xref: /wasmtime-44.0.1/crates/core/src/alloc.rs (revision 63ecb815)
1 //! Low-level allocation and OOM-handling utilities.
2 
3 mod arc;
4 mod boxed;
5 mod try_new;
6 mod vec;
7 
8 pub use boxed::{BoxedSliceFromIterError, new_boxed_slice_from_iter};
9 pub use try_new::{TryNew, try_new};
10 pub use vec::Vec;
11 
12 use crate::error::OutOfMemory;
13 use core::{alloc::Layout, ptr::NonNull};
14 
15 /// Try to allocate a block of memory that fits the given layout, or return an
16 /// `OutOfMemory` error.
17 ///
18 /// # Safety
19 ///
20 /// Same as `alloc::alloc::alloc`: layout must have non-zero size.
21 #[inline]
22 unsafe fn try_alloc(layout: Layout) -> Result<NonNull<u8>, OutOfMemory> {
23     // Safety: same as our safety conditions.
24     debug_assert!(layout.size() > 0);
25     let ptr = unsafe { std_alloc::alloc::alloc(layout) };
26 
27     if let Some(ptr) = NonNull::new(ptr) {
28         Ok(ptr)
29     } else {
30         Err(OutOfMemory::new(layout.size()))
31     }
32 }
33