heap/allocator/region_manager.cpp

/*
 * Copyright (c) 2025 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "common_components/heap/allocator/region_manager.h"

#include <algorithm>
#include <cmath>
#include <cstdint>
#include <unistd.h>

#include "common_components/common_runtime/hooks.h"
#include "common_components/heap/allocator/region_desc.h"
#include "common_components/heap/allocator/region_list.h"
#include "common_components/heap/allocator/region_space.h"
#include "common_components/base/c_string.h"
#include "common_components/heap/collector/collector.h"
#include "common_components/heap/collector/marking_collector.h"
#include "common_components/common/base_object.h"
#include "common_components/common/scoped_object_access.h"
#include "common_components/heap/heap.h"
#include "common_components/mutator/mutator.inline.h"
#include "common_components/mutator/mutator_manager.h"
#include "common_components/heap/allocator/fix_heap.h"

#if defined(COMMON_TSAN_SUPPORT)
#include "common_components/sanitizer/sanitizer_interface.h"
#endif
#include "common_components/log/log.h"
#include "common_components/taskpool/taskpool.h"
#include "common_interfaces/base_runtime.h"

#if defined(_WIN64)
#include <sysinfoapi.h>
#endif

namespace common {
uintptr_t RegionDesc::UnitInfo::totalUnitCount = 0;
uintptr_t RegionDesc::UnitInfo::unitInfoStart = 0;
uintptr_t RegionDesc::UnitInfo::heapStartAddress = 0;

static size_t GetPageSize() noexcept
{
#if defined(_WIN64)
    SYSTEM_INFO systeminfo;
    GetSystemInfo(&systeminfo);
    if (systeminfo.dwPageSize != 0) {
        return systeminfo.dwPageSize;
    } else {
        // default page size is 4KB if get system page size failed.
        return 4 * KB;
    }
#elif defined(__APPLE__)
    // default page size is 4KB in MacOS
    return 4 * KB;
#else
    return getpagesize();
#endif
}

// System default page size
const size_t COMMON_PAGE_SIZE = GetPageSize();
const size_t AllocatorUtils::ALLOC_PAGE_SIZE = COMMON_PAGE_SIZE;
// size of huge page is 2048KB.
constexpr size_t HUGE_PAGE_UNIT_NUM = (2048 * KB) / RegionDesc::UNIT_SIZE;

#if defined(GCINFO_DEBUG) && GCINFO_DEBUG
void RegionDesc::DumpRegionDesc(LogType type) const
{
    DLOG(type, "Region index: %zu, type: %s, address: 0x%zx(start=0x%zx)-0x%zx, allocated(B) %zu, live(B) %zu",
         GetUnitIdx(), GetTypeName(), GetRegionBase(), GetRegionStart(), GetRegionEnd(), GetRegionAllocatedSize(),
         GetLiveByteCount());
}

const char* RegionDesc::GetTypeName() const
{
    static constexpr const char* regionNames[] = {
        "undefined region",
        "thread local region",
        "recent fullregion",
        "from region",
        "unmovable from region",
        "to region",
        "full pinned region",
        "recent pinned region",
        "raw pointer pinned region",
        "tl raw pointer region",
        "large region",
        "recent large region",
        "garbage region",
    };
    return regionNames[static_cast<uint8_t>(GetRegionType())];
}
#endif

void RegionDesc::VisitAllObjects(const std::function<void(BaseObject*)>&& func)
{
    uintptr_t allocPtr = GetRegionAllocPtr();
    VisitAllObjectsBefore(std::move(func), GetRegionAllocPtr());
}

void RegionDesc::VisitAllObjectsBefore(const std::function<void(BaseObject *)> &&func, uintptr_t end)
{
    uintptr_t position = GetRegionStart();

    if (IsFixedRegion()) {
        size_t size = static_cast<size_t>(GetRegionCellCount() + 1) * sizeof(uint64_t);
        while (position < end) {
            BaseObject *obj = reinterpret_cast<BaseObject *>(position);
            position += size;
            if (position > end) {
                break;
            }
            if (IsFreePinnedObject(obj)) {
                continue;
            }
            func(obj);
        }
        return;
    } else if (IsLargeRegion() && (position < end)) {
        if (IsJitFortAwaitInstallFlag()) {
            return;
        }
        func(reinterpret_cast<BaseObject *>(GetRegionStart()));
    } else if (IsSmallRegion()) {
        while (position < end) {
            // GetAllocSize should before call func, because object maybe destroy in compact gc.
            func(reinterpret_cast<BaseObject *>(position));
            size_t size = RegionSpace::GetAllocSize(*reinterpret_cast<BaseObject *>(position));
            position += size;
        }
    }
}

void RegionDesc::VisitAllObjectsWithFixedSize(size_t cellCount, const std::function<void(BaseObject*)>&& func)
{
    CHECK_CC(GetRegionType() == RegionType::FIXED_PINNED_REGION ||
        GetRegionType() == RegionType::FULL_FIXED_PINNED_REGION);
    size_t size = (cellCount + 1) * sizeof(uint64_t);
    uintptr_t position = GetRegionStart();
    uintptr_t end = GetRegionAllocPtr();
    while (position < end) {
        // GetAllocSize should before call func, because object maybe destroy in compact gc.
        BaseObject* obj = reinterpret_cast<BaseObject*>(position);
        position += size;
        if (position > end) {
            break;
        }
        func(obj);
    }
}

