1 // Copyright 2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 #![crate_name = "alloc_system"]
12 #![crate_type = "rlib"]
15 #![unstable(feature = "alloc_system",
16 reason = "this library is unlikely to be stabilized in its current \
19 #![feature(allocator)]
21 #![feature(staged_api)]
25 // The minimum alignment guaranteed by the architecture. This value is used to
26 // add fast paths for low alignment values. In practice, the alignment is a
27 // constant at the call site and the branch will be optimized out.
28 #[cfg(all(any(target_arch = "x86",
31 target_arch = "mipsel",
32 target_arch = "powerpc",
33 target_arch = "powerpc64",
34 target_arch = "powerpc64le")))]
35 const MIN_ALIGN: usize = 8;
36 #[cfg(all(any(target_arch = "x86_64",
37 target_arch = "aarch64")))]
38 const MIN_ALIGN: usize = 16;
41 pub extern "C" fn __rust_allocate(size: usize, align: usize) -> *mut u8 {
42 unsafe { imp::allocate(size, align) }
46 pub extern "C" fn __rust_deallocate(ptr: *mut u8, old_size: usize, align: usize) {
47 unsafe { imp::deallocate(ptr, old_size, align) }
51 pub extern "C" fn __rust_reallocate(ptr: *mut u8,
56 unsafe { imp::reallocate(ptr, old_size, size, align) }
60 pub extern "C" fn __rust_reallocate_inplace(ptr: *mut u8,
65 unsafe { imp::reallocate_inplace(ptr, old_size, size, align) }
69 pub extern "C" fn __rust_usable_size(size: usize, align: usize) -> usize {
70 imp::usable_size(size, align)
80 pub unsafe fn allocate(size: usize, align: usize) -> *mut u8 {
81 if align <= MIN_ALIGN {
82 libc::malloc(size as libc::size_t) as *mut u8
84 let mut out = ptr::null_mut();
85 let ret = libc::posix_memalign(&mut out, align as libc::size_t, size as libc::size_t);
94 pub unsafe fn reallocate(ptr: *mut u8, old_size: usize, size: usize, align: usize) -> *mut u8 {
95 if align <= MIN_ALIGN {
96 libc::realloc(ptr as *mut libc::c_void, size as libc::size_t) as *mut u8
98 let new_ptr = allocate(size, align);
99 ptr::copy(ptr, new_ptr, cmp::min(size, old_size));
100 deallocate(ptr, old_size, align);
105 pub unsafe fn reallocate_inplace(_ptr: *mut u8,
113 pub unsafe fn deallocate(ptr: *mut u8, _old_size: usize, _align: usize) {
114 libc::free(ptr as *mut libc::c_void)
117 pub fn usable_size(size: usize, _align: usize) -> usize {
127 type LPVOID = *mut u8;
128 type HANDLE = LPVOID;
134 fn GetProcessHeap() -> HANDLE;
135 fn HeapAlloc(hHeap: HANDLE, dwFlags: DWORD, dwBytes: SIZE_T) -> LPVOID;
136 fn HeapReAlloc(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID, dwBytes: SIZE_T) -> LPVOID;
137 fn HeapFree(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID) -> BOOL;
141 struct Header(*mut u8);
143 const HEAP_REALLOC_IN_PLACE_ONLY: DWORD = 0x00000010;
145 unsafe fn get_header<'a>(ptr: *mut u8) -> &'a mut Header {
146 &mut *(ptr as *mut Header).offset(-1)
149 unsafe fn align_ptr(ptr: *mut u8, align: usize) -> *mut u8 {
150 let aligned = ptr.offset((align - (ptr as usize & (align - 1))) as isize);
151 *get_header(aligned) = Header(ptr);
155 pub unsafe fn allocate(size: usize, align: usize) -> *mut u8 {
156 if align <= MIN_ALIGN {
157 HeapAlloc(GetProcessHeap(), 0, size as SIZE_T) as *mut u8
159 let ptr = HeapAlloc(GetProcessHeap(), 0, (size + align) as SIZE_T) as *mut u8;
163 align_ptr(ptr, align)
167 pub unsafe fn reallocate(ptr: *mut u8, _old_size: usize, size: usize, align: usize) -> *mut u8 {
168 if align <= MIN_ALIGN {
169 HeapReAlloc(GetProcessHeap(), 0, ptr as LPVOID, size as SIZE_T) as *mut u8
171 let header = get_header(ptr);
172 let new = HeapReAlloc(GetProcessHeap(),
175 (size + align) as SIZE_T) as *mut u8;
179 align_ptr(new, align)
183 pub unsafe fn reallocate_inplace(ptr: *mut u8,
188 if align <= MIN_ALIGN {
189 let new = HeapReAlloc(GetProcessHeap(),
190 HEAP_REALLOC_IN_PLACE_ONLY,
192 size as SIZE_T) as *mut u8;
203 pub unsafe fn deallocate(ptr: *mut u8, _old_size: usize, align: usize) {
204 if align <= MIN_ALIGN {
205 let err = HeapFree(GetProcessHeap(), 0, ptr as LPVOID);
206 debug_assert!(err != 0);
208 let header = get_header(ptr);
209 let err = HeapFree(GetProcessHeap(), 0, header.0 as LPVOID);
210 debug_assert!(err != 0);
214 pub fn usable_size(size: usize, _align: usize) -> usize {