8185164: GetOwnedMonitorInfo() returns incorrect owned monitor

The GetOwnedMonitorInfo() should not return a pending monitor

Reviewed-by: dholmes, dcubed, sspitsyn

hotspot/make/test/JtregNative.gmk

@@ -61,6 +61,7 @@ BUILD_HOTSPOT_JTREG_NATIVE_SRC += \
     $(HOTSPOT_TOPDIR)/test/runtime/noClassDefFoundMsg \
     $(HOTSPOT_TOPDIR)/test/compiler/floatingpoint/ \
     $(HOTSPOT_TOPDIR)/test/compiler/calls \
+    $(HOTSPOT_TOPDIR)/test/serviceability/jvmti/GetOwnedMonitorInfo \
     $(HOTSPOT_TOPDIR)/test/serviceability/jvmti/GetNamedModule \
     $(HOTSPOT_TOPDIR)/test/serviceability/jvmti/IsModifiableModule \
     $(HOTSPOT_TOPDIR)/test/serviceability/jvmti/AddModuleReads \
@@ -92,6 +93,7 @@ endif
 ifeq ($(TOOLCHAIN_TYPE), solstudio)
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_liboverflow := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libSimpleClassFileLoadHook := -lc
+    BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libGetOwnedMonitorInfoTest := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libGetNamedModuleTest := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libIsModifiableModuleTest := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LDFLAGS_libAddModuleReadsTest := -lc

hotspot/src/share/vm/runtime/objectMonitor.cpp

@@ -307,6 +307,8 @@ void ObjectMonitor::enter(TRAPS) {
   { // Change java thread status to indicate blocked on monitor enter.
     JavaThreadBlockedOnMonitorEnterState jtbmes(jt, this);
 
+    Self->set_current_pending_monitor(this);
+
     DTRACE_MONITOR_PROBE(contended__enter, this, object(), jt);
     if (JvmtiExport::should_post_monitor_contended_enter()) {
       JvmtiExport::post_monitor_contended_enter(jt, this);
@@ -321,8 +323,6 @@ void ObjectMonitor::enter(TRAPS) {
     OSThreadContendState osts(Self->osthread());
     ThreadBlockInVM tbivm(jt);
 
-    Self->set_current_pending_monitor(this);
-
     // TODO-FIXME: change the following for(;;) loop to straight-line code.
     for (;;) {
       jt->set_suspend_equivalent();

hotspot/test/serviceability/jvmti/GetOwnedMonitorInfo/GetOwnedMonitorInfoTest.java

@@ -0,0 +1,79 @@
+/*
+ * 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.
+ */
+
+
+/**
+ * @test
+ * @bug 8185164
+ * @summary Checks that a contended monitor does not show up in the list of owned monitors
+ * @compile GetOwnedMonitorInfoTest.java
+ * @run main/othervm/native -agentlib:GetOwnedMonitorInfoTest GetOwnedMonitorInfoTest
+ */
+
+import java.io.PrintStream;
+
+public class GetOwnedMonitorInfoTest {
+
+    static {
+        try {
+            System.loadLibrary("GetOwnedMonitorInfoTest");
+        } catch (UnsatisfiedLinkError ule) {
+            System.err.println("Could not load GetOwnedMonitorInfoTest library");
+            System.err.println("java.library.path: "
+                               + System.getProperty("java.library.path"));
+            throw ule;
+        }
+    }
+
+    private static native int check();
+    private static native boolean hasEventPosted();
+
+    public static void main(String[] args) throws Exception {
+        final GetOwnedMonitorInfoTest lock = new GetOwnedMonitorInfoTest();
+
+        Thread t1 = new Thread(() -> {
+            synchronized (lock) {
+                System.out.println("Thread in sync section: "
+                                   + Thread.currentThread().getName());
+            }
+        });
+
+        // Make sure t1 contends on the monitor.
+        synchronized (lock) {
+            System.out.println("Main starting worker thread.");
+            t1.start();
+
+            // Wait for the MonitorContendedEnter event
+            while (!hasEventPosted()) {
+                System.out.println("Main waiting for event.");
+                Thread.sleep(100);
+            }
+        }
+
+        t1.join();
+
+        if (check() != 0) {
+            throw new RuntimeException("FAILED status returned from the agent");
+        }
+    }
+}

hotspot/test/serviceability/jvmti/GetOwnedMonitorInfo/libGetOwnedMonitorInfoTest.c