void RegionDesc::VisitAllObjectsBeforeCopy(const std::function<void(BaseObject*)>&& func)
{
    uintptr_t allocPtr = GetRegionAllocPtr();
    uintptr_t phaseLine = GetCopyLine();
    uintptr_t end = std::min(phaseLine, allocPtr);
    VisitAllObjectsBefore(std::move(func), end);
}

bool RegionDesc::VisitLiveObjectsUntilFalse(const std::function<bool(BaseObject*)>&& func)
{
    // no need to visit this region.
    if (GetLiveByteCount() == 0) {
        return true;
    }

    MarkingCollector& collector = reinterpret_cast<MarkingCollector&>(Heap::GetHeap().GetCollector());
    if (IsLargeRegion()) {
        if (IsJitFortAwaitInstallFlag()) {
            return true;
        }
        return func(reinterpret_cast<BaseObject *>(GetRegionStart()));
    }
    if (IsSmallRegion()) {
        uintptr_t position = GetRegionStart();
        uintptr_t allocPtr = GetRegionAllocPtr();
        while (position < allocPtr) {
            BaseObject* obj = reinterpret_cast<BaseObject*>(position);
            if (collector.IsSurvivedObject(obj) && !func(obj)) { return false; }
            position += RegionSpace::GetAllocSize(*obj);
        }
    }
    return true;
}

void RegionDesc::VisitRememberSetBeforeMarking(const std::function<void(BaseObject*)>& func)
{
    if (IsLargeRegion() && IsJitFortAwaitInstallFlag()) {
        // machine code which is not installed should skip here.
        return;
    }
    uintptr_t end = std::min(GetMarkingLine(), GetRegionAllocPtr());
    GetRSet()->VisitAllMarkedCardBefore(func, GetRegionBaseFast(), end);
}

void RegionDesc::VisitRememberSetBeforeCopy(const std::function<void(BaseObject*)>& func)
{
    if (IsLargeRegion() && IsJitFortAwaitInstallFlag()) {
        // machine code which is not installed should skip here.
        return;
    }
    uintptr_t end = std::min(GetCopyLine(), GetRegionAllocPtr());
    GetRSet()->VisitAllMarkedCardBefore(func, GetRegionBaseFast(), end);
}

void RegionDesc::VisitRememberSet(const std::function<void(BaseObject*)>& func)
{
    if (IsLargeRegion() && IsJitFortAwaitInstallFlag()) {
        // machine code which is not installed should skip here.
        return;
    }
    GetRSet()->VisitAllMarkedCardBefore(func, GetRegionBaseFast(), GetRegionAllocPtr());
}

void RegionList::MergeRegionListWithoutHead(RegionList& srcList, RegionDesc::RegionType regionType)
{
    RegionDesc *head = srcList.TakeHeadRegion();
    MergeRegionList(srcList, regionType);
    if (head) {
        srcList.PrependRegion(head, head->GetRegionType());
    }
}

void RegionList::MergeRegionList(RegionList& srcList, RegionDesc::RegionType regionType)
{
    RegionList regionList("region list cache");
    srcList.MoveTo(regionList);
    RegionDesc* head = regionList.GetHeadRegion();
    RegionDesc* tail = regionList.GetTailRegion();
    if (head == nullptr) {
        return;
    }
    std::lock_guard<std::mutex> lock(listMutex_);
    regionList.SetElementType(regionType);
    IncCounts(regionList.GetRegionCount(), regionList.GetUnitCount());
    if (listHead_ == nullptr) {
        listHead_ = head;
        listTail_ = tail;
    } else {
        tail->SetNextRegion(listHead_);
        listHead_->SetPrevRegion(tail);
        listHead_ = head;
    }
}

static const char *RegionDescRegionTypeToString(RegionDesc::RegionType type)
{
    static constexpr const char *enumStr[] = {
        [static_cast<uint8_t>(RegionDesc::RegionType::FREE_REGION)] = "FREE_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::GARBAGE_REGION)] = "GARBAGE_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::THREAD_LOCAL_REGION)] = "THREAD_LOCAL_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::THREAD_LOCAL_OLD_REGION)] = "THREAD_LOCAL_OLD_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::RECENT_FULL_REGION)] = "RECENT_FULL_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::FROM_REGION)] = "FROM_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::LONE_FROM_REGION)] = "LONE_FROM_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::EXEMPTED_FROM_REGION)] = "EXEMPTED_FROM_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::TO_REGION)] = "TO_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::OLD_REGION)] = "OLD_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::FULL_PINNED_REGION)] = "FULL_PINNED_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::RECENT_PINNED_REGION)] = "RECENT_PINNED_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::FIXED_PINNED_REGION)] = "FIXED_PINNED_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::FULL_FIXED_PINNED_REGION)] = "FULL_FIXED_PINNED_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::RAW_POINTER_REGION)] = "RAW_POINTER_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::TL_RAW_POINTER_REGION)] = "TL_RAW_POINTER_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::RECENT_LARGE_REGION)] = "RECENT_LARGE_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::LARGE_REGION)] = "LARGE_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::READ_ONLY_REGION)] = "READ_ONLY_REGION",
        [static_cast<uint8_t>(RegionDesc::RegionType::APPSPAWN_REGION)] = "APPSPAWN_REGION",
    };
    ASSERT_LOGF(type < RegionDesc::RegionType::END_OF_REGION_TYPE, "Invalid region type");
    return enumStr[static_cast<uint8_t>(type)];
}

