Port messages sent by WebIDBFactoryImpl to Mojo.

third_party/WebKit/Source/modules/indexeddb/WebIDBCallbacksImpl.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  * 1. Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *
@@ skipping 23 matching lines @@
 #include "modules/indexeddb/IDBMetadata.h"
 #include "modules/indexeddb/IDBRequest.h"
 #include "modules/indexeddb/IDBValue.h"
 #include "platform/SharedBuffer.h"
 #include "public/platform/modules/indexeddb/WebIDBCursor.h"
 #include "public/platform/modules/indexeddb/WebIDBDatabase.h"
 #include "public/platform/modules/indexeddb/WebIDBDatabaseError.h"
 #include "public/platform/modules/indexeddb/WebIDBKey.h"
 #include "public/platform/modules/indexeddb/WebIDBValue.h"
 #include "wtf/PtrUtil.h"
+#include "wtf/ThreadSpecific.h"
 #include <memory>
 
 using blink::WebIDBCursor;
 using blink::WebIDBDatabase;
 using blink::WebIDBDatabaseError;
 using blink::WebIDBKey;
 using blink::WebIDBKeyPath;
 using blink::WebIDBMetadata;
 using blink::WebIDBValue;
 using blink::WebVector;
 
 namespace blink {
 
+// This thread-specific list keeps track of instances of WebIDBCallbacksImpl
+// created by each thread. If a thread exits before they are destroyed then they
+// would otherwise be leaked because the IO thread can no longer post a task to
+// the thread on which they were created.
+using CallbacksList = std::vector<std::unique_ptr<WebIDBCallbacksImpl>>;

[dcheng, 2016/10/17 05:33:44]

Inside Blink, we should probably be using WTF::Vector.

+static ThreadSpecific<CallbacksList>& outstandingCallbacks() {

[haraken, 2016/10/18 19:01:29]

It's not really nice to use ThreadSpecific to keep track of per-worker data
structures... Would there be any per-worker class that can be used to track the
callback vector?

If there's no alternative, I'm okay with ThreadSpecific though.

[Reilly Grant (use Gerrit), 2016/10/19 00:36:51]

The only per-worker object I know of that could hold these is
IndexedDBDispatcher but that isn't accessible from Blink and the point of this
patch series is to remove IndexedDBDispatcher. That said, I think I could make
that work if that is what you prefer.

+  DEFINE_THREAD_SAFE_STATIC_LOCAL(ThreadSpecific<CallbacksList>, callbacks,
+                                  new ThreadSpecific<CallbacksList>);
+  return callbacks;
+}
+
 // static
 std::unique_ptr<WebIDBCallbacksImpl> WebIDBCallbacksImpl::create(
     IDBRequest* request) {
   return wrapUnique(new WebIDBCallbacksImpl(request));
 }
 
 WebIDBCallbacksImpl::WebIDBCallbacksImpl(IDBRequest* request)
     : m_request(request) {
   InspectorInstrumentation::asyncTaskScheduled(
       m_request->getExecutionContext(), IndexedDBNames::IndexedDB, this, true);
+  outstandingCallbacks()->push_back(wrapUnique(this));
 }
 
 WebIDBCallbacksImpl::~WebIDBCallbacksImpl() {
-  InspectorInstrumentation::asyncTaskCanceled(m_request->getExecutionContext(),
-                                              this);
+  if (m_request) {
+    InspectorInstrumentation::asyncTaskCanceled(
+        m_request->getExecutionContext(), this);
+    m_request->webCallbacksDestroyed();
+  }
+
+  CallbacksList& callbacks = *outstandingCallbacks();
+  auto it =
+      std::find_if(callbacks.begin(), callbacks.end(),

[haraken, 2016/10/18 19:01:29]

To avoid the O(N) search, would it be better to use HashSet?

Nit: I'd prefer not using an advanced C++ feature like a lambda function.

[Reilly Grant (use Gerrit), 2016/10/19 00:36:51]

The number of outstanding requests is expected to be small so I wanted to avoid
the overhead of the more complex data structure.
This usage of lambda functions is permitted by the style guide.

+                   [this](const std::unique_ptr<WebIDBCallbacksImpl>& element) {
+                     return element.get() == this;
+                   });
+  if (it != callbacks.end()) {
+    it->release();
+    callbacks.erase(it);
+  }
 }
 
 void WebIDBCallbacksImpl::onError(const WebIDBDatabaseError& error) {
+  if (!m_request)
+    return;
+
   InspectorInstrumentation::AsyncTask asyncTask(
       m_request->getExecutionContext(), this);
   m_request->onError(DOMException::create(error.code(), error.message()));
 }
 
 void WebIDBCallbacksImpl::onSuccess(const WebVector<WebString>& webStringList) {
+  if (!m_request)
+    return;
+
   Vector<String> stringList;
   for (size_t i = 0; i < webStringList.size(); ++i)
     stringList.append(webStringList[i]);
   InspectorInstrumentation::AsyncTask asyncTask(
       m_request->getExecutionContext(), this);
   m_request->onSuccess(stringList);
 }
 
