/* Copyright (C) 2016 The Android Open Source Project
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This file implements interfaces from the file jvmti.h. This implementation
* is licensed under the same terms as the file jvmti.h. The
* copyright and license information for the file jvmti.h follows.
*
* Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
#include "ti_stack.h"
#include <algorithm>
#include <list>
#include <unordered_map>
#include <vector>
#include "art_field-inl.h"
#include "art_method-inl.h"
#include "art_jvmti.h"
#include "art_method-inl.h"
#include "barrier.h"
#include "base/bit_utils.h"
#include "base/enums.h"
#include "base/mutex.h"
#include "dex/code_item_accessors-inl.h"
#include "dex/dex_file.h"
#include "dex/dex_file_annotations.h"
#include "dex/dex_file_types.h"
#include "gc_root.h"
#include "handle_scope-inl.h"
#include "jni_env_ext.h"
#include "jni_internal.h"
#include "mirror/class.h"
#include "mirror/dex_cache.h"
#include "nativehelper/scoped_local_ref.h"
#include "scoped_thread_state_change-inl.h"
#include "stack.h"
#include "ti_thread.h"
#include "thread-current-inl.h"
#include "thread_list.h"
#include "thread_pool.h"
#include "ti_thread.h"
#include "well_known_classes.h"
namespace openjdkjvmti {
template <typename FrameFn>
struct GetStackTraceVisitor : public art::StackVisitor {
GetStackTraceVisitor(art::Thread* thread_in,
size_t start_,
size_t stop_,
FrameFn fn_)
: StackVisitor(thread_in, nullptr, StackVisitor::StackWalkKind::kIncludeInlinedFrames),
fn(fn_),
start(start_),
stop(stop_) {}
GetStackTraceVisitor(const GetStackTraceVisitor&) = default;
GetStackTraceVisitor(GetStackTraceVisitor&&) = default;
bool VisitFrame() REQUIRES_SHARED(art::Locks::mutator_lock_) {
art::ArtMethod* m = GetMethod();
if (m->IsRuntimeMethod()) {
return true;
}
if (start == 0) {
m = m->GetInterfaceMethodIfProxy(art::kRuntimePointerSize);
jmethodID id = art::jni::EncodeArtMethod(m);
uint32_t dex_pc = GetDexPc(false);
jlong dex_location = (dex_pc == art::dex::kDexNoIndex) ? -1 : static_cast<jlong>(dex_pc);
jvmtiFrameInfo info = { id, dex_location };
fn(info);
if (stop == 1) {
return false; // We're done.
} else if (stop > 0) {
stop--;
}
} else {
start--;
}
return true;
}
FrameFn fn;
size_t start;
size_t stop;
};
template <typename FrameFn>
GetStackTraceVisitor<FrameFn> MakeStackTraceVisitor(art::Thread* thread_in,
size_t start,
size_t stop,
FrameFn fn) {
return GetStackTraceVisitor<FrameFn>(thread_in, start, stop, fn);
}
struct GetStackTraceVectorClosure : public art::Closure {
public:
GetStackTraceVectorClosure(size_t start, size_t stop)
: start_input(start),
stop_input(stop),
start_result(0),
stop_result(0) {}
void Run(art::Thread* self) OVERRIDE REQUIRES_SHARED(art::Locks::mutator_lock_) {
auto frames_fn = [&](jvmtiFrameInfo info) {
frames.push_back(info);
};
auto visitor = MakeStackTraceVisitor(self, start_input, stop_input, frames_fn);
visitor.WalkStack(/* include_transitions */ false);
start_result = visitor.start;
stop_result = visitor.stop;
}
const size_t start_input;
const size_t stop_input;
std::vector<jvmtiFrameInfo> frames;
size_t start_result;
size_t stop_result;
};
static jvmtiError TranslateFrameVector(const std::vector<jvmtiFrameInfo>& frames,
jint start_depth,
size_t start_result,
jint max_frame_count,
jvmtiFrameInfo* frame_buffer,
jint* count_ptr) {
size_t collected_frames = frames.size();
// Assume we're here having collected something.
DCHECK_GT(max_frame_count, 0);
// Frames from the top.
if (start_depth >= 0) {
if (start_result != 0) {
// Not enough frames.
return ERR(ILLEGAL_ARGUMENT);
}
DCHECK_LE(collected_frames, static_cast<size_t>(max_frame_count));
if (frames.size() > 0) {
memcpy(frame_buffer, frames.data(), collected_frames * sizeof(jvmtiFrameInfo));
}
*count_ptr = static_cast<jint>(frames.size());
return ERR(NONE);
}
// Frames from the bottom.
