-/* Copyright (c) 2007-2022. The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2007-2023. 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. */
#include "src/kernel/activity/MutexImpl.hpp"
#include "src/kernel/activity/Synchro.hpp"
-#if SIMGRID_HAVE_MC
-#include "simgrid/modelchecker.h"
-#include "src/mc/mc_safety.hpp"
-#define MC_CHECK_NO_DPOR() \
- xbt_assert(not MC_is_active() || mc::reduction_mode != mc::ReductionMode::dpor, \
- "Mutex is currently not supported with DPOR, use --cfg=model-check/reduction:none")
-#else
-#define MC_CHECK_NO_DPOR() (void)0
-#endif
-
XBT_LOG_NEW_DEFAULT_SUBCATEGORY(ker_mutex, ker_synchro, "Mutex kernel-space implementation");
-namespace simgrid {
-namespace kernel {
-namespace activity {
+namespace simgrid::kernel::activity {
+
+/* -------- Acquisition -------- */
bool MutexAcquisitionImpl::test(actor::ActorImpl*)
{
}
void MutexAcquisitionImpl::wait_for(actor::ActorImpl* issuer, double timeout)
{
- xbt_assert(mutex_->locked_); // it was locked either by someone else or by me during the lock_async
- xbt_assert(
- issuer == issuer_,
- "Actors can only wait acquisitions that they created themselves while this one was created by actor id %ld.",
- issuer_->get_pid());
+ xbt_assert(mutex_->owner_ != nullptr); // it was locked either by someone else or by me during the lock_async
+ xbt_assert(issuer == issuer_, "Cannot wait on acquisitions created by another actor (id %ld)", issuer_->get_pid());
xbt_assert(timeout < 0, "Timeouts on mutex acquisitions are not implemented yet.");
this->register_simcall(&issuer_->simcall_); // Block on that acquisition
// Already in the queue
}
}
+
void MutexAcquisitionImpl::finish()
{
xbt_assert(simcalls_.size() == 1, "Unexpected number of simcalls waiting: %zu", simcalls_.size());
- smx_simcall_t simcall = simcalls_.front();
+ actor::Simcall* simcall = simcalls_.front();
simcalls_.pop_front();
simcall->issuer_->waiting_synchro_ = nullptr;
simcall->issuer_->simcall_answer();
}
+/* -------- Mutex -------- */
+
+unsigned MutexImpl::next_id_ = 0;
+
MutexAcquisitionImplPtr MutexImpl::lock_async(actor::ActorImpl* issuer)
{
- auto res = MutexAcquisitionImplPtr(new kernel::activity::MutexAcquisitionImpl(issuer, this), true);
+ /* If the mutex is recursive */
+ if (is_recursive_) {
+ if (owner_ == issuer) {
+ recursive_depth++;
+ auto res = MutexAcquisitionImplPtr(new kernel::activity::MutexAcquisitionImpl(issuer, this), true);
+ res->grant();
+ return res;
+ } else if (owner_ == nullptr) { // Free
+ owner_ = issuer;
+ recursive_depth = 1;
+ auto res = MutexAcquisitionImplPtr(new kernel::activity::MutexAcquisitionImpl(issuer, this), true);
+ res->grant();
+ return res;
+ }
+
+ for (auto acq : ongoing_acquisitions_)
+ if (acq->get_issuer() == issuer) {
+ acq->recursive_depth_++;
+ return acq;
+ }
+
+ // Not yet in the ongoing acquisition list. Get in there
+ auto res = MutexAcquisitionImplPtr(new kernel::activity::MutexAcquisitionImpl(issuer, this), true);
+ ongoing_acquisitions_.push_back(res);
+ return res;
+ }
- if (locked_) {
- /* FIXME: check if the host is active ? */
- /* Somebody using the mutex, use a synchronization to get host failures */
- sleeping_.push_back(res);
- } else {
- locked_ = true;
+ // Non-recursive mutex
+ auto res = MutexAcquisitionImplPtr(new kernel::activity::MutexAcquisitionImpl(issuer, this), true);
+ if (owner_ == nullptr) { // Lock is free, take it
owner_ = issuer;
+ recursive_depth = 1;
+ res->grant();
+ } else { // Somebody is using the mutex; register the acquisition
+ ongoing_acquisitions_.push_back(res);
}
return res;
}
*/
bool MutexImpl::try_lock(actor::ActorImpl* issuer)
{
- XBT_IN("(%p, %p)", this, issuer);
- MC_CHECK_NO_DPOR();
- if (locked_) {
- XBT_OUT();
- return false;
+ if (owner_ == issuer && is_recursive_) {
+ recursive_depth++;
+ return true;
}
+ if (owner_ != nullptr)
+ return false;
- locked_ = true;
- owner_ = issuer;
- XBT_OUT();
+ owner_ = issuer;
return true;
}
void MutexImpl::unlock(actor::ActorImpl* issuer)
{
XBT_IN("(%p, %p)", this, issuer);
- xbt_assert(locked_, "Cannot release that mutex: it was not locked.");
- xbt_assert(issuer == owner_, "Cannot release that mutex: it was locked by %s (pid:%ld), not by you.",
- owner_->get_cname(), owner_->get_pid());
+ xbt_assert(issuer == owner_, "Cannot release that mutex: you're not the owner. %s is (pid:%ld).",
+ owner_ != nullptr ? owner_->get_cname() : "(nobody)", owner_ != nullptr ? owner_->get_pid() : -1);
+
+ if (is_recursive_) {
+ recursive_depth--;
+ if (recursive_depth > 0) // Still owning the lock
+ return;
+ }
- if (not sleeping_.empty()) {
+ if (not ongoing_acquisitions_.empty()) {
/* Give the ownership to the first waiting actor */
- auto acq = sleeping_.front();
- owner_ = acq->get_issuer();
+ auto acq = ongoing_acquisitions_.front();
+ ongoing_acquisitions_.pop_front();
+ owner_ = acq->get_issuer();
+ acq->grant();
+ recursive_depth = acq->recursive_depth_;
if (acq == owner_->waiting_synchro_)
acq->finish();
+ // else, the issuer is not blocked on this acquisition so no need to release it
- sleeping_.pop_front();
} else {
/* nobody to wake up */
- locked_ = false;
owner_ = nullptr;
}
XBT_OUT();
}
-/** Increase the refcount for this mutex */
-MutexImpl* MutexImpl::ref()
-{
- intrusive_ptr_add_ref(this);
- return this;
-}
-
-/** Decrease the refcount for this mutex */
-void MutexImpl::unref()
-{
- intrusive_ptr_release(this);
-}
-} // namespace activity
-} // namespace kernel
-} // namespace simgrid
+} // namespace simgrid::kernel::activity