void RegionList::PrependRegion(RegionDesc* region, RegionDesc::RegionType type)
{
    std::lock_guard<std::mutex> lock(listMutex_);
    PrependRegionLocked(region, type);
}

void RegionList::PrependRegionLocked(RegionDesc* region, RegionDesc::RegionType type)
{
    if (region == nullptr) {
        return;
    }

    DLOG(REGION, "%s (%zu, %zu)+(%zu, %zu) prepend region %p(base=%#zx)@%#zx+%zu type %u->%u", listName_,
        regionCount_, unitCount_, 1llu, region->GetUnitCount(), region, region->GetRegionBase(),
        region->GetRegionStart(), region->GetRegionAllocatedSize(), region->GetRegionType(), type);

    region->SetRegionType(type);

    size_t totalRegionSize = region->GetRegionEnd() - region->GetRegionBase();
    os::PrctlSetVMA(reinterpret_cast<void *>(region->GetRegionBase()), totalRegionSize,
                    (std::string("ArkTS Heap CMCGC Region ") + RegionDescRegionTypeToString(type)).c_str());

    region->SetPrevRegion(nullptr);
    IncCounts(1, region->GetUnitCount());
    region->SetNextRegion(listHead_);
    if (listHead_ == nullptr) {
        ASSERT_LOGF(listTail_ == nullptr, "PrependRegion listTail is not null");
        listTail_ = region;
    } else {
        listHead_->SetPrevRegion(region);
    }
    listHead_ = region;
}

void RegionList::DeleteRegionLocked(RegionDesc* del)
{
    ASSERT_LOGF(listHead_ != nullptr && listTail_ != nullptr, "illegal region list");

    RegionDesc* pre = del->GetPrevRegion();
    RegionDesc* next = del->GetNextRegion();

    del->SetNextRegion(nullptr);
    del->SetPrevRegion(nullptr);

    DLOG(REGION, "%s (%zu, %zu)-(%zu, %zu) delete region %p(start=%p),@%#zx+%zu type %u", listName_,
        regionCount_, unitCount_, 1llu, del->GetUnitCount(),
        del, del->GetRegionBase(), del->GetRegionStart(), del->GetRegionAllocatedSize(), del->GetRegionType());

    DecCounts(1, del->GetUnitCount());

    if (listHead_ == del) { // delete head
        ASSERT_LOGF(pre == nullptr, "Delete Region pre is not null");
        listHead_ = next;
        if (listHead_ == nullptr) { // now empty
            listTail_ = nullptr;
            return;
        }
    } else {
        pre->SetNextRegion(next);
    }

    if (listTail_ == del) { // delete tail
        ASSERT_LOGF(next == nullptr, "Delete Region next is not null");
        listTail_ = pre;
        if (listTail_ == nullptr) { // now empty
            listHead_ = nullptr;
            return;
        }
    } else {
        next->SetPrevRegion(pre);
    }
}

void RegionList::DumpRegionSummary() const
{
    VLOG(DEBUG, "\t%s %zu: %zu units (%zu B, alloc %zu)", listName_,
         regionCount_, unitCount_, GetAllocatedSize(true), GetAllocatedSize(false));
}

#ifndef NDEBUG
void RegionList::DumpRegionList(const char* msg)
{
    DLOG(REGION, "dump region list %s", msg);
    std::lock_guard<std::mutex> lock(listMutex_);
    for (RegionDesc *region = listHead_; region != nullptr; region = region->GetNextRegion()) {
        DLOG(REGION, "region %p @0x%zx(start=0x%zx)+%zu units [%zu+%zu, %zu) type %u prev %p next %p", region,
            region->GetRegionBase(), region->GetRegionStart(), region->GetRegionAllocatedSize(),
            region->GetUnitIdx(), region->GetUnitCount(), region->GetUnitIdx() + region->GetUnitCount(),
            region->GetRegionType(), region->GetPrevRegion(), region->GetNextRegion());
    }
}
#endif
inline void RegionManager::TagHugePage(RegionDesc* region, size_t num) const
{
#if defined (__linux__) || defined(PANDA_TARGET_OHOS)
    (void)madvise(reinterpret_cast<void*>(region->GetRegionBase()), num * RegionDesc::UNIT_SIZE, MADV_HUGEPAGE);
#else
    (void)region;
    (void)num;
#endif
}

inline void RegionManager::UntagHugePage(RegionDesc* region, size_t num) const
{
#if defined (__linux__) || defined(PANDA_TARGET_OHOS)
    (void)madvise(reinterpret_cast<void*>(region->GetRegionBase()), num * RegionDesc::UNIT_SIZE, MADV_NOHUGEPAGE);
#else
    (void)region;
    (void)num;
#endif
}