if (collected_frames < static_cast<size_t>(-start_depth)) {
return ERR(ILLEGAL_ARGUMENT);
}
size_t count = std::min(static_cast<size_t>(-start_depth), static_cast<size_t>(max_frame_count));
memcpy(frame_buffer,
&frames.data()[collected_frames + start_depth],
count * sizeof(jvmtiFrameInfo));
*count_ptr = static_cast<jint>(count);
return ERR(NONE);
}
struct GetStackTraceDirectClosure : public art::Closure {
public:
GetStackTraceDirectClosure(jvmtiFrameInfo* frame_buffer_, size_t start, size_t stop)
: frame_buffer(frame_buffer_),
start_input(start),
stop_input(stop),
index(0) {
DCHECK_GE(start_input, 0u);
}
void Run(art::Thread* self) OVERRIDE REQUIRES_SHARED(art::Locks::mutator_lock_) {
auto frames_fn = [&](jvmtiFrameInfo info) {
frame_buffer[index] = info;
++index;
};
auto visitor = MakeStackTraceVisitor(self, start_input, stop_input, frames_fn);
visitor.WalkStack(/* include_transitions */ false);
}
jvmtiFrameInfo* frame_buffer;
const size_t start_input;
const size_t stop_input;
size_t index = 0;
};
jvmtiError StackUtil::GetStackTrace(jvmtiEnv* jvmti_env ATTRIBUTE_UNUSED,
jthread java_thread,
jint start_depth,
jint max_frame_count,
jvmtiFrameInfo* frame_buffer,
jint* count_ptr) {
// It is not great that we have to hold these locks for so long, but it is necessary to ensure
// that the thread isn't dying on us.
art::ScopedObjectAccess soa(art::Thread::Current());
art::Locks::thread_list_lock_->ExclusiveLock(soa.Self());
art::Thread* thread;
jvmtiError thread_error = ERR(INTERNAL);
if (!ThreadUtil::GetAliveNativeThread(java_thread, soa, &thread, &thread_error)) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return thread_error;
}
DCHECK(thread != nullptr);
art::ThreadState state = thread->GetState();
if (state == art::ThreadState::kStarting || thread->IsStillStarting()) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return ERR(THREAD_NOT_ALIVE);
}
if (max_frame_count < 0) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return ERR(ILLEGAL_ARGUMENT);
}
if (frame_buffer == nullptr || count_ptr == nullptr) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return ERR(NULL_POINTER);
}
if (max_frame_count == 0) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
*count_ptr = 0;
return ERR(NONE);
}
if (start_depth >= 0) {
// Fast path: Regular order of stack trace. Fill into the frame_buffer directly.
GetStackTraceDirectClosure closure(frame_buffer,
static_cast<size_t>(start_depth),
static_cast<size_t>(max_frame_count));
// RequestSynchronousCheckpoint releases the thread_list_lock_ as a part of its execution.
if (!thread->RequestSynchronousCheckpoint(&closure)) {
return ERR(THREAD_NOT_ALIVE);
}
*count_ptr = static_cast<jint>(closure.index);
if (closure.index < static_cast<size_t>(start_depth)) {
return ERR(ILLEGAL_ARGUMENT);
}
return ERR(NONE);
} else {
GetStackTraceVectorClosure closure(0, 0);
// RequestSynchronousCheckpoint releases the thread_list_lock_ as a part of its execution.
if (!thread->RequestSynchronousCheckpoint(&closure)) {
return ERR(THREAD_NOT_ALIVE);
}
return TranslateFrameVector(closure.frames,
start_depth,
closure.start_result,
max_frame_count,
frame_buffer,
count_ptr);
}
}
template <typename Data>
struct GetAllStackTracesVectorClosure : public art::Closure {
GetAllStackTracesVectorClosure(size_t stop, Data* data_)
: barrier(0), stop_input(stop), data(data_) {}
void Run(art::Thread* thread) OVERRIDE
REQUIRES_SHARED(art::Locks::mutator_lock_)
REQUIRES(!data->mutex) {
art::Thread* self = art::Thread::Current();
Work(thread, self);
barrier.Pass(self);
}
void Work(art::Thread* thread, art::Thread* self)
REQUIRES_SHARED(art::Locks::mutator_lock_)
REQUIRES(!data->mutex) {
// Skip threads that are still starting.
if (thread->IsStillStarting()) {
return;
}
std::vector<jvmtiFrameInfo>* thread_frames = data->GetFrameStorageFor(self, thread);
if (thread_frames == nullptr) {
return;
}
// Now collect the data.
