Attachment 362495 Details for Bug 194810 – Patch

[patch] Patch

bug-194810-20190220151557.patch (text/plain), 15.24 KB, created by Tadeu Zagallo on 2019-02-20 06:16:36 PST

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Creator: Tadeu Zagallo

Created: 2019-02-20 06:16:36 PST

Size: 15.24 KB

patch

obsolete

>Subversion Revision: 241760
>diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
>index 6c2f02508f0426495ee4591332883cb4c6ba02d3..c20bd0daa50219c286c244eacdb214d645b16f7e 100644
>--- a/Source/JavaScriptCore/ChangeLog
>+++ b/Source/JavaScriptCore/ChangeLog
>@@ -1,3 +1,38 @@
>+2019-02-20  Tadeu Zagallo  <tzagallo@apple.com>
>+
>+        Lazily decode cached bytecode
>+        https://bugs.webkit.org/show_bug.cgi?id=194810
>+
>+        Reviewed by NOBODY (OOPS!).
>+
>+        Like lazy parsing, we should pause at code block boundaries. Instead
>+        of decoding UnlinkedFunctionExecutable's CodeBlocks, we store their
>+        offsets in the executable and lazily decode them on the next call to
>+        `unlinkedCodeBlockFor`.
>+
>+        * bytecode/UnlinkedFunctionExecutable.cpp:
>+        (JSC::UnlinkedFunctionExecutable::UnlinkedFunctionExecutable):
>+        (JSC::UnlinkedFunctionExecutable::~UnlinkedFunctionExecutable):
>+        (JSC::UnlinkedFunctionExecutable::visitChildren):
>+        (JSC::UnlinkedFunctionExecutable::unlinkedCodeBlockFor):
>+        (JSC::UnlinkedFunctionExecutable::decodeCachedCodeBlocks):
>+        * bytecode/UnlinkedFunctionExecutable.h:
>+        * runtime/CachedTypes.cpp:
>+        (JSC::CachedPtr::isEmpty const):
>+        (JSC::CachedWriteBarrier::isEmpty const):
>+        (JSC::CachedFunctionExecutable::decode const):
>+        (JSC::UnlinkedFunctionExecutable::UnlinkedFunctionExecutable):
>+        (JSC::decodeCodeBlockImpl):
>+        (JSC::decodeFunctionCodeBlock):
>+        * runtime/CachedTypes.h:
>+        (JSC::Decoder::Decoder):
>+        (JSC::Decoder::~Decoder):
>+        (JSC::Decoder::vm):
>+        (JSC::Decoder::offsetOf):
>+        (JSC::Decoder::cacheOffset):
>+        (JSC::Decoder::ptrForOffsetFromBase):
>+        (JSC::Decoder::addFinalizer):
>+
> 2019-02-19  Tadeu Zagallo  <tzagallo@apple.com>
> 
>         Move bytecode cache-related filesystem code out of CodeCache
>diff --git a/Source/JavaScriptCore/bytecode/UnlinkedFunctionExecutable.cpp b/Source/JavaScriptCore/bytecode/UnlinkedFunctionExecutable.cpp
>index a142c24055e9b3be412e361428dc1fccc16391d8..2420e784fb85124bd1851b8287291eb464092bd7 100644
>--- a/Source/JavaScriptCore/bytecode/UnlinkedFunctionExecutable.cpp
>+++ b/Source/JavaScriptCore/bytecode/UnlinkedFunctionExecutable.cpp
>@@ -28,6 +28,7 @@
> 
> #include "BuiltinExecutables.h"
> #include "BytecodeGenerator.h"
>+#include "CachedTypes.h"
> #include "ClassInfo.h"
> #include "CodeCache.h"
> #include "Debugger.h"
>@@ -103,6 +104,9 @@ UnlinkedFunctionExecutable::UnlinkedFunctionExecutable(VM* vm, Structure* struct
>     , m_scriptMode(static_cast<unsigned>(scriptMode))
>     , m_superBinding(static_cast<unsigned>(node->superBinding()))
>     , m_derivedContextType(static_cast<unsigned>(derivedContextType))
>+    , m_isCached(false)
>+    , m_unlinkedCodeBlockForCall()
>+    , m_unlinkedCodeBlockForConstruct()
>     , m_name(node->ident())
