llvm/compiler-rt/lib/scudo/standalone/release.h

//===-- release.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
//
//===----------------------------------------------------------------------===//

#ifndef SCUDO_RELEASE_H_
#define SCUDO_RELEASE_H_

#include "common.h"
#include "list.h"
#include "mem_map.h"
#include "mutex.h"
#include "thread_annotations.h"

namespace scudo {

template <typename MemMapT> class RegionReleaseRecorder { … };

class ReleaseRecorder { … };

class FragmentationRecorder { … };

template <uptr GroupSize, uptr NumGroups>
class MemoryGroupFragmentationRecorder { … };

// A buffer pool which holds a fixed number of static buffers of `uptr` elements
// for fast buffer allocation. If the request size is greater than
// `StaticBufferNumElements` or if all the static buffers are in use, it'll
// delegate the allocation to map().
template <uptr StaticBufferCount, uptr StaticBufferNumElements>
class BufferPool { … };

// A Region page map is used to record the usage of pages in the regions. It
// implements a packed array of Counters. Each counter occupies 2^N bits, enough
// to store counter's MaxValue. Ctor will try to use a static buffer first, and
// if that fails (the buffer is too small or already locked), will allocate the
// required Buffer via map(). The caller is expected to check whether the
// initialization was successful by checking isAllocated() result. For
// performance sake, none of the accessors check the validity of the arguments,
// It is assumed that Index is always in [0, N) range and the value is not
// incremented past MaxValue.
class RegionPageMap { … };

template <class ReleaseRecorderT> class FreePagesRangeTracker { … };

struct PageReleaseContext { … };

// Try to release the page which doesn't have any in-used block, i.e., they are
// all free blocks. The `PageMap` will record the number of free blocks in each
// page.
template <class ReleaseRecorderT, typename SkipRegionT>
NOINLINE void
releaseFreeMemoryToOS(PageReleaseContext &Context,
                      ReleaseRecorderT &Recorder, SkipRegionT SkipRegion) { … }

} // namespace scudo

#endif // SCUDO_RELEASE_H_