diff --git a/util/env_posix.cc b/util/env_posix.cc
index 7cdf66cec996b2d2e1060693906f6e04d535c0f6..957c5b1052e5cd993875d00b2a8fc480957b4bc1 100644
--- a/util/env_posix.cc
+++ b/util/env_posix.cc
@@ -600,9 +600,9 @@ class PosixFileLock : public FileLock {
 class PosixEnv : public Env {
  public:
   PosixEnv();
-  virtual ~PosixEnv() {
-    fprintf(stderr, "Destroying Env::Default()\n");
-    exit(1);
+
+  virtual ~PosixEnv(){
+    WaitForBGThreads();
   }
 
   void SetFD_CLOEXEC(int fd, const EnvOptions* options) {
@@ -804,6 +804,8 @@ class PosixEnv : public Env {
 
   virtual void Schedule(void (*function)(void*), void* arg);
 
+  virtual void WaitForBGThreads();
+
   virtual void StartThread(void (*function)(void* arg), void* arg);
 
   virtual Status GetTestDirectory(std::string* result) {
@@ -973,22 +975,43 @@ class PosixEnv : public Env {
   // Entry per Schedule() call
   struct BGItem { void* arg; void (*function)(void*); };
   typedef std::deque<BGItem> BGQueue;
+  int queue_size_; // number of items in BGQueue
+  bool exit_all_threads_;
   BGQueue queue_;
+  std::vector<pthread_t> threads_to_join_;
 };
 
 PosixEnv::PosixEnv() : checkedDiskForMmap_(false),
                        forceMmapOff(false),
                        page_size_(getpagesize()),
                        started_bgthread_(0),
-                       num_threads_(1) {
+                       num_threads_(1),
+                       queue_size_(0),
+                       exit_all_threads_(false) {
   PthreadCall("mutex_init", pthread_mutex_init(&mu_, nullptr));
   PthreadCall("cvar_init", pthread_cond_init(&bgsignal_, nullptr));
   bgthread_.resize(num_threads_);
 }
 
+// Signal and Join all background threads started by calls to Schedule
+void PosixEnv::WaitForBGThreads() {
+  PthreadCall("lock", pthread_mutex_lock(&mu_));
+  assert(! exit_all_threads_);
+  exit_all_threads_ = true;
+  PthreadCall("signalall", pthread_cond_broadcast(&bgsignal_));
+  PthreadCall("unlock", pthread_mutex_unlock(&mu_));
+  for (unsigned int i = 0; i < threads_to_join_.size(); i++) {
+    pthread_join(threads_to_join_[i], nullptr);
+  }
+}
+
 void PosixEnv::Schedule(void (*function)(void*), void* arg) {
   PthreadCall("lock", pthread_mutex_lock(&mu_));
 
+  if (exit_all_threads_) {
+    PthreadCall("unlock", pthread_mutex_unlock(&mu_));
+    return;
+  }
   // Start background thread if necessary
   for (; started_bgthread_ < num_threads_; started_bgthread_++) {
     PthreadCall(
@@ -997,6 +1020,7 @@ void PosixEnv::Schedule(void (*function)(void*), void* arg) {
                        nullptr,
                        &PosixEnv::BGThreadWrapper,
                        this));
+    threads_to_join_.push_back(bgthread_[started_bgthread_]);
     fprintf(stdout, "Created bg thread 0x%lx\n", bgthread_[started_bgthread_]);
   }
 
@@ -1015,10 +1039,13 @@ void PosixEnv::BGThread() {
   while (true) {
     // Wait until there is an item that is ready to run
     PthreadCall("lock", pthread_mutex_lock(&mu_));
-    while (queue_.empty()) {
+    while (queue_.empty() && !exit_all_threads_) {
       PthreadCall("wait", pthread_cond_wait(&bgsignal_, &mu_));
     }
-
+    if (exit_all_threads_) { // mechanism to let BG threads exit safely
+      PthreadCall("unlock", pthread_mutex_unlock(&mu_));
+      break;
+    }
     void (*function)(void*) = queue_.front().function;
     void* arg = queue_.front().arg;
     queue_.pop_front();
@@ -1048,17 +1075,15 @@ void PosixEnv::StartThread(void (*function)(void* arg), void* arg) {
   state->arg = arg;
   PthreadCall("start thread",
               pthread_create(&t, nullptr,  &StartThreadWrapper, state));
+  threads_to_join_.push_back(t);
 }
 
 }  // namespace
 
-static pthread_once_t once = PTHREAD_ONCE_INIT;
-static Env* default_env;
-static void InitDefaultEnv() { default_env = new PosixEnv; }
+static PosixEnv default_env;
 
 Env* Env::Default() {
-  pthread_once(&once, InitDefaultEnv);
-  return default_env;
+  return &default_env;
 }
 
 }  // namespace leveldb