Check that function being patched has no activations on any thread stack

src/runtime.cc

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 8425 matching lines @@
   HandleScope scope;
   CONVERT_ARG_CHECKED(JSArray, shared_array, 0);
   CONVERT_ARG_CHECKED(JSArray, position_change_array, 1);
 
   LiveEdit::PatchFunctionPositions(shared_array, position_change_array);
 
   return Heap::undefined_value();
 }
 
 
+static LiveEdit::FunctionPatchabilityStatus FindFunctionCodeOnStacks(
+    Handle<SharedFunctionInfo> shared) {
+  // TODO(635): check all threads, not only the current one.
+  for (StackFrameIterator it; !it.done(); it.Advance()) {
+    StackFrame* frame = it.frame();
+    if (frame->code() == shared->code()) {
+      return LiveEdit::FUNCTION_BLOCKED_ON_STACK;
+    }
+  }
+  return LiveEdit::FUNCTION_AVAILABLE_FOR_PATCH;
+}
+
+// For array of SharedFunctionInfo's (each wrapped in JSValue)
+// checks that none of them have activations on stacks (of any thread).
+// Returns array of the same length with corresponding results of
+// LiveEdit::FunctionPatchabilityStatus type.
+static Object* Runtime_LiveEditCheckStackActivations(Arguments args) {
+  ASSERT(args.length() == 1);
+  HandleScope scope;
+  CONVERT_ARG_CHECKED(JSArray, shared_array, 0);
+
+
+  int len = Smi::cast(shared_array->length())->value();
+  Handle<JSArray> result = Factory::NewJSArray(len);
+
+  for (int i = 0; i < len; i++) {
+    JSValue* wrapper = JSValue::cast(shared_array->GetElement(i));
+    Handle<SharedFunctionInfo> shared(
+        SharedFunctionInfo::cast(wrapper->value()));
+    LiveEdit::FunctionPatchabilityStatus check_res =
+        FindFunctionCodeOnStacks(shared);
+    SetElement(result, i, Handle<Smi>(Smi::FromInt(check_res)));
+  }
+
+  return *result;
+}
+
+
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
 static Object* Runtime_ProfilerResume(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
   CONVERT_CHECKED(Smi, smi_modules, args[0]);
   CONVERT_CHECKED(Smi, smi_tag, args[1]);
@@ skipping 255 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal