graal-jvmci-8: src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.cpp comparison

comparison src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.cpp @ 6817:f81a7c0c618d

7199349: NPG: PS: Crash seen in jprt Reviewed-by: johnc

author	jmasa
date	Wed, 03 Oct 2012 08:08:52 -0700
parents	da91efe96a93
children	746b070f5022

comparison

equal deleted inserted replaced

-:87ac5c0a404d
+:f81a7c0c618d
 virtual void do_oop(narrowOop* p) { CheckForPreciseMarks::do_oop_work(p); }
 };
 // We get passed the space_top value to prevent us from traversing into
 // the old_gen promotion labs, which cannot be safely parsed.
-void CardTableExtension::scavenge_contents(ObjectStartArray* start_array,
-MutableSpace* sp,
+// Do not call this method if the space is empty.
-HeapWord* space_top,
+// It is a waste to start tasks and get here only to
-PSPromotionManager* pm)
+// do no work.  If this method needs to be called
-{
+// when the space is empty, fix the calculation of
-assert(start_array != NULL && sp != NULL && pm != NULL, "Sanity");
+// end_card to allow sp_top == sp->bottom().
-assert(start_array->covered_region().contains(sp->used_region()),
-"ObjectStartArray does not cover space");
-if (sp->not_empty()) {
-oop* sp_top = (oop*)space_top;
-oop* prev_top = NULL;
-jbyte* current_card = byte_for(sp->bottom());
-jbyte* end_card     = byte_for(sp_top - 1);    // sp_top is exclusive
-// scan card marking array
-while (current_card <= end_card) {
-jbyte value = *current_card;
-// skip clean cards
-if (card_is_clean(value)) {
-current_card++;
-} else {
-// we found a non-clean card
-jbyte* first_nonclean_card = current_card++;
-oop* bottom = (oop*)addr_for(first_nonclean_card);
-// find object starting on card
-oop* bottom_obj = (oop*)start_array->object_start((HeapWord*)bottom);
-// bottom_obj = (oop*)start_array->object_start((HeapWord*)bottom);
-assert(bottom_obj <= bottom, "just checking");
-// make sure we don't scan oops we already looked at
-if (bottom < prev_top) bottom = prev_top;
-// figure out when to stop scanning
-jbyte* first_clean_card;
-oop* top;
-bool restart_scanning;
-do {
-restart_scanning = false;
-// find a clean card
-while (current_card <= end_card) {
-value = *current_card;
-if (card_is_clean(value)) break;
-current_card++;
-}
-// check if we reached the end, if so we are done
-if (current_card >= end_card) {
-first_clean_card = end_card + 1;
-current_card++;
-top = sp_top;
-} else {
-// we have a clean card, find object starting on that card
-first_clean_card = current_card++;
-top = (oop*)addr_for(first_clean_card);
-oop* top_obj = (oop*)start_array->object_start((HeapWord*)top);
-// top_obj = (oop*)start_array->object_start((HeapWord*)top);
-assert(top_obj <= top, "just checking");
-if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) {
-// an arrayOop is starting on the clean card - since we do exact store
-// checks for objArrays we are done
-} else {
-// otherwise, it is possible that the object starting on the clean card
-// spans the entire card, and that the store happened on a later card.
-// figure out where the object ends
-top = top_obj + oop(top_obj)->size();
-jbyte* top_card = CardTableModRefBS::byte_for(top - 1);   // top is exclusive
-if (top_card > first_clean_card) {
-// object ends a different card
-current_card = top_card + 1;
-if (card_is_clean(*top_card)) {
-// the ending card is clean, we are done
-first_clean_card = top_card;
-} else {
-// the ending card is not clean, continue scanning at start of do-while
-restart_scanning = true;
-}
-} else {
-// object ends on the clean card, we are done.
-assert(first_clean_card == top_card, "just checking");
-}
-}
-}
-} while (restart_scanning);
-// we know which cards to scan, now clear them
-while (first_nonclean_card < first_clean_card) {
-*first_nonclean_card++ = clean_card;
-}
-// scan oops in objects
-do {
-oop(bottom_obj)->push_contents(pm);
-bottom_obj += oop(bottom_obj)->size();
-assert(bottom_obj <= sp_top, "just checking");
-} while (bottom_obj < top);
-pm->drain_stacks_cond_depth();
-// remember top oop* scanned
-prev_top = top;
-}
-}
-}
-}
 void CardTableExtension::scavenge_contents_parallel(ObjectStartArray* start_array,
 MutableSpace* sp,
 HeapWord* space_top,
 PSPromotionManager* pm,
 uint stripe_number,
 uint stripe_total) {
 int ssize = 128; // Naked constant!  Work unit = 64k.
 int dirty_card_count = 0;
+// It is a waste to get here if empty.
+assert(sp->bottom() < sp->top(), "Should not be called if empty");
 oop* sp_top = (oop*)space_top;
-oop* sp_last = sp->bottom() == space_top ? sp_top : sp_top - 1;
 jbyte* start_card = byte_for(sp->bottom());
-jbyte* end_card   = byte_for(sp_last) + 1;
+jbyte* end_card   = byte_for(sp_top - 1) + 1;
 oop* last_scanned = NULL; // Prevent scanning objects more than once
 // The width of the stripe ssize*stripe_total must be
 // consistent with the number of stripes so that the complete slice
 // is covered.
 size_t slice_width = ssize * stripe_total;
 // last object continues into the next 'slice'.
 //
 // Note! ending cards are exclusive!
 HeapWord* slice_start = addr_for(worker_start_card);
 HeapWord* slice_end = MIN2((HeapWord*) sp_top, addr_for(worker_end_card));
+#ifdef ASSERT
+if (GCWorkerDelayMillis > 0) {
+// Delay 1 worker so that it proceeds after all the work
+// has been completed.
+if (stripe_number < 2) {
+os::sleep(Thread::current(), GCWorkerDelayMillis, false);
+}
+}
+#endif
 // If there are not objects starting within the chunk, skip it.
 if (!start_array->object_starts_in_range(slice_start, slice_end)) {
 continue;
 }

Mercurial > hg > graal-jvmci-8

comparison src/share/vm/gc_implementation/parallelScavenge/cardTableExtension.cpp @ 6817:f81a7c0c618d