diff options
Diffstat (limited to 'src/liballoc_system')
| -rw-r--r-- | src/liballoc_system/Cargo.toml | 19 | ||||
| -rw-r--r-- | src/liballoc_system/lib.rs | 411 |
2 files changed, 0 insertions, 430 deletions
diff --git a/src/liballoc_system/Cargo.toml b/src/liballoc_system/Cargo.toml deleted file mode 100644 index c34e2f203a8..00000000000 --- a/src/liballoc_system/Cargo.toml +++ /dev/null @@ -1,19 +0,0 @@ -[package] -authors = ["The Rust Project Developers"] -name = "alloc_system" -version = "0.0.0" - -[lib] -name = "alloc_system" -path = "lib.rs" -test = false -doc = false - -[dependencies] -core = { path = "../libcore" } -libc = { path = "../rustc/libc_shim" } -compiler_builtins = { path = "../rustc/compiler_builtins_shim" } - -# See comments in the source for what this dependency is -[target.'cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))'.dependencies] -dlmalloc = { path = "../rustc/dlmalloc_shim" } diff --git a/src/liballoc_system/lib.rs b/src/liballoc_system/lib.rs deleted file mode 100644 index 0e6887a5082..00000000000 --- a/src/liballoc_system/lib.rs +++ /dev/null @@ -1,411 +0,0 @@ -// Copyright 2015 The Rust Project Developers. See the COPYRIGHT -// file at the top-level directory of this distribution and at -// http://rust-lang.org/COPYRIGHT. -// -// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or -// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license -// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your -// option. This file may not be copied, modified, or distributed -// except according to those terms. - -#![no_std] -#![allow(unused_attributes)] -#![unstable(feature = "alloc_system", - reason = "this library is unlikely to be stabilized in its current \ - form or name", - issue = "32838")] - -#![feature(allocator_api)] -#![feature(core_intrinsics)] -#![feature(nll)] -#![feature(staged_api)] -#![feature(rustc_attrs)] -#![cfg_attr( - all(target_arch = "wasm32", not(target_os = "emscripten")), - feature(integer_atomics, stdsimd) -)] -#![cfg_attr(any(unix, target_os = "cloudabi", target_os = "redox"), feature(libc))] -#![rustc_alloc_kind = "lib"] - -// The minimum alignment guaranteed by the architecture. This value is used to -// add fast paths for low alignment values. -#[cfg(all(any(target_arch = "x86", - target_arch = "arm", - target_arch = "mips", - target_arch = "powerpc", - target_arch = "powerpc64", - target_arch = "asmjs", - target_arch = "wasm32")))] -#[allow(dead_code)] -const MIN_ALIGN: usize = 8; -#[cfg(all(any(target_arch = "x86_64", - target_arch = "aarch64", - target_arch = "mips64", - target_arch = "s390x", - target_arch = "sparc64")))] -#[allow(dead_code)] -const MIN_ALIGN: usize = 16; - -use core::alloc::{Alloc, GlobalAlloc, AllocErr, Layout}; -use core::ptr::NonNull; - -/// The default memory allocator provided by the operating system. -/// -/// This is based on `malloc` on Unix platforms and `HeapAlloc` on Windows, -/// plus related functions. -/// -/// This type can be used in a `static` item -/// with the `#[global_allocator]` attribute -/// to force the global allocator to be the system’s one. -/// (The default is jemalloc for executables, on some platforms.) -/// -/// ```rust -/// use std::alloc::System; -/// -/// #[global_allocator] -/// static A: System = System; -/// -/// fn main() { -/// let a = Box::new(4); // Allocates from the system allocator. -/// println!("{}", a); -/// } -/// ``` -/// -/// It can also be used directly to allocate memory -/// independently of the standard library’s global allocator. -#[stable(feature = "alloc_system_type", since = "1.28.0")] -pub struct System; - -#[unstable(feature = "allocator_api", issue = "32838")] -unsafe impl Alloc for System { - #[inline] - unsafe fn alloc(&mut self, layout: Layout) -> Result<NonNull<u8>, AllocErr> { - NonNull::new(GlobalAlloc::alloc(self, layout)).ok_or(AllocErr) - } - - #[inline] - unsafe fn alloc_zeroed(&mut self, layout: Layout) -> Result<NonNull<u8>, AllocErr> { - NonNull::new(GlobalAlloc::alloc_zeroed(self, layout)).ok_or(AllocErr) - } - - #[inline] - unsafe fn dealloc(&mut self, ptr: NonNull<u8>, layout: Layout) { - GlobalAlloc::dealloc(self, ptr.as_ptr(), layout) - } - - #[inline] - unsafe fn realloc(&mut self, - ptr: NonNull<u8>, - layout: Layout, - new_size: usize) -> Result<NonNull<u8>, AllocErr> { - NonNull::new(GlobalAlloc::realloc(self, ptr.as_ptr(), layout, new_size)).ok_or(AllocErr) - } -} - -#[cfg(any(windows, unix, target_os = "cloudabi", target_os = "redox"))] -mod realloc_fallback { - use core::alloc::{GlobalAlloc, Layout}; - use core::cmp; - use core::ptr; - - impl super::System { - pub(crate) unsafe fn realloc_fallback(&self, ptr: *mut u8, old_layout: Layout, - new_size: usize) -> *mut u8 { - // Docs for GlobalAlloc::realloc require this to be valid: - let new_layout = Layout::from_size_align_unchecked(new_size, old_layout.align()); - - let new_ptr = GlobalAlloc::alloc(self, new_layout); - if !new_ptr.is_null() { - let size = cmp::min(old_layout.size(), new_size); - ptr::copy_nonoverlapping(ptr, new_ptr, size); - GlobalAlloc::dealloc(self, ptr, old_layout); - } - new_ptr - } - } -} - -#[cfg(any(unix, target_os = "cloudabi", target_os = "redox"))] -mod platform { - extern crate libc; - - use core::ptr; - - use MIN_ALIGN; - use System; - use core::alloc::{GlobalAlloc, Layout}; - - #[stable(feature = "alloc_system_type", since = "1.28.0")] - unsafe impl GlobalAlloc for System { - #[inline] - unsafe fn alloc(&self, layout: Layout) -> *mut u8 { - if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() { - libc::malloc(layout.size()) as *mut u8 - } else { - #[cfg(target_os = "macos")] - { - if layout.align() > (1 << 31) { - return ptr::null_mut() - } - } - aligned_malloc(&layout) - } - } - - #[inline] - unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 { - if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() { - libc::calloc(layout.size(), 1) as *mut u8 - } else { - let ptr = self.alloc(layout.clone()); - if !ptr.is_null() { - ptr::write_bytes(ptr, 0, layout.size()); - } - ptr - } - } - - #[inline] - unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) { - libc::free(ptr as *mut libc::c_void) - } - - #[inline] - unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 { - if layout.align() <= MIN_ALIGN && layout.align() <= new_size { - libc::realloc(ptr as *mut libc::c_void, new_size) as *mut u8 - } else { - self.realloc_fallback(ptr, layout, new_size) - } - } - } - - #[cfg(any(target_os = "android", - target_os = "hermit", - target_os = "redox", - target_os = "solaris"))] - #[inline] - unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 { - // On android we currently target API level 9 which unfortunately - // doesn't have the `posix_memalign` API used below. Instead we use - // `memalign`, but this unfortunately has the property on some systems - // where the memory returned cannot be deallocated by `free`! - // - // Upon closer inspection, however, this appears to work just fine with - // Android, so for this platform we should be fine to call `memalign` - // (which is present in API level 9). Some helpful references could - // possibly be chromium using memalign [1], attempts at documenting that - // memalign + free is ok [2] [3], or the current source of chromium - // which still uses memalign on android [4]. - // - // [1]: https://codereview.chromium.org/10796020/ - // [2]: https://code.google.com/p/android/issues/detail?id=35391 - // [3]: https://bugs.chromium.org/p/chromium/issues/detail?id=138579 - // [4]: https://chromium.googlesource.com/chromium/src/base/+/master/ - // /memory/aligned_memory.cc - libc::memalign(layout.align(), layout.size()) as *mut u8 - } - - #[cfg(not(any(target_os = "android", - target_os = "hermit", - target_os = "redox", - target_os = "solaris")))] - #[inline] - unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 { - let mut out = ptr::null_mut(); - let ret = libc::posix_memalign(&mut out, layout.align(), layout.size()); - if ret != 0 { - ptr::null_mut() - } else { - out as *mut u8 - } - } -} - -#[cfg(windows)] -#[allow(nonstandard_style)] -mod platform { - use MIN_ALIGN; - use System; - use core::alloc::{GlobalAlloc, Layout}; - - type LPVOID = *mut u8; - type HANDLE = LPVOID; - type SIZE_T = usize; - type DWORD = u32; - type BOOL = i32; - - extern "system" { - fn GetProcessHeap() -> HANDLE; - fn HeapAlloc(hHeap: HANDLE, dwFlags: DWORD, dwBytes: SIZE_T) -> LPVOID; - fn HeapReAlloc(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID, dwBytes: SIZE_T) -> LPVOID; - fn HeapFree(hHeap: HANDLE, dwFlags: DWORD, lpMem: LPVOID) -> BOOL; - fn GetLastError() -> DWORD; - } - - #[repr(C)] - struct Header(*mut u8); - - const HEAP_ZERO_MEMORY: DWORD = 0x00000008; - - unsafe fn get_header<'a>(ptr: *mut u8) -> &'a mut Header { - &mut *(ptr as *mut Header).offset(-1) - } - - unsafe