1 /* Copyright (c) 2007-2022. 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/MutexImpl.hpp"
7 #include "src/kernel/activity/Synchro.hpp"
9 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(ker_mutex, ker_synchro, "Mutex kernel-space implementation");
15 /* -------- Acquisition -------- */
17 bool MutexAcquisitionImpl::test(actor::ActorImpl*)
19 return mutex_->owner_ == issuer_;
21 void MutexAcquisitionImpl::wait_for(actor::ActorImpl* issuer, double timeout)
23 xbt_assert(mutex_->owner_ != nullptr); // it was locked either by someone else or by me during the lock_async
24 xbt_assert(issuer == issuer_, "Cannot wait on acquisitions created by another actor (id %ld)", issuer_->get_pid());
25 xbt_assert(timeout < 0, "Timeouts on mutex acquisitions are not implemented yet.");
27 this->register_simcall(&issuer_->simcall_); // Block on that acquisition
29 if (mutex_->get_owner() == issuer_) { // I'm the owner
32 // Already in the queue
35 void MutexAcquisitionImpl::finish()
37 xbt_assert(simcalls_.size() == 1, "Unexpected number of simcalls waiting: %zu", simcalls_.size());
38 actor::Simcall* simcall = simcalls_.front();
39 simcalls_.pop_front();
41 simcall->issuer_->waiting_synchro_ = nullptr;
42 simcall->issuer_->simcall_answer();
45 /* -------- Mutex -------- */
47 unsigned MutexImpl::next_id_ = 0;
49 MutexAcquisitionImplPtr MutexImpl::lock_async(actor::ActorImpl* issuer)
51 auto res = MutexAcquisitionImplPtr(new kernel::activity::MutexAcquisitionImpl(issuer, this), true);
53 if (owner_ != nullptr) {
54 /* Somebody is using the mutex; register the acquisition */
55 ongoing_acquisitions_.push_back(res);
62 /** Tries to lock the mutex for a actor
64 * @param issuer the actor that tries to acquire the mutex
65 * @return whether we managed to lock the mutex
67 bool MutexImpl::try_lock(actor::ActorImpl* issuer)
69 XBT_IN("(%p, %p)", this, issuer);
70 if (owner_ != nullptr) {
80 /** Unlock a mutex for a actor
82 * Unlocks the mutex and gives it to a actor waiting for it.
83 * If the unlocker is not the owner of the mutex nothing happens.
84 * If there are no actor waiting, it sets the mutex as free.
86 void MutexImpl::unlock(actor::ActorImpl* issuer)
88 XBT_IN("(%p, %p)", this, issuer);
89 xbt_assert(issuer == owner_, "Cannot release that mutex: you're not the owner. %s is (pid:%ld).",
90 owner_ != nullptr ? owner_->get_cname() : "(nobody)", owner_ != nullptr ? owner_->get_pid() : -1);
92 if (not ongoing_acquisitions_.empty()) {
93 /* Give the ownership to the first waiting actor */
94 auto acq = ongoing_acquisitions_.front();
95 ongoing_acquisitions_.pop_front();
97 owner_ = acq->get_issuer();
98 if (acq == owner_->waiting_synchro_)
100 // else, the issuer is not blocked on this acquisition so no need to release it
103 /* nobody to wake up */
109 } // namespace activity
110 } // namespace kernel
111 } // namespace simgrid