| /* Copyright (C) 2017 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 <functional> |
| #include <iosfwd> |
| #include <mutex> |
| |
| #include "deopt_manager.h" |
| |
| #include "art_jvmti.h" |
| #include "art_method-inl.h" |
| #include "base/enums.h" |
| #include "base/mutex-inl.h" |
| #include "dex/dex_file_annotations.h" |
| #include "dex/modifiers.h" |
| #include "events-inl.h" |
| #include "gc/collector_type.h" |
| #include "gc/heap.h" |
| #include "gc/scoped_gc_critical_section.h" |
| #include "instrumentation.h" |
| #include "jit/jit.h" |
| #include "jni/jni_internal.h" |
| #include "mirror/class-inl.h" |
| #include "mirror/object_array-inl.h" |
| #include "nativehelper/scoped_local_ref.h" |
| #include "read_barrier_config.h" |
| #include "runtime_callbacks.h" |
| #include "scoped_thread_state_change-inl.h" |
| #include "scoped_thread_state_change.h" |
| #include "thread-current-inl.h" |
| #include "thread_list.h" |
| #include "ti_phase.h" |
| |
| namespace openjdkjvmti { |
| |
| // TODO We should make this much more selective in the future so we only return true when we |
| // actually care about the method at this time (ie active frames had locals changed). For now we |
| // just assume that if anything has changed any frame's locals we care about all methods. If nothing |
| // has we only care about methods with active breakpoints on them. In the future we should probably |
| // rewrite all of this to instead do this at the ShadowFrame or thread granularity. |
| bool JvmtiMethodInspectionCallback::IsMethodBeingInspected(art::ArtMethod* method) { |
| // In non-java-debuggable runtimes the breakpoint check would miss if we have breakpoints on |
| // methods that are inlined. Since these features are best effort in non-java-debuggable |
| // runtimes it is OK to be less precise. For debuggable runtimes, inlining is disabled. |
| return manager_->HaveLocalsChanged() || manager_->MethodHasBreakpoints(method); |
| } |
| |
| DeoptManager::DeoptManager() |
| : deoptimization_status_lock_("JVMTI_DeoptimizationStatusLock", |
| static_cast<art::LockLevel>( |
| art::LockLevel::kClassLinkerClassesLock + 1)), |
| deoptimization_condition_("JVMTI_DeoptimizationCondition", deoptimization_status_lock_), |
| performing_deoptimization_(false), |
| global_deopt_count_(0), |
| deopter_count_(0), |
| breakpoint_status_lock_("JVMTI_BreakpointStatusLock", |
| static_cast<art::LockLevel>(art::LockLevel::kAbortLock + 1)), |
| inspection_callback_(this), |
| set_local_variable_called_(false) { } |
| |
| void DeoptManager::Setup() { |
| art::ScopedThreadStateChange stsc(art::Thread::Current(), |
| art::ThreadState::kWaitingForDebuggerToAttach); |
| art::ScopedSuspendAll ssa("Add method Inspection Callback"); |
| art::RuntimeCallbacks* callbacks = art::Runtime::Current()->GetRuntimeCallbacks(); |
| callbacks->AddMethodInspectionCallback(&inspection_callback_); |
| } |
| |
| void DeoptManager::Shutdown() { |
| art::ScopedThreadStateChange stsc(art::Thread::Current(), |
| art::ThreadState::kWaitingForDebuggerToAttach); |
| art::ScopedSuspendAll ssa("remove method Inspection Callback"); |
| art::RuntimeCallbacks* callbacks = art::Runtime::Current()->GetRuntimeCallbacks(); |
| callbacks->RemoveMethodInspectionCallback(&inspection_callback_); |
| } |
| |
| void DeoptManager::DumpDeoptInfo(art::Thread* self, std::ostream& stream) { |
| art::ScopedObjectAccess soa(self); |
| art::MutexLock mutll(self, *art::Locks::thread_list_lock_); |
| art::MutexLock mudsl(self, deoptimization_status_lock_); |
| art::MutexLock mubsl(self, breakpoint_status_lock_); |
| stream << "Deoptimizer count: " << deopter_count_ << "\n"; |
| stream << "Global deopt count: " << global_deopt_count_ << "\n"; |
| stream << "Can perform OSR: " << !set_local_variable_called_.load() << "\n"; |
| for (const auto& [bp, loc] : this->breakpoint_status_) { |
| stream << "Breakpoint: " << bp->PrettyMethod() << " @ 0x" << std::hex << loc << "\n"; |
| } |
| struct DumpThreadDeoptCount : public art::Closure { |
| public: |
| DumpThreadDeoptCount(std::ostream& stream, std::mutex& mu) |
| : cnt_(0), stream_(stream), mu_(mu) {} |
| void Run(art::Thread* self) override { |
| { |
| std::lock_guard<std::mutex> lg(mu_); |
