8297106: Remove the -Xcheck:jni local reference capacity checking

Reviewed-by: dcubed, kevinw

src/hotspot/share/prims/jniCheck.cpp

@@ -46,9 +46,6 @@
 #include "utilities/formatBuffer.hpp"
 #include "utilities/utf8.hpp"
 
-// Complain every extra number of unplanned local refs
-#define CHECK_JNI_LOCAL_REF_CAP_WARN_THRESHOLD 32
-
 // Heap objects are allowed to be directly referenced only in VM code,
 // not in native code.
 
@@ -202,17 +199,6 @@ check_pending_exception(JavaThread* thr) {
   }
 }
 
-/**
- * Add to the planned number of handles. I.e. plus current live & warning threshold
- */
-static inline void
-add_planned_handle_capacity(JNIHandleBlock* handles, size_t capacity) {
-  handles->set_planned_capacity(capacity +
-                                handles->get_number_of_live_handles() +
-                                CHECK_JNI_LOCAL_REF_CAP_WARN_THRESHOLD);
-}
-
-
 static inline void
 functionEnterCritical(JavaThread* thr)
 {
@@ -244,18 +230,7 @@ functionEnterExceptionAllowed(JavaThread* thr)
 static inline void
 functionExit(JavaThread* thr)
 {
-  JNIHandleBlock* handles = thr->active_handles();
+  // No checks at this time
-  size_t planned_capacity = handles->get_planned_capacity();
-  size_t live_handles = handles->get_number_of_live_handles();
-  if (live_handles > planned_capacity) {
-    IN_VM(
-      tty->print_cr("WARNING: JNI local refs: " SIZE_FORMAT ", exceeds capacity: " SIZE_FORMAT,
-                    live_handles, planned_capacity);
-      thr->print_stack();
-    )
-    // Complain just the once, reset to current + warn threshold
-    add_planned_handle_capacity(handles, 0);
-  }
 }
 
 static inline void
@@ -746,9 +721,6 @@ JNI_ENTRY_CHECKED(jint,
     if (capacity < 0)
       NativeReportJNIFatalError(thr, "negative capacity");
     jint result = UNCHECKED()->PushLocalFrame(env, capacity);
-    if (result == JNI_OK) {
-      add_planned_handle_capacity(thr->active_handles(), capacity);
-    }
     functionExit(thr);
     return result;
 JNI_END
@@ -850,12 +822,6 @@ JNI_ENTRY_CHECKED(jint,
       NativeReportJNIFatalError(thr, "negative capacity");
     }
     jint result = UNCHECKED()->EnsureLocalCapacity(env, capacity);
-    if (result == JNI_OK) {
-      // increase local ref capacity if needed
-      if ((size_t)capacity > thr->active_handles()->get_planned_capacity()) {
-        add_planned_handle_capacity(thr->active_handles(), capacity);
-      }
-    }
     functionExit(thr);
     return result;
 JNI_END

src/hotspot/share/runtime/jniHandles.cpp

@@ -356,7 +356,6 @@ JNIHandleBlock* JNIHandleBlock::allocate_block(JavaThread* thread, AllocFailType
   block->_top = 0;
   block->_next = NULL;
   block->_pop_frame_link = NULL;
-  block->_planned_capacity = block_size_in_oops;
   // _last, _free_list & _allocate_before_rebuild initialized in allocate_handle
   debug_only(block->_last = NULL);
   debug_only(block->_free_list = NULL);
@@ -550,22 +549,6 @@ size_t JNIHandleBlock::length() const {
   return result;
 }
 
-class CountJNIHandleClosure: public OopClosure {
-private:
-  int _count;
-public:
-  CountJNIHandleClosure(): _count(0) {}
-  virtual void do_oop(oop* ooph) { _count++; }
-  virtual void do_oop(narrowOop* unused) { ShouldNotReachHere(); }
-  int count() { return _count; }
-};
-
-const size_t JNIHandleBlock::get_number_of_live_handles() {
-  CountJNIHandleClosure counter;
-  oops_do(&counter);
-  return counter.count();
-}
-
 // This method is not thread-safe, i.e., must be called while holding a lock on the
 // structure.
 size_t JNIHandleBlock::memory_usage() const {

src/hotspot/share/runtime/jniHandles.hpp

@@ -147,8 +147,6 @@ class JNIHandleBlock : public CHeapObj<mtInternal> {
   JNIHandleBlock* _pop_frame_link;              // Block to restore on PopLocalFrame call
   uintptr_t*      _free_list;                   // Handle free list
 
