twizzler_rt_abi/
alloc.rs

1//! Functions for allocating memory from the runtime.
2
3use core::alloc::Layout;
4
5bitflags::bitflags! {
6    /// Flags for allocation functions.
7    pub struct AllocFlags : crate::bindings::alloc_flags {
8        /// Zero memory. The memory zeroed depends on the function called.
9        const ZERO_MEMORY = crate::bindings::ZERO_MEMORY;
10    }
11}
12
13/// Allocate runtime memory with the given layout and flags. Returns None on allocation failure.
14///
15/// # Flags
16///   - ZERO_MEMORY: Zero the newly-allocated memory before returning it to the user.
17pub fn twz_rt_malloc(layout: Layout, flags: AllocFlags) -> Option<*mut u8> {
18    unsafe {
19        let ptr = crate::bindings::twz_rt_malloc(layout.size(), layout.align(), flags.bits());
20        if ptr.is_null() {
21            None
22        } else {
23            Some(ptr.cast())
24        }
25    }
26}
27
28/// Reallocate runtime memory pointed to by ptr, with a given layout and flags, to new_size. The new
29/// size can be larger or smaller than the original, and may move while maintaining layout
30/// constraints. If the allocation moves, the old memory will be copied over and automatically
31/// freed.
32///
33/// # Safety
34/// Caller must ensure that any no other references to this memory are alive.
35///
36/// # Flags
37///   - ZERO_MEMORY: If the allocation size grows, zero the newly-allocated memory before returning
38///     it to the user. If the allocation size shrinks, zero the old, now unused, part of the memory
39///     before freeing. If the allocation moves, zero the old allocation before freeing.
40pub unsafe fn twz_rt_realloc(
41    ptr: *mut u8,
42    layout: Layout,
43    new_size: usize,
44    flags: AllocFlags,
45) -> Option<*mut u8> {
46    unsafe {
47        let ptr = crate::bindings::twz_rt_realloc(
48            ptr.cast(),
49            layout.size(),
50            layout.align(),
51            new_size,
52            flags.bits(),
53        );
54        if ptr.is_null() {
55            None
56        } else {
57            Some(ptr.cast())
58        }
59    }
60}
61
62/// Deallocate runtime memory pointed to by ptr, with a given layout and flags.
63///
64/// # Safety
65/// Caller must ensure that any no other references to this memory are alive.
66///
67/// # Flags
68///   - ZERO_MEMORY: Zero the old memory before freeing.
69pub unsafe fn twz_rt_dealloc(ptr: *mut u8, layout: Layout, flags: AllocFlags) {
70    unsafe {
71        crate::bindings::twz_rt_dealloc(ptr.cast(), layout.size(), layout.align(), flags.bits())
72    }
73}
twizzler_rt_abi/alloc.rs

twizzler_rt_abi/
alloc.rs