fn align_ptr(ptr: *mut u8, align: usize) -> *mut u8 { - let aligned = ptr.add(align - (ptr as usize & (align - 1))); - *get_header(aligned) = Header(ptr); - aligned - } - - #[inline] - unsafe fn allocate_with_flags(layout: Layout, flags: DWORD) -> *mut u8 { - let ptr = if layout.align() <= MIN_ALIGN { - HeapAlloc(GetProcessHeap(), flags, layout.size()) - } else { - let size = layout.size() + layout.align(); - let ptr = HeapAlloc(GetProcessHeap(), flags, size); - if ptr.is_null() { - ptr - } else { - align_ptr(ptr, layout.align()) - } - }; - ptr as *mut u8 - } - - #[stable(feature = "alloc_system_type", since = "1.28.0")] - unsafe impl GlobalAlloc for System { - #[inline] - unsafe fn alloc(&self, layout: Layout) -> *mut u8 { - allocate_with_flags(layout, 0) - } - - #[inline] - unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 { - allocate_with_flags(layout, HEAP_ZERO_MEMORY) - } - - #[inline] - unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) { - if layout.align() <= MIN_ALIGN { - let err = HeapFree(GetProcessHeap(), 0, ptr as LPVOID); - debug_assert!(err != 0, "Failed to free heap memory: {}", - GetLastError()); - } else { - let header = get_header(ptr); - let err = HeapFree(GetProcessHeap(), 0, header.0 as LPVOID); - debug_assert!(err != 0, "Failed to free heap memory: {}", - GetLastError()); - } - } - - #[inline] - unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 { - if layout.align() <= MIN_ALIGN { - HeapReAlloc(GetProcessHeap(), 0, ptr as LPVOID, new_size) as *mut u8 - } else { - self.realloc_fallback(ptr, layout, new_size) - } - } - } -} - -// This is an implementation of a global allocator on the wasm32 platform when -// emscripten is not in use. In that situation there's no actual runtime for us -// to lean on for allocation, so instead we provide our own! -// -// The wasm32 instruction set has two instructions for getting the current -// amount of memory and growing the amount of memory. These instructions are the -// foundation on which we're able to build an allocator, so we do so! Note that -// the instructions are also pretty "global" and this is the "global" allocator -// after all! -// -// The current allocator here is the `dlmalloc` crate which we've got included -// in the rust-lang/rust repository as a submodule. The crate is a port of -// dlmalloc.c from C to Rust and is basically just so we can have "pure Rust" -// for now which is currently technically required (can't link with C yet). -// -// The crate itself provides a global allocator which on wasm has no -// synchronization as there are no threads! -#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))] -mod platform { - extern crate dlmalloc; - - use core::alloc::{GlobalAlloc, Layout}; - use System; - - static mut DLMALLOC: dlmalloc::Dlmalloc = dlmalloc::DLMALLOC_INIT; - - #[stable(feature = "alloc_system_type", since = "1.28.0")] - unsafe impl GlobalAlloc for System { - #[inline] - unsafe fn alloc(&self, layout: Layout) -> *mut u8 { - let _lock = lock::lock(); - DLMALLOC.malloc(layout.size(), layout.align()) - } - - #[inline] - unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 { - let _lock = lock::lock(); - DLMALLOC.calloc(layout.size(), layout.align()) - } - - #[inline] - unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) { - let _lock = lock::lock(); - DLMALLOC.free(ptr, layout.size(), layout.align()) - } - - #[inline] - unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 { - let _lock = lock::lock(); - DLMALLOC.realloc(ptr, layout.size(), layout.align(), new_size) - } - } - - #[cfg(target_feature = "atomics")] - mod lock { - use core::arch::wasm32; - use core::sync::atomic::{AtomicI32, Ordering::SeqCst}; - - static LOCKED: AtomicI32 = AtomicI32::new(0); - - pub struct DropLock; - - pub fn lock() -> DropLock { - loop { - if LOCKED.swap(1, SeqCst) == 0 { - return DropLock - } - unsafe { - let r = wasm32::atomic::wait_i32( - &LOCKED as *const AtomicI32 as *mut i32, - 1, // expected value - -1, // timeout - ); - debug_assert!(r == 0 || r == 1); - } - } - } - - impl Drop for DropLock { - fn drop(&mut self) { - let r = LOCKED.swap(0, SeqCst); - debug_assert_eq!(r, 1); - unsafe { - wasm32::atomic::wake( - &LOCKED as *const AtomicI32 as *mut i32, - 1, // only one thread - ); - } - } - } - } - - #[cfg(not(target_feature = "atomics"))] - mod lock { - #[inline] - pub fn lock() {} // no atomics, no threads, that's easy! - } -} |