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

//===-- sanitizer_allocator_secondary.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

// Fixed array to store LargeMmapAllocator chunks list, limited to 32K total
// allocated chunks. To be used in memory constrained or not memory hungry cases
// (currently, 32 bits and internal allocator).
class LargeMmapAllocatorPtrArrayStatic { … };

// Much less restricted LargeMmapAllocator chunks list (comparing to
// PtrArrayStatic). Backed by mmaped memory region and can hold up to 1M chunks.
// ReservedAddressRange was used instead of just MAP_NORESERVE to achieve the
// same functionality in Fuchsia case, which does not support MAP_NORESERVE.
class LargeMmapAllocatorPtrArrayDynamic { … };

#if SANITIZER_WORDSIZE == 32
typedef LargeMmapAllocatorPtrArrayStatic DefaultLargeMmapAllocatorPtrArray;
#else
DefaultLargeMmapAllocatorPtrArray;
#endif

// This class can (de)allocate only large chunks of memory using mmap/unmap.
// The main purpose of this allocator is to cover large and rare allocation
// sizes not covered by more efficient allocators (e.g. SizeClassAllocator64).
template <class MapUnmapCallback = NoOpMapUnmapCallback,
          class PtrArrayT = DefaultLargeMmapAllocatorPtrArray,
          class AddressSpaceViewTy = LocalAddressSpaceView>
class LargeMmapAllocator { … };