[oilpan]: fix deadlock when leaving a safepoint and sweeping.

Source/modules/webdatabase/DatabaseBackendBase.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple 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 117 matching lines @@
     result = statement.step();
     if (result != SQLResultDone) {
         WTF_LOG_ERROR("Failed to step statement to set value in database (%s)", query.ascii().data());
         return false;
     }
 
     return true;
 }
 
 // FIXME: move all guid-related functions to a DatabaseVersionTracker class.
-static Mutex& guidMutex()
+static RecursiveMutex& guidMutex()
 {
-    AtomicallyInitializedStatic(Mutex&, mutex = *new Mutex);
+    AtomicallyInitializedStatic(RecursiveMutex&, mutex = *new RecursiveMutex);
     return mutex;
 }
 
 typedef HashMap<DatabaseGuid, String> GuidVersionMap;
 static GuidVersionMap& guidToVersionMap()
 {
     // Ensure the the mutex is locked.
-    ASSERT(!guidMutex().tryLock());
+    ASSERT(guidMutex().locked());
     DEFINE_STATIC_LOCAL(GuidVersionMap, map, ());
     return map;
 }
 
 // NOTE: Caller must lock guidMutex().
 static inline void updateGuidVersionMap(DatabaseGuid guid, String newVersion)
 {
     // Ensure the the mutex is locked.
-    ASSERT(!guidMutex().tryLock());
+    ASSERT(guidMutex().locked());
 
     // Note: It is not safe to put an empty string into the guidToVersionMap() map.
     // That's because the map is cross-thread, but empty strings are per-thread.
     // The copy() function makes a version of the string you can use on the current
     // thread, but we need a string we can keep in a cross-thread data structure.
     // FIXME: This is a quite-awkward restriction to have to program with.
 
     // Map null string to empty string (see comment above).
     guidToVersionMap().set(guid, newVersion.isEmpty() ? String() : newVersion.isolatedCopy());
 }
 
 typedef HashMap<DatabaseGuid, HashSet<DatabaseBackendBase*>*> GuidDatabaseMap;
 static GuidDatabaseMap& guidToDatabaseMap()
 {
     // Ensure the the mutex is locked.
-    ASSERT(!guidMutex().tryLock());
+    ASSERT(guidMutex().locked());
     DEFINE_STATIC_LOCAL(GuidDatabaseMap, map, ());
     return map;
 }
 
 static DatabaseGuid guidForOriginAndName(const String& origin, const String& name)
 {
     // Ensure the the mutex is locked.
-    ASSERT(!guidMutex().tryLock());
+    ASSERT(guidMutex().locked());
 
     String stringID = origin + "/" + name;
 
     typedef HashMap<String, int> IDGuidMap;
     DEFINE_STATIC_LOCAL(IDGuidMap, stringIdentifierToGUIDMap, ());
     DatabaseGuid guid = stringIdentifierToGUIDMap.get(stringID);
     if (!guid) {
         static int currentNewGUID = 1;
         guid = currentNewGUID++;
         stringIdentifierToGUIDMap.set(stringID, guid);
@@ skipping 474 matching lines @@
 {
     executionContext()->addConsoleMessage(StorageMessageSource, ErrorMessageLevel, message);
 }
 
 ExecutionContext* DatabaseBackendBase::executionContext() const
 {
     return databaseContext()->executionContext();
 }
 
 } // namespace blink