Extra suspend count modification failure logging.

Change-Id: I18738c94f8abe7afec588f7b91685e2cbdf7eefc

1 files changed, 4 insertions, 2 deletions

diff --git a/src/thread_list.cc b/src/thread_list.cc
index 45b79665c0..e8b412c291 100644
--- a/src/thread_list.cc
+++ b/src/thread_list.cc
@@ -75,8 +75,10 @@ void ThreadList::ModifySuspendCount(Thread* thread, int delta, bool for_debugger
 #endif
   if (delta == -1 && thread->suspend_count_ <= 0) {
     // This is expected if you attach a thread during a GC.
-    if (!thread->IsStillStarting()) {
-      LOG(FATAL) << *thread << " suspend count already zero";
+    if (UNLIKELY(!thread->IsStillStarting())) {
+      std::ostringstream ss;
+      Runtime::Current()->GetThreadList()->DumpLocked(ss);
+      LOG(FATAL) << *thread << " suspend count already zero.\n" << ss.str();
     }
     return;
   }