1.1 --- a/src/share/vm/utilities/taskqueue.hpp Thu Jun 13 11:16:38 2013 -0700
1.2 +++ b/src/share/vm/utilities/taskqueue.hpp Thu Jun 13 22:02:40 2013 -0700
1.3 @@ -340,8 +340,12 @@
1.4 if (dirty_n_elems == N - 1) {
1.5 // Actually means 0, so do the push.
1.6 uint localBot = _bottom;
1.7 - // g++ complains if the volatile result of the assignment is unused.
1.8 - const_cast<E&>(_elems[localBot] = t);
1.9 + // g++ complains if the volatile result of the assignment is
1.10 + // unused, so we cast the volatile away. We cannot cast directly
1.11 + // to void, because gcc treats that as not using the result of the
1.12 + // assignment. However, casting to E& means that we trigger an
1.13 + // unused-value warning. So, we cast the E& to void.
1.14 + (void)const_cast<E&>(_elems[localBot] = t);
1.15 OrderAccess::release_store(&_bottom, increment_index(localBot));
1.16 TASKQUEUE_STATS_ONLY(stats.record_push());
1.17 return true;
1.18 @@ -397,7 +401,12 @@
1.19 return false;
1.20 }
1.21
1.22 - const_cast<E&>(t = _elems[oldAge.top()]);
1.23 + // g++ complains if the volatile result of the assignment is
1.24 + // unused, so we cast the volatile away. We cannot cast directly
1.25 + // to void, because gcc treats that as not using the result of the
1.26 + // assignment. However, casting to E& means that we trigger an
1.27 + // unused-value warning. So, we cast the E& to void.
1.28 + (void) const_cast<E&>(t = _elems[oldAge.top()]);
1.29 Age newAge(oldAge);
1.30 newAge.increment();
1.31 Age resAge = _age.cmpxchg(newAge, oldAge);
1.32 @@ -640,8 +649,12 @@
1.33 uint dirty_n_elems = dirty_size(localBot, top);
1.34 assert(dirty_n_elems < N, "n_elems out of range.");
1.35 if (dirty_n_elems < max_elems()) {
1.36 - // g++ complains if the volatile result of the assignment is unused.
1.37 - const_cast<E&>(_elems[localBot] = t);
1.38 + // g++ complains if the volatile result of the assignment is
1.39 + // unused, so we cast the volatile away. We cannot cast directly
1.40 + // to void, because gcc treats that as not using the result of the
1.41 + // assignment. However, casting to E& means that we trigger an
1.42 + // unused-value warning. So, we cast the E& to void.
1.43 + (void) const_cast<E&>(_elems[localBot] = t);
1.44 OrderAccess::release_store(&_bottom, increment_index(localBot));
1.45 TASKQUEUE_STATS_ONLY(stats.record_push());
1.46 return true;
1.47 @@ -665,7 +678,12 @@
1.48 // This is necessary to prevent any read below from being reordered
1.49 // before the store just above.
1.50 OrderAccess::fence();
1.51 - const_cast<E&>(t = _elems[localBot]);
1.52 + // g++ complains if the volatile result of the assignment is
1.53 + // unused, so we cast the volatile away. We cannot cast directly
1.54 + // to void, because gcc treats that as not using the result of the
1.55 + // assignment. However, casting to E& means that we trigger an
1.56 + // unused-value warning. So, we cast the E& to void.
1.57 + (void) const_cast<E&>(t = _elems[localBot]);
1.58 // This is a second read of "age"; the "size()" above is the first.
1.59 // If there's still at least one element in the queue, based on the
1.60 // "_bottom" and "age" we've read, then there can be no interference with