@@ -0,0 +1,264 @@
+/*
+ * 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 <stdio.h>
+#include <string.h>
+#include "jvmti.h"
+#include "jni.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef JNI_ENV_ARG
+
+#ifdef __cplusplus
+#define JNI_ENV_ARG(x, y) y
+#define JNI_ENV_PTR(x) x
+#else
+#define JNI_ENV_ARG(x,y) x, y
+#define JNI_ENV_PTR(x) (*x)
+#endif
+
+#endif
+
+#define PASSED 0
+#define FAILED 2
+
+#define TEST_CLASS "GetOwnedMonitorInfoTest"
+
+static volatile jboolean event_has_posted = JNI_FALSE;
+static volatile jint status = PASSED;
+
+static jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved);
+
+static void ShowErrorMessage(jvmtiEnv *jvmti, jvmtiError errCode, const char *message) {
+    char *errMsg;
+    jvmtiError result;
+
+    result = (*jvmti)->GetErrorName(jvmti, errCode, &errMsg);
+    if (result == JVMTI_ERROR_NONE) {
+        fprintf(stderr, "%s: %s (%d)\n", message, errMsg, errCode);
+        (*jvmti)->Deallocate(jvmti, (unsigned char *)errMsg);
+    } else {
+        fprintf(stderr, "%s (%d)\n", message, errCode);
+    }
+}
+
+static jboolean CheckLockObject(JNIEnv *env, jobject monitor) {
+    jclass testClass;
+
+    testClass = (*env)->FindClass(env, TEST_CLASS);
+    if (testClass == NULL) {
+        fprintf(stderr, "MonitorContendedEnter: " TEST_CLASS " not found\n");
+        status = FAILED;
+        event_has_posted = JNI_TRUE;
+        return JNI_FALSE;
+    }
+
+    return (*env)->IsInstanceOf(env, monitor, testClass);
+}
+
+JNIEXPORT void JNICALL
+MonitorContendedEnter(jvmtiEnv *jvmti, JNIEnv *env, jthread thread, jobject monitor) {
+    jvmtiError err;
+    jvmtiThreadInfo threadInfo;
+    jint monitorCount;
+    jobject *ownedMonitors;
+
+    if (CheckLockObject(env, monitor) == JNI_FALSE) {
+        return;
+    }
+
+    err = (*jvmti)->GetThreadInfo(jvmti, thread, &threadInfo);
+    if (err != JVMTI_ERROR_NONE) {
+        ShowErrorMessage(jvmti, err,
+                         "MonitorContendedEnter: error in JVMTI GetThreadInfo");
+        status = FAILED;
+        event_has_posted = JNI_TRUE;
+        return;
+    }
+    err = (*jvmti)->GetOwnedMonitorInfo(jvmti, thread, &monitorCount, &ownedMonitors);
+    if (err != JVMTI_ERROR_NONE) {
+        ShowErrorMessage(jvmti, err,
+                         "MonitorContendedEnter: error in JVMTI GetOwnedMonitorInfo");
+        status = FAILED;
+        event_has_posted = JNI_TRUE;
+        return;
+    }
+
+    printf("MonitorContendedEnter: %s owns %d monitor(s)\n",
+           threadInfo.name, monitorCount);
+
+    (*jvmti)->Deallocate(jvmti, (unsigned char *)ownedMonitors);
+    (*jvmti)->Deallocate(jvmti, (unsigned char *)threadInfo.name);
+
+    if (monitorCount != 0) {
+        fprintf(stderr, "MonitorContendedEnter: FAIL: monitorCount should be zero.\n");
+        status = FAILED;
+    }
+
+    event_has_posted = JNI_TRUE;
+}
+
+JNIEXPORT void JNICALL
+MonitorContendedEntered(jvmtiEnv *jvmti, JNIEnv *env, jthread thread, jobject monitor) {
+    jvmtiError err;
+    jvmtiThreadInfo threadInfo;
+    jint monitorCount;
+    jobject *ownedMonitors;
+
+    if (CheckLockObject(env, monitor) == JNI_FALSE) {
+        return;
+    }
+
+    err = (*jvmti)->GetThreadInfo(jvmti, thread, &threadInfo);
+    if (err != JVMTI_ERROR_NONE) {
+        ShowErrorMessage(jvmti, err,
+                         "MonitorContendedEntered: error in JVMTI GetThreadInfo");
+        status = FAILED;
+        return;
+    }
+    err = (*jvmti)->GetOwnedMonitorInfo(jvmti, thread, &monitorCount, &ownedMonitors);
+    if (err != JVMTI_ERROR_NONE) {
+        ShowErrorMessage(jvmti, err,
+                         "MonitorContendedEntered: error in JVMTI GetOwnedMonitorInfo");
+        status = FAILED;
+        return;
+    }
+
