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

runtime/vm/object.h

 // 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 1903 matching lines @@
   bool HasOneTarget() const;
   bool HasReceiverClassId(intptr_t class_id) const;
 
   static RawICData* New(const Function& owner,
                         const String& target_name,
                         const Array& arguments_descriptor,
                         intptr_t deopt_id,
                         intptr_t num_args_tested);
   static RawICData* NewFrom(const ICData& from, intptr_t num_args_tested);
 
+  // Generates a new ICData with descriptor data copied (shallow clone).
+  // Entry array of the result is the same as in 'from'. Once entry array is
+  // created, it can only change the 'count', all other properties are invariant
+  // (target, cids, number of checks).
+  static RawICData* CloneDescriptor(const ICData& from);
+
   static intptr_t TestEntryLengthFor(intptr_t num_args);
 
   static intptr_t TargetIndexFor(intptr_t num_args) {
     return num_args;
   }
 
   static intptr_t CountIndexFor(intptr_t num_args) {
     return (num_args + 1);
   }
 
@@ skipping 675 matching lines @@
   // functions.
   int32_t SourceFingerprint() const;
 
   // Return false and report an error if the fingerprint does not match.
   bool CheckSourceFingerprint(const char* prefix, int32_t fp) const;
 
   // Works with map [deopt-id] -> ICData.
   void SaveICDataMap(
       const ZoneGrowableArray<const ICData*>& deopt_id_to_ic_data,
       const Array& edge_counters_array) const;
+  // Uses saved ICData to populate the table 'deopt_id_to_ic_data'. Clone
+  // descriptors if 'clone_descriptors' true.
   void RestoreICDataMap(
-      ZoneGrowableArray<const ICData*>* deopt_id_to_ic_data) const;
+      ZoneGrowableArray<const ICData*>* deopt_id_to_ic_data,
+      bool clone_descriptors) const;
 
   RawArray* ic_data_array() const;
   void ClearICDataArray() const;
 
   // Sets deopt reason in all ICData-s with given deopt_id.
   void SetDeoptReasonForAll(intptr_t deopt_id, ICData::DeoptReasonId reason);
 
   static const int kCtorPhaseInit = 1 << 0;
   static const int kCtorPhaseBody = 1 << 1;
   static const int kCtorPhaseAll = (kCtorPhaseInit | kCtorPhaseBody);
@@ skipping 5565 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_