| use crate::alloc::{GlobalAlloc, Layout, System}; |
| use crate::ptr; |
| use crate::sys_common::alloc::{realloc_fallback, MIN_ALIGN}; |
| |
| #[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 { |
| libc::aligned_alloc(layout.align(), layout.size()) as *mut u8 |
| } |
| } |
| |
| #[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 { |
| realloc_fallback(self, ptr, layout, new_size) |
| } |
| } |
| } |