1 /*

     2  * Copyright (c) 2019 SAP SE. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 #include <stdio.h>

    25 #include <string.h>

    26 #include "jvmti.h"

    27 #include "jni.h"

    28 

    29 #ifdef __cplusplus

    30 extern "C" {

    31 #endif

    32 

    33 #ifndef JNI_ENV_ARG

    34 

    35 #ifdef __cplusplus

    36 #define JNI_ENV_ARG(x, y) y

    37 #define JNI_ENV_PTR(x) x

    38 #else

    39 #define JNI_ENV_ARG(x,y) x, y

    40 #define JNI_ENV_PTR(x) (*x)

    41 #endif

    42 

    43 #endif

    44 

    45 #define FAILED -1

    46 

    47 static jvmtiEnv *jvmti;

    48 

    49 static jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved);

    50 

    51 static void ShowErrorMessage(jvmtiEnv *jvmti, jvmtiError errCode, const char *message) {

    52     char *errMsg;

    53     jvmtiError result;

    54 

    55     result = (*jvmti)->GetErrorName(jvmti, errCode, &errMsg);

    56     if (result == JVMTI_ERROR_NONE) {

    57         fprintf(stderr, "%s: %s (%d)\n", message, errMsg, errCode);

    58         (*jvmti)->Deallocate(jvmti, (unsigned char *)errMsg);

    59     } else {

    60         fprintf(stderr, "%s (%d)\n", message, errCode);

    61     }

    62 }

    63 

    64 JNIEXPORT jint JNICALL

    65 Agent_OnLoad(JavaVM *jvm, char *options, void *reserved) {

    66     return Agent_Initialize(jvm, options, reserved);

    67 }

    68 

    69 JNIEXPORT jint JNICALL

    70 Agent_OnAttach(JavaVM *jvm, char *options, void *reserved) {

    71     return Agent_Initialize(jvm, options, reserved);

    72 }

    73 

    74 JNIEXPORT jint JNICALL

    75 JNI_OnLoad(JavaVM *jvm, void *reserved) {

    76     jint res;

    77     JNIEnv *env;

    78 

    79     res = JNI_ENV_PTR(jvm)->GetEnv(JNI_ENV_ARG(jvm, (void **) &env),

    80                                    JNI_VERSION_9);

    81     if (res != JNI_OK || env == NULL) {

    82         fprintf(stderr, "Error: GetEnv call failed(%d)!\n", res);

    83         return JNI_ERR;

    84     }

    85 

    86     return JNI_VERSION_9;

    87 }

    88 

    89 static

    90 jint Agent_Initialize(JavaVM *jvm, char *options, void *reserved) {

    91     jint res;

    92     jvmtiError err;

    93     jvmtiCapabilities caps;

    94 

    95     printf("Agent_OnLoad started\n");

    96 

    97     memset(&caps, 0, sizeof(caps));

    98 

    99     res = JNI_ENV_PTR(jvm)->GetEnv(JNI_ENV_ARG(jvm, (void **) &jvmti),

   100                                    JVMTI_VERSION_9);

   101     if (res != JNI_OK || jvmti == NULL) {

   102         fprintf(stderr, "Error: wrong result of a valid call to GetEnv!\n");

   103         return JNI_ERR;

   104     }

   105 

   106     caps.can_get_owned_monitor_info = 1;

   107 

   108     err = (*jvmti)->AddCapabilities(jvmti, &caps);

   109     if (err != JVMTI_ERROR_NONE) {

   110         ShowErrorMessage(jvmti, err,

   111                          "Agent_OnLoad: error in JVMTI AddCapabilities");

   112         return JNI_ERR;

   113     }

   114 

   115     err = (*jvmti)->GetCapabilities(jvmti, &caps);

   116     if (err != JVMTI_ERROR_NONE) {

   117         ShowErrorMessage(jvmti, err,

   118                          "Agent_OnLoad: error in JVMTI GetCapabilities");

   119         return JNI_ERR;

   120     }

   121 

   122     if (!caps.can_get_owned_monitor_info) {

   123         fprintf(stderr, "Warning: GetOwnedMonitorInfo is not implemented\n");

   124         return JNI_ERR;

   125     }

   126 

   127     printf("Agent_OnLoad finished\n");

   128     return JNI_OK;

   129 }

   130 

   131 JNIEXPORT jint JNICALL

   132 Java_GetOwnedMonitorInfoWithEATest_getOwnedMonitorInfo(JNIEnv *env, jclass cls, jobject targetThread, jobjectArray resOwnedMonitors) {

   133     jvmtiError err;

   134     jvmtiThreadInfo threadInfo;

   135     jint monitorCount;

   136     jobject* monitors;

   137     jint idx;

   138 

   139     err = (*jvmti)->GetThreadInfo(jvmti, targetThread, &threadInfo);

   140     if (err != JVMTI_ERROR_NONE) {

   141         ShowErrorMessage(jvmti, err,

   142                 "getOwnedMonitorsFor: error in JVMTI GetThreadInfo");

   143         return FAILED;

   144     }

   145 

   146     err = (*jvmti)->GetOwnedMonitorInfo(jvmti, targetThread, &monitorCount, &monitors);

   147     if (err != JVMTI_ERROR_NONE) {

   148         ShowErrorMessage(jvmti, err,

   149                 "getOwnedMonitorsFor: error in JVMTI GetOwnedMonitorInfo");

   150         return FAILED;

   151     }

   152 

   153     printf("getOwnedMonitorsFor: %s owns %d monitor(s)\n", threadInfo.name, monitorCount);

   154 

   155     for (idx = 0; idx < monitorCount; idx++) {

   156       (*env)->SetObjectArrayElement(env, resOwnedMonitors, idx, monitors[idx]);

   157     }

   158 

   159     (*jvmti)->Deallocate(jvmti, (unsigned char *) monitors);

   160     (*jvmti)->Deallocate(jvmti, (unsigned char *) threadInfo.name);

   161     return monitorCount;

   162 }

   163 

   164 #ifdef __cplusplus

   165 }

   166 #endif