+    printf("MonitorContendedEntered: %s owns %d monitor(s)\n",
+           threadInfo.name, monitorCount);
+
+    (*jvmti)->Deallocate(jvmti, (unsigned char *)ownedMonitors);
+    (*jvmti)->Deallocate(jvmti, (unsigned char *)threadInfo.name);
+
+    if (monitorCount != 1) {
+        fprintf(stderr, "MonitorContendedEnter: FAIL: monitorCount should be one.\n");
+        status = FAILED;
+    }
+}
+
+JNIEXPORT jint JNICALL
+Agent_OnLoad(JavaVM *jvm, char *options, void *reserved) {
+    return Agent_Initialize(jvm, options, reserved);
+}
+
+JNIEXPORT jint JNICALL
+Agent_OnAttach(JavaVM *jvm, char *options, void *reserved) {
+    return Agent_Initialize(jvm, options, reserved);
+}
+
+JNIEXPORT jint JNICALL
+JNI_OnLoad(JavaVM *jvm, void *reserved) {
+    return JNI_VERSION_1_8;
+}
+
+static
+jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved) {
+    jint res;
+    jvmtiError err;
+    jvmtiEnv *jvmti;
+    jvmtiCapabilities caps;
+    jvmtiEventCallbacks callbacks;
+
+    printf("Agent_OnLoad started\n");
+
+    res = JNI_ENV_PTR(jvm)->GetEnv(JNI_ENV_ARG(jvm, (void **) &jvmti),
+                                   JVMTI_VERSION_1);
+    if (res != JNI_OK || jvmti == NULL) {
+        fprintf(stderr, "Error: wrong result of a valid call to GetEnv!\n");
+        return JNI_ERR;
+    }
+
+    err = (*jvmti)->GetPotentialCapabilities(jvmti, &caps);
+    if (err != JVMTI_ERROR_NONE) {
+        ShowErrorMessage(jvmti, err,
+                         "Agent_OnLoad: error in JVMTI GetPotentialCapabilities");
+        return JNI_ERR;
+    }
+
+    err = (*jvmti)->AddCapabilities(jvmti, &caps);
+    if (err != JVMTI_ERROR_NONE) {
+        ShowErrorMessage(jvmti, err,
+                         "Agent_OnLoad: error in JVMTI AddCapabilities");
+        return JNI_ERR;
+    }
+
+    err = (*jvmti)->GetCapabilities(jvmti, &caps);
+    if (err != JVMTI_ERROR_NONE) {
+        ShowErrorMessage(jvmti, err,
+                         "Agent_OnLoad: error in JVMTI GetCapabilities");
+        return JNI_ERR;
+    }
+
+    if (!caps.can_generate_monitor_events) {
+        fprintf(stderr, "Warning: Monitor events are not implemented\n");
+        return JNI_ERR;
+    }
+    if (!caps.can_get_owned_monitor_info) {
+        fprintf(stderr, "Warning: GetOwnedMonitorInfo is not implemented\n");
+        return JNI_ERR;
+    }
+
+    callbacks.MonitorContendedEnter   = &MonitorContendedEnter;
+    callbacks.MonitorContendedEntered = &MonitorContendedEntered;
+
+    err = (*jvmti)->SetEventCallbacks(jvmti, &callbacks, sizeof(jvmtiEventCallbacks));
+    if (err != JVMTI_ERROR_NONE) {
+        ShowErrorMessage(jvmti, err,
+                         "Agent_OnLoad: error in JVMTI SetEventCallbacks");
+        return JNI_ERR;
+    }
+
+    err = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
+                                             JVMTI_EVENT_MONITOR_CONTENDED_ENTER, NULL);
+    if (err != JVMTI_ERROR_NONE) {
+        ShowErrorMessage(jvmti, err,
+                         "Agent_OnLoad: error in JVMTI SetEventNotificationMode #1");
+        return JNI_ERR;
+    }
+    err = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
+                                             JVMTI_EVENT_MONITOR_CONTENDED_ENTERED, NULL);
+    if (err != JVMTI_ERROR_NONE) {
+        ShowErrorMessage(jvmti, err,
+                         "Agent_OnLoad: error in JVMTI SetEventNotificationMode #2");
+        return JNI_ERR;
+    }
+    printf("Agent_OnLoad finished\n");
+    return JNI_OK;
+}
+
+JNIEXPORT jint JNICALL
+Java_GetOwnedMonitorInfoTest_check(JNIEnv *env, jclass cls) {
+    return status;
+}
+
+JNIEXPORT jboolean JNICALL
+Java_GetOwnedMonitorInfoTest_hasEventPosted(JNIEnv *env, jclass cls) {
+    return event_has_posted;
+}
+
+#ifdef __cplusplus
+}
+#endif