1 /*

     2  * Copyright (c) 2018, Oracle and/or its affiliates. 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 

    28 #ifdef __cplusplus

    29 extern "C" {

    30 #endif

    31 

    32 #ifndef JNI_ENV_ARG

    33 

    34 #ifdef __cplusplus

    35 #define JNI_ENV_ARG(x, y) y

    36 #define JNI_ENV_PTR(x) x

    37 #else

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

    39 #define JNI_ENV_PTR(x) (*x)

    40 #endif

    41 

    42 #endif

    43 

    44 static jvmtiEnv *jvmti = NULL;

    45 static jvmtiCapabilities caps;

    46 static jvmtiEventCallbacks callbacks;

    47 static jboolean framePopReceived = JNI_FALSE;

    48 

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

    50 

    51 JNIEXPORT

    52 jint JNICALL Agent_OnLoad(JavaVM *jvm, char *options, void *reserved) {

    53     return Agent_Initialize(jvm, options, reserved);

    54 }

    55 

    56 JNIEXPORT

    57 jint JNICALL Agent_OnAttach(JavaVM *jvm, char *options, void *reserved) {

    58     return Agent_Initialize(jvm, options, reserved);

    59 }

    60 

    61 JNIEXPORT

    62 jint JNICALL JNI_OnLoad(JavaVM *jvm, void *reserved) {

    63     return JNI_VERSION_9;

    64 }

    65 

    66 

    67 static void reportError(const char *msg, int err) {

    68     fprintf(stdout, "%s, error: %d\n", msg, err);

    69     fflush(stdout);

    70 }

    71 

    72 

    73 static void JNICALL

    74 FramePop(jvmtiEnv *jvmti_env, JNIEnv *env, jthread thread,

    75          jmethodID method, jboolean wasPoppedByException)

    76 {

    77     jvmtiError err;

    78     jclass cls = NULL;

    79     char* csig = NULL;

    80     char* name = NULL;

    81     char* sign = NULL;

    82 

    83     framePopReceived = JNI_TRUE;

    84 

    85     err = (*jvmti_env)->GetMethodDeclaringClass(jvmti_env, method, &cls);

    86     if (err != JVMTI_ERROR_NONE) {

    87         reportError("FramePop: GetMethodDeclaringClass failed", err);

    88     }

    89     err = (*jvmti_env)->GetClassSignature(jvmti_env, cls, &csig, NULL);

    90     if (err != JVMTI_ERROR_NONE) {

    91         reportError("FramePop: GetClassSignature failed", err);

    92     }

    93     err = (*jvmti_env)->GetMethodName(jvmti_env, method, &name, &sign, NULL);

    94     if (err != JVMTI_ERROR_NONE) {

    95         reportError("FramePop: GetMethodName failed", err);

    96     }

    97     fprintf(stdout, "FramePop event from method: %s %s%s\n", csig, name, sign);

    98     fflush(stdout);

    99 

   100     (*jvmti_env)->Deallocate(jvmti_env, (unsigned char*)csig);

   101     (*jvmti_env)->Deallocate(jvmti_env, (unsigned char*)name);

   102     (*jvmti_env)->Deallocate(jvmti_env, (unsigned char*)sign);

   103 }

   104 

   105 static

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

   107     jint res;

   108     jvmtiError err;

   109 

   110     res = JNI_ENV_PTR(jvm)->GetEnv(JNI_ENV_ARG(jvm, (void **) &jvmti), JVMTI_VERSION_9);

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

   112         reportError("GetEnv(JVMTI_VERSION_9) failed", res);

   113         return JNI_ERR;

   114     }

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

   116     if (err != JVMTI_ERROR_NONE) {

   117         reportError("GetPotentialCapabilities failed", err);

   118         return JNI_ERR;

   119     }

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

   121     if (err != JVMTI_ERROR_NONE) {

   122         reportError("AddCapabilities failed",err);

   123         return JNI_ERR;

   124     }

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

   126     if (err != JVMTI_ERROR_NONE) {

   127         reportError("GetCapabilities failed", err);

   128         return JNI_ERR;

   129     }

   130     if (caps.can_generate_frame_pop_events) {

   131         callbacks.FramePop = &FramePop;

   132         err = (*jvmti)->SetEventCallbacks(jvmti, &callbacks, sizeof(callbacks));

   133         if (err != JVMTI_ERROR_NONE) {

   134             reportError("SetEventCallbacks failed", err);

   135             return JNI_ERR;

   136         }

   137     }

   138     return JNI_OK;

   139 }

   140 

   141 JNIEXPORT jboolean JNICALL

   142 Java_NotifyFramePopTest_canGenerateFramePopEvents(JNIEnv *env, jclass cls) {

   143     return caps.can_generate_frame_pop_events ? JNI_TRUE : JNI_FALSE;

   144 }

   145 

   146 JNIEXPORT void JNICALL

   147 Java_NotifyFramePopTest_setFramePopNotificationMode(JNIEnv *env, jclass cl, jboolean enable) {

   148     jvmtiEventMode mode = enable ? JVMTI_ENABLE : JVMTI_DISABLE;

   149     jvmtiError err = (*jvmti)->SetEventNotificationMode(jvmti, mode, JVMTI_EVENT_FRAME_POP, NULL);

   150     if (err != JVMTI_ERROR_NONE) {

   151         reportError("Failed to set notification mode for FRAME_POP events", err);

   152     }

   153 }

   154 

   155 JNIEXPORT void JNICALL

   156 Java_NotifyFramePopTest_notifyFramePop(JNIEnv *env, jclass cls, jthread thread)

   157 {

   158     jvmtiError err= (*jvmti)->NotifyFramePop(jvmti, thread, 1);

   159     if (err != JVMTI_ERROR_NONE) {

   160         reportError("NotifyFramePop failed", err);

   161     }

   162 }

   163 

   164 JNIEXPORT jboolean JNICALL

   165 Java_NotifyFramePopTest_framePopReceived(JNIEnv *env, jclass cls) {

   166     jboolean result = framePopReceived;

   167     framePopReceived = JNI_FALSE;

   168     return result;

   169 }

   170 

   171 #ifdef __cplusplus

   172 }

   173 #endif