comparison DEPENDENCIES/generic/include/boost/interprocess/detail/intermodule_singleton_common.hpp @ 16:2665513ce2d3

Add boost headers

+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2009-2012. 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.
+//
+//////////////////////////////////////////////////////////////////////////////
+
+#ifndef BOOST_INTERPROCESS_INTERMODULE_SINGLETON_COMMON_HPP
+#define BOOST_INTERPROCESS_INTERMODULE_SINGLETON_COMMON_HPP
+
+#if defined(_MSC_VER)&&(_MSC_VER>=1200)
+#pragma once
+#endif
+
+#include <boost/interprocess/detail/config_begin.hpp>
+#include <boost/interprocess/detail/workaround.hpp>
+
+#include <boost/interprocess/detail/atomic.hpp>
+#include <boost/interprocess/detail/os_thread_functions.hpp>
+#include <boost/interprocess/exceptions.hpp>
+#include <boost/type_traits/type_with_alignment.hpp>
+#include <boost/interprocess/detail/mpl.hpp>
+#include <boost/interprocess/sync/spin/wait.hpp>
+#include <boost/assert.hpp>
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <string>
+#include <sstream>
+
+namespace boost{
+namespace interprocess{
+namespace ipcdetail{
+
+namespace intermodule_singleton_helpers {
+
+inline void get_pid_creation_time_str(std::string &s)
+{
+   std::stringstream stream;
+   stream << get_current_process_id() << '_';
+   stream.precision(6);
+   stream << std::fixed << get_current_process_creation_time();
+   s = stream.str();
+}
+
+inline const char *get_map_base_name()
+{  return "bip.gmem.map.";  }
+
+inline void get_map_name(std::string &map_name)
+{
+   get_pid_creation_time_str(map_name);
+   map_name.insert(0, get_map_base_name());
+}
+
+inline std::size_t get_map_size()
+{  return 65536;  }
+
+template<class ThreadSafeGlobalMap>
+struct thread_safe_global_map_dependant;
+
+}  //namespace intermodule_singleton_helpers {
+
+//This class contains common code for all singleton types, so that we instantiate this
+//code just once per module. This class also holds a thread soafe global map
+//to be used by all instances protected with a reference count
+template<class ThreadSafeGlobalMap>
+class intermodule_singleton_common
+{
+   public:
+   typedef void*(singleton_constructor_t)(ThreadSafeGlobalMap &);
+   typedef void (singleton_destructor_t)(void *, ThreadSafeGlobalMap &);
+
+   static const ::boost::uint32_t Uninitialized       = 0u;
+   static const ::boost::uint32_t Initializing        = 1u;
+   static const ::boost::uint32_t Initialized         = 2u;
+   static const ::boost::uint32_t Broken              = 3u;
+   static const ::boost::uint32_t Destroyed           = 4u;
+
+   //Initialize this_module_singleton_ptr, creates the global map if needed and also creates an unique
+   //opaque type in global map through a singleton_constructor_t function call,
+   //initializing the passed pointer to that unique instance.
+   //
+   //We have two concurrency types here. a)the global map/singleton creation must
+   //be safe between threads of this process but in different modules/dlls. b)
+   //the pointer to the singleton is per-module, so we have to protect this
+   //initization between threads of the same module.
+   //
+   //All static variables declared here are shared between inside a module
+   //so atomic operations will synchronize only threads of the same module.
+   static void initialize_singleton_logic
+      (void *&ptr, volatile boost::uint32_t &this_module_singleton_initialized, singleton_constructor_t constructor, bool phoenix)
+   {
+      //If current module is not initialized enter to lock free logic
+      if(atomic_read32(&this_module_singleton_initialized) != Initialized){
+         //Now a single thread of the module will succeed in this CAS.
