42 lines
1.2 KiB
Rust
42 lines
1.2 KiB
Rust
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#![feature(allocator_api, slice_ptr_get)]
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use std::alloc::{Allocator as _, Global, GlobalAlloc, Layout, System};
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#[global_allocator]
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static ALLOCATOR: Allocator = Allocator;
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struct Allocator;
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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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// use specific size to avoid getting triggered by rt
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if layout.size() == 123 {
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println!("Allocated!")
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}
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System.alloc(layout)
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}
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unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
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if layout.size() == 123 {
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println!("Dellocated!")
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}
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System.dealloc(ptr, layout)
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}
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}
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fn main() {
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// Only okay because we explicitly set a global allocator that uses the system allocator!
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let l = Layout::from_size_align(123, 1).unwrap();
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let ptr = Global.allocate(l).unwrap().as_non_null_ptr(); // allocating with Global...
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unsafe {
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System.deallocate(ptr, l);
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} // ... and deallocating with System.
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let ptr = System.allocate(l).unwrap().as_non_null_ptr(); // allocating with System...
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unsafe {
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Global.deallocate(ptr, l);
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} // ... and deallocating with Global.
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}
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