src/hotspot/share/gc/shared/workgroup.cpp

*** 424,434 ****
  
  bool SubTasksDone::try_claim_task(uint t) {
    assert(t < _n_tasks, "bad task id.");
    uint old = _tasks[t];
    if (old == 0) {
!     old = Atomic::cmpxchg(1u, &_tasks[t], 0u);
    }
    bool res = old == 0;
  #ifdef ASSERT
    if (res) {
      assert(_claimed < _n_tasks, "Too many tasks claimed; missing clear?");
--- 424,434 ----
  
  bool SubTasksDone::try_claim_task(uint t) {
    assert(t < _n_tasks, "bad task id.");
    uint old = _tasks[t];
    if (old == 0) {
!     old = Atomic::cmpxchg(&_tasks[t], 0u, 1u);
    }
    bool res = old == 0;
  #ifdef ASSERT
    if (res) {
      assert(_claimed < _n_tasks, "Too many tasks claimed; missing clear?");
*** 441,451 ****
  void SubTasksDone::all_tasks_completed(uint n_threads) {
    uint observed = _threads_completed;
    uint old;
    do {
      old = observed;
!     observed = Atomic::cmpxchg(old+1, &_threads_completed, old);
    } while (observed != old);
    // If this was the last thread checking in, clear the tasks.
    uint adjusted_thread_count = (n_threads == 0 ? 1 : n_threads);
    if (observed + 1 == adjusted_thread_count) {
      clear();
--- 441,451 ----
  void SubTasksDone::all_tasks_completed(uint n_threads) {
    uint observed = _threads_completed;
    uint old;
    do {
      old = observed;
!     observed = Atomic::cmpxchg(&_threads_completed, old, old+1);
    } while (observed != old);
    // If this was the last thread checking in, clear the tasks.
    uint adjusted_thread_count = (n_threads == 0 ? 1 : n_threads);
    if (observed + 1 == adjusted_thread_count) {
      clear();
*** 469,479 ****
  }
  
  bool SequentialSubTasksDone::try_claim_task(uint& t) {
    t = _n_claimed;
    while (t < _n_tasks) {
!     uint res = Atomic::cmpxchg(t+1, &_n_claimed, t);
      if (res == t) {
        return true;
      }
      t = res;
    }
--- 469,479 ----
  }
  
  bool SequentialSubTasksDone::try_claim_task(uint& t) {
    t = _n_claimed;
    while (t < _n_tasks) {
!     uint res = Atomic::cmpxchg(&_n_claimed, t, t+1);
      if (res == t) {
        return true;
      }
      t = res;
    }
*** 481,491 ****
  }
  
  bool SequentialSubTasksDone::all_tasks_completed() {
    uint complete = _n_completed;
    while (true) {
!     uint res = Atomic::cmpxchg(complete+1, &_n_completed, complete);
      if (res == complete) {
        break;
      }
      complete = res;
    }
--- 481,491 ----
  }
  
  bool SequentialSubTasksDone::all_tasks_completed() {
    uint complete = _n_completed;
    while (true) {
!     uint res = Atomic::cmpxchg(&_n_completed, complete, complete+1);
      if (res == complete) {
        break;
      }
      complete = res;
    }