+         //trying to pass from Uninitialized to Initializing
+         ::boost::uint32_t previous_module_singleton_initialized = atomic_cas32
+            (&this_module_singleton_initialized, Initializing, Uninitialized);
+         //If the thread succeeded the CAS (winner) it will compete with other
+         //winner threads from other modules to create the global map
+         if(previous_module_singleton_initialized == Destroyed){
+            //Trying to resurrect a dead Phoenix singleton. Just try to
+            //mark it as uninitialized and start again
+            if(phoenix){
+               atomic_cas32(&this_module_singleton_initialized, Uninitialized, Destroyed);
+               previous_module_singleton_initialized = atomic_cas32
+                  (&this_module_singleton_initialized, Initializing, Uninitialized);
+            }
+            //Trying to resurrect a non-Phoenix dead singleton is an error
+            else{
+               throw interprocess_exception("Boost.Interprocess: Dead reference on non-Phoenix singleton of type");
+            }
+         }
+         if(previous_module_singleton_initialized == Uninitialized){
+            try{
+               //Now initialize the global map, this function must solve concurrency
+               //issues between threads of several modules
+               initialize_global_map_handle();
+               //Now try to create the singleton in global map.
+               //This function solves concurrency issues
+               //between threads of several modules
+               void *tmp = constructor(get_map());
+               //Increment the module reference count that reflects how many
+               //singletons this module holds, so that we can safely destroy
+               //module global map object when no singleton is left
+               atomic_inc32(&this_module_singleton_count);
+               //Insert a barrier before assigning the pointer to
+               //make sure this assignment comes after the initialization
+               atomic_write32(&this_module_singleton_initialized, Initializing);
+               //Assign the singleton address to the module-local pointer
+               ptr = tmp;
+               //Memory barrier inserted, all previous operations should complete
+               //before this one. Now marked as initialized
+               atomic_write32(&this_module_singleton_initialized, Initialized);
+            }
+            catch(...){
+               //Mark singleton failed to initialize
+               atomic_write32(&this_module_singleton_initialized, Broken);
+               throw;
+            }
+         }
+         //If previous state was initializing, this means that another winner thread is
+         //trying to initialize the singleton. Just wait until completes its work.
+         else if(previous_module_singleton_initialized == Initializing){
+            spin_wait swait;
+            while(1){
+               previous_module_singleton_initialized = atomic_read32(&this_module_singleton_initialized);
+               if(previous_module_singleton_initialized >= Initialized){
+                  //Already initialized, or exception thrown by initializer thread
+                  break;
+               }
+               else if(previous_module_singleton_initialized == Initializing){
+                  swait.yield();
+               }
+               else{
+                  //This can't be happening!
+                  BOOST_ASSERT(0);
+               }
+            }
+         }
+         else if(previous_module_singleton_initialized == Initialized){
+            //Nothing to do here, the singleton is ready
+         }
+         //If previous state was greater than initialized, then memory is broken
+         //trying to initialize the singleton.
+         else{//(previous_module_singleton_initialized > Initialized)
+            throw interprocess_exception("boost::interprocess::intermodule_singleton initialization failed");
+         }
+      }
+      BOOST_ASSERT(ptr != 0);
+   }
+
+   static void finalize_singleton_logic(void *&ptr, volatile boost::uint32_t &this_module_singleton_initialized, singleton_destructor_t destructor)
+   {
+      //Protect destruction against lazy singletons not initialized in this execution
+      if(ptr){
+         //Note: this destructor might provoke a Phoenix singleton
+         //resurrection. This means that this_module_singleton_count
+         //might change after this call.
+         destructor(ptr, get_map());
+         ptr = 0;
+
+         //Memory barrier to make sure pointer is nulled.
+         //Mark this singleton as destroyed.
+         atomic_write32(&this_module_singleton_initialized, Destroyed);
+
+         //If this is the last singleton of this module
+         //apply map destruction.
