feat: add malloc&free 1

This commit is contained in:
2023-01-19 23:00:54 +08:00
parent e44aa7f60c
commit ead7eddf1f
2 changed files with 21 additions and 7 deletions

View File

@@ -1,5 +1,16 @@
#[no_mangle]
pub unsafe fn malloc_1(len: usize) -> *mut u8 {
let mut buffer: std::mem::ManuallyDrop<Vec<u8>> = std::mem::ManuallyDrop::new(Vec::with_capacity(len as usize));
buffer.as_mut_ptr() as *mut u8
}
#[no_mangle]
pub unsafe fn free_1(ptr: *mut u8, len: usize) {
std::mem::drop(Vec::from_raw_parts(ptr as *mut u8, 0, len as usize))
}
#[no_mangle]
pub unsafe fn malloc_2(len: usize) -> *mut u8 {
let mut buf = Vec::with_capacity(len);
let ptr = buf.as_mut_ptr();
std::mem::forget(buf);
@@ -7,20 +18,20 @@ pub unsafe fn malloc_1(len: usize) -> *mut u8 {
}
#[no_mangle]
pub unsafe fn free_1(ptr: *mut u8, len: usize) {
pub unsafe fn free_2(ptr: *mut u8, len: usize) {
let data = Vec::from_raw_parts(ptr, len, len);
std::mem::drop(data);
}
#[no_mangle]
pub unsafe fn malloc_2(len: usize) -> *mut u8 {
pub unsafe fn malloc_3(len: usize) -> *mut u8 {
let align = std::mem::align_of::<usize>();
let layout = std::alloc::Layout::from_size_align_unchecked(len, align);
std::alloc::alloc(layout)
}
#[no_mangle]
pub unsafe fn free_2(ptr: *mut u8, len: usize) {
pub unsafe fn free_3(ptr: *mut u8, len: usize) {
let align = std::mem::align_of::<usize>();
let layout = std::alloc::Layout::from_size_align_unchecked(len, align);
std::alloc::dealloc(ptr, layout)
@@ -28,14 +39,16 @@ pub unsafe fn free_2(ptr: *mut u8, len: usize) {
fn main() {
unsafe {
println!("Malloc-1");
println!("Malloc & Free - 1");
let p = malloc_1(1024);
println!("Free-1");
free_1(p, 1024);
println!("Malloc-2");
println!("Malloc & Free - 2");
let p = malloc_2(1024);
println!("Free-2");
free_2(p, 1024);
println!("Malloc & Free - 3");
let p = malloc_3(1024);
free_3(p, 1024);
}
}