| std::string name; |
| self->GetThreadName(name); |
| stream_ << "Thread " << name << " (id: " << std::dec << self->GetThreadId() |
| << ") force interpreter count " << self->ForceInterpreterCount() << "\n"; |
| } |
| // Increment this after unlocking the mutex so we won't race its destructor. |
| cnt_++; |
| } |
| |
| void WaitForCount(size_t threads) { |
| while (cnt_.load() != threads) { |
| sched_yield(); |
| } |
| } |
| |
| private: |
| std::atomic<size_t> cnt_; |
| std::ostream& stream_; |
| std::mutex& mu_; |
| }; |
| |
| std::mutex mu; |
| DumpThreadDeoptCount dtdc(stream, mu); |
| auto func = [](art::Thread* thread, void* ctx) { |
| reinterpret_cast<DumpThreadDeoptCount*>(ctx)->Run(thread); |
| }; |
| art::Runtime::Current()->GetThreadList()->ForEach(func, &dtdc); |
| } |
| |
| void DeoptManager::FinishSetup() { |
| art::Thread* self = art::Thread::Current(); |
| art::MutexLock mu(self, deoptimization_status_lock_); |
| |
| art::Runtime* runtime = art::Runtime::Current(); |
| // See if we need to do anything. |
| if (!runtime->IsJavaDebuggable()) { |
| // See if we can enable all JVMTI functions. If this is false, only kArtTiVersion agents can be |
| // retrieved and they will all be best-effort. |
| if (PhaseUtil::GetPhaseUnchecked() == JVMTI_PHASE_ONLOAD) { |
| // We are still early enough to change the compiler options and get full JVMTI support. |
| LOG(INFO) << "Openjdkjvmti plugin loaded on a non-debuggable runtime. Changing runtime to " |
| << "debuggable state. Please pass '--debuggable' to dex2oat and " |
| << "'-Xcompiler-option --debuggable' to dalvikvm in the future."; |
| DCHECK(runtime->GetJit() == nullptr) << "Jit should not be running yet!"; |
| runtime->AddCompilerOption("--debuggable"); |
| runtime->SetJavaDebuggable(true); |
| } else { |
| LOG(WARNING) << "Openjdkjvmti plugin was loaded on a non-debuggable Runtime. Plugin was " |
| << "loaded too late to change runtime state to DEBUGGABLE. Only kArtTiVersion " |
| << "(0x" << std::hex << kArtTiVersion << ") environments are available. Some " |
| << "functionality might not work properly."; |
| if (runtime->GetJit() == nullptr && |
| runtime->GetJITOptions()->UseJitCompilation() && |
| !runtime->GetInstrumentation()->IsForcedInterpretOnly()) { |
| // If we don't have a jit we should try to start the jit for performance reasons. We only |
| // need to do this for late attach on non-debuggable processes because for debuggable |
| // processes we already rely on jit and we cannot force this jit to start if we are still in |
| // OnLoad since the runtime hasn't started up sufficiently. This is only expected to happen |
| // on userdebug/eng builds. |
| LOG(INFO) << "Attempting to start jit for openjdkjvmti plugin."; |
| // Note: use rwx allowed = true, because if this is the system server, we will not be |
| // allowed to allocate any JIT code cache, anyways. |
| runtime->CreateJitCodeCache(/*rwx_memory_allowed=*/true); |
| runtime->CreateJit(); |
| if (runtime->GetJit() == nullptr) { |
| LOG(WARNING) << "Could not start jit for openjdkjvmti plugin. This process might be " |
| << "quite slow as it is running entirely in the interpreter. Try running " |
| << "'setenforce 0' and restarting this process."; |
| } |
| } |
| } |
| runtime->DeoptimizeBootImage(); |
| } |
| } |
| |
| bool DeoptManager::MethodHasBreakpoints(art::ArtMethod* method) { |
| art::MutexLock lk(art::Thread::Current(), breakpoint_status_lock_); |
| return MethodHasBreakpointsLocked(method); |
| } |
| |
| bool DeoptManager::MethodHasBreakpointsLocked(art::ArtMethod* method) { |
| auto elem = breakpoint_status_.find(method); |
| return elem != breakpoint_status_.end() && elem->second != 0; |
| } |
| |
| void DeoptManager::RemoveDeoptimizeAllMethods() { |
| art::Thread* self = art::Thread::Current(); |
| art::ScopedThreadSuspension sts(self, art::ThreadState::kSuspended); |
| deoptimization_status_lock_.ExclusiveLock(self); |
| RemoveDeoptimizeAllMethodsLocked(self); |
| } |
| |
| void DeoptManager::AddDeoptimizeAllMethods() { |
| art::Thread* self = art::Thread::Current(); |
| art::ScopedThreadSuspension sts(self, art::ThreadState::kSuspended); |
| deoptimization_status_lock_.ExclusiveLock(self); |