+         //Note: singletons are destroyed when the module is unloaded
+         //so no threads should be executing or holding references
+         //to this module
+         if(1 == atomic_dec32(&this_module_singleton_count)){
+            destroy_global_map_handle();
+         }
+      }
+   }
+
+   private:
+   static ThreadSafeGlobalMap &get_map()
+   {
+      return *static_cast<ThreadSafeGlobalMap *>(static_cast<void *>(&mem_holder.map_mem[0]));
+   }
+
+   static void initialize_global_map_handle()
+   {
+      //Obtain unique map name and size
+      spin_wait swait;
+      while(1){
+         //Try to pass map state to initializing
+         ::boost::uint32_t tmp = atomic_cas32(&this_module_map_initialized, Initializing, Uninitialized);
+         if(tmp == Initialized || tmp == Broken){
+            break;
+         }
+         else if(tmp == Destroyed){
+            tmp = atomic_cas32(&this_module_map_initialized, Uninitialized, Destroyed);
+            continue;
+         }
+         //If some other thread is doing the work wait
+         else if(tmp == Initializing){
+            swait.yield();
+         }
+         else{ //(tmp == Uninitialized)
+            //If not initialized try it again?
+            try{
+               //Remove old global map from the system
+               intermodule_singleton_helpers::thread_safe_global_map_dependant<ThreadSafeGlobalMap>::remove_old_gmem();
+               //in-place construction of the global map class
+               intermodule_singleton_helpers::thread_safe_global_map_dependant
+                  <ThreadSafeGlobalMap>::construct_map(static_cast<void*>(&get_map()));
+               //Use global map's internal lock to initialize the lock file
+               //that will mark this gmem as "in use".
+               typename intermodule_singleton_helpers::thread_safe_global_map_dependant<ThreadSafeGlobalMap>::
+                  lock_file_logic f(get_map());
+               //If function failed (maybe a competing process has erased the shared
+               //memory between creation and file locking), retry with a new instance.
+               if(f.retry()){
+                  get_map().~ThreadSafeGlobalMap();
+                  atomic_write32(&this_module_map_initialized, Destroyed);
+               }
+               else{
+                  //Locking succeeded, so this global map module-instance is ready
+                  atomic_write32(&this_module_map_initialized, Initialized);
+                  break;
+               }
+            }
+            catch(...){
+               //
+               throw;
+            }
+         }
+      }
+   }
+
+   static void destroy_global_map_handle()
+   {
+      if(!atomic_read32(&this_module_singleton_count)){
+         //This module is being unloaded, so destroy
+         //the global map object of this module
+         //and unlink the global map if it's the last
+         typename intermodule_singleton_helpers::thread_safe_global_map_dependant<ThreadSafeGlobalMap>::
+            unlink_map_logic f(get_map());
+         (get_map()).~ThreadSafeGlobalMap();
+         atomic_write32(&this_module_map_initialized, Destroyed);
+         //Do some cleanup for other processes old gmem instances
+         intermodule_singleton_helpers::thread_safe_global_map_dependant<ThreadSafeGlobalMap>::remove_old_gmem();
+      }
+   }
+
+   //Static data, zero-initalized without any dependencies
+   //this_module_singleton_count is the number of singletons used by this module
+   static volatile boost::uint32_t this_module_singleton_count;
+
+   //this_module_map_initialized is the state of this module's map class object.
+   //Values: Uninitialized, Initializing, Initialized, Broken
+   static volatile boost::uint32_t this_module_map_initialized;
+
+   //Raw memory to construct the global map manager
+   static struct mem_holder_t
+   {
+      ::boost::detail::max_align aligner;
+      char map_mem [sizeof(ThreadSafeGlobalMap)];
+   } mem_holder;
+};
+
+template<class ThreadSafeGlobalMap>
+volatile boost::uint32_t intermodule_singleton_common<ThreadSafeGlobalMap>::this_module_singleton_count;
+
+template<class ThreadSafeGlobalMap>
+volatile boost::uint32_t intermodule_singleton_common<ThreadSafeGlobalMap>::this_module_map_initialized;
+
+template<class ThreadSafeGlobalMap>
+typename intermodule_singleton_common<ThreadSafeGlobalMap>::mem_holder_t
+   intermodule_singleton_common<ThreadSafeGlobalMap>::mem_holder;
+
+//A reference count to be stored in global map holding the number
+//of singletons (one per module) attached to the instance pointed by
+//the internal ptr.
