Lazy peer API.

runtime/vm/dart_api_impl.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 "include/dart_api.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart.h"
@@ skipping 4172 matching lines @@
 
 DART_EXPORT void Dart_InitPerfEventsSupport(Dart_FileWriterFunction function) {
   Dart::set_perf_events_writer(function);
 }
 
 
 DART_EXPORT void Dart_InitFlowGraphPrinting(Dart_FileWriterFunction function) {
   Dart::set_flow_graph_writer(function);
 }
 
+
+// --- Peer support ---
+
+
+DART_EXPORT Dart_Handle Dart_GetPeer(Dart_Handle object, void** peer) {
+  if (peer == NULL) {
+    RETURN_NULL_ERROR(peer);
+  }
+  Isolate* isolate = Isolate::Current();
+  const Object& obj = Object::Handle(isolate, Api::UnwrapHandle(object));
+  if (obj.IsNull()) {
+    RETURN_TYPE_ERROR(isolate, object, Object);
+  }
+  if (obj.IsSmi()) {

[Anton Muhin, 2012/09/13 06:27:07]

that's up to you, but this dependence on internal representation of integers
looks a bit sketchy, not sure if it'll impose a real problem.

Similarly, later there might be arrays which store unwrapped doubles and there
might be complicated cases/performance implications.

As a variant: maybe prohibit peers for some core types like bool/double/int/num?

[cshapiro, 2012/09/15 01:23:41]

I think your suggestion to prohibit the bool type and the num subtypes is very
attractive.  I have also added a test case for these things.  Done.

+    const char* msg = "%s expects argument 'object' to be heap allocated.";
+    return Api::NewError(msg, CURRENT_FUNC);
+  }
+  {
+    NoGCScope no_gc;
+    RawObject* raw_obj = obj.raw();
+    *peer = isolate->heap()->GetPeer(raw_obj);
+  }
+  if (*peer == NULL) {
+    const char* msg = "%s: expects 'object' to have its peer value set";
+    return Api::NewError(msg, CURRENT_FUNC);
+  }
+  return Api::Success(isolate);
+}
+
+
+DART_EXPORT Dart_Handle Dart_SetPeer(Dart_Handle object, void* peer) {
+  Isolate* isolate = Isolate::Current();
+  const Object& obj = Object::Handle(isolate, Api::UnwrapHandle(object));
+  if (obj.IsNull()) {
+    RETURN_TYPE_ERROR(isolate, object, Object);
+  }
+  if (obj.IsSmi()) {
+    const char* msg = "%s expects argument 'object' to be heap allocated.";
+    return Api::NewError(msg, CURRENT_FUNC);
+  }
+  {
+    NoGCScope no_gc;
+    RawObject* raw_obj = obj.raw();
+    isolate->heap()->SetPeer(raw_obj, peer);
+  }
+  return Api::Success(isolate);
+}
+
+
+DART_EXPORT bool Dart_HasPeer(Dart_Handle object) {
+  Isolate* isolate = Isolate::Current();
+  NoGCScope no_gc;
+  RawObject* raw_obj = Api::UnwrapHandle(object);
+  return raw_obj->IsHeapObject() && (isolate->heap()->GetPeer(raw_obj) != NULL);
+}
+
 }  // namespace dart