-  // Check JNI, "planned capacity" for current frame (or push/ensure)
-  size_t          _planned_capacity;
   static int      _blocks_allocated;            // For debugging/printing
 
   // Fill block with bad_handle values
@@ -179,11 +177,6 @@ class JNIHandleBlock : public CHeapObj<mtInternal> {
   // Traversal of handles
   void oops_do(OopClosure* f);
 
-  // Checked JNI support
-  void set_planned_capacity(size_t planned_capacity) { _planned_capacity = planned_capacity; }
-  const size_t get_planned_capacity() { return _planned_capacity; }
-  const size_t get_number_of_live_handles();
-
   // Debugging
   bool chain_contains(jobject handle) const;    // Does this block or following blocks contain handle
   bool contains(jobject handle) const;          // Does this block contain handle

src/java.base/share/man/java.1

@@ -816,10 +816,6 @@ A JNI call was made without checking for a pending exception from a
 previous JNI call, and the current call is not safe when an exception
 may be pending.
 .IP \[bu] 2
-The number of JNI local references existing when a JNI function
-terminates exceeds the number guaranteed to be available.
-See the \f[V]EnsureLocalcapacity\f[R] function.
-.IP \[bu] 2
 A class descriptor is in decorated format (\f[V]Lname;\f[R]) when it
 should not be.
 .IP \[bu] 2

test/hotspot/jtreg/runtime/jni/checked/TestCheckedEnsureLocalCapacity.java

@@ -1,91 +0,0 @@
-/*
- * Copyright (c) 2017, 2021, 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 8193222
- * @summary Check EnsureLocalCapacity doesn't shrink unexpectedly
- * @library /test/lib
- * @run main/native TestCheckedEnsureLocalCapacity launch
- */
-import jdk.test.lib.Utils;
-import jdk.test.lib.process.ProcessTools;
-import jdk.test.lib.process.OutputAnalyzer;
-
-public class TestCheckedEnsureLocalCapacity {
-
-    static {
-        System.loadLibrary("TestCheckedEnsureLocalCapacity");
-    }
-
-    // Calls EnsureLocalCapacity(capacity) and then creates "copies" number
-    // of LocalRefs to "o".
-    // If capacity > copies no warning should ensue (with the bug fixed).
-    // If copies > capacity + warning-threshold then we still get a warning.
-    private static native void ensureCapacity(Object o, int capacity, int copies);
-
-    private static int[][] testArgs = {
-        { 60, 45 }, // good: capacity > copies
-        { 1, 45 }   // bad: copies >> capacity
-    };
-
-    // Patterns EXCEED_WARNING and WARNING are not anchored to the beginning
-    // of lines to allow matching interleaved output.
-
-    private static final String EXCEED_WARNING =
-        "WARNING: JNI local refs: \\d++, exceeds capacity:";
-
-    private static final String WARNING = "WARNING:";
-
-    public static void main(String[] args) throws Throwable {
-        if (args.length == 2) {
-            ensureCapacity(new Object(),
-                           Integer.parseInt(args[0]),
-                           Integer.parseInt(args[1]));
-            return;
-        }
-
-        // No warning
-        ProcessTools.executeTestJvm("-Xcheck:jni",
-                                    "-Djava.library.path=" + Utils.TEST_NATIVE_PATH,
-                                    "TestCheckedEnsureLocalCapacity",
-                                    Integer.toString(testArgs[0][0]),
-                                    Integer.toString(testArgs[0][1])).
-            shouldHaveExitValue(0).
-            // check no capacity warning
-            stdoutShouldNotMatch(EXCEED_WARNING).
-            // check no other warning
-            stdoutShouldNotMatch(WARNING).
-            reportDiagnosticSummary();
-
-        // Warning
-        ProcessTools.executeTestJvm("-Xcheck:jni",
-                                    "-Djava.library.path=" + Utils.TEST_NATIVE_PATH,
-                                    "TestCheckedEnsureLocalCapacity",
-                                    Integer.toString(testArgs[1][0]),
-                                    Integer.toString(testArgs[1][1])).
-            shouldHaveExitValue(0).
-            // check for capacity warning
-            stdoutShouldMatch(EXCEED_WARNING).
-            reportDiagnosticSummary();
-    }
-}

