Provide a mechanism for dumping of heap profiles on predefined events.

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 6ea666142ba5ae7913cf576edf757c12cef34c9f..c7d06328e287fa021ef61ba4ab75e0d5a7f4619b 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -30,6 +30,7 @@ DEFINE_FLAG(bool, report_usage_count, false,
             "Track function usage and report.");
 DEFINE_FLAG(bool, trace_isolates, false,
             "Trace isolate creation and shut down.");
+DECLARE_FLAG(bool, heap_profile_out_of_memory);
 DECLARE_FLAG(bool, generate_gdb_symbols);
 
 
@@ -139,6 +140,18 @@ bool IsolateMessageHandler::IsCurrentIsolate() const {
 
 bool IsolateMessageHandler::ProcessUnhandledException(const Object& result) {
   isolate_->object_store()->set_sticky_error(Error::Cast(result));
+  if (FLAG_heap_profile_out_of_memory) {
+    Instance& exception = Instance::Handle();
+    if (result.IsUnhandledException()) {
+      exception ^= UnhandledException::Cast(result).exception();
+    } else {
+      ASSERT(result.IsError());
+      exception ^= result.raw();

[siva, 2012/12/10 05:06:36]

I think this else part is not needed and the OOM check can be done under
if (result.IsUnhandledException()) {
  ....
   ...
} itself.

+    }
+    if (exception.raw() == isolate_->object_store()->out_of_memory()) {
+      isolate_->heap()->ProfileToFile("out-of-memory");
+    }
+  }
   // Invoke the dart unhandled exception callback if there is one.
   if (Isolate::UnhandledExceptionCallback() != NULL) {
     Dart_EnterScope();