size_t FreeRegionManager::ReleaseGarbageRegions(size_t targetCachedSize)
{
    size_t dirtyBytes = dirtyUnitTree_.GetTotalCount() * RegionDesc::UNIT_SIZE;
    if (dirtyBytes <= targetCachedSize) {
        VLOG(DEBUG, "release heap garbage memory 0 bytes, cache %zu(%zu) bytes", dirtyBytes, targetCachedSize);
        return 0;
    }

    size_t releasedBytes = 0;
    while (dirtyBytes > targetCachedSize) {
        std::lock_guard<std::mutex> lock1(dirtyUnitTreeMutex_);
        auto node = dirtyUnitTree_.RootNode();
        if (node == nullptr) { break; }
        uint32_t idx = node->GetIndex();
        uint32_t num = node->GetCount();
        dirtyUnitTree_.ReleaseRootNode();

        std::lock_guard<std::mutex> lock2(releasedUnitTreeMutex_);
        LOGF_CHECK(releasedUnitTree_.MergeInsert(idx, num, true)) <<
            "tid " << GetTid() << ": failed to release garbage units[" <<
            idx << "+" << num << ", " << (idx + num) << ")";
        releasedBytes += (num * RegionDesc::UNIT_SIZE);
        dirtyBytes = dirtyUnitTree_.GetTotalCount() * RegionDesc::UNIT_SIZE;
    }
    VLOG(DEBUG, "release heap garbage memory %zu bytes, cache %zu(%zu) bytes",
         releasedBytes, dirtyBytes, targetCachedSize);
    return releasedBytes;
}

void RegionManager::Initialize(size_t nRegion, uintptr_t regionInfoAddr)
{
    size_t metadataSize = GetMetadataSize(nRegion);
    size_t alignedHeapStart = RoundUp<size_t>(regionInfoAddr + metadataSize, RegionDesc::UNIT_SIZE);
    // align the start of region to 256KB
    /***
     * |***********|<-metadataSize->|**********************|
     * |**padding**|***RegionUnit***|*******Region*********|
     *  ^           ^                ^
     *  |           |                |
     *  |    reginInfoStart    alignedHeapStart
     * regionInfoAddr
    */
    regionInfoStart_ = alignedHeapStart - metadataSize;
    regionHeapStart_ = alignedHeapStart;
#ifdef _WIN64
    MemoryMap::CommitMemory(reinterpret_cast<void*>(regionInfoStart_), metadataSize);
#endif
    regionHeapEnd_ = regionHeapStart_ + nRegion * RegionDesc::UNIT_SIZE;
    inactiveZone_ = regionHeapStart_;
    // propagate region heap layout
    RegionDesc::Initialize(nRegion, regionInfoStart_, regionHeapStart_);
    freeRegionManager_.Initialize(nRegion);

    DLOG(REPORT, "region info @0x%zx+%zu, heap [0x%zx, 0x%zx), unit count %zu", regionInfoAddr, metadataSize,
         regionHeapStart_, regionHeapEnd_, nRegion);
#ifdef USE_HWASAN
    ASAN_UNPOISON_MEMORY_REGION(reinterpret_cast<const volatile void *>(regionInfoAddr),
        metadataSize + nRegion * RegionDesc::UNIT_SIZE);
    const uintptr_t p_addr = regionInfoAddr;
    const uintptr_t p_size = metadataSize + nRegion * RegionDesc::UNIT_SIZE;
    LOG_COMMON(DEBUG) << std::hex << "set [" << p_addr <<
                         std::hex << ", " << p_addr + p_size << ") unpoisoned\n";
#endif
}

void RegionManager::ReclaimRegion(RegionDesc* region)
{
    size_t num = region->GetUnitCount();
    size_t unitIndex = region->GetUnitIdx();
    if (num >= HUGE_PAGE_UNIT_NUM) {
        UntagHugePage(region, num);
    }
    DLOG(REGION, "reclaim region %p(base=%#zx)@%#zx+%zu type %u", region,
         region->GetRegionBase(), region->GetRegionStart(), region->GetRegionAllocatedSize(),
         region->GetRegionType());

    region->InitFreeUnits();
    freeRegionManager_.AddGarbageUnits(unitIndex, num);
}

size_t RegionManager::ReleaseRegion(RegionDesc* region)
{
    size_t res = region->GetRegionSize();
    size_t num = region->GetUnitCount();
    size_t unitIndex = region->GetUnitIdx();
    if (num >= HUGE_PAGE_UNIT_NUM) {
        UntagHugePage(region, num);
    }
    DLOG(REGION, "release region %p @%#zx+%zu type %u", region, region->GetRegionStart(),
        region->GetRegionAllocatedSize(), region->GetRegionType());

    region->InitFreeUnits();
    RegionDesc::ReleaseUnits(unitIndex, num);
    freeRegionManager_.AddReleaseUnits(unitIndex, num);
    return res;
}

void RegionManager::CountLiveObject(const BaseObject* obj)
{
    RegionDesc* region = RegionDesc::GetRegionDescAt(reinterpret_cast<HeapAddress>(obj));
    region->AddLiveByteCount(obj->GetSize());
}

