[inspector] unconditionally pause on OOM

src/inspector/v8-debugger.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/inspector/v8-debugger.h"
 
 #include "src/inspector/debugger-script.h"
 #include "src/inspector/inspected-context.h"
 #include "src/inspector/protocol/Protocol.h"
 #include "src/inspector/script-breakpoint.h"
@@ skipping 54 matching lines @@
 V8Debugger::~V8Debugger() {}
 
 void V8Debugger::enable() {
   if (m_enableCount++) return;
   DCHECK(!enabled());
   v8::HandleScope scope(m_isolate);
   v8::debug::SetDebugEventListener(m_isolate, &V8Debugger::v8DebugEventCallback,
                                    v8::External::New(m_isolate, this));
   v8::debug::SetAsyncTaskListener(m_isolate, &V8Debugger::v8AsyncTaskListener,
                                   this);
+  v8::debug::SetOutOfMemoryCallback(m_isolate, &V8Debugger::v8OOMCallback,
+                                    this);
   m_debuggerContext.Reset(m_isolate, v8::debug::GetDebugContext(m_isolate));
   v8::debug::ChangeBreakOnException(m_isolate, v8::debug::NoBreakOnException);
   m_pauseOnExceptionsState = v8::debug::NoBreakOnException;
   compileDebuggerScript();
 }
 
 void V8Debugger::disable() {
   if (--m_enableCount) return;
   DCHECK(enabled());
   clearBreakpoints();
   m_debuggerScript.Reset();
   m_debuggerContext.Reset();
   allAsyncTasksCanceled();
   m_wasmTranslation.Clear();
   v8::debug::SetDebugEventListener(m_isolate, nullptr);
   v8::debug::SetAsyncTaskListener(m_isolate, nullptr, nullptr);
+  v8::debug::SetOutOfMemoryCallback(m_isolate, &V8Debugger::v8OOMCallback,
+                                    nullptr);
+  m_isolate->RestoreOriginalHeapLimit();
 }
 
 bool V8Debugger::enabled() const { return !m_debuggerScript.IsEmpty(); }
 
 void V8Debugger::getCompiledScripts(
     int contextGroupId,
     std::vector<std::unique_ptr<V8DebuggerScript>>& result) {
   v8::HandleScope scope(m_isolate);
   v8::PersistentValueVector<v8::debug::Script> scripts(m_isolate);
   v8::debug::GetLoadedScripts(m_isolate, scripts);
@@ skipping 372 matching lines @@
       v8::Local<v8::Value> hitBreakpointNumber =
           hitBreakpointNumbers->Get(debuggerContext(), i).ToLocalChecked();
       DCHECK(hitBreakpointNumber->IsInt32());
       breakpointIds.push_back(String16::fromInteger(
           hitBreakpointNumber->Int32Value(debuggerContext()).FromJust()));
     }
   }
 
   m_pausedContext = pausedContext;
   m_executionState = executionState;
-  V8DebuggerAgentImpl::SkipPauseRequest result = agent->didPause(
-      pausedContext, exception, breakpointIds, isPromiseRejection, isUncaught);
+  V8DebuggerAgentImpl::SkipPauseRequest result =
+      agent->didPause(pausedContext, exception, breakpointIds,
+                      isPromiseRejection, isUncaught, m_scheduledOOMBreak);
   if (result == V8DebuggerAgentImpl::RequestNoSkip) {
     m_runningNestedMessageLoop = true;
     int groupId = m_inspector->contextGroupId(pausedContext);
     DCHECK(groupId);
     v8::Context::Scope scope(pausedContext);
     v8::Local<v8::Context> context = m_isolate->GetCurrentContext();
     CHECK(!context.IsEmpty() &&
           context != v8::debug::GetDebugContext(m_isolate));
     m_inspector->client()->runMessageLoopOnPause(groupId);
     // The agent may have been removed in the nested loop.
     agent = m_inspector->enabledDebuggerAgentForGroup(
         m_inspector->contextGroupId(pausedContext));
     if (agent) agent->didContinue();
     m_runningNestedMessageLoop = false;
   }
+  if (m_scheduledOOMBreak) m_isolate->RestoreOriginalHeapLimit();
+  m_scheduledOOMBreak = false;
   m_pausedContext.Clear();
   m_executionState.Clear();
 
   if (result == V8DebuggerAgentImpl::RequestStepFrame) {
     v8::debug::PrepareStep(m_isolate, v8::debug::StepFrame);
   } else if (result == V8DebuggerAgentImpl::RequestStepInto) {
     v8::debug::PrepareStep(m_isolate, v8::debug::StepIn);
   } else if (result == V8DebuggerAgentImpl::RequestStepOut) {
     v8::debug::PrepareStep(m_isolate, v8::debug::StepOut);
   }
 }
 
+void V8Debugger::v8OOMCallback(void* data) {
+  V8Debugger* thisPtr = static_cast<V8Debugger*>(data);
+  thisPtr->m_isolate->IncreaseHeapLimitForDebugging();
+  thisPtr->m_scheduledOOMBreak = true;
+  thisPtr->setPauseOnNextStatement(true);
+}
+
 void V8Debugger::v8DebugEventCallback(
     const v8::debug::EventDetails& eventDetails) {
   V8Debugger* thisPtr = toV8Debugger(eventDetails.GetCallbackData());
   thisPtr->handleV8DebugEvent(eventDetails);
 }
 
 v8::Local<v8::Value> V8Debugger::callInternalGetterFunction(
     v8::Local<v8::Object> object, const char* functionName) {
   v8::MicrotasksScope microtasks(m_isolate,
                                  v8::MicrotasksScope::kDoNotRunMicrotasks);
@@ skipping 472 matching lines @@
 
   size_t stackSize =
       fullStack ? V8StackTraceImpl::maxCallStackSizeToCapture : 1;
   if (m_inspector->enabledRuntimeAgentForGroup(contextGroupId))
     stackSize = V8StackTraceImpl::maxCallStackSizeToCapture;
 
   return V8StackTraceImpl::capture(this, contextGroupId, stackSize);
 }
 
 }  // namespace v8_inspector