1 /* Copyright (c) 2007-2019. 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/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(ConditionVariable, 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 cond->wait(mutex, timeout, simcall->issuer_);
31 ConditionVariableImpl::ConditionVariableImpl() : cond_(this) {}
32 ConditionVariableImpl::~ConditionVariableImpl() = default;
35 * @brief Signalizes a condition.
37 * Signalizes a condition and wakes up a sleeping process.
38 * If there are no process sleeping, no action is done.
40 void ConditionVariableImpl::signal()
42 XBT_DEBUG("Signal condition %p", this);
44 /* If there are processes waiting for the condition choose one and try
45 to make it acquire the mutex */
46 if (not sleeping_.empty()) {
47 auto& proc = sleeping_.front();
48 sleeping_.pop_front();
50 /* Destroy waiter's synchronization */
51 proc.waiting_synchro = nullptr;
53 /* Now transform the cond wait simcall into a mutex lock one */
54 smx_simcall_t simcall = &proc.simcall;
55 MutexImpl* simcall_mutex;
56 if (simcall->call_ == SIMCALL_COND_WAIT)
57 simcall_mutex = simcall_cond_wait__get__mutex(simcall);
59 simcall_mutex = simcall_cond_wait_timeout__get__mutex(simcall);
60 simcall->call_ = SIMCALL_MUTEX_LOCK;
62 simcall_mutex->lock(simcall->issuer_);
68 * @brief Broadcasts a condition.
70 * Signal ALL processes waiting on a condition.
71 * If there are no process waiting, no action is done.
73 void ConditionVariableImpl::broadcast()
75 XBT_DEBUG("Broadcast condition %p", this);
77 /* Signal the condition until nobody is waiting on it */
78 while (not sleeping_.empty())
82 void ConditionVariableImpl::wait(smx_mutex_t mutex, double timeout, actor::ActorImpl* issuer)
84 XBT_DEBUG("Wait condition %p", this);
86 /* If there is a mutex unlock it */
87 if (mutex != nullptr) {
88 xbt_assert(mutex->owner_ == issuer,
89 "Actor %s cannot wait on ConditionVariable %p since it does not own the provided mutex %p",
90 issuer->get_cname(), this, mutex);
92 mutex->unlock(issuer);
95 RawImplPtr synchro(new RawImpl());
96 synchro->set_host(issuer->get_host()).set_timeout(timeout).start();
97 synchro->register_simcall(&issuer->simcall);
98 sleeping_.push_back(*issuer);
101 // boost::intrusive_ptr<ConditionVariableImpl> support:
102 void intrusive_ptr_add_ref(simgrid::kernel::activity::ConditionVariableImpl* cond)
104 cond->refcount_.fetch_add(1, std::memory_order_relaxed);
107 void intrusive_ptr_release(simgrid::kernel::activity::ConditionVariableImpl* cond)
109 if (cond->refcount_.fetch_sub(1, std::memory_order_release) == 1) {
110 std::atomic_thread_fence(std::memory_order_acquire);
111 xbt_assert(cond->sleeping_.empty(), "Cannot destroy conditional since someone is still using it");
115 } // namespace activity
116 } // namespace kernel
117 } // namespace simgrid