Function ralloc::sbrk

pub unsafe extern fn sbrk(size: isize) -> *mut u8

SBRK symbol which can coexist with the allocator.

SBRK-ing directly (from the BRK syscall or libc) might make the state inconsistent. This function makes sure that's not happening.

With the exception of being able to coexist, it follows the same rules. Refer to the relevant documentation.

Failure

On failure the maximum pointer (!0 as *mut u8) is returned.