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| 1 | +/* |
| 2 | + * Copyright 2025 VMware, Inc. |
| 3 | + * |
| 4 | + * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | + * you may not use this file except in compliance with the License. |
| 6 | + * You may obtain a copy of the License at |
| 7 | + * |
| 8 | + * https://www.apache.org/licenses/LICENSE-2.0 |
| 9 | + * |
| 10 | + * Unless required by applicable law or agreed to in writing, software |
| 11 | + * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | + * See the License for the specific language governing permissions and |
| 14 | + * limitations under the License. |
| 15 | + */ |
| 16 | +package io.micrometer.benchmark; |
| 17 | + |
| 18 | +import io.micrometer.common.lang.Nullable; |
| 19 | +import org.openjdk.jmh.annotations.Mode; |
| 20 | +import org.openjdk.jmh.profile.GCProfiler; |
| 21 | +import org.openjdk.jmh.profile.LinuxPerfAsmProfiler; |
| 22 | +import org.openjdk.jmh.profile.LinuxPerfNormProfiler; |
| 23 | +import org.openjdk.jmh.runner.Runner; |
| 24 | +import org.openjdk.jmh.runner.RunnerException; |
| 25 | +import org.openjdk.jmh.runner.options.ChainedOptionsBuilder; |
| 26 | +import org.openjdk.jmh.runner.options.Options; |
| 27 | +import org.openjdk.jmh.runner.options.OptionsBuilder; |
| 28 | +import org.openjdk.jmh.runner.options.TimeValue; |
| 29 | + |
| 30 | +import java.util.Arrays; |
| 31 | +import java.util.BitSet; |
| 32 | +import java.util.Locale; |
| 33 | +import java.util.Random; |
| 34 | +import java.util.concurrent.TimeUnit; |
| 35 | + |
| 36 | +public class BenchmarkSupport { |
| 37 | + |
| 38 | + // Making things deterministic |
| 39 | + private static final Random RANDOM = new Random(0x5EAL); |
| 40 | + |
| 41 | + // A generic number of test instances to use. Making sure it's small |
| 42 | + // enough for L2 even for moderately sized objects, yet big enough |
| 43 | + // to confuse JIT. |
| 44 | + public static final int DEFAULT_POOL_SIZE = 1 << 12; |
| 45 | + |
| 46 | + // A bitmask that would prevent an incremented number escaping |
| 47 | + // DEFAULT_POOL_SIZE by a simple AND operation. |
| 48 | + public static final int DEFAULT_MASK = DEFAULT_POOL_SIZE - 1; |
| 49 | + |
| 50 | + // To prevent any kind of JIT assumption that a specific instance |
| 51 | + // corresponds to a specific sample (shouldn't happen, but anyway), |
| 52 | + // we need to walk them at a different rate. 2 is a bad choice, |
| 53 | + // because it will discard half of the samples, but for every |
| 54 | + // n = 2^k the value of 3 will be a divisor of either n + 1 or |
| 55 | + // 2n + 1. |
| 56 | + public static final int SAMPLE_STEP = 3; |
| 57 | + |
| 58 | + private BenchmarkSupport() { |
| 59 | + } |
| 60 | + |
| 61 | + /** |
| 62 | + * When you need to break existing patterns in an array. |
| 63 | + */ |
| 64 | + public static <T> T[] shuffle(T[] values) { |
| 65 | + for (int i = 0; i < values.length; i++) { |
| 66 | + int target = RANDOM.nextInt(values.length); |
| 67 | + T buffer = values[target]; |
| 68 | + values[target] = values[i]; |
| 69 | + values[i] = buffer; |
| 70 | + } |
| 71 | + |
| 72 | + return values; |
| 73 | + } |
| 74 | + |
| 75 | + /** |
| 76 | + * Create a bit mask with [count] of [options] bits set. A simple method to select a |
| 77 | + * combination of unique items using each bit as the presence mark for every item. |
| 78 | + * @param count Number of bits to be set. |
| 79 | + * @param options Number of all possible options. |
| 80 | + */ |
| 81 | + public static BitSet selection(int count, int options) { |
| 82 | + if (count > options) { |
| 83 | + throw new IllegalArgumentException( |
| 84 | + "Requested count " + count + " is bigger than list of available options (" + options + ")"); |
| 85 | + } |
| 86 | + |
| 87 | + if (count < 0) { |
| 88 | + throw new IllegalArgumentException( |
| 89 | + "Number of selected options must be non-negative, " + count + " provided"); |
| 90 | + } |
| 91 | + |
| 92 | + BitSet reply = new BitSet(options); |
| 93 | + |
| 94 | + if (count == options) { |
| 95 | + for (int i = 0; i < count; i++) { |
| 96 | + reply.set(i); |
| 97 | + } |
| 98 | + return reply; |
| 99 | + } |
