Implement prologue weak persistent handles.

runtime/vm/dart_api_impl_test.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 "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"
@@ skipping 1543 matching lines @@
   }
 
   // All weak references should now be cleared.
   EXPECT(Dart_IsNull(weak1));
   EXPECT(Dart_IsNull(weak2));
   EXPECT(Dart_IsNull(weak3));
   EXPECT(Dart_IsNull(weak4));
 }
 
 
+TEST_CASE(PrologueWeakPersistentHandles) {
+  Dart_Handle old_pwph = Dart_Null();
+  EXPECT(Dart_IsNull(old_pwph));
+  Dart_Handle new_pwph = Dart_Null();
+  EXPECT(Dart_IsNull(new_pwph));
+  Dart_EnterScope();
+  {
+    DARTSCOPE(Isolate::Current());
+    String& str = String::Handle();
+    str ^= String::New("new space prologue weak", Heap::kNew);
+    new_pwph = Dart_NewPrologueWeakPersistentHandle(Api::NewLocalHandle(str),
+                                                    NULL,
+                                                    NULL);
+    EXPECT_VALID(new_pwph);
+    EXPECT(!Dart_IsNull(new_pwph));
+    str ^= String::New("old space prologue weak", Heap::kOld);
+    old_pwph = Dart_NewPrologueWeakPersistentHandle(Api::NewLocalHandle(str),
+                                                    NULL,
+                                                    NULL);
+    EXPECT_VALID(old_pwph);
+    EXPECT(!Dart_IsNull(old_pwph));
+    str ^= String::null();
+  }
+  Dart_ExitScope();
+  EXPECT_VALID(new_pwph);
+  EXPECT(!Dart_IsNull(new_pwph));
+  EXPECT(Dart_IsPrologueWeakPersistentHandle(new_pwph));
+  EXPECT_VALID(old_pwph);
+  EXPECT(!Dart_IsNull(old_pwph));
+  EXPECT(Dart_IsPrologueWeakPersistentHandle(old_pwph));
+  // Garbage collect new space without invoking API callbacks.
+  Isolate::Current()->heap()->CollectGarbage(Heap::kNew,
+                                             Heap::kIgnoreApiCallbacks);
+  // Both prologue weak handles should be preserved.
+  EXPECT(!Dart_IsNull(new_pwph));
+  EXPECT(!Dart_IsNull(old_pwph));
+  // Garbage collect old space without invoking API callbacks.
+  Isolate::Current()->heap()->CollectGarbage(Heap::kOld,
+                                             Heap::kIgnoreApiCallbacks);
+  // Both prologue weak handles should be preserved.
+  EXPECT(!Dart_IsNull(new_pwph));
+  EXPECT(!Dart_IsNull(old_pwph));
+  // Garbage collect new space invoking API callbacks.
+  Isolate::Current()->heap()->CollectGarbage(Heap::kNew,
+                                             Heap::kInvokeApiCallbacks);
+  // The prologue weak handle with a new space referent should now be
+  // cleared.  The old space referent should be preserved.
+  EXPECT(Dart_IsNull(new_pwph));
+  EXPECT(!Dart_IsNull(old_pwph));
+  Isolate::Current()->heap()->CollectGarbage(Heap::kOld,
+                                             Heap::kInvokeApiCallbacks);
+  // The prologue weak handle with an old space referent should now be
+  // cleared.  The new space referent should remain cleared.
+  EXPECT(Dart_IsNull(new_pwph));
+  EXPECT(Dart_IsNull(old_pwph));
+}
+
+
 TEST_CASE(ImplicitReferences) {
   Dart_Handle strong = Dart_Null();
   EXPECT(Dart_IsNull(strong));
 
   Dart_Handle weak1 = Dart_Null();
   EXPECT(Dart_IsNull(weak1));
 
   Dart_Handle weak2 = Dart_Null();
   EXPECT(Dart_IsNull(weak2));
 
@@ skipping 3104 matching lines @@
   // We should have received the expected number of interrupts.
   EXPECT_EQ(kInterruptCount, interrupt_count);
 
   // Give the spawned thread enough time to properly exit.
   Isolate::SetInterruptCallback(saved);
 }
 
 #endif  // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64).
 
 }  // namespace dart