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8329858: G1: Make G1VerifyLiveAndRemSetClosure stateless
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Reviewed-by: ayang, tschatzl
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@stefank
stefank committed Apr 9, 2024
1 parent 492b954 commit 5c9f036
Showing 1 changed file with 44 additions and 35 deletions.
79 changes: 44 additions & 35 deletions src/hotspot/share/gc/g1/g1HeapRegion.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -462,17 +462,31 @@ static bool is_oop_safe(oop obj) {
return true;
}

class G1VerifyFailureCounter {
size_t _count;

public:
G1VerifyFailureCounter() : _count(0) {}

// Increases the failure counter and return whether this has been the first failure.
bool record_failure() {
_count++;
return _count == 1;
}

size_t count() const { return _count; }
};

// Closure that glues together validity check for oop references (first),
// then optionally verifies the remembered set for that reference.
class G1VerifyLiveAndRemSetClosure : public BasicOopIterateClosure {
VerifyOption _vo;
oop _containing_obj;
size_t _num_failures;
const VerifyOption _vo;
const oop _containing_obj;
G1VerifyFailureCounter* const _failures;

// Increases the failure counter and return whether this has been the first failure.
bool record_failure() {
_num_failures++;
return _num_failures == 1;
return _failures->record_failure();
}

static void print_object(outputStream* out, oop obj) {
Expand All @@ -486,18 +500,22 @@ class G1VerifyLiveAndRemSetClosure : public BasicOopIterateClosure {
template <class T>
struct Checker {
G1CollectedHeap* _g1h;
G1VerifyLiveAndRemSetClosure* _cl;
G1VerifyFailureCounter* _failures;
oop _containing_obj;
T* _p;
oop _obj;

Checker(G1VerifyLiveAndRemSetClosure* cl, oop containing_obj, T* p, oop obj) :
Checker(G1VerifyFailureCounter* failures, oop containing_obj, T* p, oop obj) :
_g1h(G1CollectedHeap::heap()),
_cl(cl),
_failures(failures),
_containing_obj(containing_obj),
_p(p),
_obj(obj) { }

bool record_failure() {
return _failures->record_failure();
}

void print_containing_obj(outputStream* out, HeapRegion* from) {
log_error(gc, verify)("Field " PTR_FORMAT " of obj " PTR_FORMAT " in region " HR_FORMAT,
p2i(_p), p2i(_containing_obj), HR_FORMAT_PARAMS(from));
Expand All @@ -516,7 +534,8 @@ class G1VerifyLiveAndRemSetClosure : public BasicOopIterateClosure {
VerifyOption _vo;
bool _is_in_heap;

LiveChecker(G1VerifyLiveAndRemSetClosure* cl, oop containing_obj, T* p, oop obj, VerifyOption vo) : Checker<T>(cl, containing_obj, p, obj) {
LiveChecker(G1VerifyFailureCounter* failures, oop containing_obj, T* p, oop obj, VerifyOption vo)
: Checker<T>(failures, containing_obj, p, obj) {
_vo = vo;
_is_in_heap = this->_g1h->is_in(obj);
}
Expand All @@ -532,7 +551,7 @@ class G1VerifyLiveAndRemSetClosure : public BasicOopIterateClosure {

MutexLocker x(G1RareEvent_lock, Mutex::_no_safepoint_check_flag);

if (this->_cl->record_failure()) {
if (this->record_failure()) {
log.error("----------");
}

Expand All @@ -558,7 +577,8 @@ class G1VerifyLiveAndRemSetClosure : public BasicOopIterateClosure {
CardValue _cv_obj;
CardValue _cv_field;

RemSetChecker(G1VerifyLiveAndRemSetClosure* cl, oop containing_obj, T* p, oop obj) : Checker<T>(cl, containing_obj, p, obj) {
RemSetChecker(G1VerifyFailureCounter* failures, oop containing_obj, T* p, oop obj)
: Checker<T>(failures, containing_obj, p, obj) {
_from = this->_g1h->heap_region_containing(p);
_to = this->_g1h->heap_region_containing(obj);

Expand All @@ -585,7 +605,7 @@ class G1VerifyLiveAndRemSetClosure : public BasicOopIterateClosure {

MutexLocker x(G1RareEvent_lock, Mutex::_no_safepoint_check_flag);

if (this->_cl->record_failure()) {
if (this->record_failure()) {
log.error("----------");
}
log.error("Missing rem set entry:");
Expand All @@ -598,9 +618,7 @@ class G1VerifyLiveAndRemSetClosure : public BasicOopIterateClosure {

template <class T>
void do_oop_work(T* p) {
assert(_containing_obj != nullptr, "must be");

if (num_failures() >= G1MaxVerifyFailures) {
if (_failures->count() >= G1MaxVerifyFailures) {
return;
}

Expand All @@ -610,31 +628,24 @@ class G1VerifyLiveAndRemSetClosure : public BasicOopIterateClosure {
}
oop obj = CompressedOops::decode_raw_not_null(heap_oop);

LiveChecker<T> live_check(this, _containing_obj, p, obj, _vo);
LiveChecker<T> live_check(_failures, _containing_obj, p, obj, _vo);
if (live_check.failed()) {
live_check.report_error();
// There is no point in doing remset verification if the reference is bad.
return;
}

RemSetChecker<T> remset_check(this, _containing_obj, p, obj);
RemSetChecker<T> remset_check(_failures, _containing_obj, p, obj);
if (remset_check.failed()) {
remset_check.report_error();
}
}

public:
G1VerifyLiveAndRemSetClosure(G1CollectedHeap* g1h, VerifyOption vo) :
_vo(vo),
_containing_obj(nullptr),
_num_failures(0) { }

void set_containing_obj(oop const obj) {
assert(!G1CollectedHeap::heap()->is_obj_dead_cond(obj, _vo), "Precondition");
_containing_obj = obj;
}

size_t num_failures() const { return _num_failures; }
G1VerifyLiveAndRemSetClosure(oop containing_obj, VerifyOption vo, G1VerifyFailureCounter* failures)
: _vo(vo),
_containing_obj(containing_obj),
_failures(failures) {}

virtual inline void do_oop(narrowOop* p) { do_oop_work(p); }
virtual inline void do_oop(oop* p) { do_oop_work(p); }
Expand All @@ -643,9 +654,7 @@ class G1VerifyLiveAndRemSetClosure : public BasicOopIterateClosure {
bool HeapRegion::verify_liveness_and_remset(VerifyOption vo) const {
G1CollectedHeap* g1h = G1CollectedHeap::heap();

G1VerifyLiveAndRemSetClosure cl(g1h, vo);

size_t other_failures = 0;
G1VerifyFailureCounter failures;

HeapWord* p;
for (p = bottom(); p < top(); p += block_size(p)) {
Expand All @@ -656,13 +665,13 @@ bool HeapRegion::verify_liveness_and_remset(VerifyOption vo) const {
}

if (is_oop_safe(obj)) {
cl.set_containing_obj(obj);
G1VerifyLiveAndRemSetClosure cl(obj, vo, &failures);
obj->oop_iterate(&cl);
} else {
other_failures++;
failures.record_failure();
}

if ((cl.num_failures() + other_failures) >= G1MaxVerifyFailures) {
if (failures.count() >= G1MaxVerifyFailures) {
return true;
}
}
Expand All @@ -672,7 +681,7 @@ bool HeapRegion::verify_liveness_and_remset(VerifyOption vo) const {
p2i(p), p2i(top()));
return true;
}
return (cl.num_failures() + other_failures) != 0;
return failures.count() != 0;
}

bool HeapRegion::verify(VerifyOption vo) const {
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