ceph/src/boost/libs/container/src/global_resource.cpp

   1 //////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2015-2015. Distributed under the Boost
   4 // Software License, Version 1.0. (See accompanying file
   5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/container for documentation.
   8 //
   9 //////////////////////////////////////////////////////////////////////////////
  10
  11 #define BOOST_CONTAINER_SOURCE
  12 #include <boost/container/pmr/memory_resource.hpp>
  13 #include <boost/container/pmr/global_resource.hpp>
  14 #include <boost/core/no_exceptions_support.hpp>
  15 #include <boost/container/throw_exception.hpp>
  16 #include <boost/container/detail/dlmalloc.hpp>  //For global lock
  17
  18 #include <cstddef>
  19 #include <new>
  20
  21 namespace boost {
  22 namespace container {
  23 namespace pmr {
  24
  25 class new_delete_resource_imp
  26    : public memory_resource
  27 {
  28    public:
  29
  30    virtual ~new_delete_resource_imp()
  31    {}
  32
  33    virtual void* do_allocate(std::size_t bytes, std::size_t alignment)
  34    {  (void)bytes; (void)alignment; return new char[bytes];  }
  35
  36    virtual void do_deallocate(void* p, std::size_t bytes, std::size_t alignment)
  37    {  (void)bytes; (void)alignment; delete[]((char*)p);  }
  38
  39    virtual bool do_is_equal(const memory_resource& other) const BOOST_NOEXCEPT
  40    {  return &other == this;   }
  41 } new_delete_resource_instance;
  42
  43 struct null_memory_resource_imp
  44    : public memory_resource
  45 {
  46    public:
  47
  48    virtual ~null_memory_resource_imp()
  49    {}
  50
  51    virtual void* do_allocate(std::size_t bytes, std::size_t alignment)
  52    {
  53       (void)bytes; (void)alignment;
  54       throw_bad_alloc();
  55       return 0;
  56    }
  57
  58    virtual void do_deallocate(void* p, std::size_t bytes, std::size_t alignment)
  59    {  (void)p;  (void)bytes; (void)alignment;  }
  60
  61    virtual bool do_is_equal(const memory_resource& other) const BOOST_NOEXCEPT
  62    {  return &other == this;   }
  63 } null_memory_resource_instance;
  64
  65 BOOST_CONTAINER_DECL memory_resource* new_delete_resource() BOOST_NOEXCEPT
  66 {
  67    return &new_delete_resource_instance;
  68 }
  69
  70 BOOST_CONTAINER_DECL memory_resource* null_memory_resource() BOOST_NOEXCEPT
  71 {
  72    return &null_memory_resource_instance;
  73 }
  74
  75 static memory_resource *default_memory_resource = &new_delete_resource_instance;
  76
  77 BOOST_CONTAINER_DECL memory_resource* set_default_resource(memory_resource* r) BOOST_NOEXCEPT
  78 {
  79    //TO-DO: synchronizes-with part using atomics
  80    if(dlmalloc_global_sync_lock()){
  81       memory_resource *previous = default_memory_resource;
  82       default_memory_resource = r ? r : new_delete_resource();
  83       dlmalloc_global_sync_unlock();
  84       return previous;
  85    }
  86    else{
  87       return new_delete_resource();
  88    }
  89 }
  90
  91 BOOST_CONTAINER_DECL memory_resource* get_default_resource() BOOST_NOEXCEPT
  92 {
  93    //TO-DO: synchronizes-with part using atomics
  94    if(dlmalloc_global_sync_lock()){
  95       memory_resource *current = default_memory_resource;
  96       dlmalloc_global_sync_unlock();
  97       return current;
  98    }
  99    else{
 100       return new_delete_resource();
 101    }
 102 }
 103
 104 }  //namespace pmr {
 105 }  //namespace container {
 106 }  //namespace boost {