X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/2ca35a707044d033c33cb4f016e6ffddfded0d05..783573d576fa9ac43c007c6031bce185d882f92b:/include/simgrid/s4u/Mutex.hpp

diff --git a/include/simgrid/s4u/Mutex.hpp b/include/simgrid/s4u/Mutex.hpp
index 241ae36f91..0d1f2277a0 100644
--- a/include/simgrid/s4u/Mutex.hpp
+++ b/include/simgrid/s4u/Mutex.hpp
@@ -19,14 +19,27 @@ namespace s4u {
 
 class ConditionVariable;
 
+/** @brief A classical mutex, but blocking in the simulation world
+ *  @ingroup s4u_api
+ *
+ * It is strictly impossible to use a real mutex, such as
+ * [std::mutex](http://en.cppreference.com/w/cpp/thread/mutex)
+ * or [pthread_mutex_t](http://pubs.opengroup.org/onlinepubs/007908775/xsh/pthread_mutex_lock.html),
+ * because it would block the whole simulation.
+ * Instead, you should use the present class, that is a drop-in replacement of
+ * [std::mutex](http://en.cppreference.com/w/cpp/thread/mutex).
+ *
+ * As for any S4U object, Mutexes are using the @ref "RAII idiom" s4u_raii for memory management.
+ * Use createMutex() to get a ::MutexPtr to a newly created mutex and only manipulate ::MutexPtr.
+ *
+ */
 XBT_PUBLIC_CLASS Mutex {
-friend ConditionVariable;
-private:
-  friend simgrid::simix::Mutex;
-  simgrid::simix::Mutex* mutex_;
-  Mutex(simgrid::simix::Mutex* mutex) : mutex_(mutex) {}
-public:
+  friend ConditionVariable;
+  friend simgrid::simix::MutexImpl;
+  simgrid::simix::MutexImpl* mutex_;
+  explicit Mutex(simgrid::simix::MutexImpl * mutex) : mutex_(mutex) {}
 
+  /* refcounting of the intrusive_ptr is delegated to the implementation object */
   friend void intrusive_ptr_add_ref(Mutex* mutex)
   {
     xbt_assert(mutex);
@@ -37,15 +50,18 @@ public:
     xbt_assert(mutex);
     SIMIX_mutex_unref(mutex->mutex_);
   }
+public:
   using Ptr = boost::intrusive_ptr<Mutex>;
 
   // No copy:
+  /** You cannot create a new mutex by copying an existing one. Use MutexPtr instead */
   Mutex(Mutex const&) = delete;
+  /** You cannot create a new mutex by value assignment either. Use MutexPtr instead */
   Mutex& operator=(Mutex const&) = delete;
 
+  /** Constructs a new mutex */
   static Ptr createMutex();
 
-public:
   void lock();
   void unlock();
   bool try_lock();