+struct ref_count_ptr
+{
+   ref_count_ptr(void *p, boost::uint32_t count)
+      : ptr(p), singleton_ref_count(count)
+   {}
+   void *ptr;
+   //This reference count serves to count the number of attached
+   //modules to this singleton
+   volatile boost::uint32_t singleton_ref_count;
+};
+
+
+//Now this class is a singleton, initializing the singleton in
+//the first get() function call if LazyInit is true. If false
+//then the singleton will be initialized when loading the module.
+template<typename C, bool LazyInit, bool Phoenix, class ThreadSafeGlobalMap>
+class intermodule_singleton_impl
+{
+   public:
+
+   static C& get()   //Let's make inlining easy
+   {
+      if(!this_module_singleton_ptr){
+         if(lifetime.dummy_function()){  //This forces lifetime instantiation, for reference counted destruction
+            atentry_work();
+         }
+      }
+      return *static_cast<C*>(this_module_singleton_ptr);
+   }
+
+   private:
+
+   static void atentry_work()
+   {
+      intermodule_singleton_common<ThreadSafeGlobalMap>::initialize_singleton_logic
+         (this_module_singleton_ptr, this_module_singleton_initialized, singleton_constructor, Phoenix);
+   }
+
+   static void atexit_work()
+   {
+      intermodule_singleton_common<ThreadSafeGlobalMap>::finalize_singleton_logic
+         (this_module_singleton_ptr, this_module_singleton_initialized, singleton_destructor);
+   }
+
+   //These statics will be zero-initialized without any constructor call dependency
+   //this_module_singleton_ptr will be a module-local pointer to the singleton
+   static void*                      this_module_singleton_ptr;
+
+   //this_module_singleton_count will be used to synchronize threads of the same module
+   //for access to a singleton instance, and to flag the state of the
+   //singleton.
+   static volatile boost::uint32_t   this_module_singleton_initialized;
+
+   //This class destructor will trigger singleton destruction
+   struct lifetime_type_lazy
+   {
+      bool dummy_function()
+      {  return m_dummy == 0; }
+
+      ~lifetime_type_lazy()
+      {
+         if(!Phoenix){
+            atexit_work();
+         }
+      }
+
+      //Dummy volatile so that the compiler can't resolve its value at compile-time
+      //and can't avoid lifetime_type instantiation if dummy_function() is called.
+      static volatile int m_dummy;
+   };
+
+   struct lifetime_type_static
+      : public lifetime_type_lazy
+   {
+      lifetime_type_static()
+      {  atentry_work();  }
+   };
+
+   typedef typename if_c
+      <LazyInit, lifetime_type_lazy, lifetime_type_static>::type lifetime_type;
+
+   static lifetime_type lifetime;
+
+   //A functor to be executed inside global map lock that just
+   //searches for the singleton in map and if not present creates a new one.