auto frames_fn = [&](jvmtiFrameInfo info) {
thread_frames->push_back(info);
};
auto visitor = MakeStackTraceVisitor(thread, 0u, stop_input, frames_fn);
visitor.WalkStack(/* include_transitions */ false);
}
art::Barrier barrier;
const size_t stop_input;
Data* data;
};
template <typename Data>
static void RunCheckpointAndWait(Data* data, size_t max_frame_count) {
GetAllStackTracesVectorClosure<Data> closure(max_frame_count, data);
size_t barrier_count = art::Runtime::Current()->GetThreadList()->RunCheckpoint(&closure, nullptr);
if (barrier_count == 0) {
return;
}
art::Thread* self = art::Thread::Current();
art::ScopedThreadStateChange tsc(self, art::ThreadState::kWaitingForCheckPointsToRun);
closure.barrier.Increment(self, barrier_count);
}
jvmtiError StackUtil::GetAllStackTraces(jvmtiEnv* env,
jint max_frame_count,
jvmtiStackInfo** stack_info_ptr,
jint* thread_count_ptr) {
if (max_frame_count < 0) {
return ERR(ILLEGAL_ARGUMENT);
}
if (stack_info_ptr == nullptr || thread_count_ptr == nullptr) {
return ERR(NULL_POINTER);
}
struct AllStackTracesData {
AllStackTracesData() : mutex("GetAllStackTraces", art::LockLevel::kAbortLock) {}
~AllStackTracesData() {
JNIEnv* jni_env = art::Thread::Current()->GetJniEnv();
for (jthread global_thread_ref : thread_peers) {
jni_env->DeleteGlobalRef(global_thread_ref);
}
}
std::vector<jvmtiFrameInfo>* GetFrameStorageFor(art::Thread* self, art::Thread* thread)
REQUIRES_SHARED(art::Locks::mutator_lock_)
REQUIRES(!mutex) {
art::MutexLock mu(self, mutex);
threads.push_back(thread);
jthread peer = art::Runtime::Current()->GetJavaVM()->AddGlobalRef(
self, thread->GetPeerFromOtherThread());
thread_peers.push_back(peer);
frames.emplace_back(new std::vector<jvmtiFrameInfo>());
return frames.back().get();
}
art::Mutex mutex;
// Storage. Only access directly after completion.
std::vector<art::Thread*> threads;
// "thread_peers" contains global references to their peers.
std::vector<jthread> thread_peers;
std::vector<std::unique_ptr<std::vector<jvmtiFrameInfo>>> frames;
};
AllStackTracesData data;
RunCheckpointAndWait(&data, static_cast<size_t>(max_frame_count));
art::Thread* current = art::Thread::Current();
// Convert the data into our output format.
// Note: we use an array of jvmtiStackInfo for convenience. The spec says we need to
// allocate one big chunk for this and the actual frames, which means we need
// to either be conservative or rearrange things later (the latter is implemented).
std::unique_ptr<jvmtiStackInfo[]> stack_info_array(new jvmtiStackInfo[data.frames.size()]);
std::vector<std::unique_ptr<jvmtiFrameInfo[]>> frame_infos;
frame_infos.reserve(data.frames.size());
// Now run through and add data for each thread.
size_t sum_frames = 0;
for (size_t index = 0; index < data.frames.size(); ++index) {
jvmtiStackInfo& stack_info = stack_info_array.get()[index];
memset(&stack_info, 0, sizeof(jvmtiStackInfo));
const std::vector<jvmtiFrameInfo>& thread_frames = *data.frames[index].get();
// For the time being, set the thread to null. We'll fix it up in the second stage.
stack_info.thread = nullptr;
stack_info.state = JVMTI_THREAD_STATE_SUSPENDED;
size_t collected_frames = thread_frames.size();
if (max_frame_count == 0 || collected_frames == 0) {
stack_info.frame_count = 0;
stack_info.frame_buffer = nullptr;
continue;
}
DCHECK_LE(collected_frames, static_cast<size_t>(max_frame_count));
jvmtiFrameInfo* frame_info = new jvmtiFrameInfo[collected_frames];
frame_infos.emplace_back(frame_info);
jint count;
jvmtiError translate_result = TranslateFrameVector(thread_frames,
0,
0,
static_cast<jint>(collected_frames),
frame_info,
&count);
DCHECK(translate_result == JVMTI_ERROR_NONE);
stack_info.frame_count = static_cast<jint>(collected_frames);
stack_info.frame_buffer = frame_info;
sum_frames += static_cast<size_t>(count);
}
// No errors, yet. Now put it all into an output buffer.
size_t rounded_stack_info_size = art::RoundUp(sizeof(jvmtiStackInfo) * data.frames.size(),
alignof(jvmtiFrameInfo));
size_t chunk_size = rounded_stack_info_size + sum_frames * sizeof(jvmtiFrameInfo);
unsigned char* chunk_data;
jvmtiError alloc_result = env->Allocate(chunk_size, &chunk_data);
if (alloc_result != ERR(NONE)) {
return alloc_result;
}
jvmtiStackInfo* stack_info = reinterpret_cast<jvmtiStackInfo*>(chunk_data);
// First copy in all the basic data.
memcpy(stack_info, stack_info_array.get(), sizeof(jvmtiStackInfo) * data.frames.size());
// Now copy the frames and fix up the pointers.
jvmtiFrameInfo* frame_info = reinterpret_cast<jvmtiFrameInfo*>(
chunk_data + rounded_stack_info_size);
for (size_t i = 0; i < data.frames.size(); ++i) {
jvmtiStackInfo& old_stack_info = stack_info_array.get()[i];
jvmtiStackInfo& new_stack_info = stack_info[i];
// Translate the global ref into a local ref.
new_stack_info.thread =
static_cast<JNIEnv*>(current->GetJniEnv())->NewLocalRef(data.thread_peers[i]);
if (old_stack_info.frame_count > 0) {
// Only copy when there's data - leave the nullptr alone.
size_t frames_size = static_cast<size_t>(old_stack_info.frame_count) * sizeof(jvmtiFrameInfo);
memcpy(frame_info, old_stack_info.frame_buffer, frames_size);
new_stack_info.frame_buffer = frame_info;
frame_info += old_stack_info.frame_count;
}
}
*stack_info_ptr = stack_info;
*thread_count_ptr = static_cast<jint>(data.frames.size());
return ERR(NONE);
}
jvmtiError StackUtil::GetThreadListStackTraces(jvmtiEnv* env,
jint thread_count,
const jthread* thread_list,
jint max_frame_count,
jvmtiStackInfo** stack_info_ptr) {
if (max_frame_count < 0) {
return ERR(ILLEGAL_ARGUMENT);
}
if (thread_count < 0) {
return ERR(ILLEGAL_ARGUMENT);
}
if (thread_count == 0) {
*stack_info_ptr = nullptr;
return ERR(NONE);
}
if (thread_list == nullptr || stack_info_ptr == nullptr) {
return ERR(NULL_POINTER);
}
art::Thread* current = art::Thread::Current();
art::ScopedObjectAccess soa(current); // Now we know we have the shared lock.
struct SelectStackTracesData {
SelectStackTracesData() : mutex("GetSelectStackTraces", art::LockLevel::kAbortLock) {}
std::vector<jvmtiFrameInfo>* GetFrameStorageFor(art::Thread* self, art::Thread* thread)
REQUIRES_SHARED(art::Locks::mutator_lock_)
REQUIRES(!mutex) {
art::ObjPtr<art::mirror::Object> peer = thread->GetPeerFromOtherThread();
for (size_t index = 0; index != handles.size(); ++index) {
if (peer == handles[index].Get()) {
// Found the thread.
art::MutexLock mu(self, mutex);
threads.push_back(thread);
thread_list_indices.push_back(index);
frames.emplace_back(new std::vector<jvmtiFrameInfo>());
return frames.back().get();
}
}
return nullptr;
}
art::Mutex mutex;
// Selection data.
std::vector<art::Handle<art::mirror::Object>> handles;
// Storage. Only access directly after completion.
std::vector<art::Thread*> threads;
std::vector<size_t> thread_list_indices;
std::vector<std::unique_ptr<std::vector<jvmtiFrameInfo>>> frames;
};
SelectStackTracesData data;
// Decode all threads to raw pointers. Put them into a handle scope to avoid any moving GC bugs.
art::VariableSizedHandleScope hs(current);
for (jint i = 0; i != thread_count; ++i) {
if (thread_list[i] == nullptr) {
return ERR(INVALID_THREAD);
}
if (!soa.Env()->IsInstanceOf(thread_list[i], art::WellKnownClasses::java_lang_Thread)) {
return ERR(INVALID_THREAD);
}
data.handles.push_back(hs.NewHandle(soa.Decode<art::mirror::Object>(thread_list[i])));
}
RunCheckpointAndWait(&data, static_cast<size_t>(max_frame_count));
// Convert the data into our output format.
// Note: we use an array of jvmtiStackInfo for convenience. The spec says we need to
// allocate one big chunk for this and the actual frames, which means we need
// to either be conservative or rearrange things later (the latter is implemented).
std::unique_ptr<jvmtiStackInfo[]> stack_info_array(new jvmtiStackInfo[data.frames.size()]);
std::vector<std::unique_ptr<jvmtiFrameInfo[]>> frame_infos;
frame_infos.reserve(data.frames.size());
// Now run through and add data for each thread.
size_t sum_frames = 0;
for (size_t index = 0; index < data.frames.size(); ++index) {
jvmtiStackInfo& stack_info = stack_info_array.get()[index];
memset(&stack_info, 0, sizeof(jvmtiStackInfo));
art::Thread* self = data.threads[index];
const std::vector<jvmtiFrameInfo>& thread_frames = *data.frames[index].get();
// For the time being, set the thread to null. We don't have good ScopedLocalRef
// infrastructure.
DCHECK(self->GetPeerFromOtherThread() != nullptr);
stack_info.thread = nullptr;
stack_info.state = JVMTI_THREAD_STATE_SUSPENDED;
size_t collected_frames = thread_frames.size();
if (max_frame_count == 0 || collected_frames == 0) {
stack_info.frame_count = 0;
stack_info.frame_buffer = nullptr;
continue;
}
DCHECK_LE(collected_frames, static_cast<size_t>(max_frame_count));
jvmtiFrameInfo* frame_info = new jvmtiFrameInfo[collected_frames];
frame_infos.emplace_back(frame_info);
jint count;
jvmtiError translate_result = TranslateFrameVector(thread_frames,
0,
0,
static_cast<jint>(collected_frames),
frame_info,
&count);
DCHECK(translate_result == JVMTI_ERROR_NONE);
stack_info.frame_count = static_cast<jint>(collected_frames);
stack_info.frame_buffer = frame_info;
sum_frames += static_cast<size_t>(count);
}
// No errors, yet. Now put it all into an output buffer. Note that this is not frames.size(),
// potentially.
