Add extra tracing to Debug_InterruptIsolate test.

runtime/vm/debugger_api_impl_test.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "include/dart_mirrors_api.h"
 #include "include/dart_tools_api.h"
 #include "platform/assert.h"
 #include "vm/dart_api_impl.h"
 #include "vm/lockers.h"
 #include "vm/unit_test.h"
 
 namespace dart {
 
 DECLARE_FLAG(bool, background_compilation);
 DECLARE_FLAG(int, optimization_counter_threshold);
 DECLARE_FLAG(bool, use_osr);
+DECLARE_FLAG(bool, trace_shutdown);
 
 #ifndef PRODUCT
 
 static bool breakpoint_hit = false;
 static int  breakpoint_hit_counter = 0;
 static Dart_Handle script_lib = NULL;
 
 static const bool verbose = true;
 
 static void LoadScript(const char* source) {
@@ skipping 1479 matching lines @@
   EXPECT_VALID(result);
 
   Dart_Handle retval = Invoke("main");
   EXPECT_VALID(retval);
   Dart_ExitScope();
   Dart_ShutdownIsolate();
 }
 
 
 TEST_CASE(Debug_InterruptIsolate) {
+  bool saved_flag = FLAG_trace_shutdown;
+  FLAG_trace_shutdown = true;
   sync = new Monitor();
   Dart_SetIsolateEventHandler(&TestInterruptIsolate);
   EXPECT(interrupt_isolate_id == ILLEGAL_ISOLATE_ID);
   Dart_SetPausedEventHandler(InterruptIsolateHandler);
   int result = OSThread::Start("DebugInterruptIsolate", InterruptIsolateRun, 0);
   EXPECT_EQ(0, result);
 
   // Wait for the test isolate to be created.
   {
+    OS::PrintErr("Waiting for isolate to be created\n");
     MonitorLocker ml(sync);
     while (interrupt_isolate_id == ILLEGAL_ISOLATE_ID) {
       ml.Wait();
     }
   }
   EXPECT(interrupt_isolate_id != ILLEGAL_ISOLATE_ID);
 
   Dart_Isolate isolate = Dart_GetIsolate(interrupt_isolate_id);
   EXPECT(isolate != NULL);
   Dart_InterruptIsolate(isolate);
 
   // Wait for the test isolate to be interrupted.
   {
+    OS::PrintErr("Waiting for isolate to be interrupted\n");
     MonitorLocker ml(sync);
     while (!isolate_interrupted || !pause_event_handled) {
       ml.Wait();
     }
   }
   EXPECT(isolate_interrupted);
   EXPECT(pause_event_handled);
 
   // Wait for the test isolate to shutdown.
   {
+    OS::PrintErr("Waiting for isolate to be shut down\n");
     MonitorLocker ml(sync);
     while (interrupt_isolate_id != ILLEGAL_ISOLATE_ID) {
       ml.Wait();
     }
   }
   EXPECT(interrupt_isolate_id == ILLEGAL_ISOLATE_ID);
+  OS::PrintErr("Complete\n");
+  FLAG_trace_shutdown = saved_flag;
 }
 
 
 static void StackTraceDump1BreakpointHandler(
                 Dart_IsolateId isolate_id,
                 intptr_t bp_id,
                 const Dart_CodeLocation& location) {
   Dart_StackTrace trace;
   Dart_GetStackTrace(&trace);
   const int kStackTraceLen = 4;
@@ skipping 761 matching lines @@
       " null, 5, 17, 5, 18, 9, 19, 12,"
       " null, 6, 21, 1,"
       " null, 8, 24, 1, 25, 5, 26, 6, 27, 8,"
       " null, 9, 29, 1]",
       tokens_cstr);
 }
 
 #endif
 
 }  // namespace dart