Changeset 240637 in webkit for trunk/Source/JavaScriptCore/tools/JSDollarVM.cpp

Timestamp:

Jan 28, 2019, 8:33:33 PM (6 years ago)

Author:

[email protected]

Message:

[JSC] Reduce size of memory used for ShadowChicken
​https://bugs.webkit.org/show_bug.cgi?id=193546

Reviewed by Mark Lam.

This patch lazily instantiate ShadowChicken. We do not need this until we start logging ShadowChicken packets.
The removal of ShadowChicken saves 55KB memory.

• debugger/DebuggerCallFrame.cpp:

(JSC::DebuggerCallFrame::create):

• ftl/FTLLowerDFGToB3.cpp:

(JSC::FTL::DFG::LowerDFGToB3::ensureShadowChickenPacket):

• heap/Heap.cpp:

(JSC::Heap::stopThePeriphery):
(JSC::Heap::addCoreConstraints):

• jit/CCallHelpers.cpp:

(JSC::CCallHelpers::ensureShadowChickenPacket):

• jit/JITExceptions.cpp:

(JSC::genericUnwind):

• jit/JITOpcodes.cpp:

(JSC::JIT::emit_op_log_shadow_chicken_prologue):
(JSC::JIT::emit_op_log_shadow_chicken_tail):

• jit/JITOpcodes32_64.cpp:

(JSC::JIT::emit_op_log_shadow_chicken_prologue):
(JSC::JIT::emit_op_log_shadow_chicken_tail):

• jit/JITOperations.cpp:
• llint/LLIntSlowPaths.cpp:

(JSC::LLInt::LLINT_SLOW_PATH_DECL):

• runtime/JSGlobalObject.cpp:

(JSC::JSGlobalObject::setDebugger):

• runtime/JSGlobalObject.h:

(JSC::JSGlobalObject::setDebugger): Deleted.

• runtime/VM.cpp:

(JSC::VM::VM):
(JSC::VM::ensureShadowChicken):

• runtime/VM.h:

(JSC::VM::shadowChicken):

• tools/JSDollarVM.cpp:

(JSC::functionShadowChickenFunctionsOnStack):
(JSC::changeDebuggerModeWhenIdle):

File:

• trunk/Source/JavaScriptCore/tools/JSDollarVM.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/tools/JSDollarVM.cpp

@@ -1933 +1933 @@
 {
     VM& vm = exec->vm();
-    return JSValue::encode(vm.shadowChicken().functionsOnStack(exec));
+    auto scope = DECLARE_THROW_SCOPE(vm);
+    if (auto* shadowChicken = vm.shadowChicken())
+        return JSValue::encode(shadowChicken->functionsOnStack(exec));
+
+    JSArray* result = constructEmptyArray(exec, 0);
+    RETURN_IF_EXCEPTION(scope, { });
+    StackVisitor::visit(exec, &vm, [&] (StackVisitor& visitor) -> StackVisitor::Status {
+        if (visitor->isInlinedFrame())
+            return StackVisitor::Continue;
+        if (visitor->isWasmFrame())
+            return StackVisitor::Continue;
+        result->push(exec, jsCast<JSObject*>(visitor->callee().asCell()));
+        scope.releaseAssertNoException(); // This function is only called from tests.
+        return StackVisitor::Continue;
+    });
+    return JSValue::encode(result);
 }
 
@@ -2048 +2063 @@
         Options::forceDebuggerBytecodeGeneration() = newDebuggerMode;
         vm->deleteAllCode(PreventCollectionAndDeleteAllCode);
+        if (mode == DebuggerMode::DebuggerOn)
+            vm->ensureShadowChicken();
     });
     return JSValue::encode(jsUndefined());