size_t rounded_stack_info_size = art::RoundUp(sizeof(jvmtiStackInfo) * thread_count,
alignof(jvmtiFrameInfo));
size_t chunk_size = rounded_stack_info_size + sum_frames * sizeof(jvmtiFrameInfo);
unsigned char* chunk_data;
jvmtiError alloc_result = env->Allocate(chunk_size, &chunk_data);
if (alloc_result != ERR(NONE)) {
return alloc_result;
}
jvmtiStackInfo* stack_info = reinterpret_cast<jvmtiStackInfo*>(chunk_data);
jvmtiFrameInfo* frame_info = reinterpret_cast<jvmtiFrameInfo*>(
chunk_data + rounded_stack_info_size);
for (size_t i = 0; i < static_cast<size_t>(thread_count); ++i) {
// Check whether we found a running thread for this.
// Note: For simplicity, and with the expectation that the list is usually small, use a simple
// search. (The list is *not* sorted!)
auto it = std::find(data.thread_list_indices.begin(), data.thread_list_indices.end(), i);
if (it == data.thread_list_indices.end()) {
// No native thread. Must be new or dead. We need to fill out the stack info now.
// (Need to read the Java "started" field to know whether this is starting or terminated.)
art::ObjPtr<art::mirror::Object> peer = soa.Decode<art::mirror::Object>(thread_list[i]);
art::ObjPtr<art::mirror::Class> klass = peer->GetClass();
art::ArtField* started_field = klass->FindDeclaredInstanceField("started", "Z");
CHECK(started_field != nullptr);
bool started = started_field->GetBoolean(peer) != 0;
constexpr jint kStartedState = JVMTI_JAVA_LANG_THREAD_STATE_NEW;
constexpr jint kTerminatedState = JVMTI_THREAD_STATE_TERMINATED |
JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED;
stack_info[i].thread = reinterpret_cast<JNIEnv*>(soa.Env())->NewLocalRef(thread_list[i]);
stack_info[i].state = started ? kTerminatedState : kStartedState;
stack_info[i].frame_count = 0;
stack_info[i].frame_buffer = nullptr;
} else {
// Had a native thread and frames.
size_t f_index = it - data.thread_list_indices.begin();
jvmtiStackInfo& old_stack_info = stack_info_array.get()[f_index];
jvmtiStackInfo& new_stack_info = stack_info[i];
memcpy(&new_stack_info, &old_stack_info, sizeof(jvmtiStackInfo));
new_stack_info.thread = reinterpret_cast<JNIEnv*>(soa.Env())->NewLocalRef(thread_list[i]);
if (old_stack_info.frame_count > 0) {
// Only copy when there's data - leave the nullptr alone.
size_t frames_size =
static_cast<size_t>(old_stack_info.frame_count) * sizeof(jvmtiFrameInfo);
memcpy(frame_info, old_stack_info.frame_buffer, frames_size);
new_stack_info.frame_buffer = frame_info;
frame_info += old_stack_info.frame_count;
}
}
}
*stack_info_ptr = stack_info;
return ERR(NONE);
}
// Walks up the stack counting Java frames. This is not StackVisitor::ComputeNumFrames, as
// runtime methods and transitions must not be counted.
struct GetFrameCountVisitor : public art::StackVisitor {
explicit GetFrameCountVisitor(art::Thread* thread)
: art::StackVisitor(thread, nullptr, art::StackVisitor::StackWalkKind::kIncludeInlinedFrames),
count(0) {}
bool VisitFrame() REQUIRES_SHARED(art::Locks::mutator_lock_) {
art::ArtMethod* m = GetMethod();
const bool do_count = !(m == nullptr || m->IsRuntimeMethod());
if (do_count) {
count++;
}
return true;
}
size_t count;
};
struct GetFrameCountClosure : public art::Closure {
public:
GetFrameCountClosure() : count(0) {}
void Run(art::Thread* self) OVERRIDE REQUIRES_SHARED(art::Locks::mutator_lock_) {
GetFrameCountVisitor visitor(self);
visitor.WalkStack(false);
count = visitor.count;
}
size_t count;
};
jvmtiError StackUtil::GetFrameCount(jvmtiEnv* env ATTRIBUTE_UNUSED,
jthread java_thread,
jint* count_ptr) {
// It is not great that we have to hold these locks for so long, but it is necessary to ensure
// that the thread isn't dying on us.
