jdk-sandbox: comparison src/hotspot/share/gc/shenandoah/shenandoahNMethod.cpp

equal deleted inserted replaced

-:8b6cc0bb93d0
+:9186be5c78ba
+/*
+* Copyright (c) 2019, Red Hat, Inc. All rights reserved.
+*
+* This code is free software; you can redistribute it and/or modify it
+* under the terms of the GNU General Public License version 2 only, as
+* published by the Free Software Foundation.
+*
+* This code is distributed in the hope that it will be useful, but WITHOUT
+* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+* version 2 for more details (a copy is included in the LICENSE file that
+* accompanied this code).
+*
+* You should have received a copy of the GNU General Public License version
+* 2 along with this work; if not, write to the Free Software Foundation,
+* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+*
+* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+* or visit www.oracle.com if you need additional information or have any
+* questions.
+*
+*/
+#include "precompiled.hpp"
+#include "gc/shenandoah/shenandoahClosures.inline.hpp"
+#include "gc/shenandoah/shenandoahConcurrentRoots.hpp"
+#include "gc/shenandoah/shenandoahHeap.inline.hpp"
+#include "gc/shenandoah/shenandoahNMethod.inline.hpp"
+#include "memory/resourceArea.hpp"
+ShenandoahNMethod::ShenandoahNMethod(nmethod* nm, GrowableArray<oop*>& oops, bool non_immediate_oops) :
+_nm(nm), _oops(NULL), _oops_count(0), _unregistered(false) {
+if (!oops.is_empty()) {
+_oops_count = oops.length();
+_oops = NEW_C_HEAP_ARRAY(oop*, _oops_count, mtGC);
+for (int c = 0; c < _oops_count; c++) {
+_oops[c] = oops.at(c);
+}
+}
+_has_non_immed_oops = non_immediate_oops;
+assert_same_oops();
+}
+ShenandoahNMethod::~ShenandoahNMethod() {
+if (_oops != NULL) {
+FREE_C_HEAP_ARRAY(oop*, _oops);
+}
+}
+class ShenandoahHasCSetOopClosure : public OopClosure {
+private:
+ShenandoahHeap* const _heap;
+bool                  _has_cset_oops;
+public:
+ShenandoahHasCSetOopClosure() :
+_heap(ShenandoahHeap::heap()),
+_has_cset_oops(false) {
+}
+bool has_cset_oops() const {
+return _has_cset_oops;
+}
+void do_oop(oop* p) {
+oop value = RawAccess<>::oop_load(p);
+if (!_has_cset_oops && _heap->in_collection_set(value)) {
+_has_cset_oops = true;
+}
+}
+void do_oop(narrowOop* p) {
+ShouldNotReachHere();
+}
+};
+bool ShenandoahNMethod::has_cset_oops(ShenandoahHeap *heap) {
+ShenandoahHasCSetOopClosure cl;
+oops_do(&cl);
+return cl.has_cset_oops();
+}
+void ShenandoahNMethod::update() {
+ResourceMark rm;
+bool non_immediate_oops = false;
+GrowableArray<oop*> oops;
+detect_reloc_oops(nm(), oops, non_immediate_oops);
+if (oops.length() != _oops_count) {
+if (_oops != NULL) {
+FREE_C_HEAP_ARRAY(oop*, _oops);
+_oops = NULL;
+}
+_oops_count = oops.length();
+if (_oops_count > 0) {
+_oops = NEW_C_HEAP_ARRAY(oop*, _oops_count, mtGC);
+}
+}
+for (int index = 0; index < _oops_count; index ++) {
+_oops[index] = oops.at(index);
+}
+_has_non_immed_oops = non_immediate_oops;
+assert_same_oops();
+}
+void ShenandoahNMethod::oops_do(OopClosure* oops, bool fix_relocations) {
+for (int c = 0; c < _oops_count; c ++) {
+oops->do_oop(_oops[c]);
+}
+oop* const begin = _nm->oops_begin();
+oop* const end = _nm->oops_end();
+for (oop* p = begin; p < end; p++) {
+if (*p != Universe::non_oop_word()) {
+oops->do_oop(p);
+}
+}
+if (fix_relocations && _has_non_immed_oops) {
+_nm->fix_oop_relocations();
+}
+}
+void ShenandoahNMethod::detect_reloc_oops(nmethod* nm, GrowableArray<oop*>& oops, bool& has_non_immed_oops) {
+has_non_immed_oops = false;
+// Find all oops relocations
+RelocIterator iter(nm);
+while (iter.next()) {
+if (iter.type() != relocInfo::oop_type) {
+// Not an oop
+continue;
+}
+oop_Relocation* r = iter.oop_reloc();
+if (!r->oop_is_immediate()) {
+// Non-immediate oop found
+has_non_immed_oops = true;
+continue;
+}
+if (r->oop_value() != NULL) {
+// Non-NULL immediate oop found. NULL oops can safely be
+// ignored since the method will be re-registered if they
+// are later patched to be non-NULL.