void RegionManager::AssembleLargeGarbageCandidates()
{
    largeRegionList_.MergeRegionList(recentLargeRegionList_, RegionDesc::RegionType::LARGE_REGION);
}

void RegionManager::AssemblePinnedGarbageCandidates()
{
    pinnedRegionList_.MergeRegionListWithoutHead(recentPinnedRegionList_, RegionDesc::RegionType::FULL_PINNED_REGION);
    RegionDesc* region = pinnedRegionList_.GetHeadRegion();
    for (size_t i = 0; i < FIXED_PINNED_REGION_COUNT; i++) {
        fixedPinnedRegionList_[i]->MergeRegionListWithoutHead(*recentFixedPinnedRegionList_[i],
            RegionDesc::RegionType::FULL_FIXED_PINNED_REGION);
    }
}

void RegionManager::ClearRSet()
{
    auto clearFunc = [](RegionDesc* region) {
        region->ClearRSet();
    };
    recentPinnedRegionList_.VisitAllRegions(clearFunc);
    pinnedRegionList_.VisitAllRegions(clearFunc);
    recentLargeRegionList_.VisitAllRegions(clearFunc);
    largeRegionList_.VisitAllRegions(clearFunc);
    rawPointerRegionList_.VisitAllRegions(clearFunc);
    appSpawnRegionList_.VisitAllRegions(clearFunc);
    for (size_t i = 0; i < FIXED_PINNED_REGION_COUNT; i++) {
        recentFixedPinnedRegionList_[i]->VisitAllRegions(clearFunc);
        fixedPinnedRegionList_[i]->VisitAllRegions(clearFunc);
    }
}

void RegionManager::ForEachObjectUnsafe(const std::function<void(BaseObject*)>& visitor) const
{
    for (uintptr_t regionAddr = regionHeapStart_; regionAddr < inactiveZone_;) {
        RegionDesc* region = RegionDesc::GetRegionDescAt(regionAddr);
        uintptr_t next = region->GetRegionEnd();
        regionAddr = next;
        if (!region->IsValidRegion() || region->IsFreeRegion() || region -> IsGarbageRegion()) {
            continue;
        }
        region->VisitAllObjects([&visitor](BaseObject* object) { visitor(object); });
    }
}

void RegionManager::ForEachObjectSafe(const std::function<void(BaseObject*)>& visitor) const
{
    ScopedEnterSaferegion enterSaferegion(false);
    STWParam stwParam{"visit-all-objects"};
    ScopedStopTheWorld stw(stwParam);
    ForEachObjectUnsafe(visitor);
}

void RegionManager::ForEachAwaitingJitFortUnsafe(const std::function<void(BaseObject*)>& visitor) const
{
    ASSERT(BaseRuntime::GetInstance()->GetMutatorManager().WorldStopped());
    for (const auto jitFort : awaitingJitFort_) {
        visitor(jitFort);
    }
}

RegionDesc *RegionManager::TakeRegion(size_t num, RegionDesc::UnitRole type, bool expectPhysicalMem, bool allowGC,
    bool isCopy)
{
    // a chance to invoke heuristic gc.
    if (allowGC && !Heap::GetHeap().IsGcStarted()) {
        Heap::GetHeap().TryHeuristicGC();
    }

    // check for allocation since we do not want gc threads and mutators do any harm to each other.
    size_t size = num * RegionDesc::UNIT_SIZE;
    RequestForRegion(size);

    RegionDesc* head = garbageRegionList_.TakeHeadRegion();
    if (head != nullptr) {
        DLOG(REGION, "take garbage region %p@%#zx+%zu", head, head->GetRegionStart(), head->GetRegionSize());
        if (head->GetUnitCount() == num) {
            auto idx = head->GetUnitIdx();
#ifdef USE_HWASAN
            const uintptr_t pAddr = RegionDesc::GetUnitAddress(idx);
            ASAN_UNPOISON_MEMORY_REGION(reinterpret_cast<const volatile void *>(pAddr), size);
            LOG_COMMON(DEBUG) << std::hex << "set [" << pAddr <<
                                std::hex << ", " << pAddr + size << ") unpoisoned\n";
#endif
            RegionDesc::ClearUnits(idx, num);
            DLOG(REGION, "reuse garbage region %p@%#zx+%zu", head, head->GetRegionStart(), head->GetRegionSize());
            return RegionDesc::ResetRegion(idx, num, type);
        } else {
            DLOG(REGION, "reclaim garbage region %p@%#zx+%zu", head, head->GetRegionStart(), head->GetRegionSize());
            ReclaimRegion(head);
        }
    }

    RegionDesc* region = freeRegionManager_.TakeRegion(num, type, expectPhysicalMem);
    if (region != nullptr) {
        if (num >= HUGE_PAGE_UNIT_NUM) {
            TagHugePage(region, num);
        }
        return region;
    }

    // when free regions are not enough for allocation
    if (num <= GetInactiveUnitCount()) {
        uintptr_t addr = inactiveZone_.fetch_add(size);

