From 63d238ad4d74226fae3321cb5c128f03160dacb2 Mon Sep 17 00:00:00 2001
From: Martin Quinson <martin.quinson@ens-rennes.fr>
Date: Mon, 13 Nov 2023 00:55:37 +0100
Subject: [PATCH] Check in the right location that a mutex is provided to
 cond_wait

---
 src/kernel/activity/ConditionVariableImpl.cpp | 18 ++++++++----------
 src/kernel/activity/MutexImpl.cpp             |  2 +-
 src/kernel/actor/SynchroObserver.hpp          |  1 +
 3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/kernel/activity/ConditionVariableImpl.cpp b/src/kernel/activity/ConditionVariableImpl.cpp
index fdc23b405b..ec3fb6ae52 100644
--- a/src/kernel/activity/ConditionVariableImpl.cpp
+++ b/src/kernel/activity/ConditionVariableImpl.cpp
@@ -62,16 +62,14 @@ void ConditionVariableImpl::wait(MutexImpl* mutex, double timeout, actor::ActorI
   XBT_DEBUG("Wait condition %p", this);
   xbt_assert(std::isfinite(timeout), "timeout is not finite!");
 
-  /* If there is a mutex unlock it */
-  if (mutex != nullptr) {
-    auto* owner = mutex->get_owner();
-    xbt_assert(owner == issuer,
-               "Actor %s cannot wait on ConditionVariable %p since it does not own the provided mutex %p (which is "
-               "owned by %s).",
-               issuer->get_cname(), this, mutex, (owner == nullptr ? "nobody" : owner->get_cname()));
-    mutex_ = mutex;
-    mutex->unlock(issuer);
-  }
+  /* Unlock the provided mutex (the simcall observer ensures that one is provided, no need to check) */
+  auto* owner = mutex->get_owner();
+  xbt_assert(owner == issuer,
+             "Actor %s cannot wait on ConditionVariable %p since it does not own the provided mutex %p (which is "
+             "owned by %s).",
+             issuer->get_cname(), this, mutex, (owner == nullptr ? "nobody" : owner->get_cname()));
+  mutex_ = mutex;
+  mutex->unlock(issuer);
 
   SynchroImplPtr synchro(new SynchroImpl([this, issuer]() {
     this->remove_sleeping_actor(*issuer);
diff --git a/src/kernel/activity/MutexImpl.cpp b/src/kernel/activity/MutexImpl.cpp
index c981c3ee76..cac3e9524d 100644
--- a/src/kernel/activity/MutexImpl.cpp
+++ b/src/kernel/activity/MutexImpl.cpp
@@ -74,7 +74,7 @@ MutexAcquisitionImplPtr MutexImpl::lock_async(actor::ActorImpl* issuer)
     return res;
   }
 
-  // None-recursive mutex
+  // Non-recursive mutex
   auto res = MutexAcquisitionImplPtr(new kernel::activity::MutexAcquisitionImpl(issuer, this), true);
   if (owner_ == nullptr) { // Lock is free, take it
     owner_  = issuer;
diff --git a/src/kernel/actor/SynchroObserver.hpp b/src/kernel/actor/SynchroObserver.hpp
index dc10e63afe..b2bfd31fe8 100644
--- a/src/kernel/actor/SynchroObserver.hpp
+++ b/src/kernel/actor/SynchroObserver.hpp
@@ -92,6 +92,7 @@ public:
                             double timeout = -1.0)
       : ResultingSimcall(actor, false), cond_(cond), mutex_(mutex), timeout_(timeout)
   {
+    xbt_assert(mutex != nullptr, "Cannot wait on a condition variable without a valid mutex");
   }
   void serialize(std::stringstream& stream) const override;
   std::string to_string() const override;
-- 
2.20.1