Dart: Better handle leak checks. close() is async.

mojo/dart/embedder/mojo_natives.cc

Index: mojo/dart/embedder/mojo_natives.cc
diff --git a/mojo/dart/embedder/mojo_natives.cc b/mojo/dart/embedder/mojo_natives.cc
index 2546dece72632f441f6e4178fff22a938426b3f3..530945ca8ea8eee664b0fe758b5bfe93b3510f9b 100644
--- a/mojo/dart/embedder/mojo_natives.cc
+++ b/mojo/dart/embedder/mojo_natives.cc
@@ -4,6 +4,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <set>
 #include <vector>
 
 #include "base/logging.h"
@@ -11,6 +12,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "dart/runtime/include/dart_api.h"
 #include "mojo/dart/embedder/builtin.h"
+#include "mojo/dart/embedder/isolate_data.h"
 #include "mojo/public/c/system/core.h"
 #include "mojo/public/cpp/system/core.h"
 
@@ -122,7 +124,11 @@ static void MojoHandleCloserCallback(void* isolate_data,
   CloserCallbackPeer* callback_peer =
       reinterpret_cast<CloserCallbackPeer*>(peer);
   if (callback_peer->handle != MOJO_HANDLE_INVALID) {
-    MojoClose(callback_peer->handle);
+    MojoResult res = MojoClose(callback_peer->handle);
+    if (res == MOJO_RESULT_OK) {
+      LOG(ERROR) << "Handle Finalizer closing handle:\n\tisolate: "

[sky, 2015/03/11 17:17:57]

Why the LOG(ERROR) here? Doesn't MOJO_RESULT_OK mean the close was successful?

[zra, 2015/03/11 18:58:20]

If the finalizer callback successfully closes a handle, it means that the handle
was leaked from the Dart code. I'll add a comment.

+                 << "\n\thandle: " << callback_peer->handle;
+    }
   }
   delete callback_peer;
 }
@@ -167,6 +173,13 @@ void MojoHandle_Register(Dart_NativeArguments arguments) {
     return;
   }
 
+  // Add the handle to this isolate's set.
+  Dart_Isolate isolate = Dart_CurrentIsolate();
+  void* data = Dart_IsolateData(isolate);
+  IsolateData* isolate_data = reinterpret_cast<IsolateData*>(data);
+  isolate_data->unclosed_handles.insert(raw_handle);
+
+  // Set up a finalizer.
   CloserCallbackPeer* callback_peer = new CloserCallbackPeer();
   callback_peer->handle = static_cast<MojoHandle>(raw_handle);
   Dart_NewWeakPersistentHandle(mojo_handle_instance,
@@ -180,6 +193,12 @@ void MojoHandle_Close(Dart_NativeArguments arguments) {
   int64_t handle;
   CHECK_INTEGER_ARGUMENT(arguments, 0, &handle, InvalidArgument);
 
+  // Remove the handle from this isolate's set.
+  Dart_Isolate isolate = Dart_CurrentIsolate();
+  void* data = Dart_IsolateData(isolate);
+  IsolateData* isolate_data = reinterpret_cast<IsolateData*>(data);
+  isolate_data->unclosed_handles.erase(handle);
+
   MojoResult res = MojoClose(static_cast<MojoHandle>(handle));
 
   Dart_SetIntegerReturnValue(arguments, static_cast<int64_t>(res));