Add Polymorphic Memory Resource utilities and rework the separately compiled library:

- Dlmalloc's based C function are boost_cont_xxx no longer exported, but wrapped into C++ linkage dlmalloc_xxx functions to effectively reuse Boost's dynamic library and autolink machinery instead of rewriting machinery to compile the C source file.
- Refactored scoped_allocator_adaptor's construct logic as it was shared with polymorphic allocator's one. Moved common logic to detail/dispatch_uses_allocator.hpp. Refactored also scoped_allocator_adaptor test utilities to be reused with polymorphic_allocator tests.

src/monotonic_buffer_resource.cpp

@@ -0,0 +1,154 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Ion Gaztanaga 2015-2015. 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/container for documentation.
+//
+//////////////////////////////////////////////////////////////////////////////
+
+#define BOOST_CONTAINER_SOURCE
+#include <boost/container/detail/config_begin.hpp>
+#include <boost/container/detail/workaround.hpp>
+
+#include <boost/container/pmr/monotonic_buffer_resource.hpp>
+#include <boost/container/pmr/global_resource.hpp>
+
+#include <boost/container/detail/min_max.hpp>
+#include <boost/intrusive/detail/math.hpp>
+#include <boost/container/throw_exception.hpp>
+
+
+#include <cstddef>
+
+namespace {
+
+#ifdef BOOST_HAS_INTPTR_T
+typedef boost::uintptr_t   uintptr_type;
+#else
+typedef std::size_t        uintptr_type;
+#endif
+
+static const std::size_t minimum_buffer_size = 2*sizeof(void*);
+
+}  //namespace {
+
+namespace boost {
+namespace container {
+namespace pmr {
+
+void monotonic_buffer_resource::increase_next_buffer()
+{
+   m_next_buffer_size = (std::size_t(-1)/2 < m_next_buffer_size) ? std::size_t(-1) : m_next_buffer_size*2;
+}
+
+void monotonic_buffer_resource::increase_next_buffer_at_least_to(std::size_t minimum_size)
+{
+   if(m_next_buffer_size < minimum_size){
+      if(bi::detail::is_pow2(minimum_size)){
+         m_next_buffer_size = minimum_size;
+      }
+      else if(std::size_t(-1)/2 < minimum_size){
+         m_next_buffer_size = minimum_size;
+      }
+      else{
+         m_next_buffer_size = bi::detail::ceil_pow2(minimum_size);
+      }
+   }
+}
+
+monotonic_buffer_resource::monotonic_buffer_resource(memory_resource* upstream) BOOST_NOEXCEPT
+   : m_memory_blocks(upstream ? *upstream : *get_default_resource())
+   , m_current_buffer(0u)
+   , m_current_buffer_size(0u)
+   , m_next_buffer_size(initial_next_buffer_size)
+{}
+
+monotonic_buffer_resource::monotonic_buffer_resource(std::size_t initial_size, memory_resource* upstream) BOOST_NOEXCEPT
+   : m_memory_blocks(upstream ? *upstream : *get_default_resource())
+   , m_current_buffer(0u)
+   , m_current_buffer_size(0u)
+   , m_next_buffer_size(minimum_buffer_size)
+{                                         //In case initial_size is zero
+   this->increase_next_buffer_at_least_to(initial_size + !initial_size);
+}
+
+monotonic_buffer_resource::monotonic_buffer_resource(void* buffer, std::size_t buffer_size, memory_resource* upstream) BOOST_NOEXCEPT
+   : m_memory_blocks(upstream ? *upstream : *get_default_resource())
+   , m_current_buffer(buffer)
+   , m_current_buffer_size(buffer_size)
+   , m_next_buffer_size
+      (bi::detail::previous_or_equal_pow2
+         (boost::container::container_detail::max_value(buffer_size, std::size_t(initial_next_buffer_size))))
+{  this->increase_next_buffer(); }
+
+monotonic_buffer_resource::~monotonic_buffer_resource()
+{  this->release();  }
+
+void monotonic_buffer_resource::release() BOOST_NOEXCEPT
+{  m_memory_blocks.release();  }
+
+memory_resource* monotonic_buffer_resource::upstream_resource() const BOOST_NOEXCEPT
+{  return &m_memory_blocks.upstream_resource();   }
+
+std::size_t monotonic_buffer_resource::remaining_storage(std::size_t alignment, std::size_t &wasted_due_to_alignment) const BOOST_NOEXCEPT
+{
+   const uintptr_type up_alignment_minus1 = alignment - 1u;
+   const uintptr_type up_alignment_mask = ~up_alignment_minus1;
+   const uintptr_type up_addr = uintptr_type(m_current_buffer);
+   const uintptr_type up_aligned_addr = (up_addr + up_alignment_minus1) & up_alignment_mask;
+   wasted_due_to_alignment = std::size_t(up_aligned_addr - up_addr);
+   return m_current_buffer_size <= wasted_due_to_alignment ? 0u : m_current_buffer_size - wasted_due_to_alignment;
+}
+
+std::size_t monotonic_buffer_resource::remaining_storage(std::size_t alignment) const BOOST_NOEXCEPT
+{
+   std::size_t ignore_this;
+   return this->remaining_storage(alignment, ignore_this);
+}
+
+const void *monotonic_buffer_resource::current_buffer() const BOOST_NOEXCEPT
+{  return m_current_buffer;  }
+
+std::size_t monotonic_buffer_resource::next_buffer_size() const BOOST_NOEXCEPT
+{  return m_next_buffer_size;  }
+
+void *monotonic_buffer_resource::allocate_from_current(std::size_t aligner, std::size_t bytes)
+{
+   char * p = (char*)m_current_buffer + aligner;
+   m_current_buffer = p + bytes;
+   m_current_buffer_size -= aligner + bytes;
+   return p;
+}
+
+void* monotonic_buffer_resource::do_allocate(std::size_t bytes, std::size_t alignment)
+{
+   if(alignment > memory_resource::max_align)
+      throw_bad_alloc();
+
+   //See if there is room in current buffer
+   std::size_t aligner = 0u;
+   if(this->remaining_storage(alignment, aligner) < bytes){
+      //Update next_buffer_size to at least bytes
+      this->increase_next_buffer_at_least_to(bytes);
+      //Now allocate and update internal data
+      m_current_buffer = (char*)m_memory_blocks.allocate(m_next_buffer_size);
+      m_current_buffer_size = m_next_buffer_size;
+      this->increase_next_buffer();
+   }
+   //Enough internal storage, extract from it
+   return this->allocate_from_current(aligner, bytes);
+}
+
+void monotonic_buffer_resource::do_deallocate(void* p, std::size_t bytes, std::size_t alignment) BOOST_NOEXCEPT
+{  (void)p; (void)bytes;  (void)alignment;  }
+
+bool monotonic_buffer_resource::do_is_equal(const memory_resource& other) const BOOST_NOEXCEPT
+{  return this == dynamic_cast<const monotonic_buffer_resource*>(&other);  }
+
+}  //namespace pmr {
+}  //namespace container {
+}  //namespace boost {
+
+#include <boost/container/detail/config_end.hpp>