Collect TokenStreams into the vm isolate snapshot instead of Scripts.

runtime/vm/clustered_snapshot.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/clustered_snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
@@ skipping 4792 matching lines @@
     for (intptr_t i = 0; i < num_clusters_; i++) {
       clusters_[i]->PostLoad(refs, kind_, zone_);
     }
   }
 
   // Setup native resolver for bootstrap impl.
   Bootstrap::SetupNativeResolver();
 }
 
 
-// An object visitor which will iterate over all the script objects in the heap
-// and either count them or collect them into an array. This is used during
-// full snapshot generation of the VM isolate to write out all script
-// objects and their accompanying token streams.
-class ScriptVisitor : public ObjectVisitor {
+// An object visitor which will iterate over all the token stream objects in the
+// heap and either count them or collect them into an array. This is used during
+// full snapshot generation of the VM isolate to write out all token streams so
+// they will be shared across all isolates.
+class TokenStreamVisitor : public ObjectVisitor {
  public:
-  explicit ScriptVisitor(Thread* thread) :
+  explicit TokenStreamVisitor(Thread* thread) :
       objHandle_(Object::Handle(thread->zone())),
       count_(0),
-      scripts_(NULL) {}
+      token_streams_(NULL) {}
 
-  ScriptVisitor(Thread* thread, const Array* scripts) :
+  TokenStreamVisitor(Thread* thread, const Array* token_streams) :
       objHandle_(Object::Handle(thread->zone())),
       count_(0),
-      scripts_(scripts) {}
+      token_streams_(token_streams) {}
 
   void VisitObject(RawObject* obj) {
-    if (obj->IsScript()) {
-      if (scripts_ != NULL) {
+    if (obj->IsTokenStream()) {
+      if (token_streams_ != NULL) {
         objHandle_ = obj;
-        scripts_->SetAt(count_, objHandle_);
+        token_streams_->SetAt(count_, objHandle_);
       }
       count_ += 1;
     }
   }
 
   intptr_t count() const { return count_; }
 
  private:
   Object& objHandle_;
   intptr_t count_;
-  const Array* scripts_;
+  const Array* token_streams_;
 };
 
 
 FullSnapshotWriter::FullSnapshotWriter(Snapshot::Kind kind,
                                        uint8_t** vm_isolate_snapshot_buffer,
                                        uint8_t** isolate_snapshot_buffer,
                                        ReAlloc alloc,
                                        InstructionsWriter* instructions_writer)
     : thread_(Thread::Current()),
       kind_(kind),
       vm_isolate_snapshot_buffer_(vm_isolate_snapshot_buffer),
       isolate_snapshot_buffer_(isolate_snapshot_buffer),
       alloc_(alloc),
       vm_isolate_snapshot_size_(0),
       isolate_snapshot_size_(0),
       instructions_writer_(instructions_writer),
-      scripts_(Array::Handle(zone())),
+      token_streams_(Array::Handle(zone())),
       saved_symbol_table_(Array::Handle(zone())),
       new_vm_symbol_table_(Array::Handle(zone())) {
   ASSERT(isolate_snapshot_buffer_ != NULL);
   ASSERT(alloc_ != NULL);
   ASSERT(isolate() != NULL);
   ASSERT(ClassFinalizer::AllClassesFinalized());
   ASSERT(isolate() != NULL);
   ASSERT(heap() != NULL);
   ObjectStore* object_store = isolate()->object_store();
   ASSERT(object_store != NULL);
 
 #if defined(DEBUG)
   // Ensure the class table is valid.
   isolate()->ValidateClassTable();
 #endif
   // Can't have any mutation happening while we're serializing.
   ASSERT(isolate()->background_compiler() == NULL);
 
   if (vm_isolate_snapshot_buffer != NULL) {
     NOT_IN_PRODUCT(TimelineDurationScope tds(thread(),
         Timeline::GetIsolateStream(), "PrepareNewVMIsolate"));
 
     // Collect all the script objects and their accompanying token stream

[Florian Schneider, 2016/07/12 22:36:08]

Update comment here as well.

