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 <jni.h>
25 #include <jvmti.h>
26 #include <jvmti_common.hpp>
27 #include <atomic>
28
29 static jvmtiEnv *jvmti = nullptr;
30 static jint error_count = 0;
31
32 extern "C" JNIEXPORT jint JNICALL
33 Agent_OnLoad(JavaVM *vm, char *options, void *reserved) {
34 if (vm->GetEnv((void **)&jvmti, JVMTI_VERSION) != JNI_OK) {
35 LOG("Could not initialize JVMTI\n");
36 return JNI_ERR;
37 }
38 jvmtiCapabilities caps;
39 memset(&caps, 0, sizeof(caps));
40 caps.can_support_virtual_threads = 1;
41 caps.can_suspend = 1;
42 caps.can_signal_thread = 1;
43 jvmtiError err = jvmti->AddCapabilities(&caps);
44 if (err != JVMTI_ERROR_NONE) {
45 LOG("JVMTI AddCapabilities error: %d\n", err);
46 return JNI_ERR;
47 }
48
49 return JNI_OK;
50 }
51
52
53 extern "C" JNIEXPORT jboolean JNICALL
54 Java_GetThreadStateMountedTest_trySuspendInWaitingState(JNIEnv* jni, jclass clazz, jthread vthread) {
55 const int max_retries = 10;
56 for (int i = 0; i < max_retries; i++) {
57 // wait a bit
58 sleep_ms(100);
59
60 // suspend the thread
61 LOG("suspend vthread (%d)\n", i);
62 suspend_thread(jvmti, jni, vthread);
63
64 jint state = get_thread_state(jvmti, jni, vthread);
65 if ((state & JVMTI_THREAD_STATE_WAITING) != 0) {
66 LOG("suspended in WAITING state\n");
67 return JNI_TRUE;
68 }
69 LOG("suspended vthread is not waiting: state = %x (%s)\n", state, TranslateState(state));
70 LOG("resume vthread\n");
71 resume_thread(jvmti, jni, vthread);
72 }
73 LOG("ERROR: failed to suspend in WAITING state in %d tries\n", max_retries);
74 return JNI_FALSE;
75
76 }
77
78 static void verify_thread_state(const char *name, JNIEnv* jni,
79 jthread thread, jint expected_strong, jint expected_weak)
80 {
81 jint state = get_thread_state(jvmti, jni, thread);
82 LOG("%s state(%x): %s\n", name, state, TranslateState(state));
83 bool failed = false;
84 // check 1: all expected_strong bits are set
85 jint actual_strong = state & expected_strong;
86 if (actual_strong != expected_strong) {
87 failed = true;
88 jint missed = expected_strong - actual_strong;
89 LOG(" ERROR: some mandatory bits are not set (%x): %s\n",
90 missed, TranslateState(missed));
91 }
92 // check 2: no bits other than (expected_strong | expected_weak) are set
93 jint actual_full = state & (expected_strong | expected_weak);
94 if (actual_full != state) {
95 failed = true;
96 jint unexpected = state - actual_full;
97 LOG(" ERROR: some unexpected bits are set (%x): %s\n",
98 unexpected, TranslateState(unexpected));
99 }
100 // check 3: expected_weak checks
101 if (expected_weak != 0) {
102 // check 3a: at least 1 bit from expected_weak is set
103 if ((state & expected_weak) == 0) {
104 failed = true;
105 LOG(" ERROR: no expected 'weak' bits are set\n");
106 }
107 // check 3b: not all expected_weak bits are set
108 if ((state & expected_weak) == expected_weak) {
109 failed = true;
110 LOG(" ERROR: all expected 'weak' bits are set\n");
111 }
112 }
113
114 if (failed) {
115 LOG(" expected 'strong' state (%x): %s\n", expected_strong, TranslateState(expected_strong));
116 LOG(" expected 'weak' state (%x): %s\n", expected_weak, TranslateState(expected_weak));
117 error_count++;
118 }
119 }
120
121 extern "C" JNIEXPORT void JNICALL
122 Java_GetThreadStateMountedTest_testThread(
123 JNIEnv* jni, jclass clazz, jthread vthread, jboolean is_vthread_suspended,
124 jboolean test_interrupt,
125 jint expected_strong, jint expected_weak)
126 {
127 jint exp_ct_state = JVMTI_THREAD_STATE_ALIVE
128 | JVMTI_THREAD_STATE_WAITING
129 | JVMTI_THREAD_STATE_WAITING_INDEFINITELY;
130 jint exp_vt_state = expected_strong
131 | JVMTI_THREAD_STATE_ALIVE;
132
133 jthread cthread = get_carrier_thread(jvmti, jni, vthread);
134
135 verify_thread_state("cthread", jni, cthread,
136 exp_ct_state, 0);
137 verify_thread_state("vthread", jni, vthread,
138 exp_vt_state | (is_vthread_suspended ? JVMTI_THREAD_STATE_SUSPENDED : 0),
139 expected_weak);
140
141 // suspend ctread and verify
142 LOG("suspend cthread\n");
143 suspend_thread(jvmti, jni, cthread);
144 verify_thread_state("cthread", jni, cthread,
145 exp_ct_state | JVMTI_THREAD_STATE_SUSPENDED, 0);
146 verify_thread_state("vthread", jni, vthread,
147 exp_vt_state | (is_vthread_suspended ? JVMTI_THREAD_STATE_SUSPENDED : 0),
148 expected_weak);
149
150 // suspend vthread and verify
151 if (!is_vthread_suspended) {
152 LOG("suspend vthread\n");
153 suspend_thread(jvmti, jni, vthread);
154 verify_thread_state("cthread", jni, cthread,
155 exp_ct_state | JVMTI_THREAD_STATE_SUSPENDED, 0);
156 verify_thread_state("vthread", jni, vthread,
157 exp_vt_state | JVMTI_THREAD_STATE_SUSPENDED, expected_weak);
158 }
159
160 // resume cthread and verify
161 LOG("resume cthread\n");
162 resume_thread(jvmti, jni, cthread);
163 verify_thread_state("cthread", jni, cthread,
164 exp_ct_state, 0);
165 verify_thread_state("vthread", jni, vthread,
166 exp_vt_state | JVMTI_THREAD_STATE_SUSPENDED, expected_weak);
167
168 if (test_interrupt) {
169 // interrupt vthread (while it's suspended)
170 LOG("interrupt vthread\n");
171 check_jvmti_status(jni, jvmti->InterruptThread(vthread), "error in JVMTI InterruptThread");
172 verify_thread_state("cthread", jni, cthread,
173 exp_ct_state, 0);
174 verify_thread_state("vthread", jni, vthread,
175 exp_vt_state | JVMTI_THREAD_STATE_SUSPENDED | JVMTI_THREAD_STATE_INTERRUPTED,
176 expected_weak);
177 }
178
179 // resume vthread
180 LOG("resume vthread\n");
181 resume_thread(jvmti, jni, vthread);
182
183 // don't verify thread state after InterruptThread and ResumeThread
184 }
185
186 extern "C" JNIEXPORT int JNICALL
187 Java_GetThreadStateMountedTest_getErrorCount(JNIEnv* jni, jclass clazz) {
188 return error_count;
189 }
190
191
192 static std::atomic<bool> time_to_exit(false);
193
194 extern "C" JNIEXPORT void JNICALL
195 Java_GetThreadStateMountedTest_runFromNative(JNIEnv* jni, jclass clazz, jobject runnable) {
196 jmethodID mid = jni->GetStaticMethodID(clazz, "runUpcall", "(Ljava/lang/Runnable;)V");
197 if (mid == nullptr) {
198 jni->FatalError("failed to get runUpcall method");
199 return;
200 }
201 jni->CallStaticVoidMethod(clazz, mid, runnable);
202 }
203
204 extern "C" JNIEXPORT void JNICALL
205 Java_GetThreadStateMountedTest_waitInNative(JNIEnv* jni, jclass clazz) {
206 // Notify main thread that we are ready
207 jfieldID fid = jni->GetStaticFieldID(clazz, "waitInNativeReady", "Z");
208 if (fid == nullptr) {
209 jni->FatalError("cannot get waitInNativeReady field");
210 return;
211 }
212 jni->SetStaticBooleanField(clazz, fid, JNI_TRUE);
213
214 while (!time_to_exit) {
215 sleep_ms(100);
216 }
217 }
218
219 extern "C" JNIEXPORT void JNICALL
220 Java_GetThreadStateMountedTest_endWait(JNIEnv* jni, jclass clazz) {
221 time_to_exit = true;
222 }