54 lines
1.2 KiB
C++
54 lines
1.2 KiB
C++
#pragma once
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#include "pal_bsd.h"
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namespace snmalloc
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{
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/**
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* FreeBSD-specific platform abstraction layer.
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*
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* This adds aligned allocation using `MAP_ALIGNED` to the generic BSD
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* implementation. This flag is supported by NetBSD and FreeBSD.
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*/
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template<class OS>
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class PALBSD_Aligned : public PALBSD<OS>
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{
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public:
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/**
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* Bitmap of PalFeatures flags indicating the optional features that this
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* PAL supports.
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*
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* This class adds support for aligned allocation.
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*/
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static constexpr uint64_t pal_features =
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AlignedAllocation | PALBSD<OS>::pal_features;
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/**
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* Reserve memory at a specific alignment.
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*/
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template<bool committed>
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void* reserve(size_t size, size_t align) noexcept
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{
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// Alignment must be a power of 2.
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SNMALLOC_ASSERT(align == bits::next_pow2(align));
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align = bits::max<size_t>(4096, align);
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size_t log2align = bits::next_pow2_bits(align);
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void* p = mmap(
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nullptr,
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size,
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PROT_READ | PROT_WRITE,
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MAP_PRIVATE | MAP_ANONYMOUS | MAP_ALIGNED(log2align),
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-1,
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0);
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if (p == MAP_FAILED)
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PALBSD<OS>::error("Out of memory");
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return p;
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}
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};
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} // namespace snmalloc
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