sourceturner
49 lines
1.4 KiB
Rust
49 lines
1.4 KiB
Rust
//! `malloc.h` implementation.
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//!
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//! Non-POSIX, see <https://man7.org/linux/man-pages/man3/posix_memalign.3.html>.
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use crate::{
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header::errno::ENOMEM,
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platform::{
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self, ERRNO, Pal, Sys,
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types::{c_void, size_t},
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},
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};
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use core::ptr;
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/// See <https://man7.org/linux/man-pages/man3/posix_memalign.3.html>.
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#[deprecated]
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#[unsafe(no_mangle)]
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pub unsafe extern "C" fn pvalloc(size: size_t) -> *mut c_void {
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let page_size = Sys::getpagesize();
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// Find the smallest multiple of the page size in which the requested size
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// will fit. The result of the division will always be less than or equal
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// to size_t::MAX - 1, and the num_pages calculation will therefore never
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// overflow.
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let num_pages = if size != 0 {
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(size - 1) / page_size + 1
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} else {
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0
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};
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match num_pages.checked_mul(page_size) {
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Some(alloc_size) => {
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let ptr = unsafe { platform::alloc_align(alloc_size, page_size) };
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if ptr.is_null() {
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platform::ERRNO.set(ENOMEM);
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}
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ptr
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}
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None => {
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platform::ERRNO.set(ENOMEM);
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ptr::null_mut()
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}
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}
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}
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/// See <https://man7.org/linux/man-pages/man3/malloc_usable_size.3.html>.
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#[unsafe(no_mangle)]
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pub unsafe extern "C" fn malloc_usable_size(ptr: *mut c_void) -> size_t {
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unsafe { platform::alloc_usable_size(ptr) }
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}
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