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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "dalvik_system_VMStack.h"
#include <type_traits>
#include "nativehelper/jni_macros.h"
#include "art_method-inl.h"
#include "gc/task_processor.h"
#include "jni/jni_internal.h"
#include "mirror/class-inl.h"
#include "mirror/class_loader.h"
#include "mirror/object-inl.h"
#include "native_util.h"
#include "nth_caller_visitor.h"
#include "scoped_fast_native_object_access-inl.h"
#include "scoped_thread_state_change-inl.h"
#include "thread_list.h"
namespace art HIDDEN {
template <typename T,
typename ResultT =
typename std::result_of<T(Thread*, const ScopedFastNativeObjectAccess&)>::type>
static ResultT GetThreadStack(const ScopedFastNativeObjectAccess& soa,
jobject peer,
T fn)
REQUIRES_SHARED(Locks::mutator_lock_) {
ResultT trace = nullptr;
ObjPtr<mirror::Object> decoded_peer = soa.Decode<mirror::Object>(peer);
if (decoded_peer == soa.Self()->GetPeer()) {
trace = fn(soa.Self(), soa);
return trace;
}
// Suspend thread to build stack trace.
ScopedThreadSuspension sts(soa.Self(), ThreadState::kNative);
Runtime* runtime = Runtime::Current();
ThreadList* thread_list = runtime->GetThreadList();
Thread* thread = thread_list->SuspendThreadByPeer(peer, SuspendReason::kInternal);
if (thread != nullptr) {
// If we were asked for the HeapTaskDaemon's stack trace, we went ahead and suspended it.
// It's usually already in a suspended state anyway. But we should immediately give up and
// resume it, since we must be able to allocate while generating the stack trace.
if (!runtime->GetHeap()->GetTaskProcessor()->IsRunningThread(thread, /*wait=*/true)) {
{
// Must be runnable to create returned array.
ScopedObjectAccess soa2(soa.Self());
trace = fn(thread, soa);
}
// Else either thread is the HeapTaskDaemon, or we couldn't identify the thread yet. The
// HeapTaskDaemon can appear in enumerations before it is registered with the task
// processor, and we don't wait indefinitely, so there is a tiny chance of the latter.
}
// Restart suspended thread.
bool resumed = thread_list->Resume(thread, SuspendReason::kInternal);
DCHECK(resumed);
}
return trace;
}
static jint VMStack_fillStackTraceElements(JNIEnv* env, jclass, jobject javaThread,
jobjectArray javaSteArray) {
ScopedFastNativeObjectAccess soa(env);
auto fn = [](Thread* thread, const ScopedFastNativeObjectAccess& soaa)
REQUIRES_SHARED(Locks::mutator_lock_) -> jobject {
return thread->CreateInternalStackTrace(soaa);
};
jobject trace = GetThreadStack(soa, javaThread, fn);
if (trace == nullptr) {
return 0;
}
int32_t depth;
Thread::InternalStackTraceToStackTraceElementArray(soa, trace, javaSteArray, &depth);
return depth;
}
// Returns the defining class loader of the caller's caller.
static jobject VMStack_getCallingClassLoader(JNIEnv* env, jclass) {
ScopedFastNativeObjectAccess soa(env);
NthCallerVisitor visitor(soa.Self(), 2);
visitor.WalkStack();
if (UNLIKELY(visitor.caller == nullptr)) {
// The caller is an attached native thread.
return nullptr;
}
return soa.AddLocalReference<jobject>(visitor.caller->GetDeclaringClass()->GetClassLoader());
}
static jobject VMStack_getClosestUserClassLoader(JNIEnv* env, jclass) {
struct ClosestUserClassLoaderVisitor : public StackVisitor {
explicit ClosestUserClassLoaderVisitor(Thread* thread)
: StackVisitor(thread, nullptr, StackVisitor::StackWalkKind::kIncludeInlinedFrames),
class_loader(nullptr) {}
bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
DCHECK(class_loader == nullptr);
ObjPtr<mirror::Class> c = GetMethod()->GetDeclaringClass();
// c is null for runtime methods.
if (c != nullptr) {
ObjPtr<mirror::Object> cl = c->GetClassLoader();
if (cl != nullptr) {
class_loader = cl;
return false;
}
}
return true;
}
ObjPtr<mirror::Object> class_loader;
};
ScopedFastNativeObjectAccess soa(env);
ClosestUserClassLoaderVisitor visitor(soa.Self());
visitor.WalkStack();
return soa.AddLocalReference<jobject>(visitor.class_loader);
}
// Returns the class of the caller's caller's caller.
static jclass VMStack_getStackClass2(JNIEnv* env, jclass) {
ScopedFastNativeObjectAccess soa(env);
NthCallerVisitor visitor(soa.Self(), 3);
visitor.WalkStack();
if (UNLIKELY(visitor.caller == nullptr)) {
// The caller is an attached native thread.
return nullptr;
}
return soa.AddLocalReference<jclass>(visitor.caller->GetDeclaringClass());
}
static jobjectArray VMStack_getThreadStackTrace(JNIEnv* env, jclass, jobject javaThread) {
ScopedFastNativeObjectAccess soa(env);
auto fn = [](Thread* thread, const ScopedFastNativeObjectAccess& soaa)
REQUIRES_SHARED(Locks::mutator_lock_) -> jobject {
return thread->CreateInternalStackTrace(soaa);
};
jobject trace = GetThreadStack(soa, javaThread, fn);
if (trace == nullptr) {
return nullptr;
}
return Thread::InternalStackTraceToStackTraceElementArray(soa, trace);
}
static jobjectArray VMStack_getAnnotatedThreadStackTrace(JNIEnv* env, jclass, jobject javaThread) {
ScopedFastNativeObjectAccess soa(env);
auto fn = [](Thread* thread, const ScopedFastNativeObjectAccess& soaa)
REQUIRES_SHARED(Locks::mutator_lock_) -> jobjectArray {
return thread->CreateAnnotatedStackTrace(soaa);
};
return GetThreadStack(soa, javaThread, fn);
}
static JNINativeMethod gMethods[] = {
FAST_NATIVE_METHOD(VMStack, fillStackTraceElements, "(Ljava/lang/Thread;[Ljava/lang/StackTraceElement;)I"),
FAST_NATIVE_METHOD(VMStack, getCallingClassLoader, "()Ljava/lang/ClassLoader;"),
FAST_NATIVE_METHOD(VMStack, getClosestUserClassLoader, "()Ljava/lang/ClassLoader;"),
FAST_NATIVE_METHOD(VMStack, getStackClass2, "()Ljava/lang/Class;"),
FAST_NATIVE_METHOD(VMStack, getThreadStackTrace, "(Ljava/lang/Thread;)[Ljava/lang/StackTraceElement;"),
FAST_NATIVE_METHOD(VMStack, getAnnotatedThreadStackTrace, "(Ljava/lang/Thread;)[Ldalvik/system/AnnotatedStackTraceElement;"),
};
void register_dalvik_system_VMStack(JNIEnv* env) {
REGISTER_NATIVE_METHODS("dalvik/system/VMStack");
}
} // namespace art
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