| 100 | + |
| 101 | + for (int flag = 0; flag < count; flag++) { |
| 102 | + // with [remaining] positions left, we select a _disabled_ |
| 103 | + // bit N to install, meaning we have to pretend that all |
| 104 | + // _enabled_ bits don't exist at all. |
| 105 | + |
| 106 | + int remaining = options - flag; |
| 107 | + int next = RANDOM.nextInt(remaining); |
| 108 | + int skipped = 0; |
| 109 | + |
| 110 | + for (int bit = 0; bit < options; bit++) { |
| 111 | + if (reply.get(bit)) { |
| 112 | + skipped++; |
| 113 | + continue; |
| 114 | + } |
| 115 | + |
| 116 | + if (bit == skipped + next) { |
| 117 | + reply.set(bit); |
| 118 | + break; |
| 119 | + } |
| 120 | + } |
| 121 | + |
| 122 | + // bit can be as much as options - 1 in the previous loop, thus >= |
| 123 | + if (skipped + next >= options) { |
| 124 | + String message = String.format( |
| 125 | + "Failed to set the bit: while looking to set option #%d out of total %d, disabled bit #%d should have been enabled, however, %d bits were skipped in %s", |
| 126 | + flag, options, next, skipped, reply); |
| 127 | + throw new IllegalStateException(message); |
| 128 | + } |
| 129 | + } |
| 130 | + |
| 131 | + return reply; |
| 132 | + } |
| 133 | + |
| 134 | + public static BitSet selection(int minimum, int maximum, int options) { |
| 135 | + int count = minimum + RANDOM.nextInt(maximum - minimum + 1); |
| 136 | + return selection(count, options); |
| 137 | + } |
| 138 | + |
| 139 | + public static BitSet selection(int options) { |
| 140 | + return selection(RANDOM.nextInt(options + 1), options); |
| 141 | + } |
| 142 | + |
| 143 | + public static class ModeUniformDistribution { |
| 144 | + |
| 145 | + private ModeUniformDistribution() { |
| 146 | + } |
| 147 | + |
| 148 | + /** |
| 149 | + * <p> |
| 150 | + * A silly mock distribution to test the reaction of the code to different input |
| 151 | + * sizes. With the specified probability, the [mode] value will be returned, |
| 152 | + * otherwise a value between [minimum] and [maximum] (inclusively, but without the |
| 153 | + * mode) will be selected uniformly. |
| 154 | + * </p> |
| 155 | + * |
| 156 | + * <p> |
| 157 | + * The reason for not taking any nonsilly distribution is the generic case modeled |
| 158 | + * here, a case with a distinct mode, but without the probability of other values |
| 159 | + * falling off sharply with the distance from the mode. This allows both to see |
| 160 | + * how code reacts to the position of that mode and to confuse the JIT regarding |
| 161 | + * any assumptions (beyond mode value) and machinery like predictors. Using just a |
| 162 | + * bell-like distribution here would either shrink the mode or reduce output to |
| 163 | + * 3-5 values that would totally dominate everything else, so it requires a tight |
| 164 | + * bell mixed with a uniform distribution to blend in all possibilities. This is |
| 165 | + * exactly what this method does, with replacing the distribution by explicit |
| 166 | + * boost for a specific value to keep things less error-prone (no one ever will |
| 167 | + * plot these values or look at them in the debugger again). |
| 168 | + * </p> |
| 169 | + * @param minimum The minimum amount that can be selected, inclusive. |
| 170 | + * @param maximum The maximum amount that can be selected, inclusive. |
| 171 | + * @param mode The value that appears with increased probability. |
| 172 | + * @param probability The probability of selecting the value instead of using |
| 173 | + * uniform distribution. |
| 174 | + * @return Value that differs from uniform distribution by a more often selected |
| 175 | + * mode, according to passed probability. |
| 176 | + */ |
| 177 | + public static int sample(int minimum, int maximum, int mode, double probability) { |
| 178 | + if (mode < minimum || mode > maximum) { |
| 179 | + throw new IllegalArgumentException( |
| 180 | + "Provided mode " + mode + " isn't in the min/max interval [" + minimum + ", " + maximum + "]"); |
| 181 | + } |
| 182 | + |
| 183 | + if (RANDOM.nextDouble() < probability) { |
| 184 | + return mode; |
| 185 | + } |
| 186 | + |
| 187 | + // excluding mode here, so upper bound is maximum, not maximum + 1 |