>     , m_ecmaName(node->ecmaName())
>     , m_inferredName(node->inferredName())
>@@ -120,6 +124,12 @@ UnlinkedFunctionExecutable::UnlinkedFunctionExecutable(VM* vm, Structure* struct
>         setClassSource(node->classSource());
> }
> 
>+UnlinkedFunctionExecutable::~UnlinkedFunctionExecutable()
>+{
>+    if (m_isCached)
>+        m_decoder.~RefPtr();
>+}
>+
> void UnlinkedFunctionExecutable::destroy(JSCell* cell)
> {
>     static_cast<UnlinkedFunctionExecutable*>(cell)->~UnlinkedFunctionExecutable();
>@@ -130,8 +140,10 @@ void UnlinkedFunctionExecutable::visitChildren(JSCell* cell, SlotVisitor& visito
>     UnlinkedFunctionExecutable* thisObject = jsCast<UnlinkedFunctionExecutable*>(cell);
>     ASSERT_GC_OBJECT_INHERITS(thisObject, info());
>     Base::visitChildren(thisObject, visitor);
>-    visitor.append(thisObject->m_unlinkedCodeBlockForCall);
>-    visitor.append(thisObject->m_unlinkedCodeBlockForConstruct);
>+    if (!thisObject->m_isCached) {
>+        visitor.append(thisObject->m_unlinkedCodeBlockForCall);
>+        visitor.append(thisObject->m_unlinkedCodeBlockForConstruct);
>+    }
> }
> 
> SourceCode UnlinkedFunctionExecutable::linkedSourceCode(const SourceCode& passedParentSource) const
>@@ -213,6 +225,8 @@ UnlinkedFunctionCodeBlock* UnlinkedFunctionExecutable::unlinkedCodeBlockFor(
>     VM& vm, const SourceCode& source, CodeSpecializationKind specializationKind, 
>     DebuggerMode debuggerMode, ParserError& error, SourceParseMode parseMode)
> {
>+    if (m_isCached)
>+        decodeCachedCodeBlocks();
>     switch (specializationKind) {
>     case CodeForCall:
>         if (UnlinkedFunctionCodeBlock* codeBlock = m_unlinkedCodeBlockForCall.get())
>@@ -244,6 +258,29 @@ UnlinkedFunctionCodeBlock* UnlinkedFunctionExecutable::unlinkedCodeBlockFor(
>     return result;
> }
> 
>+void UnlinkedFunctionExecutable::decodeCachedCodeBlocks()
>+{
>+    ASSERT(m_isCached);
>+    ASSERT(m_decoder);
>+    ASSERT(m_cachedCodeBlockForCallOffset || m_cachedCodeBlockForConstructOffset);
>+
>+    RefPtr<Decoder> decoder = WTFMove(m_decoder);
>+    int32_t cachedCodeBlockForCallOffset = m_cachedCodeBlockForCallOffset;
>+    int32_t cachedCodeBlockForConstructOffset = m_cachedCodeBlockForConstructOffset;
>+
>+    DeferGC deferGC(decoder->vm().heap);
>+
>+    // No need to clear m_unlinkedCodeBlockForCall here, since we moved the decoder out of the same slot
>+    if (cachedCodeBlockForCallOffset)
>+        decodeFunctionCodeBlock(*decoder, cachedCodeBlockForCallOffset, m_unlinkedCodeBlockForCall, this);
>+    if (cachedCodeBlockForConstructOffset)
>+        decodeFunctionCodeBlock(*decoder, cachedCodeBlockForConstructOffset, m_unlinkedCodeBlockForConstruct, this);
>+    else
>+        m_unlinkedCodeBlockForConstruct.clear();
>+
>+    m_isCached = false;
>+}
>+
> UnlinkedFunctionExecutable::RareData& UnlinkedFunctionExecutable::ensureRareDataSlow()
> {
>     ASSERT(!m_rareData);
>diff --git a/Source/JavaScriptCore/bytecode/UnlinkedFunctionExecutable.h b/Source/JavaScriptCore/bytecode/UnlinkedFunctionExecutable.h
>index defd2f08b87181e6b7f4ff60156907fdb6eb397f..1a7a37f2cc93bb5f595b0d92dfc354f0a6e24ff5 100644
>--- a/Source/JavaScriptCore/bytecode/UnlinkedFunctionExecutable.h
>+++ b/Source/JavaScriptCore/bytecode/UnlinkedFunctionExecutable.h