+   //If singleton constructor throws, the exception is propagated
+   struct init_atomic_func
+   {
+      init_atomic_func(ThreadSafeGlobalMap &m)
+         : m_map(m)
+      {}
+
+      void operator()()
+      {
+         ref_count_ptr *rcount = intermodule_singleton_helpers::thread_safe_global_map_dependant
+            <ThreadSafeGlobalMap>::find(m_map, typeid(C).name());
+         if(!rcount){
+            C *p = new C;
+            try{
+               ref_count_ptr val(p, 0u);
+               rcount = intermodule_singleton_helpers::thread_safe_global_map_dependant
+                           <ThreadSafeGlobalMap>::insert(m_map, typeid(C).name(), val);
+            }
+            catch(...){
+               intermodule_singleton_helpers::thread_safe_global_map_dependant
+                           <ThreadSafeGlobalMap>::erase(m_map, typeid(C).name());
+               delete p;
+               throw;
+            }
+         }
+         if(Phoenix){
+            std::atexit(&atexit_work);
+         }
+         atomic_inc32(&rcount->singleton_ref_count);
+         ret_ptr = rcount->ptr;
+      }
+      void *data() const
+         { return ret_ptr;  }
+
+      private:
+      ThreadSafeGlobalMap &m_map;
+      void *ret_ptr;
+   };
+
+   //A functor to be executed inside global map lock that just
+   //deletes the singleton in map if the attached count reaches to zero
+   struct fini_atomic_func
+   {
+      fini_atomic_func(ThreadSafeGlobalMap &m)
+         : m_map(m)
+      {}
+
+      void operator()()
+      {
+         ref_count_ptr *rcount = intermodule_singleton_helpers::thread_safe_global_map_dependant
+            <ThreadSafeGlobalMap>::find(m_map, typeid(C).name());
+            //The object must exist
+         BOOST_ASSERT(rcount);
+         BOOST_ASSERT(rcount->singleton_ref_count > 0);
+         //Check if last reference
+         if(atomic_dec32(&rcount->singleton_ref_count) == 1){
+            //If last, destroy the object
+            BOOST_ASSERT(rcount->ptr != 0);
+            C *pc = static_cast<C*>(rcount->ptr);
+            //Now destroy map entry
+            bool destroyed = intermodule_singleton_helpers::thread_safe_global_map_dependant
+                        <ThreadSafeGlobalMap>::erase(m_map, typeid(C).name());
+            (void)destroyed;  BOOST_ASSERT(destroyed == true);
+            delete pc;
+         }
+      }
+      void *data() const
+         { return ret_ptr;  }
+
+      private:
+      ThreadSafeGlobalMap &m_map;
+      void *ret_ptr;
+   };
+
+   //A wrapper to execute init_atomic_func
+   static void *singleton_constructor(ThreadSafeGlobalMap &map)
+   {
+      init_atomic_func f(map);
+      intermodule_singleton_helpers::thread_safe_global_map_dependant
+                  <ThreadSafeGlobalMap>::atomic_func(map, f);
+      return f.data();
+   }
+
+   //A wrapper to execute fini_atomic_func
+   static void singleton_destructor(void *p, ThreadSafeGlobalMap &map)
+   {  (void)p;
+      fini_atomic_func f(map);
+      intermodule_singleton_helpers::thread_safe_global_map_dependant
+                  <ThreadSafeGlobalMap>::atomic_func(map, f);
+   }
+};
+
+template <typename C, bool L, bool P, class ThreadSafeGlobalMap>
+volatile int intermodule_singleton_impl<C, L, P, ThreadSafeGlobalMap>::lifetime_type_lazy::m_dummy = 0;
+
+//These will be zero-initialized by the loader
+template <typename C, bool L, bool P, class ThreadSafeGlobalMap>
+void *intermodule_singleton_impl<C, L, P, ThreadSafeGlobalMap>::this_module_singleton_ptr = 0;
+
+template <typename C, bool L, bool P, class ThreadSafeGlobalMap>
+volatile boost::uint32_t intermodule_singleton_impl<C, L, P, ThreadSafeGlobalMap>::this_module_singleton_initialized = 0;
+
+template <typename C, bool L, bool P, class ThreadSafeGlobalMap>
+typename intermodule_singleton_impl<C, L, P, ThreadSafeGlobalMap>::lifetime_type
+   intermodule_singleton_impl<C, L, P, ThreadSafeGlobalMap>::lifetime;
+
+}  //namespace ipcdetail{
+}  //namespace interprocess{
+}  //namespace boost{
+
+#include <boost/interprocess/detail/config_end.hpp>
+
+#endif   //#ifndef BOOST_INTERPROCESS_INTERMODULE_SINGLETON_COMMON_HPP