DArena

Native arena allocator

Context

_images/ditaa-32ae12e88f03327267b234e678e21c1b6711d526.png

#include <xo/alloc2/DArena.hpp>

Arena memory layout

 <------------------------reserved-------------------------->
 <------------committed-----------><-------uncommitted------>
 <--allocated--><----available---->

 XXXXXXXXXXXXXXX___________________..........................
^               ^                  ^                         ^
lo              free               limit                     hi

 [X] allocated:   in use
 [_] committed:   physical memory obtained
 [.] uncommitted: mapped in virtual memory, not backed by memory

Representation for a single allocation

               free_(pre)
                   v

                   <-------------z1--------------->
          < guard ><  hz  ><     req_z     >< dz  >< guard >

used <==  +++++++++0000zzzz@@@@@@@@@@@@@@@@@ppppppp+++++++++ ==> avail

                   ^       ^                                ^
                   header  mem                              |
                   ^                                        |
                   last_header_                   free_(post)

           [+] guard surrounding each allocation, for simple sanitize checks
           [0] unused header bits (available for application metadata)
           [z] record allocation size
           [@] new allocated memory
           [p] padding (to uintptr_t alignment)

Class

Warning

doxygenclass: Cannot find class “xo::mm::DArena” in doxygen xml output for project “xodoxxml” from directory: /build/xo-alloc2/build/docs/dox/xml

Member Variables

Warning

doxygengroup: Cannot find group “mm-arena-instance-vars” in doxygen xml output for project “xodoxxml” from directory: /build/xo-alloc2/build/docs/dox/xml

Type Traits

Warning

doxygengroup: Cannot find group “mm-arena-traits” in doxygen xml output for project “xodoxxml” from directory: /build/xo-alloc2/build/docs/dox/xml

Constructors

Warning

doxygengroup: Cannot find group “mm-arena-ctors” in doxygen xml output for project “xodoxxml” from directory: /build/xo-alloc2/build/docs/dox/xml

Methods

Warning

doxygengroup: Cannot find group “mm-arena-methods” in doxygen xml output for project “xodoxxml” from directory: /build/xo-alloc2/build/docs/dox/xml