550
551 void DefNewGeneration::adjust_desired_tenuring_threshold() {
552 // Set the desired survivor size to half the real survivor space
553 _tenuring_threshold =
554 age_table()->compute_tenuring_threshold(to()->capacity()/HeapWordSize);
555 }
556
557 void DefNewGeneration::collect(bool full,
558 bool clear_all_soft_refs,
559 size_t size,
560 bool is_tlab) {
561 assert(full || size > 0, "otherwise we don't want to collect");
562
563 GenCollectedHeap* gch = GenCollectedHeap::heap();
564
565 _gc_timer->register_gc_start(os::elapsed_counter());
566 DefNewTracer gc_tracer;
567 gc_tracer.report_gc_start(gch->gc_cause(), _gc_timer->gc_start());
568
569 _next_gen = gch->next_gen(this);
570 assert(_next_gen != NULL,
571 "This must be the youngest gen, and not the only gen");
572
573 // If the next generation is too full to accommodate promotion
574 // from this generation, pass on collection; let the next generation
575 // do it.
576 if (!collection_attempt_is_safe()) {
577 if (Verbose && PrintGCDetails) {
578 gclog_or_tty->print(" :: Collection attempt not safe :: ");
579 }
580 gch->set_incremental_collection_failed(); // Slight lie: we did not even attempt one
581 return;
582 }
583 assert(to()->is_empty(), "Else not collection_attempt_is_safe");
584
585 init_assuming_no_promotion_failure();
586
587 GCTraceTime t1(GCCauseString("GC", gch->gc_cause()), PrintGC && !PrintGCDetails, true, NULL);
588 // Capture heap used before collection (for printing).
589 size_t gch_prev_used = gch->used();
590
591 gch->trace_heap_before_gc(&gc_tracer);
884
885 void DefNewGeneration::reset_scratch() {
886 // If contributing scratch in to_space, mangle all of
887 // to_space if ZapUnusedHeapArea. This is needed because
888 // top is not maintained while using to-space as scratch.
889 if (ZapUnusedHeapArea) {
890 to()->mangle_unused_area_complete();
891 }
892 }
893
894 bool DefNewGeneration::collection_attempt_is_safe() {
895 if (!to()->is_empty()) {
896 if (Verbose && PrintGCDetails) {
897 gclog_or_tty->print(" :: to is not empty :: ");
898 }
899 return false;
900 }
901 if (_next_gen == NULL) {
902 GenCollectedHeap* gch = GenCollectedHeap::heap();
903 _next_gen = gch->next_gen(this);
904 assert(_next_gen != NULL,
905 "This must be the youngest gen, and not the only gen");
906 }
907 return _next_gen->promotion_attempt_is_safe(used());
908 }
909
910 void DefNewGeneration::gc_epilogue(bool full) {
911 DEBUG_ONLY(static bool seen_incremental_collection_failed = false;)
912
913 assert(!GC_locker::is_active(), "We should not be executing here");
914 // Check if the heap is approaching full after a collection has
915 // been done. Generally the young generation is empty at
916 // a minimum at the end of a collection. If it is not, then
917 // the heap is approaching full.
918 GenCollectedHeap* gch = GenCollectedHeap::heap();
919 if (full) {
920 DEBUG_ONLY(seen_incremental_collection_failed = false;)
921 if (!collection_attempt_is_safe() && !_eden_space->is_empty()) {
922 if (Verbose && PrintGCDetails) {
923 gclog_or_tty->print("DefNewEpilogue: cause(%s), full, not safe, set_failed, set_alloc_from, clear_seen",
924 GCCause::to_string(gch->gc_cause()));
925 }
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550
551 void DefNewGeneration::adjust_desired_tenuring_threshold() {
552 // Set the desired survivor size to half the real survivor space
553 _tenuring_threshold =
554 age_table()->compute_tenuring_threshold(to()->capacity()/HeapWordSize);
555 }
556
557 void DefNewGeneration::collect(bool full,
558 bool clear_all_soft_refs,
559 size_t size,
560 bool is_tlab) {
561 assert(full || size > 0, "otherwise we don't want to collect");
562
563 GenCollectedHeap* gch = GenCollectedHeap::heap();
564
565 _gc_timer->register_gc_start(os::elapsed_counter());
566 DefNewTracer gc_tracer;
567 gc_tracer.report_gc_start(gch->gc_cause(), _gc_timer->gc_start());
568
569 _next_gen = gch->next_gen(this);
570
571 // If the next generation is too full to accommodate promotion
572 // from this generation, pass on collection; let the next generation
573 // do it.
574 if (!collection_attempt_is_safe()) {
575 if (Verbose && PrintGCDetails) {
576 gclog_or_tty->print(" :: Collection attempt not safe :: ");
577 }
578 gch->set_incremental_collection_failed(); // Slight lie: we did not even attempt one
579 return;
580 }
581 assert(to()->is_empty(), "Else not collection_attempt_is_safe");
582
583 init_assuming_no_promotion_failure();
584
585 GCTraceTime t1(GCCauseString("GC", gch->gc_cause()), PrintGC && !PrintGCDetails, true, NULL);
586 // Capture heap used before collection (for printing).
587 size_t gch_prev_used = gch->used();
588
589 gch->trace_heap_before_gc(&gc_tracer);
882
883 void DefNewGeneration::reset_scratch() {
884 // If contributing scratch in to_space, mangle all of
885 // to_space if ZapUnusedHeapArea. This is needed because
886 // top is not maintained while using to-space as scratch.
887 if (ZapUnusedHeapArea) {
888 to()->mangle_unused_area_complete();
889 }
890 }
891
892 bool DefNewGeneration::collection_attempt_is_safe() {
893 if (!to()->is_empty()) {
894 if (Verbose && PrintGCDetails) {
895 gclog_or_tty->print(" :: to is not empty :: ");
896 }
897 return false;
898 }
899 if (_next_gen == NULL) {
900 GenCollectedHeap* gch = GenCollectedHeap::heap();
901 _next_gen = gch->next_gen(this);
902 }
903 return _next_gen->promotion_attempt_is_safe(used());
904 }
905
906 void DefNewGeneration::gc_epilogue(bool full) {
907 DEBUG_ONLY(static bool seen_incremental_collection_failed = false;)
908
909 assert(!GC_locker::is_active(), "We should not be executing here");
910 // Check if the heap is approaching full after a collection has
911 // been done. Generally the young generation is empty at
912 // a minimum at the end of a collection. If it is not, then
913 // the heap is approaching full.
914 GenCollectedHeap* gch = GenCollectedHeap::heap();
915 if (full) {
916 DEBUG_ONLY(seen_incremental_collection_failed = false;)
917 if (!collection_attempt_is_safe() && !_eden_space->is_empty()) {
918 if (Verbose && PrintGCDetails) {
919 gclog_or_tty->print("DefNewEpilogue: cause(%s), full, not safe, set_failed, set_alloc_from, clear_seen",
920 GCCause::to_string(gch->gc_cause()));
921 }
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