src/hotspot/share/gc/shenandoah/shenandoahEvacOOMHandler.cpp

*** 57,67 ****
      wait_for_no_evac_threads();
      return;
    }
  
    while (true) {
!     jint other = Atomic::cmpxchg(threads_in_evac + 1, &_threads_in_evac, threads_in_evac);
      if (other == threads_in_evac) {
        // Success: caller may safely enter evacuation
        DEBUG_ONLY(ShenandoahThreadLocalData::set_evac_allowed(Thread::current(), true));
        return;
      } else {
--- 57,67 ----
      wait_for_no_evac_threads();
      return;
    }
  
    while (true) {
!     jint other = Atomic::cmpxchg(&_threads_in_evac, threads_in_evac, threads_in_evac + 1);
      if (other == threads_in_evac) {
        // Success: caller may safely enter evacuation
        DEBUG_ONLY(ShenandoahThreadLocalData::set_evac_allowed(Thread::current(), true));
        return;
      } else {
*** 96,107 ****
    assert(ShenandoahThreadLocalData::is_evac_allowed(Thread::current()), "sanity");
    assert(!ShenandoahThreadLocalData::is_oom_during_evac(Thread::current()), "TL oom-during-evac must not be set");
  
    jint threads_in_evac = Atomic::load_acquire(&_threads_in_evac);
    while (true) {
!     jint other = Atomic::cmpxchg((threads_in_evac - 1) | OOM_MARKER_MASK,
!                                   &_threads_in_evac, threads_in_evac);
      if (other == threads_in_evac) {
        // Success: wait for other threads to get out of the protocol and return.
        wait_for_no_evac_threads();
        return;
      } else {
--- 96,106 ----
    assert(ShenandoahThreadLocalData::is_evac_allowed(Thread::current()), "sanity");
    assert(!ShenandoahThreadLocalData::is_oom_during_evac(Thread::current()), "TL oom-during-evac must not be set");
  
    jint threads_in_evac = Atomic::load_acquire(&_threads_in_evac);
    while (true) {
!     jint other = Atomic::cmpxchg(&_threads_in_evac, threads_in_evac, (threads_in_evac - 1) | OOM_MARKER_MASK);
      if (other == threads_in_evac) {
        // Success: wait for other threads to get out of the protocol and return.
        wait_for_no_evac_threads();
        return;
      } else {