--- a/hotspot/src/share/vm/gc/shared/space.inline.hpp Sat Apr 02 05:39:25 2016 +0200
+++ b/hotspot/src/share/vm/gc/shared/space.inline.hpp Fri Apr 01 10:16:31 2016 +0200
@@ -28,7 +28,6 @@
#include "gc/serial/markSweep.inline.hpp"
#include "gc/shared/collectedHeap.hpp"
#include "gc/shared/generation.hpp"
-#include "gc/shared/liveRange.hpp"
#include "gc/shared/space.hpp"
#include "gc/shared/spaceDecorator.hpp"
#include "memory/universe.hpp"
@@ -117,9 +116,6 @@
HeapWord* end_of_live= q; // One byte beyond the last byte of the last
// live object.
HeapWord* first_dead = space->end(); // The first dead object.
- LiveRange* liveRange = NULL; // The current live range, recorded in the
- // first header of preceding free area.
- space->_first_dead = first_dead;
const intx interval = PrefetchScanIntervalInBytes;
@@ -158,16 +154,8 @@
// otherwise, it really is a free region.
- // for the previous LiveRange, record the end of the live objects.
- if (liveRange) {
- liveRange->set_end(q);
- }
-
- // record the current LiveRange object.
- // liveRange->start() is overlaid on the mark word.
- liveRange = (LiveRange*)q;
- liveRange->set_start(end);
- liveRange->set_end(end);
+ // q is a pointer to a dead object. Use this dead memory to store a pointer to the next live object.
+ (*(HeapWord**)q) = end;
// see if this is the first dead region.
if (q < first_dead) {
@@ -180,9 +168,6 @@
}
assert(q == t, "just checking");
- if (liveRange != NULL) {
- liveRange->set_end(q);
- }
space->_end_of_live = end_of_live;
if (end_of_live < first_dead) {
first_dead = end_of_live;
@@ -227,9 +212,9 @@
if (space->_first_dead == t) {
q = t;
} else {
- // $$$ This is funky. Using this to read the previously written
- // LiveRange. See also use below.
- q = (HeapWord*)oop(space->_first_dead)->mark()->decode_pointer();
+ // The first dead object is no longer an object. At that memory address,
+ // there is a pointer to the first live object that the previous phase found.
+ q = *((HeapWord**)(space->_first_dead));
}
}
@@ -247,11 +232,10 @@
debug_only(prev_q = q);
q += size;
} else {
- // q is not a live object, so its mark should point at the next
- // live object
debug_only(prev_q = q);
- q = (HeapWord*) oop(q)->mark()->decode_pointer();
- assert(q > prev_q, "we should be moving forward through memory");
+ // q is not a live object, instead it points at the next live object
+ q = *(HeapWord**)q;
+ assert(q > prev_q, "we should be moving forward through memory, q: " PTR_FORMAT ", prev_q: " PTR_FORMAT, p2i(q), p2i(prev_q));
}
}