Add script streaming API

src/background-parsing-task.cc

Index: src/background-parsing-task.cc
diff --git a/src/background-parsing-task.cc b/src/background-parsing-task.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fc6630f680dd2d1b3e2f399008e615915ef0b22e
--- /dev/null
+++ b/src/background-parsing-task.cc
@@ -0,0 +1,75 @@
+// Copyright 2014 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/background-parsing-task.h"
+
+#include "src/parser.h"
+
+namespace v8 {
+namespace internal {
+
+static const int kBackgroundParserThreadStackSize = 64 * KB;

[jochen (gone - plz use gerrit), 2014/09/09 08:06:20]

should this be FLAG_stack_size

[marja, 2014/09/09 11:46:30]

Done.

+
+StreamedSource::~StreamedSource() {
+  delete source_stream;
+  delete cached_data;
+  delete info;
+  delete parser;
+}
+
+
+BackgroundParsingTask::BackgroundParsingTask(
+    StreamedSource* source, ScriptCompiler::CompileOptions options,
+    Isolate* isolate)
+    : source_(source), options_(options) {
+  // Prepare the data for the internalization phase and compilation phase, which
+  // will happen in the main thread after parsing.
+  source->info = new i::CompilationInfoWithZone(source->source_stream,
+                                                source->encoding, isolate);
+  source->info->MarkAsGlobal();
+
+  // We don't set the context to the CompilationInfo yet, because the background
+  // thread cannot do anything with it anyway. We set it just before compilation
+  // on the foreground thread.
+  DCHECK(options == ScriptCompiler::kProduceParserCache ||
+         options == ScriptCompiler::kProduceCodeCache ||
+         options == ScriptCompiler::kNoCompileOptions);
+  source->allow_lazy =
+      !i::Compiler::DebuggerWantsEagerCompilation(source->info);
+  source->hash_seed = isolate->heap()->HashSeed();
+}
+
+
+void BackgroundParsingTask::Run() {
+  DisallowHeapAllocation no_allocation;
+  DisallowHandleAllocation no_handles;
+  DisallowHandleDereference no_deref;
+
+  ScriptData* script_data = NULL;
+  if (options_ == ScriptCompiler::kProduceParserCache ||
+      options_ == ScriptCompiler::kProduceCodeCache) {
+    source_->info->SetCachedData(&script_data, options_);
+  }
+
+  uintptr_t limit =
+      reinterpret_cast<uintptr_t>(&limit) - kBackgroundParserThreadStackSize;
+  Parser::ParseInfo parse_info = {limit, source_->hash_seed,
+                                  &source_->unicode_cache};
+
+  // Parser needs to stay alive for finalizing the parsing on the main
+  // thread. Passing &parse_info is OK because Parser doesn't store it.
+  source_->parser = new Parser(source_->info, &parse_info);
+  source_->parser->set_allow_lazy(source_->allow_lazy);
+  source_->parser->ParseOnBackground();
+
+  if (script_data != NULL) {
+    source_->cached_data = new ScriptCompiler::CachedData(
+        script_data->data(), script_data->length(),
+        ScriptCompiler::CachedData::BufferOwned);
+    script_data->ReleaseDataOwnership();
+    delete script_data;
+  }
+}
+}

[jochen (gone - plz use gerrit), 2014/09/09 08:06:20]

nit // namespace internal

also, empty line above this one

[marja, 2014/09/09 11:46:30]

git cl format removes the empty line if I put one there.

[marja, 2014/09/09 11:46:30]

Counter nit: this seems pretty customary:

$ git grep "// namespace v8::internal" | wc -l
691
$ git grep "// namespace internal" | wc -l
96

So not changing this; also, there's no risk of misunderstanding it.

+}  // namespace v8::internal

[jochen (gone - plz use gerrit), 2014/09/09 08:06:20]

// namespace v8