46 lines
1.3 KiB
Rust
46 lines
1.3 KiB
Rust
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#![cfg(feature = "std")]
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use core::ptr::null_mut;
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use core::slice::{from_raw_parts, from_raw_parts_mut};
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use nix::sys::mman;
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/* from linux kernel headers.
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#define HUGETLB_FLAG_ENCODE_SHIFT 26
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#define HUGETLB_FLAG_ENCODE_MASK 0x3f
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#define HUGETLB_FLAG_ENCODE_64KB (16 << HUGETLB_FLAG_ENCODE_SHIFT)
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#define HUGETLB_FLAG_ENCODE_512KB (19 << HUGETLB_FLAG_ENCODE_SHIFT)
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#define HUGETLB_FLAG_ENCODE_1MB (20 << HUGETLB_FLAG_ENCODE_SHIFT)
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#define HUGETLB_FLAG_ENCODE_2MB (21 << HUGETLB_FLAG_ENCODE_SHIFT)
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*/
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pub struct MMappedMemory {
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pointer: *mut u8,
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size: usize,
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}
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impl MMappedMemory {
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pub unsafe fn new(size: usize) -> MMappedMemory {
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let p: *mut u8 = mman::mmap(
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null_mut(),
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size,
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mman::ProtFlags::PROT_READ | mman::ProtFlags::PROT_WRITE,
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mman::MapFlags::MAP_PRIVATE
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| mman::MapFlags::MAP_ANONYMOUS
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| mman::MapFlags::MAP_HUGETLB,
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-1,
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0,
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)
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.unwrap() as *mut u8;
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MMappedMemory { pointer: p, size }
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}
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pub fn slice(&self) -> &[u8] {
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unsafe { from_raw_parts(self.pointer, self.size) }
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}
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pub fn slice_mut(&self) -> &mut [u8] {
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unsafe { from_raw_parts_mut(self.pointer, self.size) }
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}
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}
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