Imported existing code

libraries/include/boost/interprocess/sync/emulation/interprocess_mutex.hpp

@@ -0,0 +1,81 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2005-2008. Distributed under the Boost
+// Software License, Version 1.0. (See accompanying file
+// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/interprocess for documentation.
+//
+//////////////////////////////////////////////////////////////////////////////
+
+#include <boost/interprocess/detail/posix_time_types_wrk.hpp>
+
+namespace boost {
+
+namespace interprocess {
+
+inline interprocess_mutex::interprocess_mutex() 
+   : m_s(0) 
+{
+   //Note that this class is initialized to zero.
+   //So zeroed memory can be interpreted as an
+   //initialized mutex
+}
+
+inline interprocess_mutex::~interprocess_mutex() 
+{
+   //Trivial destructor
+}
+
+inline void interprocess_mutex::lock(void)
+{
+   do{
+      boost::uint32_t prev_s = detail::atomic_cas32(const_cast<boost::uint32_t*>(&m_s), 1, 0);
+
+      if (m_s == 1 && prev_s == 0){
+            break;
+      }
+      // relinquish current timeslice
+      detail::thread_yield();
+   }while (true);
+}
+
+inline bool interprocess_mutex::try_lock(void)
+{
+   boost::uint32_t prev_s = detail::atomic_cas32(const_cast<boost::uint32_t*>(&m_s), 1, 0);   
+   return m_s == 1 && prev_s == 0;
+}
+
+inline bool interprocess_mutex::timed_lock(const boost::posix_time::ptime &abs_time)
+{
+   if(abs_time == boost::posix_time::pos_infin){
+      this->lock();
+      return true;
+   }
+   //Obtain current count and target time
+   boost::posix_time::ptime now = microsec_clock::universal_time();
+
+   if(now >= abs_time) return false;
+
+   do{
+      if(this->try_lock()){
+         break;
+      }
+      now = microsec_clock::universal_time();
+
+      if(now >= abs_time){
+         return false;
+      }
+      // relinquish current time slice
+     detail::thread_yield();
+   }while (true);
+
+   return true;
+}
+
+inline void interprocess_mutex::unlock(void)
+{  detail::atomic_cas32(const_cast<boost::uint32_t*>(&m_s), 0, 1);   }
+
+}  //namespace interprocess {
+
+}  //namespace boost {