| /* |
| * Copyright (C) 2017-2019 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #pragma once |
| |
| #include "Bits.h" |
| #include "EligibilityResult.h" |
| #include "IsoPage.h" |
| #include "Packed.h" |
| #include "Vector.h" |
| |
| namespace bmalloc { |
| |
| template<typename Config> class IsoHeapImpl; |
| |
| class IsoDirectoryBaseBase { |
| public: |
| IsoDirectoryBaseBase() { } |
| virtual ~IsoDirectoryBaseBase() { } |
| |
| virtual void didDecommit(unsigned index) = 0; |
| }; |
| |
| template<typename Config> |
| class IsoDirectoryBase : public IsoDirectoryBaseBase { |
| public: |
| IsoDirectoryBase(IsoHeapImpl<Config>&); |
| |
| IsoHeapImpl<Config>& heap() { return m_heap; } |
| |
| virtual void didBecome(const LockHolder&, IsoPage<Config>*, IsoPageTrigger) = 0; |
| |
| protected: |
| IsoHeapImpl<Config>& m_heap; |
| }; |
| |
| template<typename Config, unsigned passedNumPages> |
| class IsoDirectory : public IsoDirectoryBase<Config> { |
| public: |
| static constexpr unsigned numPages = passedNumPages; |
| |
| IsoDirectory(IsoHeapImpl<Config>&); |
| |
| // Find the first page that is eligible for allocation and return it. May return null if there is no |
| // such thing. May allocate a new page if we have an uncommitted page. |
| EligibilityResult<Config> takeFirstEligible(const LockHolder&); |
| |
| void didBecome(const LockHolder&, IsoPage<Config>*, IsoPageTrigger) override; |
| |
| // This gets called from a bulk decommit function in the Scavenger, so no locks are held. This function |
| // needs to get the heap lock. |
| void didDecommit(unsigned index) override; |
| |
| // Iterate over all empty and committed pages, and put them into the vector. This also records the |
| // pages as being decommitted. It's the caller's job to do the actual decommitting. |
| void scavenge(const LockHolder&, Vector<DeferredDecommit>&); |
| #if BUSE(PARTIAL_SCAVENGE) |
| void scavengeToHighWatermark(const LockHolder&, Vector<DeferredDecommit>&); |
| #endif |
| |
| template<typename Func> |
| void forEachCommittedPage(const LockHolder&, const Func&); |
| |
| private: |
| void scavengePage(const LockHolder&, size_t, Vector<DeferredDecommit>&); |
| |
| std::array<PackedAlignedPtr<IsoPage<Config>, IsoPage<Config>::pageSize>, numPages> m_pages { }; |
| // NOTE: I suppose that this could be two bitvectors. But from working on the GC, I found that the |
| // number of bitvectors does not matter as much as whether or not they make intuitive sense. |
| Bits<numPages> m_eligible; |
| Bits<numPages> m_empty; |
| Bits<numPages> m_committed; |
| unsigned m_firstEligibleOrDecommitted { 0 }; |
| #if BUSE(PARTIAL_SCAVENGE) |
| unsigned m_highWatermark { 0 }; |
| #endif |
| }; |
| |
| } // namespace bmalloc |
| |