Add new MethodTable method to get an estimated size for a cell
https://bugs.webkit.org/show_bug.cgi?id=154838
Patch by Joseph Pecoraro <pecoraro@apple.com> on 2016-02-29
Reviewed by Filip Pizlo.
The new class method estimatedSize(JSCell*) estimates the size for a single cell.
As the name implies, this is meant to be an approximation. It is more important
that big objects report a large size, then to get perfect size information for
all objects in the heap.
Base implementation (JSCell):
- returns the MarkedBlock bucket size for this cell.
- This gets us the object size include inline storage. Basically a better sizeof.
Subclasses with "Extra Memory Cost":
- Any class that reports extra memory (reportExtraMemoryVisited) should include that in the estimated size.
- E.g. CodeBlock, JSGenericTypedArrayView, WeakMapData, etc.
Subclasses with "Copied Space" storage:
- Any class with data in copied space (copyBackingStore) should include that in the estimated size.
- E.g. JSObject, JSGenericTypedArrayView, JSMap, JSSet, DirectArguments, etc.
Add reportExtraMemoryVisited for UnlinkedCodeBlock's compressed unlinked
instructions because this can be larger than 1kb, which is significant.
This has one special case for RegExp generated bytecode / JIT code, which
does not currently fall into the extra memory cost or copied space storage.
In practice I haven't seen this grow to a significant cost.
* runtime/ClassInfo.h:
Add the new estimatedSize method to the table.
* bytecode/UnlinkedCodeBlock.cpp:
(JSC::UnlinkedCodeBlock::visitChildren):
(JSC::UnlinkedCodeBlock::estimatedSize):
(JSC::UnlinkedCodeBlock::setInstructions):
* bytecode/UnlinkedCodeBlock.h:
Report an extra memory cost for unlinked code blocks like
we do for linked code blocks.
* bytecode/CodeBlock.cpp:
(JSC::CodeBlock::estimatedSize):
* bytecode/CodeBlock.h:
* bytecode/UnlinkedInstructionStream.cpp:
(JSC::UnlinkedInstructionStream::sizeInBytes):
* bytecode/UnlinkedInstructionStream.h:
* runtime/DirectArguments.cpp:
(JSC::DirectArguments::estimatedSize):
* runtime/DirectArguments.h:
* runtime/JSCell.cpp:
(JSC::JSCell::estimatedSizeInBytes):
(JSC::JSCell::estimatedSize):
* runtime/JSCell.h:
* runtime/JSGenericTypedArrayView.h:
* runtime/JSGenericTypedArrayViewInlines.h:
(JSC::JSGenericTypedArrayView<Adaptor>::estimatedSize):
* runtime/JSMap.cpp:
(JSC::JSMap::estimatedSize):
* runtime/JSMap.h:
* runtime/JSObject.cpp:
(JSC::JSObject::visitButterfly):
* runtime/JSObject.h:
* runtime/JSSet.cpp:
(JSC::JSSet::estimatedSize):
* runtime/JSSet.h:
* runtime/JSString.cpp:
(JSC::JSString::estimatedSize):
* runtime/JSString.h:
* runtime/MapData.h:
(JSC::MapDataImpl::capacityInBytes):
* runtime/WeakMapData.cpp:
(JSC::WeakMapData::estimatedSize):
(JSC::WeakMapData::visitChildren):
* runtime/WeakMapData.h:
Implement estimated size following the pattern of reporting
extra visited size, or copy space memory.
* runtime/RegExp.cpp:
(JSC::RegExp::estimatedSize):
* runtime/RegExp.h:
* yarr/YarrInterpreter.h:
(JSC::Yarr::ByteDisjunction::estimatedSizeInBytes):
(JSC::Yarr::BytecodePattern::estimatedSizeInBytes):
* yarr/YarrJIT.h:
(JSC::Yarr::YarrCodeBlock::size):
Include generated bytecode / JITCode to a RegExp's size.
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@197379 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Source/JavaScriptCore/bytecode/CodeBlock.cpp b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
index bb399bf..7cfd474 100644
--- a/Source/JavaScriptCore/bytecode/CodeBlock.cpp
+++ b/Source/JavaScriptCore/bytecode/CodeBlock.cpp
@@ -2462,6 +2462,15 @@
#endif // ENABLE(DFG_JIT)
}
+size_t CodeBlock::estimatedSize(JSCell* cell)
+{
+ CodeBlock* thisObject = jsCast<CodeBlock*>(cell);
+ size_t extraMemoryAllocated = thisObject->m_instructions.size() * sizeof(Instruction);
+ if (thisObject->m_jitCode)
+ extraMemoryAllocated += thisObject->m_jitCode->size();
+ return Base::estimatedSize(cell) + extraMemoryAllocated;
+}
+
void CodeBlock::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
CodeBlock* thisObject = jsCast<CodeBlock*>(cell);
