--- old/src/hotspot/share/runtime/thread.cpp	2019-09-08 23:48:12.253098912 -0400
+++ new/src/hotspot/share/runtime/thread.cpp	2019-09-08 23:48:11.074086805 -0400
@@ -291,7 +291,6 @@
   // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
   // and ::Release()
   _ParkEvent   = ParkEvent::Allocate(this);
-  _SleepEvent  = ParkEvent::Allocate(this);
   _MuxEvent    = ParkEvent::Allocate(this);
 
 #ifdef CHECK_UNHANDLED_OOPS
@@ -456,7 +455,6 @@
   // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
   // We NULL out the fields for good hygiene.
   ParkEvent::Release(_ParkEvent); _ParkEvent   = NULL;
-  ParkEvent::Release(_SleepEvent); _SleepEvent  = NULL;
   ParkEvent::Release(_MuxEvent); _MuxEvent    = NULL;
 
   delete handle_area();
@@ -1700,7 +1698,7 @@
   _do_not_unlock_if_synchronized = false;
   _cached_monitor_info = NULL;
   _parker = Parker::Allocate(this);
-
+  _SleepEvent  = ParkEvent::Allocate(this);
   // Setup safepoint state info for this thread
   ThreadSafepointState::create(this);
 
@@ -1812,6 +1810,10 @@
   Parker::Release(_parker);
   _parker = NULL;
 
+  // Return the sleep event to the free list
+  ParkEvent::Release(_SleepEvent);
+  _SleepEvent  = NULL;
+
   // Free any remaining  previous UnrollBlock
   vframeArray* old_array = vframe_array_last();
 
@@ -3343,6 +3345,63 @@
   return NULL;
 }
 
+// java.lang.Thread.sleep support
+// Returns true if sleep time elapsed as expected, and false
+// if the thread was interrupted.
+bool JavaThread::sleep(jlong millis) {
+  assert(this == Thread::current(),  "thread consistency check");
+
+  ParkEvent * const slp = this->_SleepEvent;
+  // Because there can be races with thread interruption sending an unpark()
+  // to the event, we explicitly reset it here to avoid an immediate return.
+  // The actual interrupt state will be checked before we park().
+  slp->reset();
+  // Thread interruption establishes a happens-before ordering in the
+  // Java Memory Model, so we need to ensure we synchronize with the
+  // interrupt state.
+  OrderAccess::fence();
+
+  jlong prevtime = os::javaTimeNanos();
+
+  for (;;) {
+    // interruption has precedence over timing out
+    if (os::is_interrupted(this, true)) {
+      return false;
+    }
+
+    if (millis <= 0) {
+      return true;
+    }
+
+    {
+      ThreadBlockInVM tbivm(this);
+      OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
+
+      this->set_suspend_equivalent();
+      // cleared by handle_special_suspend_equivalent_condition() or
+      // java_suspend_self() via check_and_wait_while_suspended()
+
+      slp->park(millis);
+
+      // were we externally suspended while we were waiting?
+      this->check_and_wait_while_suspended();
+    }
+
+    // Update elapsed time tracking
+    jlong newtime = os::javaTimeNanos();
+    if (newtime - prevtime < 0) {
+      // time moving backwards, should only happen if no monotonic clock
+      // not a guarantee() because JVM should not abort on kernel/glibc bugs
+      assert(!os::supports_monotonic_clock(),
+             "unexpected time moving backwards detected in os::sleep()");
+    } else {
+      millis -= (newtime - prevtime) / NANOSECS_PER_MILLISEC;
+    }
+    prevtime = newtime;
+  }
+}
+
+
 static void compiler_thread_entry(JavaThread* thread, TRAPS) {
   assert(thread->is_Compiler_thread(), "must be compiler thread");
   CompileBroker::compiler_thread_loop();