1.1 --- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Thu Mar 12 18:17:25 2009 -0700
1.2 +++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Wed Mar 18 11:37:48 2009 -0400
1.3 @@ -786,6 +786,12 @@
1.4 }
1.5 }
1.6
1.7 +void G1CollectedHeap::abandon_gc_alloc_regions() {
1.8 + // first, make sure that the GC alloc region list is empty (it should!)
1.9 + assert(_gc_alloc_region_list == NULL, "invariant");
1.10 + release_gc_alloc_regions(true /* totally */);
1.11 +}
1.12 +
1.13 class PostMCRemSetClearClosure: public HeapRegionClosure {
1.14 ModRefBarrierSet* _mr_bs;
1.15 public:
1.16 @@ -914,6 +920,7 @@
1.17
1.18 // Make sure we'll choose a new allocation region afterwards.
1.19 abandon_cur_alloc_region();
1.20 + abandon_gc_alloc_regions();
1.21 assert(_cur_alloc_region == NULL, "Invariant.");
1.22 g1_rem_set()->as_HRInto_G1RemSet()->cleanupHRRS();
1.23 tear_down_region_lists();
1.24 @@ -954,6 +961,7 @@
1.25 if (VerifyAfterGC && total_collections() >= VerifyGCStartAt) {
1.26 HandleMark hm; // Discard invalid handles created during verification
1.27 gclog_or_tty->print(" VerifyAfterGC:");
1.28 + prepare_for_verify();
1.29 Universe::verify(false);
1.30 }
1.31 NOT_PRODUCT(ref_processor()->verify_no_references_recorded());
1.32 @@ -1306,7 +1314,7 @@
1.33 }
1.34
1.35 void G1CollectedHeap::shrink(size_t shrink_bytes) {
1.36 - release_gc_alloc_regions();
1.37 + release_gc_alloc_regions(true /* totally */);
1.38 tear_down_region_lists(); // We will rebuild them in a moment.
1.39 shrink_helper(shrink_bytes);
1.40 rebuild_region_lists();
1.41 @@ -1345,8 +1353,7 @@
1.42 _gc_time_stamp(0),
1.43 _surviving_young_words(NULL),
1.44 _in_cset_fast_test(NULL),
1.45 - _in_cset_fast_test_base(NULL)
1.46 -{
1.47 + _in_cset_fast_test_base(NULL) {
1.48 _g1h = this; // To catch bugs.
1.49 if (_process_strong_tasks == NULL || !_process_strong_tasks->valid()) {
1.50 vm_exit_during_initialization("Failed necessary allocation.");
1.51 @@ -1371,9 +1378,19 @@
1.52 }
1.53
1.54 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
1.55 - _gc_alloc_regions[ap] = NULL;
1.56 - _gc_alloc_region_counts[ap] = 0;
1.57 - }
1.58 + _gc_alloc_regions[ap] = NULL;
1.59 + _gc_alloc_region_counts[ap] = 0;
1.60 + _retained_gc_alloc_regions[ap] = NULL;
1.61 + // by default, we do not retain a GC alloc region for each ap;
1.62 + // we'll override this, when appropriate, below
1.63 + _retain_gc_alloc_region[ap] = false;
1.64 + }
1.65 +
1.66 + // We will try to remember the last half-full tenured region we
1.67 + // allocated to at the end of a collection so that we can re-use it
1.68 + // during the next collection.
1.69 + _retain_gc_alloc_region[GCAllocForTenured] = true;
1.70 +
1.71 guarantee(_task_queues != NULL, "task_queues allocation failure.");
1.72 }
1.73
1.74 @@ -2119,15 +2136,7 @@
1.75 bool doHeapRegion(HeapRegion* r) {
1.76 guarantee(_par || r->claim_value() == HeapRegion::InitialClaimValue,
1.77 "Should be unclaimed at verify points.");
1.78 - if (r->isHumongous()) {
1.79 - if (r->startsHumongous()) {
1.80 - // Verify the single H object.
