1 /*
2 * Copyright (c) 2023, 2024, 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 <cstring>
25 #include <jvmti.h>
26 #include <atomic>
27 #include "jvmti_common.hpp"
28
29 extern "C" {
30
31 static jvmtiEnv *jvmti = nullptr;
32 static std::atomic<int> thread_end_cnt(0);
33 static std::atomic<int> thread_unmount_cnt(0);
34 static std::atomic<int> thread_mount_cnt(0);
35
36 void JNICALL VirtualThreadEnd(jvmtiEnv *jvmti, JNIEnv* jni, jthread vthread) {
37 thread_end_cnt++;
38 }
39
40 void JNICALL VirtualThreadMount(jvmtiEnv* jvmti, ...) {
41 thread_mount_cnt++;
42 }
43
44 void JNICALL VirtualThreadUnmount(jvmtiEnv* jvmti, ...) {
45 thread_unmount_cnt++;
46 }
47
48 JNIEXPORT jint JNICALL
49 Java_VThreadEventTest_threadEndCount(JNIEnv* jni, jclass clazz) {
50 return thread_end_cnt;
51 }
52
53 JNIEXPORT jint JNICALL
54 Java_VThreadEventTest_threadMountCount(JNIEnv* jni, jclass clazz) {
55 return thread_mount_cnt;
56 }
57
58 JNIEXPORT jint JNICALL
59 Java_VThreadEventTest_threadUnmountCount(JNIEnv* jni, jclass clazz) {
60 return thread_unmount_cnt;
61 }
62
63 JNIEXPORT jint JNICALL
64 Agent_OnAttach(JavaVM *vm, char *options, void *reserved) {
65 jvmtiEventCallbacks callbacks;
66 jvmtiCapabilities caps;
67 jvmtiError err;
68
69 LOG("Agent_OnAttach started\n");
70 if (vm->GetEnv(reinterpret_cast<void **>(&jvmti), JVMTI_VERSION) != JNI_OK || !jvmti) {
71 LOG("Could not initialize JVMTI env\n");
72 return JNI_ERR;
73 }
74 memset(&caps, 0, sizeof(caps));
75 caps.can_support_virtual_threads = 1;
76 check_jvmti_error(jvmti->AddCapabilities(&caps), "AddCapabilities");
77
78 memset(&callbacks, 0, sizeof(callbacks));
79 callbacks.VirtualThreadEnd = &VirtualThreadEnd;
80
81 err = jvmti->SetEventCallbacks(&callbacks, (jint)sizeof(callbacks));
82 check_jvmti_error(err, "SetEventCallbacks");
83
84 err = set_ext_event_callback(jvmti, "VirtualThreadMount", VirtualThreadMount);
85 check_jvmti_error(err, "SetExtEventCallback for VirtualThreadMount");
86
87 err = set_ext_event_callback(jvmti, "VirtualThreadUnmount", VirtualThreadUnmount);
88 check_jvmti_error(err, "SetExtEventCallback for VirtualThreadUnmount");
89
90 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE, JVMTI_EVENT_VIRTUAL_THREAD_END, nullptr);
91 check_jvmti_error(err, "SetEventNotificationMode for VirtualThreadEnd");
92
93 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE, EXT_EVENT_VIRTUAL_THREAD_MOUNT, nullptr);
94 check_jvmti_error(err, "SetEventNotificationMode for VirtualThreadMount");
95
96 err = jvmti->SetEventNotificationMode(JVMTI_ENABLE, EXT_EVENT_VIRTUAL_THREAD_UNMOUNT, nullptr);
97 check_jvmti_error(err, "SetEventNotificationMode for VirtualThreadUnmount");
98
99 LOG("vthread events enabled\n");
100 return JVMTI_ERROR_NONE;
101 }
102
103 } // extern "C"
104