[rmacnak, 2016/07/12 23:22:35]

Done.

     // objects into an array so that we can write it out as part of the VM
     // isolate snapshot. We first count the number of script objects, allocate
     // an array and then fill it up with the script objects.
-    ScriptVisitor scripts_counter(thread());
-    heap()->IterateOldObjects(&scripts_counter);
-    Dart::vm_isolate()->heap()->IterateOldObjects(&scripts_counter);
-    intptr_t count = scripts_counter.count();
-    scripts_ = Array::New(count, Heap::kOld);
-    ScriptVisitor script_visitor(thread(), &scripts_);
+    TokenStreamVisitor token_streams_counter(thread());
+    heap()->IterateOldObjects(&token_streams_counter);
+    Dart::vm_isolate()->heap()->IterateOldObjects(&token_streams_counter);
+    intptr_t count = token_streams_counter.count();
+    token_streams_ = Array::New(count, Heap::kOld);
+    TokenStreamVisitor script_visitor(thread(), &token_streams_);
     heap()->IterateOldObjects(&script_visitor);
     Dart::vm_isolate()->heap()->IterateOldObjects(&script_visitor);
     ASSERT(script_visitor.count() == count);
 
     // Tuck away the current symbol table.
     saved_symbol_table_ = object_store->symbol_table();
 
     // Create a unified symbol table that will be written as the vm isolate's
     // symbol table.
     new_vm_symbol_table_ = Symbols::UnifiedSymbolTable();
 
     // Create an empty symbol table that will be written as the isolate's symbol
     // table.
     Symbols::SetupSymbolTable(isolate());
   } else {
     // Reuse the current vm isolate.
   }
 }
 
 FullSnapshotWriter::~FullSnapshotWriter() {
   // We may run Dart code afterwards, restore the symbol table if needed.
   if (!saved_symbol_table_.IsNull()) {
     isolate()->object_store()->set_symbol_table(saved_symbol_table_);
     saved_symbol_table_ = Array::null();
   }
   new_vm_symbol_table_ = Array::null();
-  scripts_ = Array::null();
+  token_streams_ = Array::null();
 }
 
 
 intptr_t FullSnapshotWriter::WriteVmIsolateSnapshot() {
   NOT_IN_PRODUCT(TimelineDurationScope tds(thread(),
       Timeline::GetIsolateStream(), "WriteVmIsolateSnapshot"));
 
   ASSERT(vm_isolate_snapshot_buffer_ != NULL);
   Serializer serializer(thread(),
                         kind_,
                         vm_isolate_snapshot_buffer_,
                         alloc_,
                         kInitialSize,
                         instructions_writer_);
 
   serializer.ReserveHeader();
   serializer.WriteVersionAndFeatures();
   /*
    * Now Write out the following
    * - the symbol table
-   * - all the scripts and token streams for these scripts
+   * - all the token streams
    * - the stub code (precompiled snapshots only)
    **/
   intptr_t num_objects = serializer.WriteVMSnapshot(new_vm_symbol_table_,
-                                                    scripts_);
+                                                    token_streams_);
   serializer.FillHeader(serializer.kind());
 
   vm_isolate_snapshot_size_ = serializer.bytes_written();
   return num_objects;
 }
 
 
 void FullSnapshotWriter::WriteIsolateFullSnapshot(
     intptr_t num_base_objects) {
   NOT_IN_PRODUCT(TimelineDurationScope tds(thread(),
@@ skipping 77 matching lines @@
 
   deserializer.ReadVMSnapshot();
 
   Dart::set_instructions_snapshot_buffer(instructions_buffer_);
   Dart::set_data_snapshot_buffer(data_buffer_);
 
   return ApiError::null();
 }
 
 }  // namespace dart