Display isolate message queue in Observatory debugger

runtime/vm/message_test.cc

Index: runtime/vm/message_test.cc
diff --git a/runtime/vm/message_test.cc b/runtime/vm/message_test.cc
index b02df4769b5ffffbf256f04329c3158290da4c66..96cf00430e2ba69a7fcba0cd213aaf4a0eee1a6d 100644
--- a/runtime/vm/message_test.cc
+++ b/runtime/vm/message_test.cc
@@ -31,19 +31,50 @@ TEST_CASE(MessageQueue_BasicOperations) {
   Message* msg1 = new Message(
       port, AllocMsg(str1), strlen(str1) + 1, Message::kNormalPriority);
   queue.Enqueue(msg1, false);
+  EXPECT(queue.Length() == 1);
   EXPECT(!queue.IsEmpty());
+  // Iterate over messages.
+  MessageQueue::Iterator it(&queue);
+  for (; it.HasNext(); it.Next()) {
+    EXPECT(it.current() == msg1);
+  }

[turnidge, 2015/05/04 17:47:13]

Unroll, as suggested below.

[Cutch, 2015/05/04 19:56:51]

Done.

 
   Message* msg2 = new Message(
       port, AllocMsg(str2), strlen(str2) + 1, Message::kNormalPriority);
   queue.Enqueue(msg2, false);
+  EXPECT(queue.Length() == 2);
   EXPECT(!queue.IsEmpty());
-
-  // Remove two messages.
+  it.Reset(&queue);
+
+  for (intptr_t it_count = 0; it.HasNext(); it.Next(), it_count++) {
+    EXPECT(it_count < 2);
+    if (it_count == 0) {
+      EXPECT(it.current() == msg1);
+    } else {
+      ASSERT(it_count == 1);
+      EXPECT(it.current() == msg2);
+    }
+  }

[turnidge, 2015/05/04 17:47:13]

I would unroll this, I think it is shorter/simpler.

(Here's how the code would look it you rewrite Next() and HasNext() as I
suggested elsewhere)

EXPECT(it.hasNext());
EXPECT(it.Next() == msg1);
EXPECT(it.hasNext());
EXPECT(it.Next() == msg2);
EXPECT(!it.hasNext());

[Cutch, 2015/05/04 19:56:51]

Done.

+
+  // Lookup messages by id.
+  EXPECT(queue.FindMessageById(reinterpret_cast<intptr_t>(msg1)) == msg1);
+  EXPECT(queue.FindMessageById(reinterpret_cast<intptr_t>(msg2)) == msg2);
+
+  // Lookup bad id.
+  EXPECT(queue.FindMessageById(0x1) == NULL);
+
+  // Remove message 1
   Message* msg = queue.Dequeue();
   EXPECT(msg != NULL);
   EXPECT_STREQ(str1, reinterpret_cast<char*>(msg->data()));
   EXPECT(!queue.IsEmpty());
 
+  // Check that only msg2 is left in the queue.
+  for (it.Reset(&queue); it.HasNext(); it.Next()) {
+    EXPECT(it.current() == msg2);
+  }

[turnidge, 2015/05/04 17:47:13]

Unroll.

[Cutch, 2015/05/04 19:56:51]

Done.

+
+  // Remove message 2
   msg = queue.Dequeue();
   EXPECT(msg != NULL);
   EXPECT_STREQ(str2, reinterpret_cast<char*>(msg->data()));