Implement a garbage collection prologue and epilogue callback mechanism.

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 472 matching lines @@
         "%s expects argument 'num_values' to be greater than 0.",
         CURRENT_FUNC);
   }
 
   WeakReference* reference = new WeakReference(keys, num_keys,
                                                values, num_values);
   state->DelayWeakReference(reference);
   return Api::Success();
 }
 
+
+// --- Garbage Collection Callbacks --
+
+
+DART_EXPORT Dart_Handle Dart_NewGcPrologueCallback(
+    Dart_GcPrologueCallback callback) {
+  Isolate* isolate = Isolate::Current();
+  CHECK_ISOLATE(isolate);
+  ApiState* state = isolate->api_state();

[turnidge, 2012/03/07 00:25:16]

You could permissibly move these callback lists to the isolate itself.  Doesn't
matter much, but it is where I would have probably put them.

[cshapiro, 2012/03/07 03:06:10]

Done.  I will move the weak references in a follow-up change.

+  ASSERT(state != NULL);
+  GcPrologueCallbacks& callbacks = state->gc_prologue_callbacks();
+  if (callbacks.Contains(callback)) {
+    return Api::NewError(
+        "%s permits only one instance of 'callback' to be present in the "
+        "prologue callback list.",
+        CURRENT_FUNC);
+  }
+  state->gc_prologue_callbacks().Add(callback);
+  return Api::Success();
+}
+
+
+DART_EXPORT Dart_Handle Dart_DeleteGcPrologueCallback(
+    Dart_GcPrologueCallback callback) {
+  Isolate* isolate = Isolate::Current();
+  CHECK_ISOLATE(isolate);
+  ApiState* state = isolate->api_state();
+  ASSERT(state != NULL);
+  GcPrologueCallbacks& callbacks = state->gc_prologue_callbacks();
+  if (!callbacks.Contains(callback)) {
+    return Api::NewError(
+        "%s expects 'callback' to be present in the prologue callback list.",
+        CURRENT_FUNC);
+  }
+  state->gc_prologue_callbacks().Remove(callback);
+  return Api::Success();
+}
+
+
+DART_EXPORT Dart_Handle Dart_NewGcEpilogueCallback(
+    Dart_GcEpilogueCallback callback) {
+  Isolate* isolate = Isolate::Current();
+  CHECK_ISOLATE(isolate);
+  ApiState* state = isolate->api_state();
+  ASSERT(state != NULL);
+  GcEpilogueCallbacks& callbacks = state->gc_epilogue_callbacks();
+  if (callbacks.Contains(callback)) {
+    return Api::NewError(
+        "%s permits only one instance of 'callback' to be present in the "
+        "epilogue callback list.",
+        CURRENT_FUNC);
+  }
+  callbacks.Add(callback);
+  return Api::Success();
+}
+
+
+DART_EXPORT Dart_Handle Dart_DeleteGcEpilogueCallback(
+    Dart_GcEpilogueCallback callback) {
+  Isolate* isolate = Isolate::Current();
+  CHECK_ISOLATE(isolate);
+  ApiState* state = isolate->api_state();
+  ASSERT(state != NULL);
+  GcEpilogueCallbacks& callbacks = state->gc_epilogue_callbacks();
+  if (!callbacks.Contains(callback)) {
+    return Api::NewError(
+        "%s expects 'callback' to be present in the epilogue callback list.",
+        CURRENT_FUNC);
+  }
+  callbacks.Remove(callback);
+  return Api::Success();
+}
+
+
 // --- Initialization and Globals ---
 
 
 DART_EXPORT bool Dart_Initialize(Dart_IsolateCreateCallback create,
                                  Dart_IsolateInterruptCallback interrupt) {
   return Dart::InitOnce(create, interrupt);
 }
 
 DART_EXPORT bool Dart_SetVMFlags(int argc, const char** argv) {
   return Flags::ProcessCommandLineFlags(argc, argv);
@@ skipping 2240 matching lines @@
       *buffer = NULL;
     }
     delete debug_region;
   } else {
     *buffer = NULL;
     *buffer_size = 0;
   }
 }
 
 }  // namespace dart