forked from GitHub/bdwgc-rust
69 lines
1.7 KiB
Rust
69 lines
1.7 KiB
Rust
extern crate libc;
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mod error;
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use libc::{c_int, c_void, size_t};
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use std::alloc::{GlobalAlloc, Layout};
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const GC_SUCCESS: c_int = 0;
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const ALLOC_ALIGN: usize = 8;
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#[repr(C)]
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struct GCStackBase {
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mem_base: *const c_void,
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reg_base: *const c_void,
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}
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#[link(name = "gc")]
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extern "C" {
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fn GC_allow_register_threads() -> c_void;
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fn GC_free(ptr: *mut c_void);
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fn GC_get_stack_base(stack_base: *mut GCStackBase) -> c_int;
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fn GC_init() -> c_void;
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fn GC_malloc(size: size_t) -> *mut c_void;
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fn GC_register_my_thread(stack_base: *const GCStackBase) -> c_int;
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fn GC_unregister_my_thread();
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}
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pub struct Allocator;
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impl Allocator {
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pub unsafe fn initialize() {
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GC_init();
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GC_allow_register_threads();
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}
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pub fn register_current_thread() -> Result<(), error::Error> {
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let mut base = GCStackBase {
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mem_base: std::ptr::null(),
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reg_base: std::ptr::null(),
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};
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if unsafe { GC_get_stack_base(&mut base) } != GC_SUCCESS {
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return Err(error::Error::new("failed to get stack base"));
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} else if unsafe { GC_register_my_thread(&base) } != GC_SUCCESS {
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return Err(error::Error::new("failed to register a thread for GC"));
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}
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Ok(())
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}
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pub fn unregister_current_thread() {
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unsafe { GC_unregister_my_thread() }
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}
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pub fn alloc(size: usize) -> *mut u8 {
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unsafe { Allocator.alloc(Layout::from_size_align_unchecked(size, ALLOC_ALIGN)) }
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}
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}
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unsafe impl GlobalAlloc for Allocator {
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unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
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GC_malloc(layout.size()) as *mut u8
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}
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unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
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GC_free(ptr as *mut c_void)
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}
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}
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