+oops.push(r->oop_addr());
+}
+}
+}
+ShenandoahNMethod* ShenandoahNMethod::for_nmethod(nmethod* nm) {
+ResourceMark rm;
+bool non_immediate_oops = false;
+GrowableArray<oop*> oops;
+detect_reloc_oops(nm, oops, non_immediate_oops);
+// No embedded oops
+if(!ShenandoahConcurrentRoots::can_do_concurrent_class_unloading() &&
+oops.is_empty() && nm->oops_begin() >= nm->oops_end()) {
+return NULL;
+}
+return new ShenandoahNMethod(nm, oops, non_immediate_oops);
+}
+void ShenandoahNMethod::heal_nmethod(nmethod* nm) {
+ShenandoahNMethod* data = gc_data(nm);
+assert(data != NULL, "Sanity");
+assert(data->lock()->owned_by_self(), "Must hold the lock");
+ShenandoahEvacuateUpdateRootsClosure cl;
+data->oops_do(&cl, true /*fix relocation*/);
+}
+#ifdef ASSERT
+void ShenandoahNMethod::assert_alive_and_correct() {
+assert(_nm->is_alive(), "only alive nmethods here");
+ShenandoahHeap* heap = ShenandoahHeap::heap();
+for (int c = 0; c < _oops_count; c++) {
+oop *loc = _oops[c];
+assert(_nm->code_contains((address) loc) || _nm->oops_contains(loc), "nmethod should contain the oop*");
+oop o = RawAccess<>::oop_load(loc);
+shenandoah_assert_correct_except(loc, o, o == NULL || heap->is_full_gc_move_in_progress());
+}
+oop* const begin = _nm->oops_begin();
+oop* const end = _nm->oops_end();
+for (oop* p = begin; p < end; p++) {
+if (*p != Universe::non_oop_word()) {
+oop o = RawAccess<>::oop_load(p);
+shenandoah_assert_correct_except(p, o, o == NULL || heap->is_full_gc_move_in_progress());
+}
+}
+}
+class ShenandoahNMethodOopDetector : public OopClosure {
+private:
+ResourceMark rm; // For growable array allocation below.
+GrowableArray<oop*> _oops;
+public:
+ShenandoahNMethodOopDetector() : _oops(10) {};
+void do_oop(oop* o) {
+_oops.append(o);
+}
+void do_oop(narrowOop* o) {
+fatal("NMethods should not have compressed oops embedded.");
+}
+GrowableArray<oop*>* oops() {
+return &_oops;
+}
+bool has_oops() {
+return !_oops.is_empty();
+}
+};
+void ShenandoahNMethod::assert_same_oops(bool allow_dead) {
+ShenandoahNMethodOopDetector detector;
+nm()->oops_do(&detector, allow_dead);
+GrowableArray<oop*>* oops = detector.oops();
+assert(oops->length() == oop_count(), "Must match");
+for (int index = 0; index < _oops_count; index ++) {
+assert(oops->contains(_oops[index]), "Must contain this oop");
+}
+for (oop* p = nm()->oops_begin(); p < nm()->oops_end(); p ++) {
+assert(oops->contains(p), "Must contain this oop");
+}
+}
+void ShenandoahNMethod::assert_no_oops(nmethod* nm, bool allow_dead) {
+ShenandoahNMethodOopDetector detector;
+nm->oops_do(&detector, allow_dead);
+assert(detector.oops()->length() == 0, "Should not have oops");
+}
+#endif
+ShenandoahNMethodTable::ShenandoahNMethodTable() :
+_heap(ShenandoahHeap::heap()),
+_size(minSize),
+_index(0),
+_iteration_in_progress(false) {
+_array = NEW_C_HEAP_ARRAY(ShenandoahNMethod*, _size, mtGC);
+}
+ShenandoahNMethodTable::~ShenandoahNMethodTable() {
+assert(_array != NULL, "Sanity");
+FREE_C_HEAP_ARRAY(ShenandoahNMethod*, _array);
+}
+void ShenandoahNMethodTable::register_nmethod(nmethod* nm) {
+assert(CodeCache_lock->owned_by_self(), "Must have CodeCache_lock held");
+assert(_index >= 0 && _index <= _size, "Sanity");
+ShenandoahNMethod* data = ShenandoahNMethod::gc_data(nm);
+ShenandoahReentrantLocker data_locker(data != NULL ? data->lock() : NULL);
+if (data != NULL) {
+assert(contain(nm), "Must have been registered");
+data->update();
+} else {
+data = ShenandoahNMethod::for_nmethod(nm);
+if (data == NULL) {
+assert(!ShenandoahConcurrentRoots::can_do_concurrent_class_unloading(),
