What are the Windows and Linux native OS/system calls made from malloc()?

Question

I recently saw the following post:

A memory allocator isn\'t lower level than malloc. (The default allocator typically calls malloc directly or indi

Answer 1

My question is- how is malloc implemented in the following Operating systems?

On Linux there are two famous malloc implementations:

dlmalloc (Doug Lea's malloc)

ptmalloc

On Linux libc like glibc, eglibc or newlib implement ptmalloc or a variant of ptmalloc.

what are the OS-specific functions which are called/implementations of malloc()?

On Unix and Linux systems sbrk and mmap system calls are used. See man 2 sbrk and man 2 mmap for more information.