1.81 - oop(r->bottom())->verify();
1.82 - size_t word_sz = oop(r->bottom())->size();
1.83 - guarantee(r->top() == r->bottom() + word_sz,
1.84 - "Only one object in a humongous region");
1.85 - }
1.86 - } else {
1.87 + if (!r->continuesHumongous()) {
1.88 VerifyObjsInRegionClosure not_dead_yet_cl(r);
1.89 r->verify(_allow_dirty);
1.90 r->object_iterate(¬_dead_yet_cl);
1.91 @@ -2179,6 +2188,7 @@
1.92 _g1h(g1h), _allow_dirty(allow_dirty) { }
1.93
1.94 void work(int worker_i) {
1.95 + HandleMark hm;
1.96 VerifyRegionClosure blk(_allow_dirty, true);
1.97 _g1h->heap_region_par_iterate_chunked(&blk, worker_i,
1.98 HeapRegion::ParVerifyClaimValue);
1.99 @@ -2644,7 +2654,7 @@
1.100 popular_region->set_popular_pending(false);
1.101 }
1.102
1.103 - release_gc_alloc_regions();
1.104 + release_gc_alloc_regions(false /* totally */);
1.105
1.106 cleanup_surviving_young_words();
1.107
1.108 @@ -2697,6 +2707,7 @@
1.109 if (VerifyAfterGC && total_collections() >= VerifyGCStartAt) {
1.110 HandleMark hm; // Discard invalid handles created during verification
1.111 gclog_or_tty->print(" VerifyAfterGC:");
1.112 + prepare_for_verify();
1.113 Universe::verify(false);
1.114 }
1.115
1.116 @@ -2735,6 +2746,10 @@
1.117
1.118 void G1CollectedHeap::set_gc_alloc_region(int purpose, HeapRegion* r) {
1.119 assert(purpose >= 0 && purpose < GCAllocPurposeCount, "invalid purpose");
1.120 + // make sure we don't call set_gc_alloc_region() multiple times on
1.121 + // the same region
1.122 + assert(r == NULL || !r->is_gc_alloc_region(),
1.123 + "shouldn't already be a GC alloc region");
1.124 HeapWord* original_top = NULL;
1.125 if (r != NULL)
1.126 original_top = r->top();
1.127 @@ -2824,6 +2839,12 @@
1.128 while (_gc_alloc_region_list != NULL) {
1.129 HeapRegion* r = _gc_alloc_region_list;
1.130 assert(r->is_gc_alloc_region(), "Invariant.");
1.131 + // We need HeapRegion::oops_on_card_seq_iterate_careful() to work on
1.132 + // newly allocated data in order to be able to apply deferred updates
1.133 + // before the GC is done for verification purposes (i.e to allow
1.134 + // G1HRRSFlushLogBuffersOnVerify). It's safe thing to do after the
1.135 + // collection.
1.136 + r->ContiguousSpace::set_saved_mark();
1.137 _gc_alloc_region_list = r->next_gc_alloc_region();
1.138 r->set_next_gc_alloc_region(NULL);
1.139 r->set_is_gc_alloc_region(false);
1.140 @@ -2851,23 +2872,55 @@
1.141 }
1.142
1.143 void G1CollectedHeap::get_gc_alloc_regions() {
1.144 + // First, let's check that the GC alloc region list is empty (it should)
1.145 + assert(_gc_alloc_region_list == NULL, "invariant");
1.146 +
1.147 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
1.148 + assert(_gc_alloc_regions[ap] == NULL, "invariant");
1.149 +
1.150 // Create new GC alloc regions.
1.151 - HeapRegion* alloc_region = _gc_alloc_regions[ap];
1.152 - // Clear this alloc region, so that in case it turns out to be
1.153 - // unacceptable, we end up with no allocation region, rather than a bad
1.154 - // one.
1.155 - _gc_alloc_regions[ap] = NULL;
1.156 - if (alloc_region == NULL || alloc_region->in_collection_set()) {
1.157 - // Can't re-use old one. Allocate a new one.
1.158 + HeapRegion* alloc_region = _retained_gc_alloc_regions[ap];
1.159 + _retained_gc_alloc_regions[ap] = NULL;
1.160 +
1.161 + if (alloc_region != NULL) {
1.162 + assert(_retain_gc_alloc_region[ap], "only way to retain a GC region");
1.163 +
1.164 + // let's make sure that the GC alloc region is not tagged as such
1.165 + // outside a GC operation
1.166 + assert(!alloc_region->is_gc_alloc_region(), "sanity");
1.167 +
1.168 + if (alloc_region->in_collection_set() ||
1.169 + alloc_region->top() == alloc_region->end() ||
1.170 + alloc_region->top() == alloc_region->bottom()) {
1.171 + // we will discard the current GC alloc region if it's in the
1.172 + // collection set (it can happen!), if it's already full (no
1.173 + // point in using it), or if it's empty (this means that it
1.174 + // was emptied during a cleanup and it should be on the free
1.175 + // list now).