| 188 | + int selection = minimum + RANDOM.nextInt(maximum - minimum); |
| 189 | + |
| 190 | + // compensating for absent mode |
| 191 | + if (selection >= mode) { |
| 192 | + return selection + 1; |
| 193 | + } |
| 194 | + |
| 195 | + return selection; |
| 196 | + } |
| 197 | + |
| 198 | + } |
| 199 | + |
| 200 | + public static ChainedOptionsBuilder defaults() { |
| 201 | + ChainedOptionsBuilder options = new OptionsBuilder().forks(1) |
| 202 | + // 0.5m warmups |
| 203 | + .warmupIterations(6) |
| 204 | + .warmupTime(new TimeValue(5L, TimeUnit.SECONDS)) |
| 205 | + // 9.5m benchmarks |
| 206 | + .measurementIterations(57) |
| 207 | + .measurementTime(new TimeValue(5L, TimeUnit.SECONDS)) |
| 208 | + .mode(Mode.AverageTime) |
| 209 | + .timeUnit(TimeUnit.NANOSECONDS) |
| 210 | + .shouldDoGC(true) |
| 211 | + .addProfiler(GCProfiler.class); |
| 212 | + |
| 213 | + // Please forgive me |
| 214 | + if (System.getProperty("os.name", "_fallback_").toLowerCase(Locale.ROOT).contains("linux")) { |
| 215 | + options.addProfiler(LinuxPerfAsmProfiler.class).addProfiler(LinuxPerfNormProfiler.class); |
| 216 | + } |
| 217 | + |
| 218 | + return options; |
| 219 | + } |
| 220 | + |
| 221 | + /** |
| 222 | + * Runs benchmarks in specified classes with defaults (10s iterations, 0.5m warmup, |
| 223 | + * 9.5m benchmark, GC & perf profilers). As usual, be aware that defaults might not |
| 224 | + * suit your case, use overrides when necessary. |
| 225 | + */ |
| 226 | + public static void run(String[] patterns, @Nullable ChainedOptionsBuilder override) throws RunnerException { |
| 227 | + ChainedOptionsBuilder options = defaults(); |
| 228 | + |
| 229 | + for (String pattern : patterns) { |
| 230 | + options.include(pattern); |
| 231 | + } |
| 232 | + |
| 233 | + Options defaults = options.build(); |
| 234 | + |
| 235 | + new Runner(override == null ? defaults : override.parent(defaults).build()).run(); |
| 236 | + } |
| 237 | + |
| 238 | + /** |
| 239 | + * @see #run(String[], ChainedOptionsBuilder) |
| 240 | + */ |
| 241 | + public static void run(String[] patterns) throws RunnerException { |
| 242 | + run(patterns, null); |
| 243 | + } |
| 244 | + |
| 245 | + /** |
| 246 | + * @see #run(String[], ChainedOptionsBuilder) |
| 247 | + */ |
| 248 | + public static void run(Class<?>[] sources, @Nullable ChainedOptionsBuilder override) throws RunnerException { |
| 249 | + String[] patterns = Arrays.stream(sources).map(Class::getCanonicalName).toArray(String[]::new); |
| 250 | + |
| 251 | + run(patterns, override); |
| 252 | + } |
| 253 | + |
| 254 | + /** |
| 255 | + * @see #run(String[], ChainedOptionsBuilder) |
| 256 | + */ |
| 257 | + public static void run(Class<?> source, @Nullable ChainedOptionsBuilder override) throws RunnerException { |
| 258 | + run(new Class<?>[] { source }, override); |
| 259 | + } |
| 260 | + |
| 261 | + /** |
| 262 | + * @see #run(String[], ChainedOptionsBuilder) |
| 263 | + */ |
| 264 | + public static void run(Class<?>... sources) throws RunnerException { |
| 265 | + run(sources, null); |
| 266 | + } |
| 267 | + |
| 268 | + /** |
| 269 | + * @see #run(String[], ChainedOptionsBuilder) |
| 270 | + */ |
| 271 | + public static void run(Class<?> source) throws RunnerException { |
| 272 | + run(source, null); |
| 273 | + } |
| 274 | + |
| 275 | + public static void main(String[] includes) throws RunnerException { |
| 276 | + ChainedOptionsBuilder builder = defaults() |
| 277 | + // Only 2m benchmarks, we're launching everything at once here |
| 278 | + .measurementIterations(24) |
| 279 | + .measurementTime(new TimeValue(5L, TimeUnit.SECONDS)); |
| 280 | + |
| 281 | + for (String pattern : includes) { |
| 282 | + builder.include(pattern); |
| 283 | + } |
| 284 | + |
| 285 | + Options options = builder.build(); |
| 286 | + |
| 287 | + Runner runner = new Runner(options); |
| 288 | + |
| 289 | + if (includes.length == 0) { |
| 290 | + System.out.println("Specify benchmark patterns as CLI arguments"); |
| 291 | + runner.list(); |
| 292 | + } |
| 293 | + else { |
| 294 | + runner.run(); |
| 295 | + } |
| 296 | + } |
| 297 | + |
| 298 | +} |
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