llvm/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h

//===-- sanitizer_allocator_primary64.h -------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Part of the Sanitizer Allocator.
//
//===----------------------------------------------------------------------===//
#ifndef SANITIZER_ALLOCATOR_H
#error This file must be included inside sanitizer_allocator.h
#endif

template<class SizeClassAllocator> struct SizeClassAllocator64LocalCache;

// SizeClassAllocator64 -- allocator for 64-bit address space.
// The template parameter Params is a class containing the actual parameters.
//
// Space: a portion of address space of kSpaceSize bytes starting at SpaceBeg.
// If kSpaceBeg is ~0 then SpaceBeg is chosen dynamically by mmap.
// Otherwise SpaceBeg=kSpaceBeg (fixed address).
// kSpaceSize is a power of two.
// At the beginning the entire space is mprotect-ed, then small parts of it
// are mapped on demand.
//
// Region: a part of Space dedicated to a single size class.
// There are kNumClasses Regions of equal size.
//
// UserChunk: a piece of memory returned to user.
// MetaChunk: kMetadataSize bytes of metadata associated with a UserChunk.

// FreeArray is an array free-d chunks (stored as 4-byte offsets)
//
// A Region looks like this:
// UserChunk1 ... UserChunkN <gap> MetaChunkN ... MetaChunk1 FreeArray

struct SizeClassAllocator64FlagMasks { … };

template <typename Allocator>
class MemoryMapper { … };

template <class Params>
class SizeClassAllocator64 { … };