/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
+#include <simgrid/Exception.hpp>
+#include <simgrid/s4u/Host.hpp>
+
#include "src/kernel/activity/SemaphoreImpl.hpp"
#include "src/kernel/activity/Synchro.hpp"
#include "src/kernel/actor/SimcallObserver.hpp"
+#include "src/kernel/resource/CpuImpl.hpp"
+
#include <cmath> // std::isfinite
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(ker_semaphore, ker_synchro, "Semaphore kernel-space implementation");
namespace kernel {
namespace activity {
-void SemaphoreImpl::acquire(actor::ActorImpl* issuer, double timeout)
+void SemAcquisitionImpl::wait_for(actor::ActorImpl* issuer, double timeout)
{
- XBT_DEBUG("Wait semaphore %p (timeout:%f)", this, timeout);
xbt_assert(std::isfinite(timeout), "timeout is not finite!");
+ xbt_assert(issuer == issuer_, "Cannot wait on acquisitions created by another actor (id %ld)", issuer_->get_pid());
+
+ XBT_DEBUG("Wait semaphore %p (timeout:%f)", this, timeout);
+
+ this->register_simcall(&issuer_->simcall_); // Block on that acquisition
+
+ if (granted_) {
+ post();
+ } else if (timeout > 0) {
+ surf_action_ = get_issuer()->get_host()->get_cpu()->sleep(timeout);
+ surf_action_->set_activity(this);
+
+ } else {
+ // Already in the queue
+ }
+}
+void SemAcquisitionImpl::post()
+{
+ finish();
+}
+void SemAcquisitionImpl::finish()
+{
+ xbt_assert(simcalls_.size() == 1, "Unexpected number of simcalls waiting: %zu", simcalls_.size());
+ smx_simcall_t simcall = simcalls_.front();
+ simcalls_.pop_front();
+
+ if (surf_action_ != nullptr) { // A timeout was declared
+ if (surf_action_->get_state() == resource::Action::State::FINISHED) { // The timeout elapsed
+ if (granted_) { // but we got the semaphore, just in time!
+ set_state(State::DONE);
+
+ } else { // we have to report that timeout
+ /* Remove myself from the list of interested parties */
+ auto issuer = get_issuer();
+ auto it = std::find_if(semaphore_->sleeping_.begin(), semaphore_->sleeping_.end(),
+ [issuer](SemAcquisitionImplPtr acqui) { return acqui->get_issuer() == issuer; });
+ xbt_assert(it != semaphore_->sleeping_.end(), "Cannot find myself in the waiting queue that I have to leave");
+ semaphore_->sleeping_.erase(it);
+
+ /* Return to the englobing simcall that the wait_for timeouted */
+ auto* observer = dynamic_cast<kernel::actor::SemAcquireSimcall*>(issuer->simcall_.observer_);
+ xbt_assert(observer != nullptr);
+ observer->set_result(true);
+ }
+ }
+ surf_action_->unref();
+ }
+
+ simcall->issuer_->waiting_synchro_ = nullptr;
+ simcall->issuer_->simcall_answer();
+}
+
+SemAcquisitionImplPtr SemaphoreImpl::acquire_async(actor::ActorImpl* issuer)
+{
+ auto res = SemAcquisitionImplPtr(new kernel::activity::SemAcquisitionImpl(issuer, this), true);
if (value_ <= 0) {
- SynchroImplPtr synchro(new SynchroImpl([this, issuer]() {
- this->remove_sleeping_actor(*issuer);
- auto* observer = dynamic_cast<kernel::actor::SemAcquireSimcall*>(issuer->simcall_.observer_);
- xbt_assert(observer != nullptr);
- observer->set_result(true);
- }));
- synchro->set_host(issuer->get_host()).set_timeout(timeout).start();
- synchro->register_simcall(&issuer->simcall_);
- sleeping_.push_back(*issuer);
+ /* No free token in the semaphore; register the acquisition */
+ sleeping_.push_back(res);
} else {
value_--;
- issuer->simcall_answer();
+ res->granted_ = true;
}
+ return res;
}
void SemaphoreImpl::release()
{
XBT_DEBUG("Sem release semaphore %p", this);
if (not sleeping_.empty()) {
- auto& actor = sleeping_.front();
+ /* Release the first waiting actor */
+
+ auto acqui = sleeping_.front();
sleeping_.pop_front();
- actor.waiting_synchro_ = nullptr;
- actor.simcall_answer();
+
+ acqui->granted_ = true;
+ if (acqui == acqui->get_issuer()->waiting_synchro_)
+ acqui->post();
+ // else, the issuer is not blocked on this acquisition so no need to release it
+
} else {
+ // nobody's waiting here
value_++;
}
}