+"Only possible when concurrent class unloading is off");
+return;
+}
+ShenandoahNMethod::attach_gc_data(nm, data);
+ShenandoahLocker locker(&_lock);
+log_register_nmethod(nm);
+append(data);
+}
+// Disarm new nmethod
+ShenandoahNMethod::disarm_nmethod(nm);
+}
+void ShenandoahNMethodTable::unregister_nmethod(nmethod* nm) {
+assert_locked_or_safepoint(CodeCache_lock);
+ShenandoahNMethod* data = ShenandoahNMethod::gc_data(nm);
+if (data == NULL) {
+assert(!ShenandoahConcurrentRoots::can_do_concurrent_class_unloading(),
+"Only possible when concurrent class unloading is off");
+ShenandoahNMethod::assert_no_oops(nm, true /*allow_dead*/);
+return;
+}
+if (Thread::current()->is_Code_cache_sweeper_thread()) {
+wait_until_concurrent_iteration_done();
+}
+log_unregister_nmethod(nm);
+ShenandoahLocker locker(&_lock);
+assert(contain(nm), "Must have been registered");
+ShenandoahReentrantLocker data_locker(data->lock());
+data->mark_unregistered();
+}
+void ShenandoahNMethodTable::flush_nmethod(nmethod* nm) {
+assert(CodeCache_lock->owned_by_self(), "Must have CodeCache_lock held");
+assert(Thread::current()->is_Code_cache_sweeper_thread(), "Must from Sweep thread");
+ShenandoahNMethod* data = ShenandoahNMethod::gc_data(nm);
+assert(data != NULL || !ShenandoahConcurrentRoots::can_do_concurrent_class_unloading(),
+"Only possible when concurrent class unloading is off");
+if (data == NULL) {
+ShenandoahNMethod::assert_no_oops(nm, true /*allow_dead*/);
+return;
+}
+// Can not alter the array when iteration is in progress
+wait_until_concurrent_iteration_done();
+log_flush_nmethod(nm);
+ShenandoahLocker locker(&_lock);
+int idx = index_of(nm);
+assert(idx >= 0 && idx < _index, "Invalid index");
+ShenandoahNMethod::attach_gc_data(nm, NULL);
+remove(idx);
+}
+bool ShenandoahNMethodTable::contain(nmethod* nm) const {
+return index_of(nm) != -1;
+}
+ShenandoahNMethod* ShenandoahNMethodTable::at(int index) const {
+assert(index >= 0 && index < _index, "Out of bound");
+return _array[index];
+}
+int ShenandoahNMethodTable::index_of(nmethod* nm) const {
+for (int index = 0; index < length(); index ++) {
+if (_array[index]->nm() == nm) {
+return index;
+}
+}
+return -1;
+}
+void ShenandoahNMethodTable::remove(int idx) {
+shenandoah_assert_locked_or_safepoint(CodeCache_lock);
+assert(!_iteration_in_progress, "Can not happen");
+assert(_index >= 0 && _index <= _size, "Sanity");
+assert(idx >= 0 && idx < _index, "Out of bound");
+ShenandoahNMethod* snm = _array[idx];
+_index --;
+_array[idx] = _array[_index];
+delete snm;
+}
+void ShenandoahNMethodTable::wait_until_concurrent_iteration_done() {
+assert(CodeCache_lock->owned_by_self(), "Lock must be held");
+while (iteration_in_progress()) {
+CodeCache_lock->wait_without_safepoint_check();
+}
+}
+void ShenandoahNMethodTable::append(ShenandoahNMethod* snm) {
+if (is_full()) {
+int new_size = 2 * _size;
+ShenandoahNMethod** old_table = _array;
+// Rebuild table and replace current one
+rebuild(new_size);
+// An iteration is in progress over early snapshot,
+// can not release the array until iteration is completed
+if (!iteration_in_progress()) {
+FREE_C_HEAP_ARRAY(ShenandoahNMethod*, old_table);
+}
+}
+_array[_index ++] = snm;
+assert(_index >= 0 && _index <= _size, "Sanity");
+}
+void ShenandoahNMethodTable::rebuild(int size) {
+ShenandoahNMethod** arr = NEW_C_HEAP_ARRAY(ShenandoahNMethod*, size, mtGC);
+for (int index = 0; index < _index; index ++) {
+arr[index] = _array[index];
+}
+_array = arr;
+_size = size;
+}
