diff -r 000000000000 -r 6474c204b198 ipc/ipdl/test/cxx/TestInterruptShutdownRace.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/ipdl/test/cxx/TestInterruptShutdownRace.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,144 @@
+#include "TestInterruptShutdownRace.h"
+
+#include "IPDLUnitTests.h"      // fail etc.
+#include "IPDLUnitTestSubprocess.h"
+
+template<>
+struct RunnableMethodTraits<mozilla::_ipdltest::TestInterruptShutdownRaceParent>
+{
+    static void RetainCallee(mozilla::_ipdltest::TestInterruptShutdownRaceParent* obj) { }
+    static void ReleaseCallee(mozilla::_ipdltest::TestInterruptShutdownRaceParent* obj) { }
+};
+
+
+namespace mozilla {
+namespace _ipdltest {
+
+//-----------------------------------------------------------------------------
+// parent
+
+namespace {
+
+// NB: this test does its own shutdown, rather than going through
+// QuitParent(), because it's testing degenerate edge cases
+
+void DeleteSubprocess()
+{
+    delete gSubprocess;
+    gSubprocess = nullptr;
+}
+
+void Done()
+{
+    passed(__FILE__);
+    QuitParent();
+}
+
+} // namespace <anon>
+
+TestInterruptShutdownRaceParent::TestInterruptShutdownRaceParent()
+{
+    MOZ_COUNT_CTOR(TestInterruptShutdownRaceParent);
+}
+
+TestInterruptShutdownRaceParent::~TestInterruptShutdownRaceParent()
+{
+    MOZ_COUNT_DTOR(TestInterruptShutdownRaceParent);
+}
+
+void
+TestInterruptShutdownRaceParent::Main()
+{
+    if (!SendStart())
+        fail("sending Start");
+}
+
+bool
+TestInterruptShutdownRaceParent::RecvStartDeath()
+{
+    // this will be ordered before the OnMaybeDequeueOne event of
+    // Orphan in the queue
+    MessageLoop::current()->PostTask(
+        FROM_HERE,
+        NewRunnableMethod(this,
+                          &TestInterruptShutdownRaceParent::StartShuttingDown));
+    return true;
+}
+
+void
+TestInterruptShutdownRaceParent::StartShuttingDown()
+{
+    // NB: we sleep here to try and avoid receiving the Orphan message
+    // while waiting for the CallExit() reply.  if we fail at that, it
+    // will cause the test to pass spuriously, because there won't be
+    // an OnMaybeDequeueOne task for Orphan
+    PR_Sleep(2000);
+
+    if (CallExit())
+        fail("connection was supposed to be interrupted");
+
+    Close();
+
+    delete static_cast<TestInterruptShutdownRaceParent*>(gParentActor);
+    gParentActor = nullptr;
+
+    XRE_GetIOMessageLoop()->PostTask(FROM_HERE,
+                                     NewRunnableFunction(DeleteSubprocess));
+
+    // this is ordered after the OnMaybeDequeueOne event in the queue
+    MessageLoop::current()->PostTask(FROM_HERE,
+                                     NewRunnableFunction(Done));
+
+    // |this| has been deleted, be mindful
+}
+
+bool
+TestInterruptShutdownRaceParent::RecvOrphan()
+{
+    // it would be nice to fail() here, but we'll process this message
+    // while waiting for the reply CallExit().  The OnMaybeDequeueOne
+    // task will still be in the queue, it just wouldn't have had any
+    // work to do, if we hadn't deleted ourself
+    return true;
+}
+
+//-----------------------------------------------------------------------------
+// child
+
+TestInterruptShutdownRaceChild::TestInterruptShutdownRaceChild()
+{
+    MOZ_COUNT_CTOR(TestInterruptShutdownRaceChild);
+}
+
+TestInterruptShutdownRaceChild::~TestInterruptShutdownRaceChild()
+{
+    MOZ_COUNT_DTOR(TestInterruptShutdownRaceChild);
+}
+
+bool
+TestInterruptShutdownRaceChild::RecvStart()
+{
+    if (!SendStartDeath())
+        fail("sending StartDeath");
+
+    // See comment in StartShuttingDown(): we want to send Orphan()
+    // while the parent is in its PR_Sleep()
+    PR_Sleep(1000);
+
+    if (!SendOrphan())
+        fail("sending Orphan");
+
+    return true;
+}
+
+bool
+TestInterruptShutdownRaceChild::AnswerExit()
+{
+    _exit(0);
+    NS_RUNTIMEABORT("unreached");
+    return false;
+}
+
+
+} // namespace _ipdltest
+} // namespace mozilla