 void WebIDBCallbacksImpl::onSuccess(WebIDBCursor* cursor,
                                     const WebIDBKey& key,
                                     const WebIDBKey& primaryKey,
                                     const WebIDBValue& value) {
+  if (!m_request)
+    return;
+
   InspectorInstrumentation::AsyncTask asyncTask(
       m_request->getExecutionContext(), this);
   m_request->onSuccess(wrapUnique(cursor), key, primaryKey,
                        IDBValue::create(value));
 }
 
 void WebIDBCallbacksImpl::onSuccess(WebIDBDatabase* backend,
                                     const WebIDBMetadata& metadata) {
-  InspectorInstrumentation::AsyncTask asyncTask(
-      m_request->getExecutionContext(), this);
-  m_request->onSuccess(wrapUnique(backend), IDBDatabaseMetadata(metadata));
+  std::unique_ptr<WebIDBDatabase> db = wrapUnique(backend);
+  if (m_request) {
+    InspectorInstrumentation::AsyncTask asyncTask(
+        m_request->getExecutionContext(), this);
+    m_request->onSuccess(std::move(db), IDBDatabaseMetadata(metadata));
+  } else if (db) {
+    db->close();
+  }
 }
 
 void WebIDBCallbacksImpl::onSuccess(const WebIDBKey& key) {
+  if (!m_request)
+    return;
+
   InspectorInstrumentation::AsyncTask asyncTask(
       m_request->getExecutionContext(), this);
   m_request->onSuccess(key);
 }
 
 void WebIDBCallbacksImpl::onSuccess(const WebIDBValue& value) {
+  if (!m_request)
+    return;
+
   InspectorInstrumentation::AsyncTask asyncTask(
       m_request->getExecutionContext(), this);
   m_request->onSuccess(IDBValue::create(value));
 }
 
 void WebIDBCallbacksImpl::onSuccess(const WebVector<WebIDBValue>& values) {
+  if (!m_request)
+    return;
+
   InspectorInstrumentation::AsyncTask asyncTask(
       m_request->getExecutionContext(), this);
   Vector<RefPtr<IDBValue>> idbValues(values.size());
   for (size_t i = 0; i < values.size(); ++i)
     idbValues[i] = IDBValue::create(values[i]);
   m_request->onSuccess(idbValues);
 }
 
 void WebIDBCallbacksImpl::onSuccess(long long value) {
+  if (!m_request)
+    return;
+
   InspectorInstrumentation::AsyncTask asyncTask(
       m_request->getExecutionContext(), this);
   m_request->onSuccess(value);
 }
 
 void WebIDBCallbacksImpl::onSuccess() {
+  if (!m_request)
+    return;
+
   InspectorInstrumentation::AsyncTask asyncTask(
       m_request->getExecutionContext(), this);
   m_request->onSuccess();
 }
 
 void WebIDBCallbacksImpl::onSuccess(const WebIDBKey& key,
                                     const WebIDBKey& primaryKey,
                                     const WebIDBValue& value) {
+  if (!m_request)
+    return;
+
   InspectorInstrumentation::AsyncTask asyncTask(
       m_request->getExecutionContext(), this);
   m_request->onSuccess(key, primaryKey, IDBValue::create(value));
 }
 
 void WebIDBCallbacksImpl::onBlocked(long long oldVersion) {
+  if (!m_request)
+    return;
+
   InspectorInstrumentation::AsyncTask asyncTask(
       m_request->getExecutionContext(), this);
   m_request->onBlocked(oldVersion);
 }
 
 void WebIDBCallbacksImpl::onUpgradeNeeded(long long oldVersion,
                                           WebIDBDatabase* database,
                                           const WebIDBMetadata& metadata,
                                           unsigned short dataLoss,
                                           WebString dataLossMessage) {
-  InspectorInstrumentation::AsyncTask asyncTask(
-      m_request->getExecutionContext(), this);
-  m_request->onUpgradeNeeded(
-      oldVersion, wrapUnique(database), IDBDatabaseMetadata(metadata),
-      static_cast<WebIDBDataLoss>(dataLoss), dataLossMessage);
+  std::unique_ptr<WebIDBDatabase> db = wrapUnique(database);
+  if (m_request) {
+    InspectorInstrumentation::AsyncTask asyncTask(
+        m_request->getExecutionContext(), this);
+    m_request->onUpgradeNeeded(
+        oldVersion, std::move(db), IDBDatabaseMetadata(metadata),
+        static_cast<WebIDBDataLoss>(dataLoss), dataLossMessage);
+  } else {
+    db->close();
+  }
+}
+
+void WebIDBCallbacksImpl::detach() {
+  m_request.clear();
 }
 
 }  // namespace blink