v/vlib/builtin/linux_bare/memory_managment.v

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module builtin
import dlmalloc
fn mm_alloc(size u64) (&byte, Errno) {
// BEGIN CONSTS
// the constants need to be here, since the initialization of other constants,
// which happen before these ones would, require malloc
mem_prot := MemProt(int(MemProt.prot_read) | int(MemProt.prot_write))
map_flags := MapFlags(int(MapFlags.map_private) | int(MapFlags.map_anonymous))
// END CONSTS
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a, e := sys_mmap(&u8(0), size + sizeof(u64), mem_prot, map_flags, -1, 0)
if e == .enoerror {
unsafe {
mut ap := &u64(a)
*ap = size
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x2 := &u8(a + sizeof(u64))
return x2, e
}
}
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return &u8(0), e
}
fn mm_free(addr &byte) Errno {
unsafe {
ap := &u64(addr - sizeof(u64))
size := *ap
return sys_munmap(addr - sizeof(u64), size + sizeof(u64))
}
}
fn system_alloc(_ voidptr, size usize) (voidptr, usize, u32) {
// BEGIN CONSTS
// the constants need to be here, since the initialization of other constants,
// which happen before these ones would, require malloc
mem_prot := MemProt(int(MemProt.prot_read) | int(MemProt.prot_write))
map_flags := MapFlags(int(MapFlags.map_private) | int(MapFlags.map_anonymous))
// END CONSTS
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a, e := sys_mmap(&u8(0), u64(size), mem_prot, map_flags, -1, 0)
if e == .enoerror {
return a, size, 0
}
return voidptr(0), 0, 0
}
fn system_remap(_ voidptr, ptr voidptr, oldsize usize, newsize usize, can_move bool) voidptr {
return voidptr(0)
}
fn system_free_part(_ voidptr, ptr voidptr, oldsize usize, newsize usize) bool {
_, e := sys_mremap(ptr, u64(oldsize), u64(newsize), 0)
if e == .enoerror {
return true
}
e2 := sys_munmap(voidptr(usize(ptr) + newsize), u64(oldsize - newsize))
return e2 == .enoerror
}
fn system_free(_ voidptr, ptr voidptr, size usize) bool {
unsafe {
return sys_munmap(ptr, u64(size)) == .enoerror
}
}
fn system_can_release_part(_ voidptr, _ u32) bool {
return true
}
fn system_allocates_zeros(_ voidptr) bool {
return true
}
fn system_page_size(_ voidptr) usize {
return 4096
}
fn get_linux_allocator() dlmalloc.Allocator {
return dlmalloc.Allocator{
alloc: system_alloc
remap: system_remap
free_part: system_free_part
free_: system_free
can_release_part: system_can_release_part
allocates_zeros: system_allocates_zeros
page_size: system_page_size
data: voidptr(0)
}
}