test/hotspot/jtreg/runtime/jni/checked/libTestCheckedEnsureLocalCapacity.c

@@ -1,49 +0,0 @@
-/*
- * Copyright (c) 2017, 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.
- */
-
-#include <jni.h>
-#include <stdio.h>
-
-void reduceLocalCapacity(JNIEnv* env) {
-    puts("reduceLocalCapacity: setting to 1");
-    (*env)->EnsureLocalCapacity(env,1);
-}
-
-JNIEXPORT void JNICALL
-Java_TestCheckedEnsureLocalCapacity_ensureCapacity(JNIEnv *env,
-                                                   jobject unused,
-                                                   jobject target,
-                                                   jint capacity,
-                                                   jint copies) {
-  int i;
-  printf("ensureCapacity: setting to %d\n", capacity);
-  (*env)->EnsureLocalCapacity(env, capacity); // set high
-  reduceLocalCapacity(env);     // sets low
-
-  printf("ensureCapacity: creating %d LocalRefs\n", copies);
-  for (i = 0; i < copies; i++) {
-    target = (*env)->NewLocalRef(env, target);
-  }
-
-  puts("ensureCapacity: done");
-}

test/jdk/ProblemList.txt

@@ -690,7 +690,6 @@ sanity/client/SwingSet/src/ButtonDemoScreenshotTest.java 8265770 macosx-all
 ############################################################################
 
 # core_svc
-tools/launcher/TestXcheckJNIWarnings.java#jdwp-agent   8296936 generic-all
 
 ############################################################################
 

test/jdk/com/sun/management/DiagnosticCommandMBean/DcmdMBeanTestCheckJni.java

@@ -1,85 +0,0 @@
-/*
- * Copyright (c) 2021, Red Hat, Inc.
- * 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     8258836
- * @summary JNI local refs exceed capacity getDiagnosticCommandInfo
- * @library /test/lib
- * @run main/othervm DcmdMBeanTestCheckJni
- */
-
-import java.lang.management.ManagementFactory;
-import javax.management.MBeanServer;
-import javax.management.ObjectName;
-import javax.management.MBeanServerConnection;
-import javax.management.remote.JMXConnectorFactory;
-import javax.management.remote.JMXConnector;
-import javax.management.remote.JMXConnectorServerFactory;
-import javax.management.remote.JMXServiceURL;
-import javax.management.remote.JMXConnectorServer;
-
-import jdk.test.lib.process.OutputAnalyzer;
-import jdk.test.lib.process.ProcessTools;
-
-public class DcmdMBeanTestCheckJni {
-
-    public static void main(String[] args) throws Exception {
-        OutputAnalyzer out = ProcessTools.executeTestJvm(
-            "-Xcheck:jni",
-            DcmdMBeanRunner.class.getName());
-        out.shouldNotMatch("WARNING: JNI local refs: \\d+, exceeds capacity: \\d+\\s+" +
-                           "at com.sun.management.internal.DiagnosticCommandImpl.getDiagnosticCommandInfo")
-           .shouldContain("DcmdMBeanRunner COMPLETE")
-           .shouldHaveExitValue(0);
-    }
-
-}
-
-class DcmdMBeanRunner {
-
-    private static final String HOTSPOT_DIAGNOSTIC_MXBEAN_NAME =
-        "com.sun.management:type=DiagnosticCommand";
-
-    public static void main(String[] args) throws Exception {
-        MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
-        JMXServiceURL url = new JMXServiceURL("rmi", null, 0);
-        JMXConnectorServer cs = null;
-        JMXConnector cc = null;
-        try {
-            cs = JMXConnectorServerFactory.newJMXConnectorServer(url, null, mbs);
-            cs.start();
-            JMXServiceURL addr = cs.getAddress();
-            cc = JMXConnectorFactory.connect(addr);
-            MBeanServerConnection mbsc = cc.getMBeanServerConnection();
-            ObjectName name = new ObjectName(HOTSPOT_DIAGNOSTIC_MXBEAN_NAME);
-            System.out.println("DiagnosticCommand MBean: " + name);
-            System.out.println("DcmdMBeanRunner COMPLETE");
-        } finally {
-            try {
-                cc.close();
-                cs.stop();
-            } catch (Exception e) { /* ignored */ }
-        }
-    }
-}