>@@ -75,6 +75,8 @@ public:
>         return instance;
>     }
> 
>+    ~UnlinkedFunctionExecutable();
>+
>     const Identifier& name() const { return m_name; }
>     const Identifier& ecmaName() const { return m_ecmaName; }
>     void setEcmaName(const Identifier& name) { m_ecmaName = name; }
>@@ -193,6 +195,8 @@ private:
>     UnlinkedFunctionExecutable(VM*, Structure*, const SourceCode&, FunctionMetadataNode*, UnlinkedFunctionKind, ConstructAbility, JSParserScriptMode, CompactVariableMap::Handle,  JSC::DerivedContextType, bool isBuiltinDefaultClassConstructor);
>     UnlinkedFunctionExecutable(Decoder&, VariableEnvironment&, const CachedFunctionExecutable&);
> 
>+    void decodeCachedCodeBlocks();
>+
>     unsigned m_firstLineOffset;
>     unsigned m_lineCount;
>     unsigned m_unlinkedFunctionNameStart;
>@@ -216,9 +220,20 @@ private:
>     unsigned m_scriptMode: 1; // JSParserScriptMode
>     unsigned m_superBinding : 1;
>     unsigned m_derivedContextType: 2;
>+    bool m_isCached : 1;
> 
>-    WriteBarrier<UnlinkedFunctionCodeBlock> m_unlinkedCodeBlockForCall;
>-    WriteBarrier<UnlinkedFunctionCodeBlock> m_unlinkedCodeBlockForConstruct;
>+    union {
>+        WriteBarrier<UnlinkedFunctionCodeBlock> m_unlinkedCodeBlockForCall;
>+        RefPtr<Decoder> m_decoder;
>+    };
>+
>+    union {
>+        WriteBarrier<UnlinkedFunctionCodeBlock> m_unlinkedCodeBlockForConstruct;
>+        struct {
>+            int32_t m_cachedCodeBlockForCallOffset;
>+            int32_t m_cachedCodeBlockForConstructOffset;
>+        };
>+    };
> 
>     Identifier m_name;
>     Identifier m_ecmaName;
>diff --git a/Source/JavaScriptCore/runtime/CachedTypes.cpp b/Source/JavaScriptCore/runtime/CachedTypes.cpp
>index acd95dfa9650ed01346215da43799285cf4662f8..94742ba64c009438339a349be7cc1ee08d381bd6 100644
>--- a/Source/JavaScriptCore/runtime/CachedTypes.cpp
>+++ b/Source/JavaScriptCore/runtime/CachedTypes.cpp
>@@ -210,65 +210,6 @@ private:
>     HashMap<const void*, ptrdiff_t> m_ptrToOffsetMap;
> };
> 
>-class Decoder {
>-    WTF_MAKE_NONCOPYABLE(Decoder);
>-    WTF_FORBID_HEAP_ALLOCATION;
>-
>-public:
>-    Decoder(VM& vm, const void* baseAddress, size_t size)
>-        : m_vm(vm)
>-        , m_baseAddress(reinterpret_cast<const uint8_t*>(baseAddress))
>-#ifndef NDEBUG
>-        , m_size(size)
>-#endif
>-    {
>-        UNUSED_PARAM(size);
>-    }
>-
>-    ~Decoder()
>-    {
>-        for (auto& pair : m_finalizers)
>-            pair.value();
>-    }
>-
>-    VM& vm() { return m_vm; }
>-
>-    ptrdiff_t offsetOf(const void* ptr)
>-    {
>-        const uint8_t* addr = static_cast<const uint8_t*>(ptr);
>-        ASSERT(addr >= m_baseAddress && addr < m_baseAddress + m_size);
>-        return addr - m_baseAddress;
>-    }
>-
>-    void cacheOffset(ptrdiff_t offset, void* ptr)
>-    {
>-        m_offsetToPtrMap.add(offset, ptr);
>-    }
>-
>-    WTF::Optional<void*> ptrForOffset(ptrdiff_t offset)
>-    {
>-        auto it = m_offsetToPtrMap.find(offset);
>-        if (it == m_offsetToPtrMap.end())
>-            return WTF::nullopt;
>-        return { it->value };
>-    }
>-
>-    template<typename Functor>
>-    void addFinalizer(ptrdiff_t offset, const Functor& fn)
>-    {
>-        m_finalizers.add(offset, fn);
>-    }
>-
>-private:
>-    VM& m_vm;
