From dba32d54d1668033356a2ad505c239411d660821 Mon Sep 17 00:00:00 2001
From: Nan Zhu <CodingCat@users.noreply.github.com>
Date: Tue, 16 Jul 2019 12:41:39 -0700
Subject: [PATCH] shutdown for multiple times (#99)

---
 src/engine.cc | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/engine.cc b/src/engine.cc
index d2b94e1d1..d87b68d6a 100644
--- a/src/engine.cc
+++ b/src/engine.cc
@@ -57,14 +57,16 @@ bool Init(int argc, char *argv[]) {
 /*! \brief finalize syncrhonization module */
 bool Finalize() {
   ThreadLocalEntry* e = EngineThreadLocal::Get();
-  utils::Check(e->engine.get() != nullptr,
-               "rabit::Finalize engine is not initialized or already been finalized.");
-  if (e->engine->Shutdown()) {
-    e->engine.reset(nullptr);
-    e->initialized = false;
-    return true;
+  if (e->engine.get() != nullptr) {
+    if (e->engine->Shutdown()) {
+      e->engine.reset(nullptr);
+      e->initialized = false;
+      return true;
+    } else {
+      return false;
+    }
   } else {
-    return false;
+    return true;
   }
 }