src/hotspot/share/runtime/threadSMR.cpp

rev 50688 : 8205195: NestedThreadsListHandleInErrorHandlingTest fails because hs_err doesn't contain _nested_thread_list_max
Summary: Grab Threads_lock in VMError::controlled_crash() so ErrorHandling tests are more stable.
Reviewed-by:

*** 1065,1076 ****
    }
  }
  
  // Print Threads class SMR info.
  void ThreadsSMRSupport::print_info_on(outputStream* st) {
!   // Only grab the Threads_lock if we don't already own it
!   // and if we are not reporting an error.
    MutexLockerEx ml((Threads_lock->owned_by_self() || VMError::is_error_reported()) ? NULL : Threads_lock);
  
    st->print_cr("Threads class SMR info:");
    st->print_cr("_java_thread_list=" INTPTR_FORMAT ", length=%u, "
                 "elements={", p2i(_java_thread_list),
--- 1065,1083 ----
    }
  }
  
  // Print Threads class SMR info.
  void ThreadsSMRSupport::print_info_on(outputStream* st) {
!   // Only grab the Threads_lock if we don't already own it and if we
!   // are not reporting an error.
!   // Note: Not grabbing the Threads_lock during during error reporting
!   // is dangerous because the data structures we want to print can be
!   // freed concurrently. However, grabbing the Threads_lock during
!   // error reporting can be equally dangerous since this thread might
!   // block during error reporting or a nested error could leave the
!   // Threads_lock held. The classic no win scenario.
!   //
    MutexLockerEx ml((Threads_lock->owned_by_self() || VMError::is_error_reported()) ? NULL : Threads_lock);
  
    st->print_cr("Threads class SMR info:");
    st->print_cr("_java_thread_list=" INTPTR_FORMAT ", length=%u, "
                 "elements={", p2i(_java_thread_list),