Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is the documentation for an old version of Boost. Click here to view this page for the latest version.

Stack allocation

Class guarded_stack_allocator
Template simple_stack_allocator< size_t, size_t, size_t >
Free function pagesize()

A fcontext_t requires a stack which will be allocated/deallocated by a StackAllocator. Boost.Context provides the default implementation stack_allocator but a customized StackAllocator can be used instead.

StackAllocator concept

A StackAllocator must satisfy the StackAllocator concept requirements shown in the following table, in which a is an object of a StackAllocator type, p is a void *, and s is a std::size_t:

expression	return type	notes
`a.allocate( s)`	`void *`	returns a pointer to `s` bytes allocated from the stack
`a.deallocate( p, s)`	`void`	deallocates `s` bytes of memory beginning at `p`, a pointer previously returned by `a.allocate()`

	Important
	The implementation of `allocate()` might include logic to protect against exceeding the context's available stack size rather than leaving it as undefined behaviour.

	Important
	Calling `deallocate()` with a pointer not returned by `allocate()` results in undefined behaviour.

	Note
	The stack is not required to be aligned; alignment takes place inside `make_fcontext()`.

	Note
	Depending on the architecture `allocate()` returns an address from the top of the stack (growing downwards) or the bottom of the stack (growing upwards).