1 // Copyright 2014 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "src/background-parsing-task.h"
6
7 #include "src/debug/debug.h"
8 #include "src/parsing/parser.h"
9
10 namespace v8 {
11 namespace internal {
12
Release()13 void StreamedSource::Release() {
14 parser.reset();
15 info.reset();
16 zone.reset();
17 }
18
BackgroundParsingTask(StreamedSource * source,ScriptCompiler::CompileOptions options,int stack_size,Isolate * isolate)19 BackgroundParsingTask::BackgroundParsingTask(
20 StreamedSource* source, ScriptCompiler::CompileOptions options,
21 int stack_size, Isolate* isolate)
22 : source_(source), stack_size_(stack_size), script_data_(nullptr) {
23 // We don't set the context to the CompilationInfo yet, because the background
24 // thread cannot do anything with it anyway. We set it just before compilation
25 // on the foreground thread.
26 DCHECK(options == ScriptCompiler::kProduceParserCache ||
27 options == ScriptCompiler::kProduceCodeCache ||
28 options == ScriptCompiler::kNoCompileOptions);
29
30 // Prepare the data for the internalization phase and compilation phase, which
31 // will happen in the main thread after parsing.
32 Zone* zone = new Zone(isolate->allocator(), ZONE_NAME);
33 ParseInfo* info = new ParseInfo(zone);
34 info->set_toplevel();
35 source->zone.reset(zone);
36 source->info.reset(info);
37 info->set_isolate(isolate);
38 info->set_source_stream(source->source_stream.get());
39 info->set_source_stream_encoding(source->encoding);
40 info->set_hash_seed(isolate->heap()->HashSeed());
41 info->set_unicode_cache(&source_->unicode_cache);
42 info->set_compile_options(options);
43 info->set_allow_lazy_parsing();
44
45 source_->info->set_cached_data(&script_data_);
46 // Parser needs to stay alive for finalizing the parsing on the main
47 // thread.
48 source_->parser.reset(new Parser(source_->info.get()));
49 source_->parser->DeserializeScopeChain(source_->info.get(),
50 MaybeHandle<ScopeInfo>());
51 }
52
53
Run()54 void BackgroundParsingTask::Run() {
55 DisallowHeapAllocation no_allocation;
56 DisallowHandleAllocation no_handles;
57 DisallowHandleDereference no_deref;
58
59 // Reset the stack limit of the parser to reflect correctly that we're on a
60 // background thread.
61 uintptr_t stack_limit = GetCurrentStackPosition() - stack_size_ * KB;
62 source_->parser->set_stack_limit(stack_limit);
63
64 // Nullify the Isolate temporarily so that the background parser doesn't
65 // accidentally use it.
66 Isolate* isolate = source_->info->isolate();
67 source_->info->set_isolate(nullptr);
68
69 source_->parser->ParseOnBackground(source_->info.get());
70
71 if (script_data_ != nullptr) {
72 source_->cached_data.reset(new ScriptCompiler::CachedData(
73 script_data_->data(), script_data_->length(),
74 ScriptCompiler::CachedData::BufferOwned));
75 script_data_->ReleaseDataOwnership();
76 delete script_data_;
77 script_data_ = nullptr;
78 }
79 source_->info->set_isolate(isolate);
80 }
81 } // namespace internal
82 } // namespace v8
83