Add --print-metrics vm flag for printing metrics to console

runtime/vm/isolate.cc

 // Copyright (c) 2013, 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 "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/json.h"
 #include "vm/code_observers.h"
@@ skipping 26 matching lines @@
 #include "vm/tags.h"
 #include "vm/thread_interrupter.h"
 #include "vm/thread_registry.h"
 #include "vm/timeline.h"
 #include "vm/timer.h"
 #include "vm/visitor.h"
 
 
 namespace dart {
 
-DECLARE_FLAG(charp, timeline_trace_dir);
+DECLARE_FLAG(bool, print_metrics);
 
 DEFINE_FLAG(bool, trace_isolates, false,
             "Trace isolate creation and shut down.");
 DEFINE_FLAG(bool, pause_isolates_on_start, false,
             "Pause isolates before starting.");
 DEFINE_FLAG(bool, pause_isolates_on_exit, false,
             "Pause isolates exiting.");
 DEFINE_FLAG(bool, break_at_isolate_spawn, false,
             "Insert a one-time breakpoint at the entrypoint for all spawned "
             "isolates");
@@ skipping 1475 matching lines @@
     api_state()->weak_persistent_handles().VisitHandles(&visitor);
     api_state()->prologue_weak_persistent_handles().VisitHandles(&visitor);
 
     if (FLAG_trace_isolates) {
       heap()->PrintSizes();
       megamorphic_cache_table()->PrintSizes();
       Symbols::DumpStats();
       OS::Print("[-] Stopping isolate:\n"
                 "\tisolate:    %s\n", name());
     }
+    if (FLAG_print_metrics) {
+      LogBlock lb(this);
+      ISL_Print("Printing metrics for %s\n", name());
+#define ISOLATE_METRIC_PRINT(type, variable, name, unit)                       \
+  ISL_Print("%s\n", metric_##variable##_.ToString());
+  ISOLATE_METRIC_LIST(ISOLATE_METRIC_PRINT);
+#undef ISOLATE_METRIC_PRINT
+      ISL_Print("\n");
+    }
   }
 
 #if defined(DEBUG)
   // No concurrent sweeper tasks should be running at this point.
   if (heap_ != NULL) {
     PageSpace* old_space = heap_->old_space();
     MonitorLocker ml(old_space->tasks_lock());
     ASSERT(old_space->tasks() == 0);
   }
 #endif
@@ skipping 600 matching lines @@
                            serialized_message_, serialized_message_len_);
 }
 
 
 void IsolateSpawnState::Cleanup() {
   SwitchIsolateScope switch_scope(I);
   Dart::ShutdownIsolate();
 }
 
 }  // namespace dart