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//! Test using `Bytes` with an allocator that hands out "odd" pointers for
//! vectors (pointers where the LSB is set).
#![cfg(not(miri))] // Miri does not support custom allocators (also, Miri is "odd" by default with 50% chance)
use std::alloc::{GlobalAlloc, Layout, System};
use std::ptr;
use bytes::Bytes;
#[global_allocator]
static ODD: Odd = Odd;
struct Odd;
unsafe impl GlobalAlloc for Odd {
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
if layout.align() == 1 && layout.size() > 0 {
// Allocate slightly bigger so that we can offset the pointer by 1
let size = layout.size() + 1;
let new_layout = match Layout::from_size_align(size, 1) {
Ok(layout) => layout,
Err(_err) => return ptr::null_mut(),
};
let ptr = System.alloc(new_layout);
if !ptr.is_null() {
ptr.offset(1)
} else {
ptr
}
} else {
System.alloc(layout)
}
}
unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
if layout.align() == 1 && layout.size() > 0 {
let size = layout.size() + 1;
let new_layout = match Layout::from_size_align(size, 1) {
Ok(layout) => layout,
Err(_err) => std::process::abort(),
};
System.dealloc(ptr.offset(-1), new_layout);
} else {
System.dealloc(ptr, layout);
}
}
}
#[test]
fn sanity_check_odd_allocator() {
let vec = vec![33u8; 1024];
let p = vec.as_ptr() as usize;
assert!(p & 0x1 == 0x1, "{:#b}", p);
}
#[test]
fn test_bytes_from_vec_drop() {
let vec = vec![33u8; 1024];
let _b = Bytes::from(vec);
}
#[test]
fn test_bytes_clone_drop() {
let vec = vec![33u8; 1024];
let b1 = Bytes::from(vec);
let _b2 = b1.clone();
}
#[test]
fn test_bytes_into_vec() {
let vec = vec![33u8; 1024];
// Test cases where kind == KIND_VEC
let b1 = Bytes::from(vec.clone());
assert_eq!(Vec::from(b1), vec);
// Test cases where kind == KIND_ARC, ref_cnt == 1
let b1 = Bytes::from(vec.clone());
drop(b1.clone());
assert_eq!(Vec::from(b1), vec);
// Test cases where kind == KIND_ARC, ref_cnt == 2
let b1 = Bytes::from(vec.clone());
let b2 = b1.clone();
assert_eq!(Vec::from(b1), vec);
// Test cases where vtable = SHARED_VTABLE, kind == KIND_ARC, ref_cnt == 1
assert_eq!(Vec::from(b2), vec);
// Test cases where offset != 0
let mut b1 = Bytes::from(vec.clone());
let b2 = b1.split_off(20);
assert_eq!(Vec::from(b2), vec[20..]);
assert_eq!(Vec::from(b1), vec[..20]);
}