Class protected_fixedsize

Boost.Coroutine2 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
	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
	The appended `guard page` is not mapped to physical memory, only virtual addresses are used.

#include <boost/coroutine2/protected_fixedsize.hpp>

struct protected_fixedsize {
    protected_fixesize(std::size_t size = traits_type::default_size());

    stack_context allocate();

    void deallocate( stack_context &);
}

`stack_context allocate()`

Preconditions:: traits_type::minimum:size() <= size and ! traits_type::is_unbounded() && ( traits_type::maximum:size() >= size).
Effects:: 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)`

Preconditions:: sctx.sp is valid, traits_type::minimum:size() <= sctx.size and ! traits_type::is_unbounded() && ( traits_type::maximum:size() >= sctx.size).
Effects:: Deallocates the stack space.

Boost C++ Libraries

Class protected_fixedsize

stack_context allocate()

void deallocate( stack_context & sctx)

`stack_context allocate()`

`void deallocate( stack_context & sctx)`