Changeset 86883 in webkit

Timestamp:

May 19, 2011 1:18:39 PM (13 years ago)

Author:

oliver@apple.com

Message:

2011-05-19 Oliver Hunt <​oliver@apple.com>

Reviewed by Geoffrey Garen.

Make Executables release their JIT code as soon as they become dead
​https://bugs.webkit.org/show_bug.cgi?id=61134

Add an ability to clear an Executable's jit code without requiring
it to be destroyed, and then call that from a finalizer.

• heap/Weak.h: (JSC::Weak::Weak): (JSC::Weak::leak):
• jit/JITCode.h: (JSC::JITCode::clear):
• runtime/Executable.cpp: (JSC::ExecutableFinalizer::finalize): (JSC::ExecutableBase::executableFinalizer):
• runtime/Executable.h: (JSC::ExecutableBase::ExecutableBase): (JSC::ExecutableBase::clearExecutableCode):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• heap/Handle.h (modified) (1 diff)
• heap/HandleHeap.h (modified) (2 diffs)
• heap/Weak.h (modified) (2 diffs)
• jit/JITCode.h (modified) (1 diff)
• runtime/Executable.cpp (modified) (1 diff)
• runtime/Executable.h (modified) (3 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2011-05-19  Oliver Hunt  <oliver@apple.com>
+
+        Reviewed by Geoffrey Garen.
+
+        Make Executables release their JIT code as soon as they become dead
+        https://bugs.webkit.org/show_bug.cgi?id=61134
+
+        Add an ability to clear an Executable's jit code without requiring
+        it to be destroyed, and then call that from a finalizer.
+
+        * heap/Weak.h:
+        (JSC::Weak::Weak):
+        (JSC::Weak::leak):
+        * jit/JITCode.h:
+        (JSC::JITCode::clear):
+        * runtime/Executable.cpp:
+        (JSC::ExecutableFinalizer::finalize):
+        (JSC::ExecutableBase::executableFinalizer):
+        * runtime/Executable.h:
+        (JSC::ExecutableBase::ExecutableBase):
+        (JSC::ExecutableBase::clearExecutableCode):
+
 2011-05-19  Adam Roben  <aroben@apple.com>
 

trunk/Source/JavaScriptCore/heap/Handle.h

@@ -48 +48 @@
 
 class HandleBase {
+    template <typename T> friend class Weak;
     friend class HandleHeap;
     friend struct JSCallbackObjectData;

trunk/Source/JavaScriptCore/heap/HandleHeap.h

@@ -71 +71 @@
 #if !ASSERT_DISABLED
     bool hasWeakOwner(HandleSlot, WeakHandleOwner*);
+    bool hasFinalizer(HandleSlot);
 #endif
 
@@ -198 +199 @@
     return toNode(handle)->weakOwner() == weakOwner;
 }
+
+inline bool HandleHeap::hasFinalizer(HandleSlot handle)
+{
+    return toNode(handle)->weakOwner();
+}
 #endif
 

trunk/Source/JavaScriptCore/heap/Weak.h

@@ -54 +54 @@
     }
 
+    enum AdoptTag { Adopt };
+    template<typename U> Weak(AdoptTag, Handle<U> handle)
+        : Handle<T>(handle.slot())
+    {
+        validateCell(get());
+    }
+    
     Weak(const Weak& other)
         : Handle<T>()
@@ -122 +129 @@
         return *this;
     }
+    
+    HandleSlot leakHandle()
+    {
+        ASSERT(HandleHeap::heapFor(slot())->hasFinalizer(slot()));
+        HandleSlot result = slot();
+        setSlot(0);
+        return result;
+    }
 
 private:

trunk/Source/JavaScriptCore/jit/JITCode.h

@@ -102 +102 @@
         }
 
+        void clear()
+        {
+            m_ref.~CodeRef();
+            new (&m_ref) CodeRef();
+        }
+
     private:
         JITCode(void* code, PassRefPtr<ExecutablePool> executablePool, size_t size)

trunk/Source/JavaScriptCore/runtime/Executable.cpp

@@ -43 +43 @@
 const ClassInfo ExecutableBase::s_info = { "Executable", 0, 0, 0 };
 
+#if ENABLE(JIT)
+class ExecutableFinalizer : public WeakHandleOwner {
+    virtual void finalize(Handle<Unknown> handle, void*)
+    {
+        Weak<ExecutableBase> executable(Weak<ExecutableBase>::Adopt, handle);
+        executable->clearExecutableCode();
+    }
+};
+
+WeakHandleOwner* ExecutableBase::executableFinalizer()
+{
+    DEFINE_STATIC_LOCAL(ExecutableFinalizer, finalizer, ());
+    return &finalizer;
+}
+#endif
+    
 const ClassInfo NativeExecutable::s_info = { "NativeExecutable", &ExecutableBase::s_info, 0, 0 };
 

trunk/Source/JavaScriptCore/runtime/Executable.h

@@ -58 +58 @@
             , m_numParametersForConstruct(numParameters)
         {
+#if ENABLE(JIT)
+            Weak<ExecutableBase> finalizer(globalData, this, executableFinalizer());
+            finalizer.leakHandle();
+#endif
         }
 
@@ -87 +91 @@
             ASSERT(m_jitCodeForConstruct);
             return m_jitCodeForConstruct;
+        }
+
+        void clearExecutableCode()
+        {
+            m_jitCodeForCall.clear();
+            m_jitCodeForConstruct.clear();
         }
 
@@ -94 +104 @@
         MacroAssemblerCodePtr m_jitCodeForCallWithArityCheck;
         MacroAssemblerCodePtr m_jitCodeForConstructWithArityCheck;
+        
+    private:
+        static WeakHandleOwner* executableFinalizer();
 #endif
     };