1 /* 2 * Copyright (C) 2008 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 "jni_internal.h" 18 #include "nth_caller_visitor.h" 19 #include "mirror/art_method-inl.h" 20 #include "mirror/class-inl.h" 21 #include "mirror/class_loader.h" 22 #include "mirror/object-inl.h" 23 #include "scoped_fast_native_object_access.h" 24 #include "scoped_thread_state_change.h" 25 #include "thread_list.h" 26 27 namespace art { 28 29 static jobject GetThreadStack(const ScopedFastNativeObjectAccess& soa, jobject peer) 30 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 31 jobject trace = nullptr; 32 if (soa.Decode<mirror::Object*>(peer) == soa.Self()->GetPeer()) { 33 trace = soa.Self()->CreateInternalStackTrace<false>(soa); 34 } else { 35 // Suspend thread to build stack trace. 36 soa.Self()->TransitionFromRunnableToSuspended(kNative); 37 ThreadList* thread_list = Runtime::Current()->GetThreadList(); 38 bool timed_out; 39 Thread* thread; 40 { 41 // Take suspend thread lock to avoid races with threads trying to suspend this one. 42 MutexLock mu(soa.Self(), *Locks::thread_list_suspend_thread_lock_); 43 thread = thread_list->SuspendThreadByPeer(peer, true, false, &timed_out); 44 } 45 if (thread != nullptr) { 46 // Must be runnable to create returned array. 47 CHECK_EQ(soa.Self()->TransitionFromSuspendedToRunnable(), kNative); 48 trace = thread->CreateInternalStackTrace<false>(soa); 49 soa.Self()->TransitionFromRunnableToSuspended(kNative); 50 // Restart suspended thread. 51 thread_list->Resume(thread, false); 52 } else { 53 if (timed_out) { 54 LOG(ERROR) << "Trying to get thread's stack failed as the thread failed to suspend within a " 55 "generous timeout."; 56 } 57 } 58 CHECK_EQ(soa.Self()->TransitionFromSuspendedToRunnable(), kNative); 59 } 60 return trace; 61 } 62 63 static jint VMStack_fillStackTraceElements(JNIEnv* env, jclass, jobject javaThread, 64 jobjectArray javaSteArray) { 65 ScopedFastNativeObjectAccess soa(env); 66 jobject trace = GetThreadStack(soa, javaThread); 67 if (trace == nullptr) { 68 return 0; 69 } 70 int32_t depth; 71 Thread::InternalStackTraceToStackTraceElementArray(soa, trace, javaSteArray, &depth); 72 return depth; 73 } 74 75 // Returns the defining class loader of the caller's caller. 76 static jobject VMStack_getCallingClassLoader(JNIEnv* env, jclass) { 77 ScopedFastNativeObjectAccess soa(env); 78 NthCallerVisitor visitor(soa.Self(), 2); 79 visitor.WalkStack(); 80 if (UNLIKELY(visitor.caller == nullptr)) { 81 // The caller is an attached native thread. 82 return nullptr; 83 } 84 return soa.AddLocalReference<jobject>(visitor.caller->GetDeclaringClass()->GetClassLoader()); 85 } 86 87 static jobject VMStack_getClosestUserClassLoader(JNIEnv* env, jclass, jobject javaBootstrap, 88 jobject javaSystem) { 89 struct ClosestUserClassLoaderVisitor : public StackVisitor { 90 ClosestUserClassLoaderVisitor(Thread* thread, mirror::Object* bootstrap, mirror::Object* system) 91 : StackVisitor(thread, NULL), bootstrap(bootstrap), system(system), class_loader(NULL) {} 92 93 bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 94 DCHECK(class_loader == NULL); 95 mirror::Class* c = GetMethod()->GetDeclaringClass(); 96 mirror::Object* cl = c->GetClassLoader(); 97 if (cl != NULL && cl != bootstrap && cl != system) { 98 class_loader = cl; 99 return false; 100 } 101 return true; 102 } 103 104 mirror::Object* bootstrap; 105 mirror::Object* system; 106 mirror::Object* class_loader; 107 }; 108 ScopedFastNativeObjectAccess soa(env); 109 mirror::Object* bootstrap = soa.Decode<mirror::Object*>(javaBootstrap); 110 mirror::Object* system = soa.Decode<mirror::Object*>(javaSystem); 111 ClosestUserClassLoaderVisitor visitor(soa.Self(), bootstrap, system); 112 visitor.WalkStack(); 113 return soa.AddLocalReference<jobject>(visitor.class_loader); 114 } 115 116 // Returns the class of the caller's caller's caller. 117 static jclass VMStack_getStackClass2(JNIEnv* env, jclass) { 118 ScopedFastNativeObjectAccess soa(env); 119 NthCallerVisitor visitor(soa.Self(), 3); 120 visitor.WalkStack(); 121 if (UNLIKELY(visitor.caller == nullptr)) { 122 // The caller is an attached native thread. 123 return nullptr; 124 } 125 return soa.AddLocalReference<jclass>(visitor.caller->GetDeclaringClass()); 126 } 127 128 static jobjectArray VMStack_getThreadStackTrace(JNIEnv* env, jclass, jobject javaThread) { 129 ScopedFastNativeObjectAccess soa(env); 130 jobject trace = GetThreadStack(soa, javaThread); 131 if (trace == nullptr) { 132 return nullptr; 133 } 134 return Thread::InternalStackTraceToStackTraceElementArray(soa, trace); 135 } 136 137 static JNINativeMethod gMethods[] = { 138 NATIVE_METHOD(VMStack, fillStackTraceElements, "!(Ljava/lang/Thread;[Ljava/lang/StackTraceElement;)I"), 139 NATIVE_METHOD(VMStack, getCallingClassLoader, "!()Ljava/lang/ClassLoader;"), 140 NATIVE_METHOD(VMStack, getClosestUserClassLoader, "!(Ljava/lang/ClassLoader;Ljava/lang/ClassLoader;)Ljava/lang/ClassLoader;"), 141 NATIVE_METHOD(VMStack, getStackClass2, "!()Ljava/lang/Class;"), 142 NATIVE_METHOD(VMStack, getThreadStackTrace, "!(Ljava/lang/Thread;)[Ljava/lang/StackTraceElement;"), 143 }; 144 145 void register_dalvik_system_VMStack(JNIEnv* env) { 146 REGISTER_NATIVE_METHODS("dalvik/system/VMStack"); 147 } 148 149 } // namespace art 150
