dalvik_system_VMStack.cc revision ab61295e55c38072095e498053b8f5bebf46ad63
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 27namespace art { 28 29static 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 bool timed_out; 38 Thread* thread; 39 { 40 // Take suspend thread lock to avoid races with threads trying to suspend this one. 41 MutexLock mu(soa.Self(), *Locks::thread_list_suspend_thread_lock_); 42 thread = ThreadList::SuspendThreadByPeer(peer, true, false, &timed_out); 43 } 44 if (thread != nullptr) { 45 // Must be runnable to create returned array. 46 CHECK_EQ(soa.Self()->TransitionFromSuspendedToRunnable(), kNative); 47 trace = thread->CreateInternalStackTrace<false>(soa); 48 soa.Self()->TransitionFromRunnableToSuspended(kNative); 49 // Restart suspended thread. 50 Runtime::Current()->GetThreadList()->Resume(thread, false); 51 } else { 52 if (timed_out) { 53 LOG(ERROR) << "Trying to get thread's stack failed as the thread failed to suspend within a " 54 "generous timeout."; 55 } 56 } 57 CHECK_EQ(soa.Self()->TransitionFromSuspendedToRunnable(), kNative); 58 } 59 return trace; 60} 61 62static jint VMStack_fillStackTraceElements(JNIEnv* env, jclass, jobject javaThread, 63 jobjectArray javaSteArray) { 64 ScopedFastNativeObjectAccess soa(env); 65 jobject trace = GetThreadStack(soa, javaThread); 66 if (trace == nullptr) { 67 return 0; 68 } 69 int32_t depth; 70 Thread::InternalStackTraceToStackTraceElementArray(soa, trace, javaSteArray, &depth); 71 return depth; 72} 73 74// Returns the defining class loader of the caller's caller. 75static jobject VMStack_getCallingClassLoader(JNIEnv* env, jclass) { 76 ScopedFastNativeObjectAccess soa(env); 77 NthCallerVisitor visitor(soa.Self(), 2); 78 visitor.WalkStack(); 79 if (UNLIKELY(visitor.caller == nullptr)) { 80 // The caller is an attached native thread. 81 return nullptr; 82 } 83 return soa.AddLocalReference<jobject>(visitor.caller->GetDeclaringClass()->GetClassLoader()); 84} 85 86static jobject VMStack_getClosestUserClassLoader(JNIEnv* env, jclass, jobject javaBootstrap, 87 jobject javaSystem) { 88 struct ClosestUserClassLoaderVisitor : public StackVisitor { 89 ClosestUserClassLoaderVisitor(Thread* thread, mirror::Object* bootstrap, mirror::Object* system) 90 : StackVisitor(thread, NULL), bootstrap(bootstrap), system(system), class_loader(NULL) {} 91 92 bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 93 DCHECK(class_loader == NULL); 94 mirror::Class* c = GetMethod()->GetDeclaringClass(); 95 mirror::Object* cl = c->GetClassLoader(); 96 if (cl != NULL && cl != bootstrap && cl != system) { 97 class_loader = cl; 98 return false; 99 } 100 return true; 101 } 102 103 mirror::Object* bootstrap; 104 mirror::Object* system; 105 mirror::Object* class_loader; 106 }; 107 ScopedFastNativeObjectAccess soa(env); 108 mirror::Object* bootstrap = soa.Decode<mirror::Object*>(javaBootstrap); 109 mirror::Object* system = soa.Decode<mirror::Object*>(javaSystem); 110 ClosestUserClassLoaderVisitor visitor(soa.Self(), bootstrap, system); 111 visitor.WalkStack(); 112 return soa.AddLocalReference<jobject>(visitor.class_loader); 113} 114 115// Returns the class of the caller's caller's caller. 116static jclass VMStack_getStackClass2(JNIEnv* env, jclass) { 117 ScopedFastNativeObjectAccess soa(env); 118 NthCallerVisitor visitor(soa.Self(), 3); 119 visitor.WalkStack(); 120 if (UNLIKELY(visitor.caller == nullptr)) { 121 // The caller is an attached native thread. 122 return nullptr; 123 } 124 return soa.AddLocalReference<jclass>(visitor.caller->GetDeclaringClass()); 125} 126 127static jobjectArray VMStack_getThreadStackTrace(JNIEnv* env, jclass, jobject javaThread) { 128 ScopedFastNativeObjectAccess soa(env); 129 jobject trace = GetThreadStack(soa, javaThread); 130 if (trace == nullptr) { 131 return nullptr; 132 } 133 return Thread::InternalStackTraceToStackTraceElementArray(soa, trace); 134} 135 136static JNINativeMethod gMethods[] = { 137 NATIVE_METHOD(VMStack, fillStackTraceElements, "!(Ljava/lang/Thread;[Ljava/lang/StackTraceElement;)I"), 138 NATIVE_METHOD(VMStack, getCallingClassLoader, "!()Ljava/lang/ClassLoader;"), 139 NATIVE_METHOD(VMStack, getClosestUserClassLoader, "!(Ljava/lang/ClassLoader;Ljava/lang/ClassLoader;)Ljava/lang/ClassLoader;"), 140 NATIVE_METHOD(VMStack, getStackClass2, "!()Ljava/lang/Class;"), 141 NATIVE_METHOD(VMStack, getThreadStackTrace, "!(Ljava/lang/Thread;)[Ljava/lang/StackTraceElement;"), 142}; 143 144void register_dalvik_system_VMStack(JNIEnv* env) { 145 REGISTER_NATIVE_METHODS("dalvik/system/VMStack"); 146} 147 148} // namespace art 149