--- old/src/hotspot/share/runtime/biasedLocking.cpp	2019-04-25 11:54:22.798097603 +0200
+++ new/src/hotspot/share/runtime/biasedLocking.cpp	2019-04-25 11:54:22.049072377 +0200
@@ -621,15 +621,13 @@
   event->commit();
 }
 
-BiasedLocking::Condition BiasedLocking::revoke_and_rebias(Handle obj, bool attempt_rebias, TRAPS) {
-  assert(!SafepointSynchronize::is_at_safepoint(), "must not be called while at safepoint");
-
+BiasedLocking::Condition fast_revoke(Handle obj, bool attempt_rebias, JavaThread* thread = NULL) {
   // We can revoke the biases of anonymously-biased objects
   // efficiently enough that we should not cause these revocations to
   // update the heuristics because doing so may cause unwanted bulk
   // revocations (which are expensive) to occur.
   markOop mark = obj->mark();
-  if (mark->is_biased_anonymously() && !attempt_rebias) {
+  if (mark->is_biased_anonymously()) {
     // We are probably trying to revoke the bias of this object due to
     // an identity hash code computation. Try to revoke the bias
     // without a safepoint. This is possible if we can successfully
@@ -640,7 +638,7 @@
     markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
     markOop res_mark = obj->cas_set_mark(unbiased_prototype, mark);
     if (res_mark == biased_value) {
-      return BIAS_REVOKED;
+      return BiasedLocking::BIAS_REVOKED;
     }
   } else if (mark->has_bias_pattern()) {
     Klass* k = obj->klass();
@@ -655,7 +653,7 @@
       markOop biased_value       = mark;
       markOop res_mark = obj->cas_set_mark(prototype_header, mark);
       assert(!obj->mark()->has_bias_pattern(), "even if we raced, should still be revoked");
-      return BIAS_REVOKED;
+      return BiasedLocking::BIAS_REVOKED;
     } else if (prototype_header->bias_epoch() != mark->bias_epoch()) {
       // The epoch of this biasing has expired indicating that the
       // object is effectively unbiased. Depending on whether we need
@@ -665,31 +663,73 @@
       // can reach this point due to various points in the runtime
       // needing to revoke biases.
       if (attempt_rebias) {
-        assert(THREAD->is_Java_thread(), "");
         markOop biased_value       = mark;
-        markOop rebiased_prototype = markOopDesc::encode((JavaThread*) THREAD, mark->age(), prototype_header->bias_epoch());
+        markOop rebiased_prototype = markOopDesc::encode(thread, mark->age(), prototype_header->bias_epoch());
         markOop res_mark = obj->cas_set_mark(rebiased_prototype, mark);
         if (res_mark == biased_value) {
-          return BIAS_REVOKED_AND_REBIASED;
+          return BiasedLocking::BIAS_REVOKED_AND_REBIASED;
         }
       } else {
         markOop biased_value       = mark;
         markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
         markOop res_mark = obj->cas_set_mark(unbiased_prototype, mark);
         if (res_mark == biased_value) {
-          return BIAS_REVOKED;
+          return BiasedLocking::BIAS_REVOKED;
         }
       }
     }
   }
+  return BiasedLocking::NOT_REVOKED;
+}
+
+BiasedLocking::Condition BiasedLocking::revoke_and_rebias_in_handshake(Handle obj, TRAPS) {
+  BiasedLocking::Condition bc = fast_revoke(obj, false);
+  if (bc != NOT_REVOKED) {
+    return bc;
+  }
+
+  markOop mark = obj->mark();
+  if (!mark->has_bias_pattern()) {
+    return NOT_BIASED;
+  }
+
+  Klass *k = obj->klass();
+  markOop prototype_header = k->prototype_header();
+  if (mark->biased_locker() == THREAD && prototype_header->bias_epoch() == mark->bias_epoch()) {
+    ResourceMark rm;
+    log_info(biasedlocking)("Revoking bias by walking my own stack:");
+    EventBiasedLockSelfRevocation event;
+    BiasedLocking::Condition cond = revoke_bias(obj(), false, false, (JavaThread*) THREAD, NULL);
+    ((JavaThread*) THREAD)->set_cached_monitor_info(NULL);
+    assert(cond == BIAS_REVOKED, "why not?");
+    if (event.should_commit()) {
+      post_self_revocation_event(&event, k);
+    }
+    return cond;
+  }
+
+  ShouldNotReachHere();
+
+  return NOT_REVOKED;
+}
+
+BiasedLocking::Condition BiasedLocking::revoke_and_rebias(Handle obj, bool attempt_rebias, TRAPS) {
+  assert(!SafepointSynchronize::is_at_safepoint(), "must not be called while at safepoint");
+  assert(!attempt_rebias || THREAD->is_Java_thread(), "");
+
+  BiasedLocking::Condition bc = fast_revoke(obj, attempt_rebias, (JavaThread*) THREAD);
+  if (bc != NOT_REVOKED) {
+    return bc;
+  }
 
   HeuristicsResult heuristics = update_heuristics(obj(), attempt_rebias);
   if (heuristics == HR_NOT_BIASED) {
     return NOT_BIASED;
   } else if (heuristics == HR_SINGLE_REVOKE) {
+    markOop mark = obj->mark();
     Klass *k = obj->klass();
     markOop prototype_header = k->prototype_header();
-    if (mark->biased_locker() == THREAD &&
+    if (mark->biased_locker_is((JavaThread*) THREAD) &&
         prototype_header->bias_epoch() == mark->bias_epoch()) {
       // A thread is trying to revoke the bias of an object biased
       // toward it, again likely due to an identity hash code