Bugfix in process handle: Do detaching from owner process separately from derefing.

src/vm/process_handle.h

Index: src/vm/process_handle.h
diff --git a/src/vm/process_handle.h b/src/vm/process_handle.h
index db9550c401b00fbb21d4d0c89e24dadfff2a4ccb..322ac639ad4b7b517d8c9017c409425e3ee5cfbe 100644
--- a/src/vm/process_handle.h
+++ b/src/vm/process_handle.h
@@ -25,15 +25,10 @@ class ProcessHandle : public Refcounted<ProcessHandle> {
  private:
   friend class Process;
 
-  static void OwnerProcessTerminating(ProcessHandle* handle) {
-    handle->lock()->Lock();
-    ASSERT(handle->process_ != NULL);
-    handle->process_ = NULL;
-    if (!handle->DecrementRefWithoutDelete()) {
-      handle->lock()->Unlock();

[kustermann, 2015/10/29 11:17:20]

The DecrementRefWithoutDelete() & Unlock/Delete is atomic and therefore racing
with normal DecrementRef().

(I've adopted that model from Port - which takes a spinlock on every deref -
which I avoid in [Refcounted].)

-    } else {
-      delete handle;
-    }
+  void OwnerProcessTerminating() {
+    ScopedSpinlock locker(&spinlock_);
+    ASSERT(process_ != NULL);
+    process_ = NULL;
   }
 
   Process* process_;