Copy ICData descriptors when starting background compilation, so that they do not change while comp…

runtime/vm/object.cc

 // Copyright (c) 2012, 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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 7100 matching lines @@
     }
     for (intptr_t i = 1; i < saved_length; i++) {
       ICData& ic_data = ICData::ZoneHandle(zone);
       ic_data ^= saved_ic_data.At(i);
       (*deopt_id_to_ic_data)[ic_data.deopt_id()] = &ic_data;
     }
   }
 }
 
 
+void Function::CopyICDataMap(
+    ZoneGrowableArray<const ICData*>* deopt_id_to_ic_data) const {
+  ASSERT(deopt_id_to_ic_data->is_empty());
+  Zone* zone = Thread::Current()->zone();
+  const Array& saved_ic_data = Array::Handle(zone, ic_data_array());
+  if (saved_ic_data.IsNull()) {
+    return;
+  }
+  const intptr_t saved_length = saved_ic_data.Length();
+  ASSERT(saved_length > 0);
+  if (saved_length > 1) {
+    const intptr_t restored_length = ICData::Cast(Object::Handle(
+        zone, saved_ic_data.At(saved_length - 1))).deopt_id() + 1;
+    deopt_id_to_ic_data->SetLength(restored_length);
+    for (intptr_t i = 0; i < restored_length; i++) {
+      (*deopt_id_to_ic_data)[i] = NULL;
+    }
+    for (intptr_t i = 1; i < saved_length; i++) {
+      ICData& ic_data = ICData::ZoneHandle(zone);
+      ic_data ^= saved_ic_data.At(i);
+      ic_data = ICData::CloneDescriptor(ic_data);
+      (*deopt_id_to_ic_data)[ic_data.deopt_id()] = &ic_data;
+    }
+  }
+}

[siva, 2015/10/27 23:36:45]

This function seems identical to RestoreICDataMap except for the CloneDescriptor
part.

Can we just call RestoreICDataMap in both cases (IsMutatorThread and
!IsMutatorThread) and then in the case of !IsMutatorThread we could do a loop to
clone the descriptors ?

Or we could add a 'clone_descriptor' parameter to RestoreICDataMap and call it
accordingly.

[srdjan, 2015/10/28 16:54:43]

Yes, passing argument clone_descriptor.
Also added (as discussed offline) Compiler::IsBackgroundCompilation().

+
+
 void Function::set_ic_data_array(const Array& value) const {
   StorePointer(&raw_ptr()->ic_data_array_, value.raw());
 }
 
 
 RawArray* Function::ic_data_array() const {
   return raw_ptr()->ic_data_array_;
 }
 
 
@@ skipping 5587 matching lines @@
       String::Handle(from.target_name()),
       Array::Handle(from.arguments_descriptor()),
       from.deopt_id(),
       num_args_tested));
   // Copy deoptimization reasons.
   result.SetDeoptReasons(from.DeoptReasons());
   return result.raw();
 }
 
 
+RawICData* ICData::CloneDescriptor(const ICData& from) {
+  Zone* zone = Thread::Current()->zone();
+  const ICData& result = ICData::Handle(ICData::NewDescriptor(
+      zone,
+      Function::Handle(zone, from.owner()),
+      String::Handle(zone, from.target_name()),
+      Array::Handle(zone, from.arguments_descriptor()),
+      from.deopt_id(),
+      from.NumArgsTested()));
+  // Preserve entry array.
+  result.set_ic_data_array(Array::Handle(zone, from.ic_data()));
+  // Copy deoptimization reasons.
+  result.SetDeoptReasons(from.DeoptReasons());
+  return result.raw();
+}
+
+
 void ICData::PrintJSONImpl(JSONStream* stream, bool ref) const {
   JSONObject jsobj(stream);
   AddCommonObjectProperties(&jsobj, "Object", ref);
   jsobj.AddServiceId(*this);
   jsobj.AddProperty("_owner", Object::Handle(owner()));
   jsobj.AddProperty("_selector", String::Handle(target_name()).ToCString());
   if (ref) {
     return;
   }
   jsobj.AddProperty("_argumentsDescriptor",
@@ skipping 9089 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart