1 /*
2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2018, SAP.
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 */
24
25 #include "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "memory/metaspace.hpp"
28 #include "runtime/mutex.hpp"
29 #include "runtime/os.hpp"
30 #include "utilities/align.hpp"
31 #include "utilities/debug.hpp"
32 #include "utilities/globalDefinitions.hpp"
33 #include "utilities/ostream.hpp"
34 #include "unittest.hpp"
35
36 #define NUM_PARALLEL_METASPACES 50
37 #define MAX_PER_METASPACE_ALLOCATION_WORDSIZE (512 * K)
38
39 //#define DEBUG_VERBOSE true
40
41 #ifdef DEBUG_VERBOSE
42
43 struct chunkmanager_statistics_t {
44 int num_specialized_chunks;
45 int num_small_chunks;
46 int num_medium_chunks;
47 int num_humongous_chunks;
48 };
49
50 extern void test_metaspace_retrieve_chunkmanager_statistics(Metaspace::MetadataType mdType, chunkmanager_statistics_t* out);
51
52 static void print_chunkmanager_statistics(outputStream* st, Metaspace::MetadataType mdType) {
53 chunkmanager_statistics_t stat;
54 test_metaspace_retrieve_chunkmanager_statistics(mdType, &stat);
55 st->print_cr("free chunks: %d / %d / %d / %d", stat.num_specialized_chunks, stat.num_small_chunks,
56 stat.num_medium_chunks, stat.num_humongous_chunks);
57 }
58
59 #endif
60
61 struct chunk_geometry_t {
62 size_t specialized_chunk_word_size;
63 size_t small_chunk_word_size;
64 size_t medium_chunk_word_size;
65 };
66
67 extern void test_metaspace_retrieve_chunk_geometry(Metaspace::MetadataType mdType, chunk_geometry_t* out);
68
69
70 class MetaspaceAllocationTest : public ::testing::Test {
71 protected:
72
73 struct {
74 size_t allocated;
75 Mutex* lock;
76 ClassLoaderMetaspace* space;
77 bool is_empty() const { return allocated == 0; }
78 bool is_full() const { return allocated >= MAX_PER_METASPACE_ALLOCATION_WORDSIZE; }
79 } _spaces[NUM_PARALLEL_METASPACES];
80
81 chunk_geometry_t _chunk_geometry;
82
83 virtual void SetUp() {
84 ::memset(_spaces, 0, sizeof(_spaces));
85 test_metaspace_retrieve_chunk_geometry(Metaspace::NonClassType, &_chunk_geometry);
86 }
87
88 virtual void TearDown() {
89 for (int i = 0; i < NUM_PARALLEL_METASPACES; i ++) {
90 if (_spaces[i].space != NULL) {
91 delete _spaces[i].space;
92 delete _spaces[i].lock;
93 }
94 }
95 }
96
97 void create_space(int i) {
98 assert(i >= 0 && i < NUM_PARALLEL_METASPACES, "Sanity");
99 assert(_spaces[i].space == NULL && _spaces[i].allocated == 0, "Sanity");
100 if (_spaces[i].lock == NULL) {
101 _spaces[i].lock = new Mutex(Monitor::native, "gtest-MetaspaceAllocationTest-lock", false, Monitor::_safepoint_check_never);
102 ASSERT_TRUE(_spaces[i].lock != NULL);
103 }
104 // Let every ~10th space be an anonymous one to test different allocation patterns.
105 const Metaspace::MetaspaceType msType = (os::random() % 100 < 10) ?
106 Metaspace::AnonymousMetaspaceType : Metaspace::StandardMetaspaceType;
107 {
108 // Pull lock during space creation, since this is what happens in the VM too
109 // (see ClassLoaderData::metaspace_non_null(), which we mimick here).
110 MutexLockerEx ml(_spaces[i].lock, Mutex::_no_safepoint_check_flag);
111 _spaces[i].space = new ClassLoaderMetaspace(_spaces[i].lock, msType);
112 }
113 _spaces[i].allocated = 0;
114 ASSERT_TRUE(_spaces[i].space != NULL);
115 }
116
117 // Returns the index of a random space where index is [0..metaspaces) and which is
118 // empty, non-empty or full.
119 // Returns -1 if no matching space exists.
120 enum fillgrade { fg_empty, fg_non_empty, fg_full };
121 int get_random_matching_space(int metaspaces, fillgrade fg) {
122 const int start_index = os::random() % metaspaces;
123 int i = start_index;
124 do {
125 if (fg == fg_empty && _spaces[i].is_empty()) {
126 return i;
127 } else if ((fg == fg_full && _spaces[i].is_full()) ||
128 (fg == fg_non_empty && !_spaces[i].is_full() && !_spaces[i].is_empty())) {
129 return i;
130 }
131 i ++;
132 if (i == metaspaces) {
133 i = 0;
134 }
135 } while (i != start_index);
136 return -1;
137 }
138
139 int get_random_emtpy_space(int metaspaces) { return get_random_matching_space(metaspaces, fg_empty); }
140 int get_random_non_emtpy_space(int metaspaces) { return get_random_matching_space(metaspaces, fg_non_empty); }
141 int get_random_full_space(int metaspaces) { return get_random_matching_space(metaspaces, fg_full); }
142
143 void do_test(Metaspace::MetadataType mdType, int metaspaces, int phases, int allocs_per_phase,
144 float probability_for_large_allocations // 0.0-1.0
145 ) {
146 // Alternate between breathing in (allocating n blocks for a random Metaspace) and
147 // breathing out (deleting a random Metaspace). The intent is to stress the coalescation
148 // and splitting of free chunks.