1.176 +
1.177 + alloc_region = NULL;
1.178 + }
1.179 + }
1.180 +
1.181 + if (alloc_region == NULL) {
1.182 + // we will get a new GC alloc region
1.183 alloc_region = newAllocRegionWithExpansion(ap, 0);
1.184 }
1.185 +
1.186 if (alloc_region != NULL) {
1.187 + assert(_gc_alloc_regions[ap] == NULL, "pre-condition");
1.188 set_gc_alloc_region(ap, alloc_region);
1.189 }
1.190 +
1.191 + assert(_gc_alloc_regions[ap] == NULL ||
1.192 + _gc_alloc_regions[ap]->is_gc_alloc_region(),
1.193 + "the GC alloc region should be tagged as such");
1.194 + assert(_gc_alloc_regions[ap] == NULL ||
1.195 + _gc_alloc_regions[ap] == _gc_alloc_region_list,
1.196 + "the GC alloc region should be the same as the GC alloc list head");
1.197 }
1.198 // Set alternative regions for allocation purposes that have reached
1.199 - // thier limit.
1.200 + // their limit.
1.201 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
1.202 GCAllocPurpose alt_purpose = g1_policy()->alternative_purpose(ap);
1.203 if (_gc_alloc_regions[ap] == NULL && alt_purpose != ap) {
1.204 @@ -2877,27 +2930,55 @@
1.205 assert(check_gc_alloc_regions(), "alloc regions messed up");
1.206 }
1.207
1.208 -void G1CollectedHeap::release_gc_alloc_regions() {
1.209 +void G1CollectedHeap::release_gc_alloc_regions(bool totally) {
1.210 // We keep a separate list of all regions that have been alloc regions in
1.211 - // the current collection pause. Forget that now.
1.212 + // the current collection pause. Forget that now. This method will
1.213 + // untag the GC alloc regions and tear down the GC alloc region
1.214 + // list. It's desirable that no regions are tagged as GC alloc
1.215 + // outside GCs.
1.216 forget_alloc_region_list();
1.217
1.218 // The current alloc regions contain objs that have survived
1.219 // collection. Make them no longer GC alloc regions.
1.220 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
1.221 HeapRegion* r = _gc_alloc_regions[ap];
1.222 - if (r != NULL && r->is_empty()) {
1.223 - {
1.224 + _retained_gc_alloc_regions[ap] = NULL;
1.225 +
1.226 + if (r != NULL) {
1.227 + // we retain nothing on _gc_alloc_regions between GCs
1.228 + set_gc_alloc_region(ap, NULL);
1.229 + _gc_alloc_region_counts[ap] = 0;
1.230 +
1.231 + if (r->is_empty()) {
1.232 + // we didn't actually allocate anything in it; let's just put
1.233 + // it on the free list
1.234 MutexLockerEx x(ZF_mon, Mutex::_no_safepoint_check_flag);
1.235 r->set_zero_fill_complete();
1.236 put_free_region_on_list_locked(r);
1.237 + } else if (_retain_gc_alloc_region[ap] && !totally) {
1.238 + // retain it so that we can use it at the beginning of the next GC
1.239 + _retained_gc_alloc_regions[ap] = r;
1.240 }
1.241 }
1.242 - // set_gc_alloc_region will also NULLify all aliases to the region
1.243 - set_gc_alloc_region(ap, NULL);
1.244 - _gc_alloc_region_counts[ap] = 0;
1.245 - }
1.246 -}
1.247 + }
1.248 +}
1.249 +
1.250 +#ifndef PRODUCT
1.251 +// Useful for debugging
1.252 +
1.253 +void G1CollectedHeap::print_gc_alloc_regions() {
1.254 + gclog_or_tty->print_cr("GC alloc regions");
1.255 + for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
1.256 + HeapRegion* r = _gc_alloc_regions[ap];
1.257 + if (r == NULL) {
1.258 + gclog_or_tty->print_cr(" %2d : "PTR_FORMAT, ap, NULL);
1.259 + } else {
1.260 + gclog_or_tty->print_cr(" %2d : "PTR_FORMAT" "SIZE_FORMAT,
1.261 + ap, r->bottom(), r->used());
1.262 + }
1.263 + }
1.264 +}
1.265 +#endif // PRODUCT
1.266
1.267 void G1CollectedHeap::init_for_evac_failure(OopsInHeapRegionClosure* cl) {
1.268 _drain_in_progress = false;
1.269 @@ -3658,7 +3739,9 @@
1.270 CardTableModRefBS* ctbs() { return _ct_bs; }
1.271
1.272 void immediate_rs_update(HeapRegion* from, oop* p, int tid) {
1.273 - _g1_rem->par_write_ref(from, p, tid);
1.274 + if (!from->is_survivor()) {
1.275 + _g1_rem->par_write_ref(from, p, tid);
1.276 + }
1.277 }
1.278
1.279 void deferred_rs_update(HeapRegion* from, oop* p, int tid) {
