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Add liballoc_system shim
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4 changed files with 155 additions and 1 deletions
3
.gitignore
vendored
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3
.gitignore
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@ -0,0 +1,3 @@
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/target/
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**/*.rs.bk
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Cargo.lock
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@ -10,3 +10,4 @@ repository = "https://github.com/Manishearth/hashglobe"
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readme = "README.md"
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[dependencies]
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libc = "0.2"
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148
src/alloc.rs
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148
src/alloc.rs
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// The minimum alignment guaranteed by the architecture. This value is used to
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// add fast paths for low alignment values. In practice, the alignment is a
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// constant at the call site and the branch will be optimized out.
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#[cfg(all(any(target_arch = "x86",
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target_arch = "arm",
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target_arch = "mips",
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target_arch = "powerpc",
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target_arch = "powerpc64",
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target_arch = "asmjs",
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target_arch = "wasm32")))]
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const MIN_ALIGN: usize = 8;
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#[cfg(all(any(target_arch = "x86_64",
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target_arch = "aarch64",
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target_arch = "mips64",
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target_arch = "s390x",
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target_arch = "sparc64")))]
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const MIN_ALIGN: usize = 16;
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pub use self::platform::{alloc, dealloc};
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#[cfg(any(unix, target_os = "redox"))]
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mod platform {
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extern crate libc;
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use std::ptr;
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use super::MIN_ALIGN;
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#[inline]
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pub unsafe fn alloc(size: usize, align: usize) -> *mut u8 {
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let ptr = if align <= MIN_ALIGN {
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libc::malloc(size) as *mut u8
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} else {
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aligned_malloc(size, align)
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};
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ptr
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}
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#[inline]
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pub unsafe fn dealloc(ptr: *mut u8, _align: usize) {
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libc::free(ptr as *mut libc::c_void)
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}
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#[cfg(any(target_os = "android", target_os = "redox"))]
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#[inline]
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unsafe fn aligned_malloc(size: usize, align: usize) -> *mut u8 {
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// On android we currently target API level 9 which unfortunately
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// doesn't have the `posix_memalign` API used below. Instead we use
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// `memalign`, but this unfortunately has the property on some systems
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// where the memory returned cannot be deallocated by `free`!
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//
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// Upon closer inspection, however, this appears to work just fine with
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// Android, so for this platform we should be fine to call `memalign`
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// (which is present in API level 9). Some helpful references could
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// possibly be chromium using memalign [1], attempts at documenting that
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// memalign + free is ok [2] [3], or the current source of chromium
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// which still uses memalign on android [4].
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//
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// [1]: https://codereview.chromium.org/10796020/
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// [2]: https://code.google.com/p/android/issues/detail?id=35391
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// [3]: https://bugs.chromium.org/p/chromium/issues/detail?id=138579
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// [4]: https://chromium.googlesource.com/chromium/src/base/+/master/
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// /memory/aligned_memory.cc
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libc::memalign(align, size) as *mut u8
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}
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#[cfg(not(any(target_os = "android", target_os = "redox")))]
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#[inline]
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unsafe fn aligned_malloc(size: usize, align: usize) -> *mut u8 {
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let mut out = ptr::null_mut();
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let ret = libc::posix_memalign(&mut out, align, size);
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if ret != 0 {
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ptr::null_mut()
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} else {
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out as *mut u8
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}
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}
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}
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#[cfg(windows)]
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#[allow(bad_style)]
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mod platform {
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use super::MIN_ALIGN;
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type LPVOID = *mut u8;
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type HANDLE = LPVOID;
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type SIZE_T = usize;
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type DWORD = u32;
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type BOOL = i32;
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extern "system" {
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fn GetProcessHeap() -> HANDLE;
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fn HeapAlloc(hHeap: HANDLE, dwFlags: DWORD, dwBytes: SIZE_T) -> LPVOID;
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fn HeapFree(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID) -> BOOL;
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fn GetLastError() -> DWORD;
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}
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#[repr(C)]
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struct Header(*mut u8);
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unsafe fn get_header<'a>(ptr: *mut u8) -> &'a mut Header {
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&mut *(ptr as *mut Header).offset(-1)
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}
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unsafe fn align_ptr(ptr: *mut u8, align: usize) -> *mut u8 {
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let aligned = ptr.offset((align - (ptr as usize & (align - 1))) as isize);
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*get_header(aligned) = Header(ptr);
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aligned
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}
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#[inline]
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unsafe fn allocate_with_flags(size: usize, align: usize, flags: DWORD) -> *mut u8
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{
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if align <= MIN_ALIGN {
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HeapAlloc(GetProcessHeap(), flags, size)
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} else {
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let size = size + align;
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let ptr = HeapAlloc(GetProcessHeap(), flags, size);
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if ptr.is_null() {
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ptr
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} else {
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align_ptr(ptr, align)
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}
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}
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}
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#[inline]
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pub unsafe fn alloc(size: usize, align: usize) -> *mut u8 {
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allocate_with_flags(size, align, 0)
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}
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#[inline]
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pub unsafe fn dealloc(ptr: *mut u8, align: usize) {
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if align <= MIN_ALIGN {
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let err = HeapFree(GetProcessHeap(), 0, ptr as LPVOID);
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debug_assert!(err != 0, "Failed to free heap memory: {}",
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GetLastError());
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} else {
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let header = get_header(ptr);
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let err = HeapFree(GetProcessHeap(), 0, header.0 as LPVOID);
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debug_assert!(err != 0, "Failed to free heap memory: {}",
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GetLastError());
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}
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}
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}
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@ -1,14 +1,16 @@
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#![feature(allocator_api)]
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#![feature(alloc)]
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extern crate alloc;
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pub use std::*;
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mod bench;
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mod table;
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mod shim;
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#[path="alloc.rs"]
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mod alloc2;
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pub mod hash_map;
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pub mod hash_set;
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