Two-threaded parser

src/parser-thread.h

+// Copyright 2014 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_PARSER_THREAD_H_
+#define V8_PARSER_THREAD_H_
+
+#include "platform.h"
+#include "platform/semaphore.h"
+#include "preparser.h"
+
+// This thread does a fast pass over the source, and produced data on lazy
+// functions. It won't interact with the V8 heap or the Isolate (for example,
+// create or dereference Handles). This will only hold if the
+// Utf16CharacterStream passed to the constructor does not interact with the V8
+// heap either.
+
+namespace v8 {
+namespace internal {
+
+class BackgroundParsingTask;
+class SingletonLogger;
+class Utf16CharacterStream;
+
+class FastParserThread : public Thread {
+ public:
+  // Used for signalling errors.
+  static const int kInvalidFunctionStart = -1;
+
+  FastParserThread();
+
+  // Should be only called by the main thread. Takes ownership of the
+  // stream. The thread can only handle one background parsing task at a time,
+  // so this cannot be called again before FinishBackgroundParsing has been
+  // called for the current task. (For the purposes of parallel preparsing, this
+  // is enough; we will never have more than one script to preparse.)
+  void StartBackgroundParsing(Utf16CharacterStream* stream,
+                              bool allow_harmony_scoping,
+                              bool allow_modules,
+                              bool allow_natives_syntax,
+                              bool allow_generators,
+                              bool allow_for_of,
+                              bool allow_harmony_numeric_literals);
+
+  void FinishBackgroundParsing();
+
+  void Run();
+
+  // Should only be called when no background task is in progress.
+  void Stop();
+
+  // Should be only called from the background thread.
+  void Produce(int start, int end, int literals, int properties,
+               StrictMode strict_mode);
+
+  // Should be only called by the main thread.
+  void Consume(int* start, int* end, int* literals, int* properties,
+               StrictMode* strict_mode);
+
+  PreParser::PreParseResult result() const;
+  const SingletonLogger* recorder() const;
+
+ private:
+  BackgroundParsingTask* current_task_;
+  Semaphore have_work_;
+  Semaphore work_done_;
+  bool should_stop_;
+};
+
+} }  // namespace v8::internal
+
+#endif  // V8_PARSER_THREAD_H_