-/* Copyright (c) 2007-2017. 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/SynchroRaw.hpp"
+#include "src/kernel/activity/Synchro.hpp"
-#include "src/simix/smx_private.hpp"
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(ker_mutex, ker_synchro, "Mutex kernel-space implementation");
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_mutex, simix_synchro, "Mutex kernel-space implementation");
+namespace simgrid::kernel::activity {
-namespace simgrid {
-namespace kernel {
-namespace activity {
+/* -------- Acquisition -------- */
-MutexImpl::MutexImpl() : mutex_(this)
+bool MutexAcquisitionImpl::test(actor::ActorImpl*)
{
- XBT_IN("(%p)", this);
- XBT_OUT();
+ return mutex_->owner_ == issuer_;
}
+void MutexAcquisitionImpl::wait_for(actor::ActorImpl* issuer, double timeout)
+{
+ 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
-MutexImpl::~MutexImpl()
+ if (mutex_->get_owner() == issuer_) { // I'm the owner
+ finish();
+ } else {
+ // Already in the queue
+ }
+}
+
+void MutexAcquisitionImpl::finish()
{
- XBT_IN("(%p)", this);
- XBT_OUT();
+ xbt_assert(simcalls_.size() == 1, "Unexpected number of simcalls waiting: %zu", simcalls_.size());
+ actor::Simcall* simcall = simcalls_.front();
+ simcalls_.pop_front();
+
+ simcall->issuer_->waiting_synchro_ = nullptr;
+ simcall->issuer_->simcall_answer();
}
-void MutexImpl::lock(smx_actor_t issuer)
+/* -------- Mutex -------- */
+
+unsigned MutexImpl::next_id_ = 0;
+
+MutexAcquisitionImplPtr MutexImpl::lock_async(actor::ActorImpl* issuer)
{
- XBT_IN("(%p; %p)", this, issuer);
- /* FIXME: check where to validate the arguments */
- smx_activity_t synchro = nullptr;
-
- if (this->locked) {
- /* FIXME: check if the host is active ? */
- /* Somebody using the mutex, use a synchronization to get host failures */
- synchro = SIMIX_synchro_wait(issuer->host, -1);
- synchro->simcalls.push_back(&issuer->simcall);
- issuer->waiting_synchro = synchro;
- this->sleeping.push_back(*issuer);
- } else {
- /* mutex free */
- this->locked = true;
- this->owner = issuer;
- SIMIX_simcall_answer(&issuer->simcall);
+ /* 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;
}
- XBT_OUT();
+
+ // 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;
}
-/** Tries to lock the mutex for a process
+/** Tries to lock the mutex for a actor
*
- * \param issuer the process that tries to acquire the mutex
- * \return whether we managed to lock the mutex
+ * @param issuer the actor that tries to acquire the mutex
+ * @return whether we managed to lock the mutex
*/
-bool MutexImpl::try_lock(smx_actor_t issuer)
+bool MutexImpl::try_lock(actor::ActorImpl* issuer)
{
- XBT_IN("(%p, %p)", this, issuer);
- if (this->locked) {
- XBT_OUT();
- return false;
+ if (owner_ == issuer && is_recursive_) {
+ recursive_depth++;
+ return true;
}
+ if (owner_ != nullptr)
+ return false;
- this->locked = true;
- this->owner = issuer;
- XBT_OUT();
+ owner_ = issuer;
return true;
}
-/** Unlock a mutex for a process
+/** Unlock a mutex for a actor
*
- * Unlocks the mutex and gives it to a process waiting for it.
+ * Unlocks the mutex and gives it to a actor waiting for it.
* If the unlocker is not the owner of the mutex nothing happens.
- * If there are no process waiting, it sets the mutex as free.
+ * If there are no actor waiting, it sets the mutex as free.
*/
-void MutexImpl::unlock(smx_actor_t issuer)
+void MutexImpl::unlock(actor::ActorImpl* issuer)
{
XBT_IN("(%p, %p)", this, issuer);
- if (not this->locked)
- THROWF(mismatch_error, 0, "Cannot release that mutex: it was not locked.");
-
- /* If the mutex is not owned by the issuer, that's not good */
- if (issuer != this->owner)
- THROWF(mismatch_error, 0, "Cannot release that mutex: it was locked by %s (pid:%ld), not by you.",
- this->owner->get_cname(), this->owner->pid);
-
- if (not this->sleeping.empty()) {
- /*process to wake up */
- smx_actor_t p = &this->sleeping.front();
- this->sleeping.pop_front();
- p->waiting_synchro = nullptr;
- this->owner = p;
- SIMIX_simcall_answer(&p->simcall);
- } else {
- /* nobody to wake up */
- this->locked = false;
- this->owner = nullptr;
- }
- XBT_OUT();
-}
-}
-}
-}
+ 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);
-/** Increase the refcount for this mutex */
-smx_mutex_t SIMIX_mutex_ref(smx_mutex_t mutex)
-{
- if (mutex != nullptr)
- intrusive_ptr_add_ref(mutex);
- return mutex;
-}
-
-/** Decrease the refcount for this mutex */
-void SIMIX_mutex_unref(smx_mutex_t mutex)
-{
- if (mutex != nullptr)
- intrusive_ptr_release(mutex);
-}
+ if (is_recursive_) {
+ recursive_depth--;
+ if (recursive_depth > 0) // Still owning the lock
+ return;
+ }
-// Simcall handlers:
+ if (not ongoing_acquisitions_.empty()) {
+ /* Give the ownership to the first waiting actor */
+ auto acq = ongoing_acquisitions_.front();
+ ongoing_acquisitions_.pop_front();
-void simcall_HANDLER_mutex_lock(smx_simcall_t simcall, smx_mutex_t mutex)
-{
- mutex->lock(simcall->issuer);
-}
+ 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
-int simcall_HANDLER_mutex_trylock(smx_simcall_t simcall, smx_mutex_t mutex)
-{
- return mutex->try_lock(simcall->issuer);
+ } else {
+ /* nobody to wake up */
+ owner_ = nullptr;
+ }
+ XBT_OUT();
}
-void simcall_HANDLER_mutex_unlock(smx_simcall_t simcall, smx_mutex_t mutex)
-{
- mutex->unlock(simcall->issuer);
-}
+} // namespace simgrid::kernel::activity
