From a67979c4e6dcea70e63cc79a105be12a9306c660 Mon Sep 17 00:00:00 2001 From: Guanqiang Han Date: Mon, 19 Jan 2026 02:33:18 +0000 Subject: [PATCH] 8375125: assert(false) failed: "Attempting to acquire lock NativeHeapTrimmer_lock/nosafepoint out of order with lock ConcurrentHashTableResize_lock/nosafepoint-2 -- possible deadlock" when using native heap trimmer Reviewed-by: dholmes, stuefe --- src/hotspot/share/classfile/stringTable.cpp | 7 +- src/hotspot/share/classfile/symbolTable.cpp | 7 +- ...stTrimNativeHeapIntervalTablesCleanup.java | 107 ++++++++++++++++++ 3 files changed, 117 insertions(+), 4 deletions(-) create mode 100644 test/hotspot/jtreg/runtime/os/TestTrimNativeHeapIntervalTablesCleanup.java diff --git a/src/hotspot/share/classfile/stringTable.cpp b/src/hotspot/share/classfile/stringTable.cpp index c775014cfac..20dfad0d980 100644 --- a/src/hotspot/share/classfile/stringTable.cpp +++ b/src/hotspot/share/classfile/stringTable.cpp @@ -1,5 +1,5 @@ /* - * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 1997, 2026, 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 @@ -614,6 +614,10 @@ struct StringTableDeleteCheck : StackObj { }; void StringTable::clean_dead_entries(JavaThread* jt) { + // BulkDeleteTask::prepare() may take ConcurrentHashTableResize_lock (nosafepoint-2). + // When NativeHeapTrimmer is enabled, SuspendMark may take NativeHeapTrimmer::_lock (nosafepoint). + // Take SuspendMark first to keep lock order and avoid deadlock. + NativeHeapTrimmer::SuspendMark sm("stringtable"); StringTableHash::BulkDeleteTask bdt(_local_table); if (!bdt.prepare(jt)) { return; @@ -621,7 +625,6 @@ void StringTable::clean_dead_entries(JavaThread* jt) { StringTableDeleteCheck stdc; StringTableDoDelete stdd; - NativeHeapTrimmer::SuspendMark sm("stringtable"); { TraceTime timer("Clean", TRACETIME_LOG(Debug, stringtable, perf)); while(bdt.do_task(jt, stdc, stdd)) { diff --git a/src/hotspot/share/classfile/symbolTable.cpp b/src/hotspot/share/classfile/symbolTable.cpp index ec639a2b4d3..c49aa10fa0d 100644 --- a/src/hotspot/share/classfile/symbolTable.cpp +++ b/src/hotspot/share/classfile/symbolTable.cpp @@ -1,5 +1,5 @@ /* - * Copyright (c) 1997, 2025, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 1997, 2026, 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 @@ -763,6 +763,10 @@ struct SymbolTableDeleteCheck : StackObj { }; void SymbolTable::clean_dead_entries(JavaThread* jt) { + // BulkDeleteTask::prepare() may take ConcurrentHashTableResize_lock (nosafepoint-2). + // When NativeHeapTrimmer is enabled, SuspendMark may take NativeHeapTrimmer::_lock (nosafepoint). + // Take SuspendMark first to keep lock order and avoid deadlock. + NativeHeapTrimmer::SuspendMark sm("symboltable"); SymbolTableHash::BulkDeleteTask bdt(_local_table); if (!bdt.prepare(jt)) { return; @@ -770,7 +774,6 @@ void SymbolTable::clean_dead_entries(JavaThread* jt) { SymbolTableDeleteCheck stdc; SymbolTableDoDelete stdd; - NativeHeapTrimmer::SuspendMark sm("symboltable"); { TraceTime timer("Clean", TRACETIME_LOG(Debug, symboltable, perf)); while (bdt.do_task(jt, stdc, stdd)) { diff --git a/test/hotspot/jtreg/runtime/os/TestTrimNativeHeapIntervalTablesCleanup.java b/test/hotspot/jtreg/runtime/os/TestTrimNativeHeapIntervalTablesCleanup.java new file mode 100644 index 00000000000..3ced98b616d --- /dev/null +++ b/test/hotspot/jtreg/runtime/os/TestTrimNativeHeapIntervalTablesCleanup.java @@ -0,0 +1,107 @@ +/* + * Copyright (c) 2026, 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. + */ + + /** + * @test + * @bug 8375125 + * @summary Trigger StringTable::clean_dead_entries or SymbolTable::clean_dead_entries + * with -XX:TrimNativeHeapInterval enabled,should not violate lock ordering. + * @requires vm.debug + * @requires vm.gc != "Epsilon" + * @library /test/lib + * @modules java.compiler + * @run main/othervm -Xms128m -Xmx128m + * -XX:TrimNativeHeapInterval=300000 + * TestTrimNativeHeapIntervalTablesCleanup string + * @run main/othervm -Xms128m -Xmx128m + * -XX:TrimNativeHeapInterval=300000 + * TestTrimNativeHeapIntervalTablesCleanup symbol + */ + +import java.util.LinkedList; +import jdk.test.lib.compiler.InMemoryJavaCompiler; + +public class TestTrimNativeHeapIntervalTablesCleanup { + + public static void main(String[] args) throws Exception{ + if (args.length != 1) { + throw new IllegalArgumentException("Expected 1 argument: string|symbol"); + } + switch (args[0]) { + case "string": + testStringTableCleanup(); + break; + case "symbol": + testSymbolTableCleanup(); + break; + default: + throw new IllegalArgumentException("Unknown mode: " + args[0]); + } + System.out.println("passed: " + args[0]); + } + + static void testStringTableCleanup() throws Exception{ + final int rounds = 30; + final int maxSize = 200_000; + final int pruneEvery = 50_000; + final int pruneCount = 25_000; + long stringNum = 0; + + for (int round = 0; round < rounds; round++) { + LinkedList list = new LinkedList<>(); + for (int i = 0; i < maxSize; i++, stringNum++) { + if (i != 0 && (i % pruneEvery) == 0) { + int toRemove = Math.min(pruneCount, list.size()); + list.subList(0, toRemove).clear(); + } + list.push(Long.toString(stringNum).intern()); + } + System.gc(); + Thread.sleep(1000); + } + } + + static void testSymbolTableCleanup() throws Exception { + final int rounds = 10; + final int classesPerRound = 100; + + for (int r = 0; r < rounds; r++) { + for (int i = 0; i < classesPerRound; i++) { + String cn = "C" + r + "_" + i; + byte[] bytes = InMemoryJavaCompiler.compile( + cn, + "public class " + cn + " { int m" + i + "() { return " + i + "; } }" + ); + new ClassLoader(null) { + @Override + protected Class findClass(String name) throws ClassNotFoundException { + if (!name.equals(cn)) throw new ClassNotFoundException(name); + return defineClass(name, bytes, 0, bytes.length); + } + }.loadClass(cn).getDeclaredConstructor().newInstance(); + } + System.gc(); + Thread.sleep(1000); + } + } +} \ No newline at end of file