smx_cond_t cond, smx_mutex_t mutex, double timeout)
19 simcall_cond_wait_timeout__set__result(simcall, 0); // default result, will be set to 1 on timeout
20 cond->wait(mutex, timeout, simcall->issuer_);
28 * @brief Signalizes a condition.
30 * Signalizes a condition and wakes up a sleeping process.
31 * If there are no process sleeping, no action is done.
33 void ConditionVariableImpl::signal()
35 XBT_DEBUG("Signal condition %p", this);
37 /* If there are processes waiting for the condition choose one and try
38 to make it acquire the mutex */
39 if (not sleeping_.empty()) {
40 auto& proc = sleeping_.front();
41 sleeping_.pop_front();
43 /* Destroy waiter's synchronization */
44 proc.waiting_synchro_ = nullptr;
46 /* Now transform the cond wait simcall into a mutex lock one */
47 smx_simcall_t simcall = &proc.simcall_;
48 MutexImpl* simcall_mutex;
49 if (simcall->call_ == simix::Simcall::COND_WAIT_TIMEOUT)
50 simcall_mutex = simcall_cond_wait_timeout__get__mutex(simcall);
52 // FIXME? using here the MC observer to solve a problem not related to MC
53 const auto* observer = dynamic_cast<mc::ConditionWaitSimcall*>(simcall->observer_);
54 xbt_assert(observer != nullptr);
55 simcall_mutex = observer->get_mutex();
57 simcall->call_ = simix::Simcall::RUN_BLOCKING;
59 simcall_mutex->lock(simcall->issuer_);
65 * @brief Broadcasts a condition.
67 * Signal ALL processes waiting on a condition.
68 * If there are no process waiting, no action is done.
70 void ConditionVariableImpl::broadcast()
72 XBT_DEBUG("Broadcast condition %p", this);
74 /* Signal the condition until nobody is waiting on it */
75 while (not sleeping_.empty())
79 void ConditionVariableImpl::wait(smx_mutex_t mutex, double timeout, actor::ActorImpl* issuer)
81 XBT_DEBUG("Wait condition %p", this);
83 /* If there is a mutex unlock it */
84 if (mutex != nullptr) {
85 xbt_assert(mutex->get_owner() == issuer,
86 "Actor %s cannot wait on ConditionVariable %p since it does not own the provided mutex %p",
87 issuer->get_cname(), this, mutex);
89 mutex->unlock(issuer);
92 RawImplPtr synchro(new RawImpl([this, issuer]() {
93 this->remove_sleeping_actor(*issuer);
94 if (issuer->simcall_.call_ == simix::Simcall::COND_WAIT_TIMEOUT)
95 simcall_cond_wait_timeout__set__result(&issuer->simcall_, 1);
97 synchro->set_host(issuer->get_host()).set_timeout(timeout).start();
98 synchro->register_simcall(&issuer->simcall_);
99 sleeping_.push_back(*issuer);
102 // boost::intrusive_ptr<ConditionVariableImpl> support:
103 void intrusive_ptr_add_ref(simgrid::kernel::activity::ConditionVariableImpl* cond)
105 cond->refcount_.fetch_add(1, std::memory_order_relaxed);
108 void intrusive_ptr_release(simgrid::kernel::activity::ConditionVariableImpl* cond)
110 if (cond->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
111 std::atomic_thread_fence(std::memory_order_acquire);
112 xbt_assert(cond->sleeping_.empty(), "Cannot destroy conditional since someone is still using it");
116 } // namespace activity
117 } // namespace kernel
118 } // namespace simgrid