...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost.Context provides the class protected_fixedsize_stack which models the stack-allocator concept. It appends a guard page at the end of each stack to protect against exceeding the stack. If the guard page is accessed (read or write operation) a segmentation fault/access violation is generated by the operating system.
Important | |
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Using protected_fixedsize_stack is expensive. That is, launching a new coroutine with a new stack is expensive; the allocated stack is just as efficient to use as any other stack. |
Note | |
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The appended |
#include <boost/context/protected_fixedsize.hpp> template< typename traitsT > struct basic_protected_fixedsize { typedef traitT traits_type; basic_protected_fixesize(std::size_t size = traits_type::default_size()); stack_context allocate(); void deallocate( stack_context &); } typedef basic_protected_fixedsize< stack_traits > protected_fixedsize
stack_context allocate()
traits_type::minimum:size()
<= size
and ! traits_type::is_unbounded() &&
( traits_type::maximum:size() >= size)
.
Allocates memory of at least size
Bytes and stores a pointer to the stack and its actual size in sctx
. Depending on the architecture
(the stack grows downwards/upwards) the stored address is the highest/lowest
address of the stack.
void deallocate( stack_context
& sctx)
sctx.sp
is valid, traits_type::minimum:size() <= sctx.size
and !
traits_type::is_unbounded()
&& (
traits_type::maximum:size()
>= sctx.size)
.
Deallocates the stack space.