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 #![cfg_attr(stage0, feature(custom_attribute))]
12 #![crate_name = "alloc_system"]
13 #![crate_type = "rlib"]
16 #![cfg_attr(not(stage0), allocator)]
17 #![unstable(feature = "alloc_system",
18 reason = "this library is unlikely to be stabilized in its current \
20 #![feature(allocator)]
23 #![feature(staged_api)]
27 // The minimum alignment guaranteed by the architecture. This value is used to
28 // add fast paths for low alignment values. In practice, the alignment is a
29 // constant at the call site and the branch will be optimized out.
30 #[cfg(all(any(target_arch = "arm",
32 target_arch = "mipsel",
33 target_arch = "powerpc")))]
34 const MIN_ALIGN: usize = 8;
35 #[cfg(all(any(target_arch = "x86",
36 target_arch = "x86_64",
37 target_arch = "aarch64")))]
38 const MIN_ALIGN: usize = 16;
41 pub extern fn __rust_allocate(size: usize, align: usize) -> *mut u8 {
42 unsafe { imp::allocate(size, align) }
46 pub extern fn __rust_deallocate(ptr: *mut u8, old_size: usize, align: usize) {
47 unsafe { imp::deallocate(ptr, old_size, align) }
51 pub extern fn __rust_reallocate(ptr: *mut u8, old_size: usize, size: usize,
52 align: usize) -> *mut u8 {
53 unsafe { imp::reallocate(ptr, old_size, size, align) }
57 pub extern fn __rust_reallocate_inplace(ptr: *mut u8, old_size: usize,
58 size: usize, align: usize) -> usize {
59 unsafe { imp::reallocate_inplace(ptr, old_size, size, align) }
63 pub extern fn __rust_usable_size(size: usize, align: usize) -> usize {
64 imp::usable_size(size, align)
75 // Apparently android doesn't have posix_memalign
76 #[cfg(target_os = "android")]
77 fn memalign(align: libc::size_t, size: libc::size_t) -> *mut libc::c_void;
79 #[cfg(not(target_os = "android"))]
80 fn posix_memalign(memptr: *mut *mut libc::c_void,
82 size: libc::size_t) -> libc::c_int;
85 pub unsafe fn allocate(size: usize, align: usize) -> *mut u8 {
86 if align <= MIN_ALIGN {
87 libc::malloc(size as libc::size_t) as *mut u8
89 #[cfg(target_os = "android")]
90 unsafe fn more_aligned_malloc(size: usize, align: usize) -> *mut u8 {
91 memalign(align as libc::size_t, size as libc::size_t) as *mut u8
93 #[cfg(not(target_os = "android"))]
94 unsafe fn more_aligned_malloc(size: usize, align: usize) -> *mut u8 {
95 let mut out = ptr::null_mut();
96 let ret = posix_memalign(&mut out,
97 align as libc::size_t,
98 size as libc::size_t);
105 more_aligned_malloc(size, align)
109 pub unsafe fn reallocate(ptr: *mut u8, old_size: usize, size: usize,
110 align: usize) -> *mut u8 {
111 if align <= MIN_ALIGN {
112 libc::realloc(ptr as *mut libc::c_void, size as libc::size_t) as *mut u8
114 let new_ptr = allocate(size, align);
115 ptr::copy(ptr, new_ptr, cmp::min(size, old_size));
116 deallocate(ptr, old_size, align);
121 pub unsafe fn reallocate_inplace(_ptr: *mut u8, old_size: usize, _size: usize,
122 _align: usize) -> usize {
126 pub unsafe fn deallocate(ptr: *mut u8, _old_size: usize, _align: usize) {
127 libc::free(ptr as *mut libc::c_void)
130 pub fn usable_size(size: usize, _align: usize) -> usize {
137 use libc::{BOOL, DWORD, HANDLE, LPVOID, SIZE_T};
141 fn GetProcessHeap() -> HANDLE;
142 fn HeapAlloc(hHeap: HANDLE, dwFlags: DWORD, dwBytes: SIZE_T) -> LPVOID;
143 fn HeapReAlloc(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID,
144 dwBytes: SIZE_T) -> LPVOID;
145 fn HeapFree(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID) -> BOOL;
149 struct Header(*mut u8);
151 const HEAP_REALLOC_IN_PLACE_ONLY: DWORD = 0x00000010;
153 unsafe fn get_header<'a>(ptr: *mut u8) -> &'a mut Header {
154 &mut *(ptr as *mut Header).offset(-1)
157 unsafe fn align_ptr(ptr: *mut u8, align: usize) -> *mut u8 {
158 let aligned = ptr.offset((align - (ptr as usize & (align - 1))) as isize);
159 *get_header(aligned) = Header(ptr);
163 pub unsafe fn allocate(size: usize, align: usize) -> *mut u8 {
164 if align <= MIN_ALIGN {
165 HeapAlloc(GetProcessHeap(), 0, size as SIZE_T) as *mut u8
167 let ptr = HeapAlloc(GetProcessHeap(), 0,
168 (size + align) as SIZE_T) as *mut u8;
169 if ptr.is_null() { return ptr }
170 align_ptr(ptr, align)
174 pub unsafe fn reallocate(ptr: *mut u8, _old_size: usize, size: usize,
175 align: usize) -> *mut u8 {
176 if align <= MIN_ALIGN {
177 HeapReAlloc(GetProcessHeap(), 0, ptr as LPVOID, size as SIZE_T) as *mut u8
179 let header = get_header(ptr);
180 let new = HeapReAlloc(GetProcessHeap(), 0, header.0 as LPVOID,
181 (size + align) as SIZE_T) as *mut u8;
182 if new.is_null() { return new }
183 align_ptr(new, align)
187 pub unsafe fn reallocate_inplace(ptr: *mut u8, old_size: usize, size: usize,
188 align: usize) -> usize {
189 if align <= MIN_ALIGN {
190 let new = HeapReAlloc(GetProcessHeap(), HEAP_REALLOC_IN_PLACE_ONLY,
191 ptr as LPVOID, size as SIZE_T) as *mut u8;
192 if new.is_null() { old_size } else { size }
198 pub unsafe fn deallocate(ptr: *mut u8, _old_size: usize, align: usize) {
199 if align <= MIN_ALIGN {
200 let err = HeapFree(GetProcessHeap(), 0, ptr as LPVOID);
201 debug_assert!(err != 0);
203 let header = get_header(ptr);
204 let err = HeapFree(GetProcessHeap(), 0, header.0 as LPVOID);
205 debug_assert!(err != 0);
209 pub fn usable_size(size: usize, _align: usize) -> usize {