src/hotspot/share/utilities/waitBarrier_generic.hpp

rev 53038 : 8214271: Fast primitive to wake many threads
Reviewed-by:
rev 53039 : [mq]: 8214271-3

*** 26,43 ****
  #define SHARE_UTILITIES_WAITBARRIER_GENERIC_HPP
  
  #include "memory/allocation.hpp"
  #include "runtime/semaphore.hpp"
  
! // Except for the barrier tag it self, it uses two counter to keep the semaphore
! // count correct and not leave any late thread hanging.
  class GenericWaitBarrier : public CHeapObj<mtInternal> {
    volatile int _barrier_tag;
    // The number of threads waiting on or about to wait on the semaphore.
    volatile int _waiters;
    // The number of threads in the wait path, before or after the tag check.
!   // Which means it can become a waiter.
    volatile int _barrier_threads;
    Semaphore _sem_barrier;
  
    // Prevent copying and assignment of GenericWaitBarrier instances.
    GenericWaitBarrier(const GenericWaitBarrier&);
--- 26,43 ----
  #define SHARE_UTILITIES_WAITBARRIER_GENERIC_HPP
  
  #include "memory/allocation.hpp"
  #include "runtime/semaphore.hpp"
  
! // Except for the barrier tag itself, it uses two counters to keep the semaphore
! // count correct and not leave any late thread waiting.
  class GenericWaitBarrier : public CHeapObj<mtInternal> {
    volatile int _barrier_tag;
    // The number of threads waiting on or about to wait on the semaphore.
    volatile int _waiters;
    // The number of threads in the wait path, before or after the tag check.
!   // These threads can become waiters.
    volatile int _barrier_threads;
    Semaphore _sem_barrier;
  
    // Prevent copying and assignment of GenericWaitBarrier instances.
    GenericWaitBarrier(const GenericWaitBarrier&);