>-    const uint8_t* m_baseAddress;
>-#ifndef NDEBUG
>-    size_t m_size;
>-#endif
>-    HashMap<ptrdiff_t, void*> m_offsetToPtrMap;
>-    HashMap<ptrdiff_t, std::function<void()>> m_finalizers;
>-};
>-
> template<typename T>
> static std::enable_if_t<std::is_same<T, SourceType<T>>::value> encode(Encoder&, T& dst, const SourceType<T>& src)
> {
>@@ -371,6 +312,8 @@ class CachedPtr : public VariableLengthObject<Source*> {
>     friend struct CachedRefPtr;
> 
> public:
>+    bool isEmpty() const { return m_isEmpty; }
>+
>     void encode(Encoder& encoder, const Source* src)
>     {
>         m_isEmpty = !src;
>@@ -451,6 +394,8 @@ private:
> template<typename T, typename Source = SourceType<T>>
> class CachedWriteBarrier : public CachedObject<WriteBarrier<Source>> {
> public:
>+    bool isEmpty() const { return m_ptr.isEmpty(); }
>+
>     void encode(Encoder& encoder, const WriteBarrier<Source> src)
>     {
>         m_ptr.encode(encoder, src.get());
>@@ -1866,8 +1811,14 @@ ALWAYS_INLINE UnlinkedFunctionExecutable* CachedFunctionExecutable::decode(Decod
>     UnlinkedFunctionExecutable* executable = new (NotNull, allocateCell<UnlinkedFunctionExecutable>(decoder.vm().heap)) UnlinkedFunctionExecutable(decoder, env, *this);
>     executable->finishCreation(decoder.vm());
> 
>-    m_unlinkedCodeBlockForCall.decode(decoder, executable->m_unlinkedCodeBlockForCall, executable);
>-    m_unlinkedCodeBlockForConstruct.decode(decoder, executable->m_unlinkedCodeBlockForConstruct, executable);
>+    if (!m_unlinkedCodeBlockForCall.isEmpty() || !m_unlinkedCodeBlockForConstruct.isEmpty()) {
>+        executable->m_isCached = true;
>+        executable->m_decoder = &decoder;
>+        if (!m_unlinkedCodeBlockForCall.isEmpty())
>+            executable->m_cachedCodeBlockForCallOffset = decoder.offsetOf(&m_unlinkedCodeBlockForCall);
>+        if (!m_unlinkedCodeBlockForConstruct.isEmpty())
>+            executable->m_cachedCodeBlockForConstructOffset = decoder.offsetOf(&m_unlinkedCodeBlockForConstruct);
>+    }
> 
>     return executable;
> }
>@@ -1897,6 +1848,9 @@ ALWAYS_INLINE UnlinkedFunctionExecutable::UnlinkedFunctionExecutable(Decoder& de
>     , m_scriptMode(cachedExecutable.scriptMode())
>     , m_superBinding(cachedExecutable.superBinding())
>     , m_derivedContextType(cachedExecutable.derivedContextType())
>+    , m_isCached(false)
>+    , m_unlinkedCodeBlockForCall()
>+    , m_unlinkedCodeBlockForConstruct()
> 
>     , m_name(cachedExecutable.name(decoder))
>     , m_ecmaName(cachedExecutable.ecmaName(decoder))
>@@ -2083,11 +2037,11 @@ std::pair<MallocPtr<uint8_t>, size_t> encodeCodeBlock(VM& vm, const SourceCodeKe
> UnlinkedCodeBlock* decodeCodeBlockImpl(VM& vm, const SourceCodeKey& key, const void* buffer, size_t size)
> {
>     const auto* cachedEntry = reinterpret_cast<const GenericCacheEntry*>(buffer);
>-    Decoder decoder(vm, buffer, size);
>+    RefPtr<Decoder> decoder = adoptRef(new Decoder(vm, buffer, size));
>     std::pair<SourceCodeKey, UnlinkedCodeBlock*> entry;
>     {
>         DeferGC deferGC(vm.heap);
>-        if (!cachedEntry->decode(decoder, entry))
>+        if (!cachedEntry->decode(*decoder, entry))
>             return nullptr;
>     }
> 
>@@ -2096,4 +2050,11 @@ UnlinkedCodeBlock* decodeCodeBlockImpl(VM& vm, const SourceCodeKey& key, const v
