1 /*
2 * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
2132 bool G1CollectedHeap::try_collect_concurrently(GCCause::Cause cause,
2133 uint gc_counter,
2134 uint old_marking_started_before) {
2135 assert_heap_not_locked();
2136 assert(should_do_concurrent_full_gc(cause),
2137 "Non-concurrent cause %s", GCCause::to_string(cause));
2138
2139 for (uint i = 1; true; ++i) {
2140 // Try to schedule an initial-mark evacuation pause that will
2141 // start a concurrent cycle.
2142 LOG_COLLECT_CONCURRENTLY(cause, "attempt %u", i);
2143 VM_G1TryInitiateConcMark op(gc_counter,
2144 cause,
2145 policy()->max_pause_time_ms());
2146 VMThread::execute(&op);
2147
2148 // Request is trivially finished.
2149 if (cause == GCCause::_g1_periodic_collection) {
2150 LOG_COLLECT_CONCURRENTLY_COMPLETE(cause, op.gc_succeeded());
2151 return op.gc_succeeded();
2152 }
2153
2154 // Lock to get consistent set of values.
2155 uint old_marking_started_after;
2156 uint old_marking_completed_after;
2157 {
2158 MutexLocker ml(Heap_lock);
2159 // Update gc_counter for retrying VMOp if needed. Captured here to be
2160 // consistent with the values we use below for termination tests. If
2161 // a retry is needed after a possible wait, and another collection
2162 // occurs in the meantime, it will cause our retry to be skipped and
2163 // we'll recheck for termination with updated conditions from that
2164 // more recent collection. That's what we want, rather than having
2165 // our retry possibly perform an unnecessary collection.
2166 gc_counter = total_collections();
2167 old_marking_started_after = _old_marking_cycles_started;
2168 old_marking_completed_after = _old_marking_cycles_completed;
2169 }
2170
2171 if (!GCCause::is_user_requested_gc(cause)) {
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1 /*
2 * Copyright (c) 2001, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
2132 bool G1CollectedHeap::try_collect_concurrently(GCCause::Cause cause,
2133 uint gc_counter,
2134 uint old_marking_started_before) {
2135 assert_heap_not_locked();
2136 assert(should_do_concurrent_full_gc(cause),
2137 "Non-concurrent cause %s", GCCause::to_string(cause));
2138
2139 for (uint i = 1; true; ++i) {
2140 // Try to schedule an initial-mark evacuation pause that will
2141 // start a concurrent cycle.
2142 LOG_COLLECT_CONCURRENTLY(cause, "attempt %u", i);
2143 VM_G1TryInitiateConcMark op(gc_counter,
2144 cause,
2145 policy()->max_pause_time_ms());
2146 VMThread::execute(&op);
2147
2148 // Request is trivially finished.
2149 if (cause == GCCause::_g1_periodic_collection) {
2150 LOG_COLLECT_CONCURRENTLY_COMPLETE(cause, op.gc_succeeded());
2151 return op.gc_succeeded();
2152 }
2153
2154 // If VMOp skipped initiating concurrent marking cycle because
2155 // we're terminating, then we're done.
2156 if (op.terminating()) {
2157 LOG_COLLECT_CONCURRENTLY(cause, "skipped: terminating");
2158 return false;
2159 }
2160
2161 // Lock to get consistent set of values.
2162 uint old_marking_started_after;
2163 uint old_marking_completed_after;
2164 {
2165 MutexLocker ml(Heap_lock);
2166 // Update gc_counter for retrying VMOp if needed. Captured here to be
2167 // consistent with the values we use below for termination tests. If
2168 // a retry is needed after a possible wait, and another collection
2169 // occurs in the meantime, it will cause our retry to be skipped and
2170 // we'll recheck for termination with updated conditions from that
2171 // more recent collection. That's what we want, rather than having
2172 // our retry possibly perform an unnecessary collection.
2173 gc_counter = total_collections();
2174 old_marking_started_after = _old_marking_cycles_started;
2175 old_marking_completed_after = _old_marking_cycles_completed;
2176 }
2177
2178 if (!GCCause::is_user_requested_gc(cause)) {
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