Changeset 89885 in webkit for trunk/Source/JavaScriptCore/jit/JITWriteBarrier.h

Timestamp:

Jun 27, 2011, 6:32:01 PM (14 years ago)

Author:

[email protected]

Message:

2011-06-27 Oliver Hunt <​[email protected]>

Reviewed by Geoffrey Garen.

Support throwing away non-running code even while other code is running
​https://bugs.webkit.org/show_bug.cgi?id=63485

Add a function to CodeBlock to support unlinking direct linked callsites,
and then with that in place add logic to discard code from any function
that is not currently on the stack.

The unlinking completely reverts any optimized call sites, such that they
may be relinked again in future.

• JavaScriptCore.exp:
• bytecode/CodeBlock.cpp: (JSC::CodeBlock::unlinkCalls): (JSC::CodeBlock::clearEvalCache):
• bytecode/CodeBlock.h: (JSC::CallLinkInfo::CallLinkInfo): (JSC::CallLinkInfo::unlink):
• bytecode/EvalCodeCache.h: (JSC::EvalCodeCache::clear):
• heap/Heap.cpp: (JSC::Heap::getConservativeRegisterRoots):
• heap/Heap.h:
• jit/JIT.cpp: (JSC::JIT::privateCompile):
• jit/JIT.h:
• jit/JITCall.cpp: (JSC::JIT::compileOpCall):
• jit/JITWriteBarrier.h: (JSC::JITWriteBarrierBase::clear):
• jsc.cpp: (GlobalObject::GlobalObject): (functionReleaseExecutableMemory):
• runtime/Executable.cpp: (JSC::EvalExecutable::unlinkCalls): (JSC::ProgramExecutable::unlinkCalls): (JSC::FunctionExecutable::discardCode): (JSC::FunctionExecutable::unlinkCalls):
• runtime/Executable.h:
• runtime/JSGlobalData.cpp: (JSC::SafeRecompiler::returnValue): (JSC::SafeRecompiler::operator()): (JSC::JSGlobalData::releaseExecutableMemory):

File:

• trunk/Source/JavaScriptCore/jit/JITWriteBarrier.h (modified) (2 diffs)

trunk/Source/JavaScriptCore/jit/JITWriteBarrier.h

@@ -69 +69 @@
     }
     
+    void clear() { clear(0); }
+
 protected:
     JITWriteBarrierBase()
@@ -95 +97 @@
 
 private:
+    void clear(void* clearedValue)
+    {
+        if (!m_location)
+            return;
+        if (m_location.executableAddress() != JITWriteBarrierFlag)
+            MacroAssembler::repatchPointer(m_location, clearedValue);
+    }
+
     CodeLocationDataLabelPtr m_location;
 };