void G1MarkSweep::mark_sweep_phase4() { // All pointers are now adjusted, move objects accordingly // It is imperative that we traverse perm_gen first in phase4. All // classes must be allocated earlier than their instances, and traversing // perm_gen first makes sure that all klassOops have moved to their new // location before any instance does a dispatch through it's klass! // The ValidateMarkSweep live oops tracking expects us to traverse spaces // in the same order in phase2, phase3 and phase4. We don't quite do that // here (perm_gen first rather than last), so we tell the validate code // to use a higher index (saved from phase2) when verifying perm_gen. G1CollectedHeap* g1h = G1CollectedHeap::heap(); Generation* pg = g1h->perm_gen(); EventMark m("4 compact heap"); TraceTime tm("phase 4", PrintGC && Verbose, true, gclog_or_tty); GenMarkSweep::trace("4"); pg->compact(); G1SpaceCompactClosure blk; g1h->heap_region_iterate(&blk); }