art::ScopedObjectAccess soa(art::Thread::Current());
art::Locks::thread_list_lock_->ExclusiveLock(soa.Self());
art::Thread* thread;
jvmtiError thread_error = ERR(INTERNAL);
if (!ThreadUtil::GetAliveNativeThread(java_thread, soa, &thread, &thread_error)) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return thread_error;
}
DCHECK(thread != nullptr);
art::ThreadState state = thread->GetState();
if (state == art::ThreadState::kStarting || thread->IsStillStarting()) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return ERR(THREAD_NOT_ALIVE);
}
if (count_ptr == nullptr) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return ERR(NULL_POINTER);
}
GetFrameCountClosure closure;
// RequestSynchronousCheckpoint releases the thread_list_lock_ as a part of its execution.
if (!thread->RequestSynchronousCheckpoint(&closure)) {
return ERR(THREAD_NOT_ALIVE);
}
*count_ptr = closure.count;
return ERR(NONE);
}
// Walks up the stack 'n' callers, when used with Thread::WalkStack.
struct GetLocationVisitor : public art::StackVisitor {
GetLocationVisitor(art::Thread* thread, size_t n_in)
: art::StackVisitor(thread, nullptr, art::StackVisitor::StackWalkKind::kIncludeInlinedFrames),
n(n_in),
count(0),
caller(nullptr),
caller_dex_pc(0) {}
bool VisitFrame() REQUIRES_SHARED(art::Locks::mutator_lock_) {
art::ArtMethod* m = GetMethod();
const bool do_count = !(m == nullptr || m->IsRuntimeMethod());
if (do_count) {
DCHECK(caller == nullptr);
if (count == n) {
caller = m;
caller_dex_pc = GetDexPc(false);
return false;
}
count++;
}
return true;
}
const size_t n;
size_t count;
art::ArtMethod* caller;
uint32_t caller_dex_pc;
};
struct GetLocationClosure : public art::Closure {
public:
explicit GetLocationClosure(size_t n_in) : n(n_in), method(nullptr), dex_pc(0) {}
void Run(art::Thread* self) OVERRIDE REQUIRES_SHARED(art::Locks::mutator_lock_) {
GetLocationVisitor visitor(self, n);
visitor.WalkStack(false);
method = visitor.caller;
dex_pc = visitor.caller_dex_pc;
}
const size_t n;
art::ArtMethod* method;
uint32_t dex_pc;
};
jvmtiError StackUtil::GetFrameLocation(jvmtiEnv* env ATTRIBUTE_UNUSED,
jthread java_thread,
jint depth,
jmethodID* method_ptr,
jlocation* location_ptr) {
// It is not great that we have to hold these locks for so long, but it is necessary to ensure
// that the thread isn't dying on us.
art::ScopedObjectAccess soa(art::Thread::Current());
art::Locks::thread_list_lock_->ExclusiveLock(soa.Self());
art::Thread* thread;
jvmtiError thread_error = ERR(INTERNAL);
if (!ThreadUtil::GetAliveNativeThread(java_thread, soa, &thread, &thread_error)) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return thread_error;
}
DCHECK(thread != nullptr);
art::ThreadState state = thread->GetState();
if (state == art::ThreadState::kStarting || thread->IsStillStarting()) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return ERR(THREAD_NOT_ALIVE);
}
if (depth < 0) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return ERR(ILLEGAL_ARGUMENT);
}
if (method_ptr == nullptr || location_ptr == nullptr) {
art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self());
return ERR(NULL_POINTER);
}
GetLocationClosure closure(static_cast<size_t>(depth));
// RequestSynchronousCheckpoint releases the thread_list_lock_ as a part of its execution.
if (!thread->RequestSynchronousCheckpoint(&closure)) {
return ERR(THREAD_NOT_ALIVE);
}
if (closure.method == nullptr) {
return ERR(NO_MORE_FRAMES);
}
*method_ptr = art::jni::EncodeArtMethod(closure.method);
if (closure.method->IsNative() || closure.method->IsProxyMethod()) {
*location_ptr = -1;
} else {
if (closure.dex_pc == art::dex::kDexNoIndex) {
return ERR(INTERNAL);
}
*location_ptr = static_cast<jlocation>(closure.dex_pc);
}
return ERR(NONE);
}
struct MonitorVisitor : public art::StackVisitor, public art::SingleRootVisitor {
// We need a context because VisitLocks needs it retrieve the monitor objects.
explicit MonitorVisitor(art::Thread* thread)
REQUIRES_SHARED(art::Locks::mutator_lock_)
: art::StackVisitor(thread,
art::Context::Create(),
art::StackVisitor::StackWalkKind::kIncludeInlinedFrames),
hs(art::Thread::Current()),
current_stack_depth(0) {}
~MonitorVisitor() {
delete context_;
}
bool VisitFrame() OVERRIDE REQUIRES_SHARED(art::Locks::mutator_lock_) {
art::Locks::mutator_lock_->AssertSharedHeld(art::Thread::Current());
if (!GetMethod()->IsRuntimeMethod()) {
art::Monitor::VisitLocks(this, AppendOwnedMonitors, this);
++current_stack_depth;
}
return true;
}
static void AppendOwnedMonitors(art::mirror::Object* owned_monitor, void* arg)
REQUIRES_SHARED(art::Locks::mutator_lock_) {
art::Locks::mutator_lock_->AssertSharedHeld(art::Thread::Current());
MonitorVisitor* visitor = reinterpret_cast<MonitorVisitor*>(arg);
art::ObjPtr<art::mirror::Object> mon(owned_monitor);
// Filter out duplicates.
