11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 #include "precompiled.hpp"
  25 #include "gc_implementation/shenandoah/heuristics/shenandoahPassiveHeuristics.hpp"
  26 #include "gc_implementation/shenandoah/shenandoahCollectionSet.hpp"
  27 #include "gc_implementation/shenandoah/shenandoahHeap.hpp"
  28 #include "gc_implementation/shenandoah/shenandoahHeapRegion.hpp"
  29 #include "gc_implementation/shenandoah/shenandoahLogging.hpp"
  30 
  31 ShenandoahPassiveHeuristics::ShenandoahPassiveHeuristics() : ShenandoahHeuristics() {
  32   // Do not allow concurrent cycles.
  33   FLAG_SET_DEFAULT(ExplicitGCInvokesConcurrent, false);
  34 
  35   // Passive runs with max speed, reacts on allocation failure.
  36   FLAG_SET_DEFAULT(ShenandoahPacing, false);
  37 





  38   // Disable known barriers by default.
  39   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahSATBBarrier);
  40   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahWriteBarrier);
  41   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahReadBarrier);
  42   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahCASBarrier);
  43   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahAcmpBarrier);
  44   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahCloneBarrier);
  45 }
  46 
  47 void ShenandoahPassiveHeuristics::choose_collection_set_from_regiondata(ShenandoahCollectionSet* cset,
  48                                                                         RegionData* data, size_t size,
  49                                                                         size_t free) {
  50   for (size_t idx = 0; idx < size; idx++) {
  51     ShenandoahHeapRegion* r = data[idx]._region;
  52     if (r->garbage() > 0) {
  53       cset->add_region(r);
  54     }
  55   }
  56 }
  57 
  58 bool ShenandoahPassiveHeuristics::should_start_normal_gc() const {
  59   // Never do concurrent GCs.
  60   return false;
  61 }
  62 
  63 bool ShenandoahPassiveHeuristics::should_process_references() {
  64   if (ShenandoahRefProcFrequency == 0) return false;
  65   // Always process references.
  66   return true;
  67 }
  68 
  69 bool ShenandoahPassiveHeuristics::should_unload_classes() {
  70   if (ShenandoahUnloadClassesFrequency == 0) return false;
  71   // Always unload classes.
  72   return true;
  73 }
  74 
  75 bool ShenandoahPassiveHeuristics::should_degenerate_cycle() {
  76   // Always fail to Full GC
  77   return false;
  78 }
  79 
  80 const char* ShenandoahPassiveHeuristics::name() {
  81   return "passive";
  82 }
  83 
  84 bool ShenandoahPassiveHeuristics::is_diagnostic() {
  85   return true;
  86 }
  87 
  88 bool ShenandoahPassiveHeuristics::is_experimental() {
  89   return false;
  90 }

  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 #include "precompiled.hpp"
  25 #include "gc_implementation/shenandoah/heuristics/shenandoahPassiveHeuristics.hpp"
  26 #include "gc_implementation/shenandoah/shenandoahCollectionSet.hpp"
  27 #include "gc_implementation/shenandoah/shenandoahHeap.hpp"
  28 #include "gc_implementation/shenandoah/shenandoahHeapRegion.hpp"
  29 #include "gc_implementation/shenandoah/shenandoahLogging.hpp"
  30 
  31 ShenandoahPassiveHeuristics::ShenandoahPassiveHeuristics() : ShenandoahAdaptiveHeuristics() {
  32   // Do not allow concurrent cycles.
  33   FLAG_SET_DEFAULT(ExplicitGCInvokesConcurrent, false);
  34 
  35   // Passive runs with max speed, reacts on allocation failure.
  36   FLAG_SET_DEFAULT(ShenandoahPacing, false);
  37 
  38   // No need for evacuation reserve with Full GC, only for Degenerated GC.
  39   if (!ShenandoahDegeneratedGC) {
  40     SHENANDOAH_ERGO_OVERRIDE_DEFAULT(ShenandoahEvacReserve, 0);
  41   }
  42 
  43   // Disable known barriers by default.
  44   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahSATBBarrier);
  45   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahWriteBarrier);
  46   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahReadBarrier);
  47   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahCASBarrier);
  48   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahAcmpBarrier);
  49   SHENANDOAH_ERGO_DISABLE_FLAG(ShenandoahCloneBarrier);
  50 }
  51 











  52 bool ShenandoahPassiveHeuristics::should_start_normal_gc() const {
  53   // Never do concurrent GCs.
  54   return false;
  55 }
  56 
  57 bool ShenandoahPassiveHeuristics::should_process_references() {
  58   if (ShenandoahRefProcFrequency == 0) return false;
  59   // Always process references.
  60   return true;
  61 }
  62 
  63 bool ShenandoahPassiveHeuristics::should_unload_classes() {
  64   if (ShenandoahUnloadClassesFrequency == 0) return false;
  65   // Always unload classes.
  66   return true;
  67 }
  68 
  69 bool ShenandoahPassiveHeuristics::should_degenerate_cycle() {
  70   // Always fail to Degenerated GC, if enabled
  71   return ShenandoahDegeneratedGC;
  72 }
  73 
  74 const char* ShenandoahPassiveHeuristics::name() {
  75   return "passive";
  76 }
  77 
  78 bool ShenandoahPassiveHeuristics::is_diagnostic() {
  79   return true;
  80 }
  81 
  82 bool ShenandoahPassiveHeuristics::is_experimental() {
  83   return false;
  84 }