[inspector] introduce limit for amount of stored async stacks

src/inspector/v8-debugger.h

 // 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.
 
 #ifndef V8_INSPECTOR_V8DEBUGGER_H_
 #define V8_INSPECTOR_V8DEBUGGER_H_
 
+#include <deque>
 #include <vector>
 
 #include "src/base/macros.h"
 #include "src/debug/debug-interface.h"
 #include "src/inspector/java-script-call-frame.h"
 #include "src/inspector/protocol/Forward.h"
 #include "src/inspector/protocol/Runtime.h"
 #include "src/inspector/v8-debugger-script.h"
 #include "src/inspector/wasm-translation.h"
 
@@ skipping 110 matching lines @@
     GENERATOR,
   };
   v8::MaybeLocal<v8::Value> getTargetScopes(v8::Local<v8::Context>,
                                             v8::Local<v8::Value>,
                                             ScopeTargetKind);
 
   v8::MaybeLocal<v8::Value> functionScopes(v8::Local<v8::Context>,
                                            v8::Local<v8::Function>);
   v8::MaybeLocal<v8::Value> generatorScopes(v8::Local<v8::Context>,
                                             v8::Local<v8::Value>);
+  void cleanupScheduledOrderIfNeeded();
 
   v8::Isolate* m_isolate;
   V8InspectorImpl* m_inspector;
   int m_enableCount;
   bool m_breakpointsActivated;
   v8::Global<v8::Object> m_debuggerScript;
   v8::Global<v8::Context> m_debuggerContext;
   v8::Local<v8::Object> m_executionState;
   v8::Local<v8::Context> m_pausedContext;
   bool m_runningNestedMessageLoop;
   int m_ignoreScriptParsedEventsCounter;
 
   using AsyncTaskToStackTrace =
       protocol::HashMap<void*, std::unique_ptr<V8StackTraceImpl>>;
   AsyncTaskToStackTrace m_asyncTaskStacks;
+  std::deque<void*> m_scheduledOrder;

[dgozman, 2016/12/16 22:36:11]

Can we instead have two maps: void* -> task_id, and task_id -> void* ?
Then we can increment the id, and just use idToTask.front(). WDYT?

[kozy, 2016/12/16 22:56:15]

Done.

+  std::unordered_set<void*> m_scheduledOrderDeleted;
   protocol::HashSet<void*> m_recurringTasks;
   int m_maxAsyncCallStackDepth;
   std::vector<void*> m_currentTasks;
   std::vector<std::unique_ptr<V8StackTraceImpl>> m_currentStacks;
   protocol::HashMap<V8DebuggerAgentImpl*, int> m_maxAsyncCallStackDepthMap;
 
   v8::debug::ExceptionBreakState m_pauseOnExceptionsState;
 
   WasmTranslation m_wasmTranslation;
 
   DISALLOW_COPY_AND_ASSIGN(V8Debugger);
 };
 
 }  // namespace v8_inspector
 
 #endif  // V8_INSPECTOR_V8DEBUGGER_H_