for (const art::Handle<art::mirror::Object>& monitor : visitor->monitors) {
if (monitor.Get() == mon.Ptr()) {
return;
}
}
visitor->monitors.push_back(visitor->hs.NewHandle(mon));
visitor->stack_depths.push_back(visitor->current_stack_depth);
}
void VisitRoot(art::mirror::Object* obj, const art::RootInfo& info ATTRIBUTE_UNUSED)
OVERRIDE REQUIRES_SHARED(art::Locks::mutator_lock_) {
for (const art::Handle<art::mirror::Object>& m : monitors) {
if (m.Get() == obj) {
return;
}
}
monitors.push_back(hs.NewHandle(obj));
stack_depths.push_back(-1);
}
art::VariableSizedHandleScope hs;
jint current_stack_depth;
std::vector<art::Handle<art::mirror::Object>> monitors;
std::vector<jint> stack_depths;
};
template<typename Fn>
struct MonitorInfoClosure : public art::Closure {
public:
explicit MonitorInfoClosure(Fn handle_results)
: err_(OK), handle_results_(handle_results) {}
void Run(art::Thread* target) OVERRIDE REQUIRES_SHARED(art::Locks::mutator_lock_) {
art::Locks::mutator_lock_->AssertSharedHeld(art::Thread::Current());
// Find the monitors on the stack.
MonitorVisitor visitor(target);
visitor.WalkStack(/* include_transitions */ false);
// Find any other monitors, including ones acquired in native code.
art::RootInfo root_info(art::kRootVMInternal);
target->GetJniEnv()->VisitMonitorRoots(&visitor, root_info);
err_ = handle_results_(visitor);
}
jvmtiError GetError() {
return err_;
}
private:
jvmtiError err_;
Fn handle_results_;
};
template <typename Fn>
static jvmtiError GetOwnedMonitorInfoCommon(const art::ScopedObjectAccessAlreadyRunnable& soa,
jthread thread,
Fn handle_results)
REQUIRES_SHARED(art::Locks::mutator_lock_) {
art::Thread* self = art::Thread::Current();
MonitorInfoClosure<Fn> closure(handle_results);
bool called_method = false;
{
art::Locks::thread_list_lock_->ExclusiveLock(self);
art::Thread* target = nullptr;
jvmtiError err = ERR(INTERNAL);
if (!ThreadUtil::GetAliveNativeThread(thread, soa, &target, &err)) {
art::Locks::thread_list_lock_->ExclusiveUnlock(self);
return err;
}
if (target != self) {
called_method = true;
// RequestSynchronousCheckpoint releases the thread_list_lock_ as a part of its execution.
// Since this deals with object references we need to avoid going to sleep.
art::ScopedAssertNoThreadSuspension sants("Getting owned monitor usage");
if (!target->RequestSynchronousCheckpoint(&closure, art::ThreadState::kRunnable)) {
return ERR(THREAD_NOT_ALIVE);
}
} else {
art::Locks::thread_list_lock_->ExclusiveUnlock(self);
}
}
// Cannot call the closure on the current thread if we have thread_list_lock since we need to call
// into the verifier which can cause the current thread to suspend for gc. Suspending would be a
// bad thing to do if we hold the ThreadListLock. For other threads since we are running it on a
// checkpoint we are fine but if the thread is the current one we need to drop the mutex first.
