Am 02.09.2012 02:01, schrieb Hartmut Kaiser:
Hey all,
Why is the minimally possible stack size in Boost.Context on Windows set to be 64k? This seems to be way too high for applications where only a minimal amount of stack is required. I assume, that since Boost.Context allocates the stack using VirtualAlloc the minimum possible value should be equal to the page size (see http://msdn.microsoft.com/en-us/library/windows/desktop/aa366887(v=vs.85).as px).
boost.context provides a default implementation of a stack-allocator (class stack_allocator) which appends each stack a guard page (guard pages will not be mapped to physical pages - you don't was memory). Function VirtualProtect() is used to set the 'guard' flag on the page and requires VirtualAlloc(). I decided to provide the same stacksize as Win32 Fiber API does - which is system's allocation granularity (64kB; using GetSystemInfo() ). If context's default stack allocation does not satisfy your requirements you can easily implement and use your own stack allocator together with make_fcontext()/jump_fcontext(). regards, Oliver