1 /*
2  * Copyright (C) 2017 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <mutex>
18 
19 #include "jni.h"
20 #include "jvmti.h"
21 
22 #include "android-base/logging.h"
23 #include "android-base/stringprintf.h"
24 #include "jni_binder.h"
25 #include "jvmti_helper.h"
26 #include "scoped_local_ref.h"
27 #include "scoped_utf_chars.h"
28 #include "test_env.h"
29 
30 namespace art {
31 
GetClassName(JNIEnv * jni_env,jclass cls)32 static std::string GetClassName(JNIEnv* jni_env, jclass cls) {
33   ScopedLocalRef<jclass> class_class(jni_env, jni_env->GetObjectClass(cls));
34   jmethodID mid = jni_env->GetMethodID(class_class.get(), "getName", "()Ljava/lang/String;");
35   ScopedLocalRef<jstring> str(
36       jni_env, reinterpret_cast<jstring>(jni_env->CallObjectMethod(cls, mid)));
37   ScopedUtfChars utf_chars(jni_env, str.get());
38   return utf_chars.c_str();
39 }
40 
41 static std::mutex gLock;
42 static std::string gCollection;
43 
ObjectAllocated(jvmtiEnv * ti_env ATTRIBUTE_UNUSED,JNIEnv * jni_env,jthread thread ATTRIBUTE_UNUSED,jobject object,jclass object_klass,jlong size)44 static void JNICALL ObjectAllocated(jvmtiEnv* ti_env ATTRIBUTE_UNUSED,
45                                     JNIEnv* jni_env,
46                                     jthread thread ATTRIBUTE_UNUSED,
47                                     jobject object,
48                                     jclass object_klass,
49                                     jlong size) {
50   std::string object_klass_descriptor = GetClassName(jni_env, object_klass);
51   ScopedLocalRef<jclass> object_klass2(jni_env, jni_env->GetObjectClass(object));
52   std::string object_klass_descriptor2 = GetClassName(jni_env, object_klass2.get());
53   std::string result = android::base::StringPrintf("ObjectAllocated type %s/%s size %zu",
54                                                    object_klass_descriptor.c_str(),
55                                                    object_klass_descriptor2.c_str(),
56                                                    static_cast<size_t>(size));
57   std::unique_lock<std::mutex> mu(gLock);
58   gCollection += result + "#";
59 }
60 
Java_android_jvmti_cts_JvmtiTrackingTest_setupObjectAllocCallback(JNIEnv * env,jclass klass ATTRIBUTE_UNUSED,jboolean enable)61 extern "C" JNIEXPORT void JNICALL Java_android_jvmti_cts_JvmtiTrackingTest_setupObjectAllocCallback(
62     JNIEnv* env, jclass klass ATTRIBUTE_UNUSED, jboolean enable) {
63   jvmtiEventCallbacks callbacks;
64   memset(&callbacks, 0, sizeof(jvmtiEventCallbacks));
65   callbacks.VMObjectAlloc = enable ? ObjectAllocated : nullptr;
66 
67   jvmtiError ret = jvmti_env->SetEventCallbacks(&callbacks, sizeof(callbacks));
68   JvmtiErrorToException(env, jvmti_env, ret);
69 }
70 
Java_android_jvmti_cts_JvmtiTrackingTest_enableAllocationTracking(JNIEnv * env,jclass klass ATTRIBUTE_UNUSED,jthread thread,jboolean enable)71 extern "C" JNIEXPORT void JNICALL Java_android_jvmti_cts_JvmtiTrackingTest_enableAllocationTracking(
72     JNIEnv* env, jclass klass ATTRIBUTE_UNUSED, jthread thread, jboolean enable) {
73   jvmtiError ret = jvmti_env->SetEventNotificationMode(
74       enable ? JVMTI_ENABLE : JVMTI_DISABLE,
75       JVMTI_EVENT_VM_OBJECT_ALLOC,
76       thread);
77   JvmtiErrorToException(env, jvmti_env, ret);
78 }
79 
80 extern "C" JNIEXPORT
Java_android_jvmti_cts_JvmtiTrackingTest_getAndResetAllocationTrackingString(JNIEnv * env,jclass klass ATTRIBUTE_UNUSED)81 jstring JNICALL Java_android_jvmti_cts_JvmtiTrackingTest_getAndResetAllocationTrackingString(
82     JNIEnv* env, jclass klass ATTRIBUTE_UNUSED) {
83   // We will have a string allocation. So only do the C++ string retrieval under lock.
84   std::string result;
85   {
86     std::unique_lock<std::mutex> mu(gLock);
87     result.swap(gCollection);
88   }
89   // Make sure we give any other threads that might have been waiting to get a last crack time to
90   // run. We will ignore their additions however.
91   bool is_empty = false;
92   do {
93     {
94       std::unique_lock<std::mutex> mu(gLock);
95       is_empty = gCollection.empty();
96       gCollection.clear();
97     }
98     sched_yield();
99   } while (!is_empty);
100 
101   if (result.empty()) {
102     return nullptr;
103   }
104 
105   return env->NewStringUTF(result.c_str());
106 }
107 
108 static JNINativeMethod gMethods[] = {
109   { "setupObjectAllocCallback", "(Z)V",
110           (void*)Java_android_jvmti_cts_JvmtiTrackingTest_setupObjectAllocCallback },
111 
112   { "enableAllocationTracking", "(Ljava/lang/Thread;Z)V",
113           (void*)Java_android_jvmti_cts_JvmtiTrackingTest_enableAllocationTracking },
114 
115   { "getAndResetAllocationTrackingString", "()Ljava/lang/String;",
116           (void*)Java_android_jvmti_cts_JvmtiTrackingTest_getAndResetAllocationTrackingString },
117 };
118 
register_android_jvmti_cts_JvmtiTrackingTest(jvmtiEnv * jenv,JNIEnv * env)119 void register_android_jvmti_cts_JvmtiTrackingTest(jvmtiEnv* jenv, JNIEnv* env) {
120   ScopedLocalRef<jclass> klass(env, GetClass(jenv, env,
121           "android/jvmti/cts/JvmtiTrackingTest", nullptr));
122   if (klass.get() == nullptr) {
123     env->ExceptionClear();
124     return;
125   }
126 
127   env->RegisterNatives(klass.get(), gMethods, sizeof(gMethods) / sizeof(JNINativeMethod));
128   if (env->ExceptionCheck()) {
129     env->ExceptionClear();
130     LOG(ERROR) << "Could not register natives for JvmtiTrackingTest class";
131   }
132 }
133 
134 }  // namespace art
135