8355627: Don't use ThreadCritical for EventLog list

Reviewed-by: shade, lmesnik, zgu

Author: coleenp

src/hotspot/share/utilities/events.cpp

@@ -26,14 +26,13 @@
 #include "memory/allocation.inline.hpp"
 #include "oops/instanceKlass.hpp"
 #include "oops/symbol.hpp"
+#include "runtime/atomic.hpp"
 #include "runtime/javaThread.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "runtime/osThread.hpp"
-#include "runtime/threadCritical.hpp"
 #include "runtime/timer.hpp"
 #include "utilities/events.hpp"
 
-
 EventLog* Events::_logs = nullptr;
 StringEventLog* Events::_messages = nullptr;
 StringEventLog* Events::_memprotect_messages = nullptr;
@@ -48,18 +47,19 @@ StringEventLog* Events::_deopt_messages = nullptr;
 StringEventLog* Events::_dll_messages = nullptr;
 
 EventLog::EventLog() {
-  // This normally done during bootstrap when we're only single
-  // threaded but use a ThreadCritical to ensure inclusion in case
-  // some are created slightly late.
-  ThreadCritical tc;
-  _next = Events::_logs;
-  Events::_logs = this;
+  // This is normally done during bootstrap when we're only single threaded,
+  // but use lock free add because there are some events that are created later.
+  EventLog* old_head;
+  do {
+    old_head = Atomic::load(&Events::_logs);
+    _next = old_head;
+  } while (Atomic::cmpxchg(&Events::_logs, old_head, this) != old_head);
 }
 
 // For each registered event logger, print out the current contents of
 // the buffer.
 void Events::print_all(outputStream* out, int max) {
-  EventLog* log = _logs;
+  EventLog* log = Atomic::load(&Events::_logs);
   while (log != nullptr) {
     log->print_log_on(out, max);
     log = log->next();
@@ -68,7 +68,7 @@ void Events::print_all(outputStream* out, int max) {
 
 // Print a single event log specified by name.
 void Events::print_one(outputStream* out, const char* log_name, int max) {
-  EventLog* log = _logs;
+  EventLog* log = Atomic::load(&Events::_logs);
   int num_printed = 0;
   while (log != nullptr) {
     if (log->matches_name_or_handle(log_name)) {
@@ -81,7 +81,7 @@ void Events::print_one(outputStream* out, const char* log_name, int max) {
   if (num_printed == 0) {
     out->print_cr("The name \"%s\" did not match any known event log. "
                   "Valid event log names are:", log_name);
-    EventLog* log = _logs;
+    EventLog* log = Atomic::load(&Events::_logs);
     while (log != nullptr) {
       log->print_names(out);
       out->cr();

test/hotspot/jtreg/runtime/ErrorHandling/ShowEventsOnCrashTest.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2025, 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 8355627
+ * @summary Test that events are listed in the hs_err_pid file
+ * @library /test/lib
+ * @requires vm.flagless
+ * @requires vm.debug == true & (os.family == "linux" | os.family == "windows")
+ * @modules java.base/jdk.internal.misc
+ * @run driver ShowEventsOnCrashTest
+ */
+
+// Note: this test can only run on debug since it relies on VMError::controlled_crash() which
+// only exists in debug builds.
+import java.io.File;
+import java.util.regex.Pattern;
+
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.process.ProcessTools;
+
+public class ShowEventsOnCrashTest {
+
+    public static void main(String[] args) throws Exception {
+
+        ProcessBuilder pb = ProcessTools.createLimitedTestJavaProcessBuilder(
+            "-XX:+UnlockDiagnosticVMOptions", "-Xmx100M", "-XX:-CreateCoredumpOnCrash",
+            "-XX:ErrorHandlerTest=2",
+            "-version");
+
+        OutputAnalyzer output_detail = new OutputAnalyzer(pb.start());
+
+        // we should have crashed with an internal error. We should definitely NOT have crashed with a segfault
+        // (which would be a sign that the assert poison page mechanism does not work).
+        output_detail.shouldMatch("# A fatal error has been detected by the Java Runtime Environment:.*");
+        output_detail.shouldMatch("# +Internal Error.*");
+        File hs_err_file = HsErrFileUtils.openHsErrFileFromOutput(output_detail);
+        // Pattern match the hs_err_pid file.
+        Pattern[] patterns = new Pattern[] {
+            Pattern.compile("Compilation events \\([0-9]* events\\):"),
+            Pattern.compile("GC Heap History \\([0-9]* events\\):"),
+            Pattern.compile("Dll operation events \\([0-9]* events\\):"),
+            Pattern.compile("Deoptimization events \\([0-9]* events\\):"),
+            Pattern.compile("Classes loaded \\([0-9]* events\\):"),
+            Pattern.compile("Classes unloaded \\([0-9]* events\\):"),
+            Pattern.compile("Classes redefined \\([0-9]* events\\):"),
+            Pattern.compile("Internal exceptions \\([0-9]* events\\):"),
+            Pattern.compile("VM Operations \\([0-9]* events\\):"),
+            Pattern.compile("Memory protections \\([0-9]* events\\):")
+        };
+
+        HsErrFileUtils.checkHsErrFileContent(hs_err_file, patterns, false);
+
+    }
+}
+