twizzler_rt_abi/
alloc.rs

1//! Functions for allocating memory from the runtime.
2
3use core::alloc::Layout;
4
5use crate::nk;
6
7bitflags::bitflags! {
8    /// Flags for allocation functions.
9    pub struct AllocFlags : crate::bindings::alloc_flags {
10        /// Zero memory. The memory zeroed depends on the function called.
11        const ZERO_MEMORY = crate::bindings::ZERO_MEMORY;
12    }
13}
14
15/// Allocate runtime memory with the given layout and flags. Returns None on allocation failure.
16///
17/// # Flags
18///   - ZERO_MEMORY: Zero the newly-allocated memory before returning it to the user.
19pub fn twz_rt_malloc(layout: Layout, flags: AllocFlags) -> Option<*mut u8> {
20    unsafe {
21        let ptr = nk!(crate::bindings::twz_rt_malloc(
22            layout.size(),
23            layout.align(),
24            flags.bits()
25        ));
26        if ptr.is_null() {
27            None
28        } else {
29            Some(ptr.cast())
30        }
31    }
32}
33
34/// Reallocate runtime memory pointed to by ptr, with a given layout and flags, to new_size. The new
35/// size can be larger or smaller than the original, and may move while maintaining layout
36/// constraints. If the allocation moves, the old memory will be copied over and automatically
37/// freed.
38///
39/// # Safety
40/// Caller must ensure that any no other references to this memory are alive.
41///
42/// # Flags
43///   - ZERO_MEMORY: If the allocation size grows, zero the newly-allocated memory before returning
44///     it to the user. If the allocation size shrinks, zero the old, now unused, part of the memory
45///     before freeing. If the allocation moves, zero the old allocation before freeing.
46pub unsafe fn twz_rt_realloc(
47    ptr: *mut u8,
48    layout: Layout,
49    new_size: usize,
50    flags: AllocFlags,
51) -> Option<*mut u8> {
52    unsafe {
53        let ptr = nk!(crate::bindings::twz_rt_realloc(
54            ptr.cast(),
55            layout.size(),
56            layout.align(),
57            new_size,
58            flags.bits(),
59        ));
60        if ptr.is_null() {
61            None
62        } else {
63            Some(ptr.cast())
64        }
65    }
66}
67
68/// Deallocate runtime memory pointed to by ptr, with a given layout and flags.
69///
70/// # Safety
71/// Caller must ensure that any no other references to this memory are alive.
72///
73/// # Flags
74///   - ZERO_MEMORY: Zero the old memory before freeing.
75pub unsafe fn twz_rt_dealloc(ptr: *mut u8, layout: Layout, flags: AllocFlags) {
76    unsafe {
77        nk!(crate::bindings::twz_rt_dealloc(
78            ptr.cast(),
79            layout.size(),
80            layout.align(),
81            flags.bits()
82        ))
83    }
84}
twizzler_rt_abi/alloc.rs

twizzler_rt_abi/
alloc.rs
