undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/micro/org/openjdk/bench/jdk/classfile/ConstantPoolBuildingClassEntry.java

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+/*
+ * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * 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.
+ */
+package org.openjdk.bench.jdk.classfile;
+
+import java.lang.classfile.constantpool.ConstantPoolBuilder;
+import java.lang.constant.ClassDesc;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.Blackhole;
+
+import static java.lang.constant.ConstantDescs.*;
+
+import static org.openjdk.bench.jdk.classfile.TestConstants.*;
+
+/**
+ * Tests constant pool builder lookup performance for ClassEntry.
+ * Note that ClassEntry is available only for reference types.
+ */
+@Warmup(iterations = 3)
+@Measurement(iterations = 5)
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+@BenchmarkMode(Mode.Throughput)
+@Fork(value = 1)
+@State(Scope.Benchmark)
+public class ConstantPoolBuildingClassEntry {
+    // JDK-8338546
+    ConstantPoolBuilder builder;
+    List<ClassDesc> classDescs;
+    List<ClassDesc> nonIdenticalClassDescs;
+    List<String> internalNames;
+    List<ClassDesc> nonDuplicateClassDescs;
+    List<String> nonDuplicateInternalNames;
+    int size;
+
+    @Setup(Level.Iteration)
+    public void setup() {
+        builder = ConstantPoolBuilder.of();
+        // Note these can only be reference types, no primitives
+        classDescs = List.of(
+                CD_Byte, CD_Object, CD_Long.arrayType(), CD_String, CD_String, CD_Object, CD_Short,
+                CD_MethodHandle, CD_MethodHandle, CD_Object, CD_Character, CD_List, CD_ArrayList,
+                CD_List, CD_Set, CD_Integer, CD_Object.arrayType(), CD_Enum, CD_Object, CD_MethodHandles_Lookup,
+                CD_Long, CD_Set, CD_Object, CD_Character, CD_Integer, CD_System, CD_String, CD_String,
+                CD_CallSite, CD_Collection, CD_List, CD_Collection, CD_String, CD_int.arrayType()
+        );
+        size = classDescs.size();
+        nonIdenticalClassDescs = classDescs.stream().map(cd -> {
+            var ret = ClassDesc.ofDescriptor(new String(cd.descriptorString()));
+            ret.hashCode(); // pre-compute hash code for cd
+            return ret;
+        }).toList();
+        internalNames = classDescs.stream().map(cd -> {
+            // also sets up builder
+            cd.hashCode(); // pre-computes hash code for cd
+            var ce = builder.classEntry(cd);
+            var ret = ce.name().stringValue();
+            ret.hashCode(); // pre-computes hash code for stringValue
+            return ret;
+        }).toList();
+        nonDuplicateClassDescs = List.copyOf(new LinkedHashSet<>(classDescs));
+        nonDuplicateInternalNames = nonDuplicateClassDescs.stream().map(cd ->
+                builder.classEntry(cd).asInternalName()).toList();
+    }
+
+    // Copied from jdk.internal.classfile.impl.Util::toInternalName
+    // to reduce internal dependencies
+    public static String toInternalName(ClassDesc cd) {
+        var desc = cd.descriptorString();
+        if (desc.charAt(0) == 'L')
+            return desc.substring(1, desc.length() - 1);
+        throw new IllegalArgumentException(desc);
+    }
+
+    /**
+     * Looking up with identical ClassDesc objects. Happens in bytecode generators reusing
+     * constant CD_Xxx.
+     */
+    @Benchmark
+    public void identicalLookup(Blackhole bh) {
+        for (var cd : classDescs) {
+            bh.consume(builder.classEntry(cd));
+        }
+    }
+
+    /**
+     * Looking up with non-identical ClassDesc objects. Happens in bytecode generators
+     * using ad-hoc Class.describeConstable().orElseThrow() or other parsed ClassDesc.
+     * Cannot use identity fast path compared to {@link #identicalLookup}.
+     */
+    @Benchmark
+    public void nonIdenticalLookup(Blackhole bh) {
+        for (var cd : nonIdenticalClassDescs) {
+            bh.consume(builder.classEntry(cd));
+        }
+    }
+
+    /**
+     * Looking up with internal names. Closest to ASM behavior.
+     * Baseline for {@link #identicalLookup}.
+     */
+    @Benchmark
+    public void internalNameLookup(Blackhole bh) {
+        for (var name : internalNames) {
+            bh.consume(builder.classEntry(builder.utf8Entry(name)));
+        }
+    }
+
+    /**
+     * The default implementation provided by {@link ConstantPoolBuilder#classEntry(ClassDesc)}.
+     * Does substring so needs to rehash and has no caching, should be very slow.
+     */
+    @Benchmark
+    public void oldStyleLookup(Blackhole bh) {
+        for (var cd : classDescs) {
+            var s = cd.isClassOrInterface() ? toInternalName(cd) : cd.descriptorString();
+            bh.consume(builder.classEntry(builder.utf8Entry(s)));
+        }
+    }
+
+    /**
+     * Measures performance of creating new class entries in new constant pools with symbols.
+     */
+    @Benchmark
+    public void freshCreationWithDescs(Blackhole bh) {
+        var cp = ConstantPoolBuilder.of();
+        for (var cd : nonDuplicateClassDescs) {
+            bh.consume(cp.classEntry(cd));
+        }
+    }
+
+    /**
+     * Measures performance of creating new class entries in new constant pools with internal names.
+     */
+    @Benchmark
+    public void freshCreationWithInternalNames(Blackhole bh) {
+        var cp = ConstantPoolBuilder.of();
+        for (var name : nonDuplicateInternalNames) {
+            bh.consume(cp.classEntry(cp.utf8Entry(name)));
+        }
+    }
+}