if (!called_method) {
closure.Run(self);
}
return closure.GetError();
}
jvmtiError StackUtil::GetOwnedMonitorStackDepthInfo(jvmtiEnv* env,
jthread thread,
jint* info_cnt,
jvmtiMonitorStackDepthInfo** info_ptr) {
if (info_cnt == nullptr || info_ptr == nullptr) {
return ERR(NULL_POINTER);
}
art::ScopedObjectAccess soa(art::Thread::Current());
std::vector<art::GcRoot<art::mirror::Object>> mons;
std::vector<uint32_t> depths;
auto handle_fun = [&] (MonitorVisitor& visitor) REQUIRES_SHARED(art::Locks::mutator_lock_) {
for (size_t i = 0; i < visitor.monitors.size(); i++) {
mons.push_back(art::GcRoot<art::mirror::Object>(visitor.monitors[i].Get()));
depths.push_back(visitor.stack_depths[i]);
}
return OK;
};
jvmtiError err = GetOwnedMonitorInfoCommon(soa, thread, handle_fun);
if (err != OK) {
return err;
}
auto nbytes = sizeof(jvmtiMonitorStackDepthInfo) * mons.size();
err = env->Allocate(nbytes, reinterpret_cast<unsigned char**>(info_ptr));
if (err != OK) {
return err;
}
*info_cnt = mons.size();
for (uint32_t i = 0; i < mons.size(); i++) {
(*info_ptr)[i] = {
soa.AddLocalReference<jobject>(mons[i].Read()),
static_cast<jint>(depths[i])
};
}
return err;
}
jvmtiError StackUtil::GetOwnedMonitorInfo(jvmtiEnv* env,
jthread thread,
jint* owned_monitor_count_ptr,
jobject** owned_monitors_ptr) {
if (owned_monitor_count_ptr == nullptr || owned_monitors_ptr == nullptr) {
return ERR(NULL_POINTER);
}
art::ScopedObjectAccess soa(art::Thread::Current());
std::vector<art::GcRoot<art::mirror::Object>> mons;
auto handle_fun = [&] (MonitorVisitor& visitor) REQUIRES_SHARED(art::Locks::mutator_lock_) {
for (size_t i = 0; i < visitor.monitors.size(); i++) {
mons.push_back(art::GcRoot<art::mirror::Object>(visitor.monitors[i].Get()));
}
return OK;
};
jvmtiError err = GetOwnedMonitorInfoCommon(soa, thread, handle_fun);
if (err != OK) {
return err;
}
auto nbytes = sizeof(jobject) * mons.size();
err = env->Allocate(nbytes, reinterpret_cast<unsigned char**>(owned_monitors_ptr));
if (err != OK) {
return err;
}
*owned_monitor_count_ptr = mons.size();
for (uint32_t i = 0; i < mons.size(); i++) {
(*owned_monitors_ptr)[i] = soa.AddLocalReference<jobject>(mons[i].Read());
}
return err;
}
jvmtiError StackUtil::NotifyFramePop(jvmtiEnv* env, jthread thread, jint depth) {
if (depth < 0) {
return ERR(ILLEGAL_ARGUMENT);
}
ArtJvmTiEnv* tienv = ArtJvmTiEnv::AsArtJvmTiEnv(env);
art::Thread* self = art::Thread::Current();
art::Thread* target;
do {
ThreadUtil::SuspendCheck(self);
art::MutexLock ucsl_mu(self, *art::Locks::user_code_suspension_lock_);
// Make sure we won't be suspended in the middle of holding the thread_suspend_count_lock_ by a
// user-code suspension. We retry and do another SuspendCheck to clear this.
if (ThreadUtil::WouldSuspendForUserCodeLocked(self)) {
continue;
}
// From now on we know we cannot get suspended by user-code.
// NB This does a SuspendCheck (during thread state change) so we need to make sure we don't
// have the 'suspend_lock' locked here.
art::ScopedObjectAccess soa(self);
art::MutexLock tll_mu(self, *art::Locks::thread_list_lock_);
jvmtiError err = ERR(INTERNAL);
if (!ThreadUtil::GetAliveNativeThread(thread, soa, &target, &err)) {
return err;
}
if (target != self) {
// TODO This is part of the spec but we could easily avoid needing to do it. We would just put
// all the logic into a sync-checkpoint.
art::MutexLock tscl_mu(self, *art::Locks::thread_suspend_count_lock_);
if (target->GetUserCodeSuspendCount() == 0) {
return ERR(THREAD_NOT_SUSPENDED);
}
}
// We hold the user_code_suspension_lock_ so the target thread is staying suspended until we are
// done (unless it's 'self' in which case we don't care since we aren't going to be returning).
// TODO We could implement this using a synchronous checkpoint and not bother with any of the
// suspension stuff. The spec does specifically say to return THREAD_NOT_SUSPENDED though.
// Find the requested stack frame.
std::unique_ptr<art::Context> context(art::Context::Create());
FindFrameAtDepthVisitor visitor(target, context.get(), depth);
visitor.WalkStack();
if (!visitor.FoundFrame()) {
return ERR(NO_MORE_FRAMES);
}
art::ArtMethod* method = visitor.GetMethod();
if (method->IsNative()) {
return ERR(OPAQUE_FRAME);
}
// From here we are sure to succeed.
bool needs_instrument = false;
// Get/create a shadow frame
art::ShadowFrame* shadow_frame = visitor.GetCurrentShadowFrame();
if (shadow_frame == nullptr) {
needs_instrument = true;
const size_t frame_id = visitor.GetFrameId();
const uint16_t num_regs = method->DexInstructionData().RegistersSize();
shadow_frame = target->FindOrCreateDebuggerShadowFrame(frame_id,
num_regs,
method,
visitor.GetDexPc());
}
{
art::WriterMutexLock lk(self, tienv->event_info_mutex_);
// Mark shadow frame as needs_notify_pop_
shadow_frame->SetNotifyPop(true);
tienv->notify_frames.insert(shadow_frame);
}
// Make sure can we will go to the interpreter and use the shadow frames.
if (needs_instrument) {
art::Runtime::Current()->GetInstrumentation()->InstrumentThreadStack(target);
}
return OK;
} while (true);
}
} // namespace openjdkjvmti