X-Git-Url: http://bilbo.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/ea74f5d95928a521a588737e81f1de94eef25d19..63d238ad4d74226fae3321cb5c128f03160dacb2:/src/kernel/activity/MutexImpl.cpp

diff --git a/src/kernel/activity/MutexImpl.cpp b/src/kernel/activity/MutexImpl.cpp
index 660d77cfe4..cac3e9524d 100644
--- a/src/kernel/activity/MutexImpl.cpp
+++ b/src/kernel/activity/MutexImpl.cpp
@@ -1,46 +1,89 @@
-/* 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/SynchroRaw.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
+#include "src/kernel/activity/Synchro.hpp"
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(ker_mutex, ker_synchro, "Mutex kernel-space implementation");
 
-namespace simgrid {
-namespace kernel {
-namespace activity {
+namespace simgrid::kernel::activity {
 
-void MutexImpl::lock(actor::ActorImpl* issuer)
+/* -------- Acquisition -------- */
+
+bool MutexAcquisitionImpl::test(actor::ActorImpl*)
+{
+  return mutex_->owner_ == issuer_;
+}
+void MutexAcquisitionImpl::wait_for(actor::ActorImpl* issuer, double timeout)
 {
-  XBT_IN("(%p; %p)", this, issuer);
-  MC_CHECK_NO_DPOR();
-
-  if (locked_) {
-    /* FIXME: check if the host is active ? */
-    /* Somebody using the mutex, use a synchronization to get host failures */
-    RawImplPtr synchro(new RawImpl([this, issuer]() { this->remove_sleeping_actor(*issuer); }));
-    (*synchro).set_host(issuer->get_host()).start();
-    synchro->register_simcall(&issuer->simcall_);
-    sleeping_.push_back(*issuer);
+  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
+
+  if (mutex_->get_owner() == issuer_) { // I'm the owner
+    finish();
   } else {
-    /* mutex free */
-    locked_ = true;
+    // Already in the queue
+  }
+}
+
+void MutexAcquisitionImpl::finish()
+{
+  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();
+}
+
+/* -------- Mutex -------- */
+
+unsigned MutexImpl::next_id_ = 0;
+
+MutexAcquisitionImplPtr MutexImpl::lock_async(actor::ActorImpl* issuer)
+{
+  /* 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;
+  }
+
+  // Non-recursive mutex
+  auto res = MutexAcquisitionImplPtr(new kernel::activity::MutexAcquisitionImpl(issuer, this), true);
+  if (owner_ == nullptr) { // Lock is free, take it
     owner_  = issuer;
-    issuer->simcall_answer();
+    recursive_depth = 1;
+    res->grant();
+  } else { // Somebody is using the mutex; register the acquisition
+    ongoing_acquisitions_.push_back(res);
   }
-  XBT_OUT();
+  return res;
 }
 
 /** Tries to lock the mutex for a actor
@@ -50,16 +93,14 @@ void MutexImpl::lock(actor::ActorImpl* issuer)
  */
 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;
 }
 
@@ -72,36 +113,32 @@ bool MutexImpl::try_lock(actor::ActorImpl* issuer)
 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 */
-    owner_ = &sleeping_.front();
-    sleeping_.pop_front();
-    owner_->waiting_synchro_ = nullptr;
-    owner_->simcall_answer();
+    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
+
   } 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