ceph/src/boost/boost/coroutine/posix/protected_stack_allocator.hpp

   1
   2 //          Copyright Oliver Kowalke 2009.
   3 // Distributed under the Boost Software License, Version 1.0.
   4 //    (See accompanying file LICENSE_1_0.txt or copy at
   5 //          http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #ifndef BOOST_COROUTINES_PROTECTED_STACK_ALLOCATOR_H
   8 #define BOOST_COROUTINES_PROTECTED_STACK_ALLOCATOR_H
   9
  10 extern "C" {
  11 #include <fcntl.h>
  12 #include <sys/mman.h>
  13 #include <sys/stat.h>
  14 #include <unistd.h>
  15 }
  16
  17 #if defined(BOOST_USE_VALGRIND)
  18 #include <valgrind/valgrind.h>
  19 #endif
  20
  21 #include <cmath>
  22 #include <cstddef>
  23 #include <new>
  24
  25 #include <boost/assert.hpp>
  26 #include <boost/config.hpp>
  27
  28 #include <boost/coroutine/detail/config.hpp>
  29 #include <boost/coroutine/stack_context.hpp>
  30 #include <boost/coroutine/stack_traits.hpp>
  31
  32 #ifdef BOOST_HAS_ABI_HEADERS
  33 #  include BOOST_ABI_PREFIX
  34 #endif
  35
  36 namespace boost {
  37 namespace coroutines {
  38
  39 template< typename traitsT >
  40 struct basic_protected_stack_allocator
  41 {
  42     typedef traitsT traits_type;
  43
  44     void allocate( stack_context & ctx, std::size_t size = traits_type::minimum_size() )
  45     {
  46         BOOST_ASSERT( traits_type::minimum_size() <= size);
  47         BOOST_ASSERT( traits_type::is_unbounded() || ( traits_type::maximum_size() >= size) );
  48
  49         // page at bottom will be used as guard-page
  50         const std::size_t pages(
  51             static_cast< std::size_t >(
  52                 std::floor(
  53                     static_cast< float >( size) / traits_type::page_size() ) ) );
  54         BOOST_ASSERT_MSG( 2 <= pages, "at least two pages must fit into stack (one page is guard-page)");
  55         const std::size_t size_( pages * traits_type::page_size() );
  56         BOOST_ASSERT( 0 != size && 0 != size_);
  57         BOOST_ASSERT( size_ <= size);
  58
  59         // conform to POSIX.4 (POSIX.1b-1993, _POSIX_C_SOURCE=199309L)
  60 #if defined(MAP_ANON)
  61         void * limit = ::mmap( 0, size_, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
  62 #else
  63         void * limit = ::mmap( 0, size_, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  64 #endif
  65         if ( MAP_FAILED == limit) throw std::bad_alloc();
  66
  67         // conforming to POSIX.1-2001
  68 #if defined(BOOST_DISABLE_ASSERTS)
  69         ::mprotect( limit, traits_type::page_size(), PROT_NONE);
  70 #else
  71         const int result( ::mprotect( limit, traits_type::page_size(), PROT_NONE) );
  72         BOOST_ASSERT( 0 == result);
  73 #endif
  74
  75         ctx.size = size_;
  76         ctx.sp = static_cast< char * >( limit) + ctx.size;
  77 #if defined(BOOST_USE_VALGRIND)
  78         ctx.valgrind_stack_id = VALGRIND_STACK_REGISTER( ctx.sp, limit);
  79 #endif
  80     }
  81
  82     void deallocate( stack_context & ctx)
  83     {
  84         BOOST_ASSERT( ctx.sp);
  85         BOOST_ASSERT( traits_type::minimum_size() <= ctx.size);
  86         BOOST_ASSERT( traits_type::is_unbounded() || ( traits_type::maximum_size() >= ctx.size) );
  87
  88 #if defined(BOOST_USE_VALGRIND)
  89         VALGRIND_STACK_DEREGISTER( ctx.valgrind_stack_id);
  90 #endif
  91         void * limit = static_cast< char * >( ctx.sp) - ctx.size;
  92         // conform to POSIX.4 (POSIX.1b-1993, _POSIX_C_SOURCE=199309L)
  93         ::munmap( limit, ctx.size);
  94     }
  95 };
  96
  97 typedef basic_protected_stack_allocator< stack_traits > protected_stack_allocator;
  98
  99 }}
 100
 101 #ifdef BOOST_HAS_ABI_HEADERS
 102 #  include BOOST_ABI_SUFFIX
 103 #endif
 104
 105 #endif // BOOST_COROUTINES_PROTECTED_STACK_ALLOCATOR_H