v/vlib/builtin/bare/mm_bare.v

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module builtin
const (
mem_prot = Mm_prot(int(Mm_prot.prot_read) | int(Mm_prot.prot_write))
mem_flags = Map_flags(int(Map_flags.map_private) | int(Map_flags.map_anonymous))
page_size = u64(Linux_mem.page_size)
)
pub fn mm_pages(size u64) u32 {
pages := (size+u64(4)+page_size)/page_size
return u32(pages)
}
pub fn mm_alloc(size u64) (byteptr, Errno) {
pages := mm_pages(size)
n_bytes := u64(pages*u32(Linux_mem.page_size))
a, e := sys_mmap(0, n_bytes, mem_prot, mem_flags, -1, 0)
if e == .enoerror {
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mut ap := &int(a)
*ap = pages
return byteptr(a+4), e
}
return byteptr(0), e
}
pub fn mm_free(addr byteptr) Errno {
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ap := &int(addr-4)
size := u64(*ap) * u64(Linux_mem.page_size)
return sys_munmap(ap, size)
}
pub fn mem_copy(dest0 voidptr, src0 voidptr, n int) voidptr {
mut dest := byteptr(dest0)
src := byteptr(src0)
for i in 0..n {
dest[i] = src[i]
}
return dest0
}
[unsafe_fn]
pub fn malloc(n int) byteptr {
if n < 0 {
panic('malloc(<0)')
}
ptr, e := mm_alloc(u64(n))
assert e == .enoerror
assert !isnil(ptr)
return ptr
}
[unsafe_fn]
pub fn free(ptr voidptr) {
assert mm_free(ptr) == .enoerror
}