#ifndef PANDA_TARGET_32
        size_t totalHeapSize = regionHeapEnd_ - regionHeapStart_;
        // 2: half space reserved for forward copy. throw oom when gc finish.
        if (GetActiveSize() * 2 > totalHeapSize) {
            if (!isCopy) {
                (void)inactiveZone_.fetch_sub(size);
                return nullptr;
            } else {
                Heap::GetHeap().SetForceThrowOOM(true);
            }
        }
#endif

        if (addr < regionHeapEnd_ - size) {
            region = RegionDesc::InitRegionAt(addr, num, type);
            size_t idx = region->GetUnitIdx();
#ifdef _WIN64
            MemoryMap::CommitMemory(
                reinterpret_cast<void*>(RegionDesc::GetUnitAddress(idx)), num * RegionDesc::UNIT_SIZE);
#endif
            (void)idx; // eliminate compilation warning
            DLOG(REGION, "take inactive units [%zu+%zu, %zu) at [0x%zx, 0x%zx)", idx, num, idx + num,
                 RegionDesc::GetUnitAddress(idx), RegionDesc::GetUnitAddress(idx + num));
            if (num >= HUGE_PAGE_UNIT_NUM) {
                TagHugePage(region, num);
            }
            if (expectPhysicalMem) {
                RegionDesc::ClearUnits(idx, num);
            }
            return region;
        } else {
            (void)inactiveZone_.fetch_sub(size);
        }
    }

    return nullptr;
}


void RegionManager::FixFixedRegionList(MarkingCollector& collector, RegionList& list, size_t cellCount, GCStats& stats)
{
    size_t garbageSize = 0;
    RegionDesc* region = list.GetHeadRegion();
    while (region != nullptr) {
        auto liveBytes = region->GetLiveByteCount();
        if (liveBytes == 0) {
            RegionDesc* del = region;
            region = region->GetNextRegion();
            list.DeleteRegion(del);

            garbageSize += CollectRegion(del);
            continue;
        }
        region->VisitAllObjectsWithFixedSize(cellCount,
            [&collector, &region, &cellCount, &garbageSize](BaseObject* object) {
            if (collector.IsSurvivedObject(object)) {
                collector.FixObjectRefFields(object);
            } else {
                DLOG(ALLOC, "reclaim pinned obj %p", object);
                garbageSize += (cellCount + 1) * sizeof(uint64_t);
                region->CollectPinnedGarbage(object, cellCount);
            }
        });
        region = region->GetNextRegion();
    }
    stats.pinnedGarbageSize += garbageSize;
}

void RegionManager::CollectFixHeapTaskForPinnedRegion(MarkingCollector &collector, RegionList &list,
                                                      FixHeapTaskList &taskList)
{
    RegionDesc *region = list.GetHeadRegion();
    while (region != nullptr) {
        auto liveBytes = region->GetLiveByteCount();
        if (liveBytes == 0) {
            PostFixHeapWorker::AddEmptyRegionToCollectDuringPostFix(&list, region);
            region = region->GetNextRegion();
            continue;
        }
        taskList.push_back({region, FIX_REGION});
        region = region->GetNextRegion();
    }
}

void RegionManager::CollectFixTasks(FixHeapTaskList& taskList)
{
    // fix all objects.
    if (Heap::GetHeap().GetGCReason() == GC_REASON_YOUNG) {
        FixHeapWorker::CollectFixHeapTasks(taskList, largeRegionList_, FIX_OLD_REGION);
        FixHeapWorker::CollectFixHeapTasks(taskList, appSpawnRegionList_, FIX_OLD_REGION);

        FixHeapWorker::CollectFixHeapTasks(taskList, recentLargeRegionList_, FIX_RECENT_OLD_REGION);
        FixHeapWorker::CollectFixHeapTasks(taskList, recentPinnedRegionList_, FIX_RECENT_OLD_REGION);
        FixHeapWorker::CollectFixHeapTasks(taskList, rawPointerRegionList_, FIX_RECENT_OLD_REGION);
        FixHeapWorker::CollectFixHeapTasks(taskList, pinnedRegionList_, FIX_OLD_REGION);

        for (size_t i = 0; i < FIXED_PINNED_REGION_COUNT; i++) {
            FixHeapWorker::CollectFixHeapTasks(taskList, *recentFixedPinnedRegionList_[i], FIX_RECENT_OLD_REGION);
            FixHeapWorker::CollectFixHeapTasks(taskList, *fixedPinnedRegionList_[i], FIX_OLD_REGION);
        }
    } else {
        // fix only survived objects.
        FixHeapWorker::CollectFixHeapTasks(taskList, largeRegionList_, FIX_REGION);
        FixHeapWorker::CollectFixHeapTasks(taskList, appSpawnRegionList_, FIX_REGION);

        // fix survived object but should be with line judgement.
        FixHeapWorker::CollectFixHeapTasks(taskList, recentLargeRegionList_, FIX_RECENT_REGION);
        FixHeapWorker::CollectFixHeapTasks(taskList, rawPointerRegionList_, FIX_RECENT_REGION);

