12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_GC_G1_G1FREEIDSET_HPP
  26 #define SHARE_GC_G1_G1FREEIDSET_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "runtime/semaphore.hpp"
  30 #include "utilities/globalDefinitions.hpp"
  31 
  32 // Represents a set of free small integer ids.




  33 class G1FreeIdSet : public CHeapObj<mtGC> {
  34   Semaphore _sem;
  35   uint* _next;
  36   uint _start;
  37   uint _size;
  38   uintx _head_index_mask;
  39   volatile uintx _head;
  40 
  41   uint head_index(uintx head) const;
  42   uintx make_head(uint index, uintx old_head) const;
  43 
  44   // Noncopyable.
  45   G1FreeIdSet(const G1FreeIdSet&);
  46   G1FreeIdSet& operator=(const G1FreeIdSet&);
  47 
  48 public:
  49   G1FreeIdSet(uint start, uint size);
  50   ~G1FreeIdSet();
  51 
  52   // Returns an unclaimed parallel id (waiting for one to be released if

  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_GC_G1_G1FREEIDSET_HPP
  26 #define SHARE_GC_G1_G1FREEIDSET_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "runtime/semaphore.hpp"
  30 #include "utilities/globalDefinitions.hpp"
  31 
  32 // Represents a set of small integer ids, from which elements can be
  33 // temporarily allocated for exclusive use.  The ids are in a
  34 // contiguous range from 'start' to 'start + size'.  Used to obtain a
  35 // distinct worker_id value for a mutator thread that doesn't normally
  36 // have such an id.
  37 class G1FreeIdSet : public CHeapObj<mtGC> {
  38   Semaphore _sem;
  39   uint* _next;
  40   uint _start;
  41   uint _size;
  42   uintx _head_index_mask;
  43   volatile uintx _head;
  44 
  45   uint head_index(uintx head) const;
  46   uintx make_head(uint index, uintx old_head) const;
  47 
  48   // Noncopyable.
  49   G1FreeIdSet(const G1FreeIdSet&);
  50   G1FreeIdSet& operator=(const G1FreeIdSet&);
  51 
  52 public:
  53   G1FreeIdSet(uint start, uint size);
  54   ~G1FreeIdSet();
  55 
  56   // Returns an unclaimed parallel id (waiting for one to be released if