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