        FixHeapWorker::CollectFixHeapTasks(taskList, recentPinnedRegionList_, FIX_RECENT_REGION);
        MarkingCollector &collector = reinterpret_cast<MarkingCollector &>(Heap::GetHeap().GetCollector());
        CollectFixHeapTaskForPinnedRegion(collector, pinnedRegionList_, taskList);
        for (size_t i = 0; i < FIXED_PINNED_REGION_COUNT; i++) {
            FixHeapWorker::CollectFixHeapTasks(taskList, *recentFixedPinnedRegionList_[i], FIX_RECENT_REGION);
            CollectFixHeapTaskForPinnedRegion(collector, *fixedPinnedRegionList_[i], taskList);
        }
    }
}


size_t RegionManager::CollectLargeGarbage()
{
    OHOS_HITRACE(HITRACE_LEVEL_COMMERCIAL, "CMCGC::CollectLargeGarbage", "");
    size_t garbageSize = 0;
    MarkingCollector& collector = reinterpret_cast<MarkingCollector&>(Heap::GetHeap().GetCollector());
    RegionDesc* region = largeRegionList_.GetHeadRegion();
    while (region != nullptr) {
        HeapAddress addr = region->GetRegionStart();
        BaseObject *obj = reinterpret_cast<BaseObject *>(addr);

        if (region->IsJitFortAwaitInstallFlag()) {
                region = region->GetNextRegion();
                continue;
        }
        if (!collector.IsSurvivedObject(obj) && !region->IsNewObjectSinceMarking(obj)) {
            DLOG(REGION, "reclaim large region %p@0x%zx+%zu type %u", region, region->GetRegionStart(),
                 region->GetRegionAllocatedSize(), region->GetRegionType());

            RegionDesc* del = region;
            region = region->GetNextRegion();
            largeRegionList_.DeleteRegion(del);
            if (IsMachineCodeObject(reinterpret_cast<HeapAddress>(obj))) {
                JitFortUnProt(del->GetRegionBaseSize(), reinterpret_cast<void*>(del->GetRegionBaseFast()));
            }
            if (del->GetRegionSize() > RegionDesc::LARGE_OBJECT_RELEASE_THRESHOLD) {
                garbageSize += ReleaseRegion(del);
            } else {
                garbageSize += CollectRegion(del);
            }
        } else {
            DLOG(REGION, "clear mark-bit for large region %p@0x%zx+%zu type %u", region, region->GetRegionStart(),
                 region->GetRegionAllocatedSize(), region->GetRegionType());
            region = region->GetNextRegion();
        }
    }

    region = recentLargeRegionList_.GetHeadRegion();
    while (region != nullptr) {
        region = region->GetNextRegion();
    }

    return garbageSize;
}

#if defined(GCINFO_DEBUG) && GCINFO_DEBUG
void RegionManager::DumpRegionDesc() const
{
    if (!ENABLE_LOG(ALLOC)) {
        return;
    }
    for (uintptr_t regionAddr = regionHeapStart; regionAddr < inactiveZone;) {
        RegionDesc* region = RegionDesc::GetRegionDescAt(regionAddr);
        regionAddr = region->GetRegionEnd();
        if (!region->IsFreeRegion()) {
            region->DumpRegionDesc(ALLOC);
        }
    }
}
#endif

void RegionManager::DumpRegionStats() const
{
    size_t totalSize = regionHeapEnd_ - regionHeapStart_;
    size_t totalUnits = totalSize / RegionDesc::UNIT_SIZE;
    size_t activeSize = inactiveZone_ - regionHeapStart_;
    size_t activeUnits = activeSize / RegionDesc::UNIT_SIZE;
    VLOG(DEBUG, "\ttotal units: %zu (%zu B)", totalUnits, totalSize);
    VLOG(DEBUG, "\tactive units: %zu (%zu B)", activeUnits, activeSize);

    garbageRegionList_.DumpRegionSummary();
    pinnedRegionList_.DumpRegionSummary();
    recentPinnedRegionList_.DumpRegionSummary();
    rawPointerRegionList_.DumpRegionSummary();
    largeRegionList_.DumpRegionSummary();
    recentLargeRegionList_.DumpRegionSummary();
    readOnlyRegionList_.DumpRegionSummary();
    appSpawnRegionList_.DumpRegionSummary();

    size_t releasedUnits = freeRegionManager_.GetReleasedUnitCount();
    size_t dirtyUnits = freeRegionManager_.GetDirtyUnitCount();
    VLOG(DEBUG, "\treleased units: %zu (%zu B)", releasedUnits, releasedUnits * RegionDesc::UNIT_SIZE);
    VLOG(DEBUG, "\tdirty units: %zu (%zu B)", dirtyUnits, dirtyUnits * RegionDesc::UNIT_SIZE);
}

void RegionManager::RequestForRegion(size_t size)
{
    if (IsGcThread()) {
        // gc thread is always permitted for allocation.
        return;
    }