149 int phases_done = 0;
150 bool allocating = true;
151 while (phases_done < phases) {
152 bool force_switch = false;
153 if (allocating) {
154 // Allocate space from metaspace, with a preference for completely empty spaces. This
155 // should provide a good mixture of metaspaces in the virtual space.
156 int index = get_random_emtpy_space(metaspaces);
157 if (index == -1) {
158 index = get_random_non_emtpy_space(metaspaces);
159 }
160 if (index == -1) {
161 // All spaces are full, switch to freeing.
162 force_switch = true;
163 } else {
164 // create space if it does not yet exist.
165 if (_spaces[index].space == NULL) {
166 create_space(index);
167 }
168 // Allocate a bunch of blocks from it. Mostly small stuff but mix in large allocations
169 // to force humongous chunk allocations.
170 int allocs_done = 0;
171 while (allocs_done < allocs_per_phase && !_spaces[index].is_full()) {
172 size_t size = 0;
173 int r = os::random() % 1000;
174 if ((float)r < probability_for_large_allocations * 1000.0) {
175 size = (os::random() % _chunk_geometry.medium_chunk_word_size) + _chunk_geometry.medium_chunk_word_size;
176 } else {
177 size = os::random() % 64;
178 }
179 // Note: In contrast to space creation, no need to lock here. ClassLoaderMetaspace::allocate() will lock itself.
180 MetaWord* const p = _spaces[index].space->allocate(size, mdType);
181 if (p == NULL) {
182 // We very probably did hit the metaspace "until-gc" limit.
183 #ifdef DEBUG_VERBOSE
184 tty->print_cr("OOM for " SIZE_FORMAT " words. ", size);
185 #endif
186 // Just switch to deallocation and resume tests.
187 force_switch = true;
188 break;
189 } else {
190 _spaces[index].allocated += size;
191 allocs_done ++;
192 }
193 }
194 }
195 } else {
196 // freeing: find a metaspace and delete it, with preference for completely filled spaces.
197 int index = get_random_full_space(metaspaces);
198 if (index == -1) {
199 index = get_random_non_emtpy_space(metaspaces);
200 }
201 if (index == -1) {
202 force_switch = true;
203 } else {
204 assert(_spaces[index].space != NULL && _spaces[index].allocated > 0, "Sanity");
205 // Note: do not lock here. In the "wild" (the VM), we do not so either (see ~ClassLoaderData()).
206 delete _spaces[index].space;
207 _spaces[index].space = NULL;
208 _spaces[index].allocated = 0;
209 }
210 }
211
212 if (force_switch) {
213 allocating = !allocating;
214 } else {
215 // periodically switch between allocating and freeing, but prefer allocation because
216 // we want to intermingle allocations of multiple metaspaces.
217 allocating = os::random() % 5 < 4;
218 }
219 phases_done ++;
220 #ifdef DEBUG_VERBOSE
221 int metaspaces_in_use = 0;
222 size_t total_allocated = 0;
223 for (int i = 0; i < metaspaces; i ++) {
224 if (_spaces[i].allocated > 0) {
225 total_allocated += _spaces[i].allocated;
226 metaspaces_in_use ++;
227 }
228 }
229 tty->print("%u:\tspaces: %d total words: " SIZE_FORMAT "\t\t\t", phases_done, metaspaces_in_use, total_allocated);
230 print_chunkmanager_statistics(tty, mdType);
231 #endif
232 }
233 #ifdef DEBUG_VERBOSE
234 tty->print_cr("Test finished. ");
235 MetaspaceUtils::print_metaspace_map(tty, mdType);
236 print_chunkmanager_statistics(tty, mdType);
237 #endif
238 }
239 };
240
241
242
243 TEST_F(MetaspaceAllocationTest, chunk_geometry) {
244 ASSERT_GT(_chunk_geometry.specialized_chunk_word_size, (size_t) 0);
245 ASSERT_GT(_chunk_geometry.small_chunk_word_size, _chunk_geometry.specialized_chunk_word_size);
246 ASSERT_EQ(_chunk_geometry.small_chunk_word_size % _chunk_geometry.specialized_chunk_word_size, (size_t)0);
247 ASSERT_GT(_chunk_geometry.medium_chunk_word_size, _chunk_geometry.small_chunk_word_size);
248 ASSERT_EQ(_chunk_geometry.medium_chunk_word_size % _chunk_geometry.small_chunk_word_size, (size_t)0);
249 }
250
251
252 TEST_VM_F(MetaspaceAllocationTest, single_space_nonclass) {
253 do_test(Metaspace::NonClassType, 1, 1000, 100, 0);
254 }
255
256 TEST_VM_F(MetaspaceAllocationTest, single_space_class) {
257 do_test(Metaspace::ClassType, 1, 1000, 100, 0);
258 }
259
260 TEST_VM_F(MetaspaceAllocationTest, multi_space_nonclass) {
261 do_test(Metaspace::NonClassType, NUM_PARALLEL_METASPACES, 100, 1000, 0.0);
262 }
263
264 TEST_VM_F(MetaspaceAllocationTest, multi_space_class) {
265 do_test(Metaspace::ClassType, NUM_PARALLEL_METASPACES, 100, 1000, 0.0);
266 }
267
268 TEST_VM_F(MetaspaceAllocationTest, multi_space_nonclass_2) {
269 // many metaspaces, with humongous chunks mixed in.
270 do_test(Metaspace::NonClassType, NUM_PARALLEL_METASPACES, 100, 1000, .006f);
271 }
272