1 /*
2 * Copyright (c) 2021, Red Hat, Inc. All rights reserved.
3 * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
58 shenandoah_assert_safepoint();
59 _epoch_id++;
60 }
61
62 ShenandoahStackWatermark::ShenandoahStackWatermark(JavaThread* jt) :
63 StackWatermark(jt, StackWatermarkKind::gc, _epoch_id),
64 _heap(ShenandoahHeap::heap()),
65 _stats(),
66 _keep_alive_cl(),
67 _evac_update_oop_cl(),
68 _cb_cl() {}
69
70 OopClosure* ShenandoahStackWatermark::closure_from_context(void* context) {
71 if (context != nullptr) {
72 assert(_heap->is_concurrent_weak_root_in_progress() ||
73 _heap->is_concurrent_mark_in_progress(),
74 "Only these two phases");
75 assert(Thread::current()->is_Worker_thread(), "Unexpected thread passing in context: " PTR_FORMAT, p2i(context));
76 return reinterpret_cast<OopClosure*>(context);
77 } else {
78 if (_heap->is_concurrent_mark_in_progress()) {
79 return &_keep_alive_cl;
80 } else if (_heap->is_concurrent_weak_root_in_progress()) {
81 assert(_heap->is_evacuation_in_progress(), "Nothing to evacuate");
82 return &_evac_update_oop_cl;
83 } else {
84 ShouldNotReachHere();
85 return nullptr;
86 }
87 }
88 }
89
90 void ShenandoahStackWatermark::start_processing_impl(void* context) {
91 NoSafepointVerifier nsv;
92 ShenandoahHeap* const heap = ShenandoahHeap::heap();
93
94 // Process the non-frame part of the thread
95 if (heap->is_concurrent_mark_in_progress()) {
96 // We need to reset all TLABs because they might be below the TAMS, and we need to mark
97 // the objects in them. Do not let mutators allocate any new objects in their current TLABs.
98 // It is also a good place to resize the TLAB sizes for future allocations.
99 retire_tlab();
100
101 _jt->oops_do_no_frames(closure_from_context(context), &_cb_cl);
102 } else if (heap->is_concurrent_weak_root_in_progress()) {
103 assert(heap->is_evacuation_in_progress(), "Should not be armed");
104 // Retire the TLABs, which will force threads to reacquire their TLABs.
105 // This is needed for two reasons. Strong one: new allocations would be with new freeset,
106 // which would be outside the collection set, so no cset writes would happen there.
107 // Weaker one: new allocations would happen past update watermark, and so less work would
108 // be needed for reference updates (would update the large filler instead).
109 retire_tlab();
110
111 _jt->oops_do_no_frames(closure_from_context(context), &_cb_cl);
112 } else {
113 ShouldNotReachHere();
114 }
115
116 // Publishes the processing start to concurrent threads
117 StackWatermark::start_processing_impl(context);
118 }
119
120 void ShenandoahStackWatermark::retire_tlab() {
121 // Retire TLAB
122 if (UseTLAB) {
123 _stats.reset();
124 _jt->tlab().retire(&_stats);
125 if (ResizeTLAB) {
126 _jt->tlab().resize();
127 }
128 }
129 }
130
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1 /*
2 * Copyright (c) 2021, Red Hat, Inc. All rights reserved.
3 * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
4 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
59 shenandoah_assert_safepoint();
60 _epoch_id++;
61 }
62
63 ShenandoahStackWatermark::ShenandoahStackWatermark(JavaThread* jt) :
64 StackWatermark(jt, StackWatermarkKind::gc, _epoch_id),
65 _heap(ShenandoahHeap::heap()),
66 _stats(),
67 _keep_alive_cl(),
68 _evac_update_oop_cl(),
69 _cb_cl() {}
70
71 OopClosure* ShenandoahStackWatermark::closure_from_context(void* context) {
72 if (context != nullptr) {
73 assert(_heap->is_concurrent_weak_root_in_progress() ||
74 _heap->is_concurrent_mark_in_progress(),
75 "Only these two phases");
76 assert(Thread::current()->is_Worker_thread(), "Unexpected thread passing in context: " PTR_FORMAT, p2i(context));
77 return reinterpret_cast<OopClosure*>(context);
78 } else {
79 if (_heap->is_concurrent_weak_root_in_progress()) {
80 assert(_heap->is_evacuation_in_progress(), "Nothing to evacuate");
81 return &_evac_update_oop_cl;
82 } else if (_heap->is_concurrent_mark_in_progress()) {
83 return &_keep_alive_cl;
84 } else {
85 ShouldNotReachHere();
86 return nullptr;
87 }
88 }
89 }
90
91 void ShenandoahStackWatermark::start_processing_impl(void* context) {
92 NoSafepointVerifier nsv;
93 ShenandoahHeap* const heap = ShenandoahHeap::heap();
94
95 // Process the non-frame part of the thread
96 if (heap->is_concurrent_weak_root_in_progress()) {
97 assert(heap->is_evacuation_in_progress(), "Should not be armed");
98 // Retire the TLABs, which will force threads to reacquire their TLABs.
99 // This is needed for two reasons. Strong one: new allocations would be with new freeset,
100 // which would be outside the collection set, so no cset writes would happen there.
101 // Weaker one: new allocations would happen past update watermark, and so less work would
102 // be needed for reference updates (would update the large filler instead).
103 retire_tlab();
104
105 _jt->oops_do_no_frames(closure_from_context(context), &_cb_cl);
106 } else if (heap->is_concurrent_mark_in_progress()) {
107 // We need to reset all TLABs because they might be below the TAMS, and we need to mark
108 // the objects in them. Do not let mutators allocate any new objects in their current TLABs.
109 // It is also a good place to resize the TLAB sizes for future allocations.
110 retire_tlab();
111
112 _jt->oops_do_no_frames(closure_from_context(context), &_cb_cl);
113 } else {
114 ShouldNotReachHere();
115 }
116
117 // Publishes the processing start to concurrent threads
118 StackWatermark::start_processing_impl(context);
119 }
120
121 void ShenandoahStackWatermark::retire_tlab() {
122 // Retire TLAB
123 if (UseTLAB) {
124 _stats.reset();
125 _jt->tlab().retire(&_stats);
126 if (ResizeTLAB) {
127 _jt->tlab().resize();
128 }
129 }
130 }
131
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