>     return entry.second;
> }
> 
>+void decodeFunctionCodeBlock(Decoder& decoder, int32_t cachedFunctionCodeBlockOffset, WriteBarrier<UnlinkedFunctionCodeBlock>& codeBlock, const JSCell* owner)
>+{
>+    ASSERT(decoder.vm().heap.isDeferred());
>+    auto* cachedCodeBlock = static_cast<const CachedWriteBarrier<CachedFunctionCodeBlock, UnlinkedFunctionCodeBlock>*>(decoder.ptrForOffsetFromBase(cachedFunctionCodeBlockOffset));
>+    cachedCodeBlock->decode(decoder, codeBlock, owner);
>+}
>+
> } // namespace JSC
>diff --git a/Source/JavaScriptCore/runtime/CachedTypes.h b/Source/JavaScriptCore/runtime/CachedTypes.h
>index bcb8acb6ce570e9726389c26d70bcba21da8d4ad..972b4c927090232ade149c2a8a95986535f0d088 100644
>--- a/Source/JavaScriptCore/runtime/CachedTypes.h
>+++ b/Source/JavaScriptCore/runtime/CachedTypes.h
>@@ -32,10 +32,79 @@ namespace JSC {
> 
> class SourceCodeKey;
> class UnlinkedCodeBlock;
>+class UnlinkedFunctionCodeBlock;
>+
>+class Decoder : public RefCounted<Decoder> {
>+    WTF_MAKE_NONCOPYABLE(Decoder);
>+
>+public:
>+    Decoder(VM& vm, const void* baseAddress, size_t size)
>+        : m_vm(vm)
>+        , m_baseAddress(reinterpret_cast<const uint8_t*>(baseAddress))
>+#ifndef NDEBUG
>+        , m_size(size)
>+#endif
>+    {
>+        UNUSED_PARAM(size);
>+    }
>+
>+    ~Decoder()
>+    {
>+        for (auto& pair : m_finalizers)
>+            pair.value();
>+    }
>+
>+    VM& vm() { return m_vm; }
>+
>+    ptrdiff_t offsetOf(const void* ptr)
>+    {
>+        const uint8_t* addr = static_cast<const uint8_t*>(ptr);
>+        ASSERT(addr >= m_baseAddress && addr < m_baseAddress + m_size);
>+        return addr - m_baseAddress;
>+    }
>+
>+    void cacheOffset(ptrdiff_t offset, void* ptr)
>+    {
>+        m_offsetToPtrMap.add(offset, ptr);
>+    }
>+
>+    WTF::Optional<void*> ptrForOffset(ptrdiff_t offset)
>+    {
>+        auto it = m_offsetToPtrMap.find(offset);
>+        if (it == m_offsetToPtrMap.end())
>+            return WTF::nullopt;
>+        return { it->value };
>+    }
>+
>+    const void* ptrForOffsetFromBase(ptrdiff_t offset)
>+    {
>+#ifndef NDEBUG
>+        ASSERT(offset > 0 && static_cast<size_t>(offset) < m_size);
>+#endif
>+        return m_baseAddress + offset;
>+    }
>+
>+    template<typename Functor>
>+    void addFinalizer(ptrdiff_t offset, const Functor& fn)
>+    {
>+        m_finalizers.add(offset, fn);
>+    }
>+
>+private:
>+    VM& m_vm;
>+    const uint8_t* m_baseAddress;
>+#ifndef NDEBUG
>+    size_t m_size;
>+#endif
>+    HashMap<ptrdiff_t, void*> m_offsetToPtrMap;
>+    HashMap<ptrdiff_t, std::function<void()>> m_finalizers;
>+};
> 
> std::pair<MallocPtr<uint8_t>, size_t> encodeCodeBlock(VM&, const SourceCodeKey&, const UnlinkedCodeBlock*);
>+
> UnlinkedCodeBlock* decodeCodeBlockImpl(VM&, const SourceCodeKey&, const void*, size_t);
> 
>+void decodeFunctionCodeBlock(Decoder&, int32_t cachedFunctionCodeBlockOffset, WriteBarrier<UnlinkedFunctionCodeBlock>&, const JSCell*);
> 
> template<typename UnlinkedCodeBlockType>
> UnlinkedCodeBlockType* decodeCodeBlock(VM& vm, const SourceCodeKey& key, const void* buffer, size_t size)

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Attachments on bug 194810: 362383 | 362495 | 363525 | 363558 | 363901