3364   if (Verbose && PrintGC) {
3365     size_t new_mem_size = _virtual_space.committed_size();
3366     size_t old_mem_size = new_mem_size + bytes;
3367     gclog_or_tty->print_cr("Shrinking %s from " SIZE_FORMAT "K to " SIZE_FORMAT "K",
3368                   name(), old_mem_size/K, new_mem_size/K);
3369   }
3370 }
3371 
3372 void ConcurrentMarkSweepGeneration::shrink(size_t bytes) {
3373   assert_locked_or_safepoint(Heap_lock);
3374   size_t size = ReservedSpace::page_align_size_down(bytes);
3375   if (size > 0) {
3376     shrink_by(size);
3377   }
3378 }
3379 
3380 bool ConcurrentMarkSweepGeneration::grow_by(size_t bytes) {
3381   assert_locked_or_safepoint(Heap_lock);
3382   bool result = _virtual_space.expand_by(bytes);
3383   if (result) {
3384     HeapWord* old_end = _cmsSpace->end();
3385     size_t new_word_size =
3386       heap_word_size(_virtual_space.committed_size());
3387     MemRegion mr(_cmsSpace->bottom(), new_word_size);
3388     _bts->resize(new_word_size);  // resize the block offset shared array
3389     Universe::heap()->barrier_set()->resize_covered_region(mr);
3390     // Hmmmm... why doesn't CFLS::set_end verify locking?
3391     // This is quite ugly; FIX ME XXX
3392     _cmsSpace->assert_locked(freelistLock());
3393     _cmsSpace->set_end((HeapWord*)_virtual_space.high());
3394 
3395     // update the space and generation capacity counters
3396     if (UsePerfData) {
3397       _space_counters->update_capacity();
3398       _gen_counters->update_all();
3399     }
3400 
3401     if (Verbose && PrintGC) {
3402       size_t new_mem_size = _virtual_space.committed_size();
3403       size_t old_mem_size = new_mem_size - bytes;
3404       gclog_or_tty->print_cr("Expanding %s from " SIZE_FORMAT "K by " SIZE_FORMAT "K to " SIZE_FORMAT "K",

3364   if (Verbose && PrintGC) {
3365     size_t new_mem_size = _virtual_space.committed_size();
3366     size_t old_mem_size = new_mem_size + bytes;
3367     gclog_or_tty->print_cr("Shrinking %s from " SIZE_FORMAT "K to " SIZE_FORMAT "K",
3368                   name(), old_mem_size/K, new_mem_size/K);
3369   }
3370 }
3371 
3372 void ConcurrentMarkSweepGeneration::shrink(size_t bytes) {
3373   assert_locked_or_safepoint(Heap_lock);
3374   size_t size = ReservedSpace::page_align_size_down(bytes);
3375   if (size > 0) {
3376     shrink_by(size);
3377   }
3378 }
3379 
3380 bool ConcurrentMarkSweepGeneration::grow_by(size_t bytes) {
3381   assert_locked_or_safepoint(Heap_lock);
3382   bool result = _virtual_space.expand_by(bytes);
3383   if (result) {

3384     size_t new_word_size =
3385       heap_word_size(_virtual_space.committed_size());
3386     MemRegion mr(_cmsSpace->bottom(), new_word_size);
3387     _bts->resize(new_word_size);  // resize the block offset shared array
3388     Universe::heap()->barrier_set()->resize_covered_region(mr);
3389     // Hmmmm... why doesn't CFLS::set_end verify locking?
3390     // This is quite ugly; FIX ME XXX
3391     _cmsSpace->assert_locked(freelistLock());
3392     _cmsSpace->set_end((HeapWord*)_virtual_space.high());
3393 
3394     // update the space and generation capacity counters
3395     if (UsePerfData) {
3396       _space_counters->update_capacity();
3397       _gen_counters->update_all();
3398     }
3399 
3400     if (Verbose && PrintGC) {
3401       size_t new_mem_size = _virtual_space.committed_size();
3402       size_t old_mem_size = new_mem_size - bytes;
3403       gclog_or_tty->print_cr("Expanding %s from " SIZE_FORMAT "K by " SIZE_FORMAT "K to " SIZE_FORMAT "K",