    Heap& heap = Heap::GetHeap();
    GCStats& gcstats = heap.GetCollector().GetGCStats();
    size_t allocatedBytes = heap.GetAllocatedSize() - gcstats.liveBytesAfterGC;
    constexpr double pi = 3.14;
    size_t availableBytesAfterGC = heap.GetMaxCapacity() - gcstats.liveBytesAfterGC;
    double heuAllocRate = std::cos((pi / 2.0) * allocatedBytes / availableBytesAfterGC) * gcstats.collectionRate;
    // for maximum performance, choose the larger one.
    double allocRate = std::max(
        static_cast<double>(BaseRuntime::GetInstance()->GetHeapParam().allocationRate) * MB / SECOND_TO_NANO_SECOND,
        heuAllocRate);
    ASSERT_LOGF(allocRate > 0.00001, "allocRate is zero"); // If it is less than 0.00001, it is considered as 0
    size_t waitTime = static_cast<size_t>(size / allocRate);
    uint64_t now = TimeUtil::NanoSeconds();
    if (prevRegionAllocTime_ + waitTime <= now) {
        prevRegionAllocTime_ = TimeUtil::NanoSeconds();
        return;
    }

    uint64_t sleepTime = std::min<uint64_t>(BaseRuntime::GetInstance()->GetHeapParam().allocationWaitTime,
                                  prevRegionAllocTime_ + waitTime - now);
    DLOG(ALLOC, "wait %zu ns to alloc %zu(B)", sleepTime, size);
    std::this_thread::sleep_for(std::chrono::nanoseconds{ sleepTime });
    prevRegionAllocTime_ = TimeUtil::NanoSeconds();
}

uintptr_t RegionManager::AllocPinnedFromFreeList(size_t cellCount)
{
    GCPhase mutatorPhase = Mutator::GetMutator()->GetMutatorPhase();
    // workaround: make sure collector doesn't fix newly allocated incomplete objects
    if (mutatorPhase == GC_PHASE_MARK || mutatorPhase == GC_PHASE_FIX) {
        return 0;
    }

    RegionList* list = fixedPinnedRegionList_[cellCount];
    std::lock_guard<std::mutex> lock(list->GetListMutex());
    uintptr_t allocPtr = list->AllocFromFreeListInLock();
    // For making bitmap comform with live object count, do not mark object repeated.
    if (allocPtr == 0 || mutatorPhase == GCPhase::GC_PHASE_IDLE) {
        return allocPtr;
    }

    // Mark new allocated pinned object.
    RegionDesc* regionDesc = RegionDesc::GetRegionDescAt(allocPtr);
    BaseObject* object = reinterpret_cast<BaseObject*>(allocPtr);
    regionDesc->MarkObject(object);
    size_t size = (cellCount + 1) * sizeof(uint64_t);
    regionDesc->AddLiveByteCount(size);
    return allocPtr;
}

uintptr_t RegionManager::AllocReadOnly(size_t size, bool allowGC)
{
    uintptr_t addr = 0;
    std::mutex& regionListMutex = readOnlyRegionList_.GetListMutex();

    std::lock_guard<std::mutex> lock(regionListMutex);
    RegionDesc* headRegion = readOnlyRegionList_.GetHeadRegion();
    if (headRegion != nullptr) {
        addr = headRegion->Alloc(size);
    }
    if (addr == 0) {
        RegionDesc* region =
            TakeRegion(1, RegionDesc::UnitRole::SMALL_SIZED_UNITS, false, allowGC);
        if (region == nullptr) {
            return 0;
        }
        DLOG(REGION, "alloc read only region @0x%zx+%zu type %u", region->GetRegionStart(),
             region->GetRegionAllocatedSize(),
             region->GetRegionType());
        GCPhase phase = Mutator::GetMutator()->GetMutatorPhase();
        if (phase == GC_PHASE_ENUM || phase == GC_PHASE_MARK || phase == GC_PHASE_REMARK_SATB ||
            phase == GC_PHASE_POST_MARK) {
            region->SetMarkingLine();
        } else if (phase == GC_PHASE_PRECOPY || phase == GC_PHASE_COPY || phase == GC_PHASE_FIX) {
            region->SetMarkingLine();
            region->SetCopyLine();
        }

        // To make sure the allocedSize are consistent, it must prepend region first then alloc object.
        readOnlyRegionList_.PrependRegionLocked(region, RegionDesc::RegionType::READ_ONLY_REGION);
        addr = region->Alloc(size);
    }

    DLOG(ALLOC, "alloc read only obj 0x%zx(%zu)", addr, size);
    return addr;
}

void RegionManager::MarkRememberSet(const std::function<void(BaseObject*)>& func)
{
    auto visitFunc = [&func](RegionDesc* region) {
        region->VisitRememberSetBeforeMarking(func);
    };
    recentPinnedRegionList_.VisitAllRegions(visitFunc);
    pinnedRegionList_.VisitAllRegions(visitFunc);
    recentLargeRegionList_.VisitAllRegions(visitFunc);
    largeRegionList_.VisitAllRegions(visitFunc);
    appSpawnRegionList_.VisitAllRegions(visitFunc);
    rawPointerRegionList_.VisitAllRegions(visitFunc);

    for (size_t i = 0; i < FIXED_PINNED_REGION_COUNT; i++) {
        recentFixedPinnedRegionList_[i]->VisitAllRegions(visitFunc);
        fixedPinnedRegionList_[i]->VisitAllRegions(visitFunc);
    }
}
} // namespace common