-/* Copyright (c) 2019-2020. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2019-2023. The SimGrid Team. All rights reserved. */
/* 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. */
-#ifndef SIMGRID_KERNEL_ACTIVITY_SEMAPHORE_HPP
-#define SIMGRID_KERNEL_ACTIVITY_SEMAPHORE_HPP
+#ifndef SIMGRID_KERNEL_ACTIVITY_SEMAPHOREIMPL_HPP
+#define SIMGRID_KERNEL_ACTIVITY_SEMAPHOREIMPL_HPP
+
+#include "simgrid/s4u/Semaphore.hpp"
+#include "src/kernel/actor/ActorImpl.hpp"
+#include "src/kernel/actor/SynchroObserver.hpp"
#include <atomic>
#include <boost/intrusive/list.hpp>
-#include "simgrid/s4u/Semaphore.hpp"
-#include "src/kernel/actor/ActorImpl.hpp"
+namespace simgrid::kernel::activity {
+
+/** Semaphore Acquisition: the act / process of acquiring the semaphore.
+ *
+ * You can declare some interest on a semaphore without being blocked waiting if it's already empty.
+ * See the documentation of the MutexAcquisitionImpl for further details.
+ */
+class XBT_PUBLIC SemAcquisitionImpl : public ActivityImpl_T<SemAcquisitionImpl> {
+ actor::ActorImpl* issuer_ = nullptr;
+ SemaphoreImpl* semaphore_ = nullptr;
+ bool granted_ = false;
+
+ friend SemaphoreImpl;
+ friend actor::SemaphoreAcquisitionObserver;
-namespace simgrid {
-namespace kernel {
-namespace activity {
+public:
+ SemAcquisitionImpl(actor::ActorImpl* issuer, SemaphoreImpl* sem) : issuer_(issuer), semaphore_(sem) {}
+ SemaphoreImplPtr get_semaphore() { return semaphore_; }
+ actor::ActorImpl* get_issuer() { return issuer_; }
+
+ bool test(actor::ActorImpl* issuer = nullptr) override { return granted_; }
+ void wait_for(actor::ActorImpl* issuer, double timeout) override;
+ void finish() override;
+ void cancel() override;
+ void set_exception(actor::ActorImpl* issuer) override
+ { /* nothing to do */
+ }
+};
class XBT_PUBLIC SemaphoreImpl {
std::atomic_int_fast32_t refcount_{1};
+ s4u::Semaphore piface_;
unsigned int value_;
+ std::deque<SemAcquisitionImplPtr> ongoing_acquisitions_;
-public:
- actor::SynchroList sleeping_; /* list of sleeping actors*/
+ static unsigned next_id_;
+ const unsigned id_ = next_id_++;
+
+ friend SemAcquisitionImpl;
+ friend actor::SemaphoreObserver;
- explicit SemaphoreImpl(unsigned int value) : value_(value){};
- ~SemaphoreImpl() = default;
+public:
+ explicit SemaphoreImpl(unsigned int value) : piface_(this), value_(value){};
SemaphoreImpl(SemaphoreImpl const&) = delete;
SemaphoreImpl& operator=(SemaphoreImpl const&) = delete;
- void acquire(actor::ActorImpl* issuer, double timeout);
+ SemAcquisitionImplPtr acquire_async(actor::ActorImpl* issuer);
void release();
- bool would_block() { return (value_ == 0); }
+ bool would_block() const { return (value_ == 0); }
- unsigned int get_capacity() { return value_; }
+ unsigned int get_capacity() const { return value_; }
+ bool is_used() const { return not ongoing_acquisitions_.empty(); }
friend void intrusive_ptr_add_ref(SemaphoreImpl* sem)
{
}
friend void intrusive_ptr_release(SemaphoreImpl* sem)
{
- if (sem->refcount_.fetch_sub(1) == 1)
+ if (sem->refcount_.fetch_sub(1) == 1) {
+ xbt_assert(not sem->is_used(), "Cannot destroy semaphore since someone is still using it");
delete sem;
+ }
}
+ unsigned get_id() const { return id_; }
+ s4u::Semaphore& sem() { return piface_; }
};
-} // namespace activity
-} // namespace kernel
-} // namespace simgrid
+} // namespace simgrid::kernel::activity
-#endif /* SIMGRID_KERNEL_ACTIVITY_SEMAPHOREIMPL_HPP_ */
+#endif /* SIMGRID_KERNEL_ACTIVITY_SEMAPHOREIMPL_HPP */