+ShenandoahNMethodTableSnapshot* ShenandoahNMethodTable::snapshot_for_iteration() {
+assert(!iteration_in_progress(), "Already in progress");
+_iteration_in_progress = true;
+return new ShenandoahNMethodTableSnapshot(this);
+}
+void ShenandoahNMethodTable::finish_iteration(ShenandoahNMethodTableSnapshot* snapshot) {
+assert(iteration_in_progress(), "Why we here?");
+assert(snapshot != NULL, "No snapshot");
+_iteration_in_progress = false;
+// Table has been rebuilt during iteration, free old table
+if (snapshot->_array != _array) {
+FREE_C_HEAP_ARRAY(ShenandoahNMethod*, snapshot->_array);
+}
+delete snapshot;
+}
+void ShenandoahNMethodTable::log_register_nmethod(nmethod* nm) {
+LogTarget(Debug, gc, nmethod) log;
+if (!log.is_enabled()) {
+return;
+}
+ResourceMark rm;
+log.print("Register NMethod: %s.%s [" PTR_FORMAT "] (%s)",
+nm->method()->method_holder()->external_name(),
+nm->method()->name()->as_C_string(),
+p2i(nm),
+nm->compiler_name());
+}
+void ShenandoahNMethodTable::log_unregister_nmethod(nmethod* nm) {
+LogTarget(Debug, gc, nmethod) log;
+if (!log.is_enabled()) {
+return;
+}
+ResourceMark rm;
+log.print("Unregister NMethod: %s.%s [" PTR_FORMAT "]",
+nm->method()->method_holder()->external_name(),
+nm->method()->name()->as_C_string(),
+p2i(nm));
+}
+void ShenandoahNMethodTable::log_flush_nmethod(nmethod* nm) {
+LogTarget(Debug, gc, nmethod) log;
+if (!log.is_enabled()) {
+return;
+}
+ResourceMark rm;
+log.print("Flush NMethod: (" PTR_FORMAT ")", p2i(nm));
+}
+#ifdef ASSERT
+void ShenandoahNMethodTable::assert_nmethods_alive_and_correct() {
+assert_locked_or_safepoint(CodeCache_lock);
+for (int index = 0; index < length(); index ++) {
+ShenandoahNMethod* m = _array[index];
+// Concurrent unloading may have dead nmethods to be cleaned by sweeper
+if (m->is_unregistered()) continue;
+m->assert_alive_and_correct();
+}
+}
+#endif
+ShenandoahNMethodTableSnapshot::ShenandoahNMethodTableSnapshot(ShenandoahNMethodTable* table) :
+_heap(ShenandoahHeap::heap()), _table(table), _array(table->_array), _length(table->_index), _claimed(0) {
+}
+void ShenandoahNMethodTableSnapshot::concurrent_nmethods_do(NMethodClosure* cl) {
+size_t stride = 256; // educated guess
+ShenandoahNMethod** list = _array;
+size_t max = (size_t)_length;
+while (_claimed < max) {
+size_t cur = Atomic::add(&_claimed, stride) - stride;
+size_t start = cur;
+size_t end = MIN2(cur + stride, max);
+if (start >= max) break;
+for (size_t idx = start; idx < end; idx++) {
+ShenandoahNMethod* data = list[idx];
+assert(data != NULL, "Should not be NULL");
+if (!data->is_unregistered()) {
+cl->do_nmethod(data->nm());
+}
+}
+}
+}
+ShenandoahConcurrentNMethodIterator::ShenandoahConcurrentNMethodIterator(ShenandoahNMethodTable* table) :
+_table(table), _table_snapshot(NULL) {
+}
+void ShenandoahConcurrentNMethodIterator::nmethods_do_begin() {
+assert(CodeCache_lock->owned_by_self(), "Lock must be held");
+assert(ShenandoahConcurrentRoots::can_do_concurrent_class_unloading(),
+"Only for concurrent class unloading");
+_table_snapshot = _table->snapshot_for_iteration();
+}
+void ShenandoahConcurrentNMethodIterator::nmethods_do(NMethodClosure* cl) {
+assert(_table_snapshot != NULL, "Must first call nmethod_do_begin()");
+_table_snapshot->concurrent_nmethods_do(cl);
+}
+void ShenandoahConcurrentNMethodIterator::nmethods_do_end() {
+assert(CodeCache_lock->owned_by_self(), "Lock must be held");
+assert(ShenandoahConcurrentRoots::can_do_concurrent_class_unloading(),
+"Only for concurrent class unloading");
+_table->finish_iteration(_table_snapshot);
+CodeCache_lock->notify_all();
+}