| AddDeoptimizeAllMethodsLocked(self); |
| } |
| |
| void DeoptManager::AddMethodBreakpoint(art::ArtMethod* method) { |
| DCHECK(method->IsInvokable()); |
| DCHECK(!method->IsProxyMethod()) << method->PrettyMethod(); |
| DCHECK(!method->IsNative()) << method->PrettyMethod(); |
| |
| art::Thread* self = art::Thread::Current(); |
| method = method->GetCanonicalMethod(); |
| bool is_default = method->IsDefault(); |
| |
| art::ScopedThreadSuspension sts(self, art::ThreadState::kSuspended); |
| deoptimization_status_lock_.ExclusiveLock(self); |
| { |
| breakpoint_status_lock_.ExclusiveLock(self); |
| |
| DCHECK_GT(deopter_count_, 0u) << "unexpected deotpimization request"; |
| |
| if (MethodHasBreakpointsLocked(method)) { |
| // Don't need to do anything extra. |
| breakpoint_status_[method]++; |
| // Another thread might be deoptimizing the very method we just added new breakpoints for. |
| // Wait for any deopts to finish before moving on. |
| breakpoint_status_lock_.ExclusiveUnlock(self); |
| WaitForDeoptimizationToFinish(self); |
| return; |
| } |
| breakpoint_status_[method] = 1; |
| breakpoint_status_lock_.ExclusiveUnlock(self); |
| } |
| auto instrumentation = art::Runtime::Current()->GetInstrumentation(); |
| if (instrumentation->IsForcedInterpretOnly()) { |
| // We are already interpreting everything so no need to do anything. |
| deoptimization_status_lock_.ExclusiveUnlock(self); |
| return; |
| } else if (is_default) { |
| AddDeoptimizeAllMethodsLocked(self); |
| } else { |
| PerformLimitedDeoptimization(self, method); |
| } |
| } |
| |
| void DeoptManager::RemoveMethodBreakpoint(art::ArtMethod* method) { |
| DCHECK(method->IsInvokable()) << method->PrettyMethod(); |
| DCHECK(!method->IsProxyMethod()) << method->PrettyMethod(); |
| DCHECK(!method->IsNative()) << method->PrettyMethod(); |
| |
| art::Thread* self = art::Thread::Current(); |
| method = method->GetCanonicalMethod(); |
| bool is_default = method->IsDefault(); |
| |
| art::ScopedThreadSuspension sts(self, art::ThreadState::kSuspended); |
| // Ideally we should do a ScopedSuspendAll right here to get the full mutator_lock_ that we might |
| // need but since that is very heavy we will instead just use a condition variable to make sure we |
| // don't race with ourselves. |
| deoptimization_status_lock_.ExclusiveLock(self); |
| bool is_last_breakpoint; |
| { |
| art::MutexLock mu(self, breakpoint_status_lock_); |
| |
| DCHECK_GT(deopter_count_, 0u) << "unexpected deotpimization request"; |
| DCHECK(MethodHasBreakpointsLocked(method)) << "Breakpoint on a method was removed without " |
| << "breakpoints present!"; |
| breakpoint_status_[method] -= 1; |
| is_last_breakpoint = (breakpoint_status_[method] == 0); |
| } |
| auto instrumentation = art::Runtime::Current()->GetInstrumentation(); |
| if (UNLIKELY(instrumentation->IsForcedInterpretOnly())) { |
| // We don't need to do anything since we are interpreting everything anyway. |
| deoptimization_status_lock_.ExclusiveUnlock(self); |
| return; |
| } else if (is_last_breakpoint) { |
| if (UNLIKELY(is_default)) { |
| RemoveDeoptimizeAllMethodsLocked(self); |
| } else { |
| PerformLimitedUndeoptimization(self, method); |
| } |
| } else { |
| // Another thread might be deoptimizing the very methods we just removed breakpoints from. Wait |
| // for any deopts to finish before moving on. |
| WaitForDeoptimizationToFinish(self); |
| } |
| } |
| |
| void DeoptManager::WaitForDeoptimizationToFinishLocked(art::Thread* self) { |
| while (performing_deoptimization_) { |
| deoptimization_condition_.Wait(self); |
| } |
| } |
| |
| void DeoptManager::WaitForDeoptimizationToFinish(art::Thread* self) { |
| WaitForDeoptimizationToFinishLocked(self); |
| deoptimization_status_lock_.ExclusiveUnlock(self); |
| } |
| |
| // Users should make sure that only gc-critical-section safe code is used while a |
| // ScopedDeoptimizationContext exists. |
| class ScopedDeoptimizationContext : public art::ValueObject { |
| public: |
| ScopedDeoptimizationContext(art::Thread* self, DeoptManager* deopt) |
| RELEASE(deopt->deoptimization_status_lock_) |
| ACQUIRE(art::Locks::mutator_lock_) |
| ACQUIRE(art::Roles::uninterruptible_) |
| : self_(self), |
| deopt_(deopt), |
| critical_section_(self_, "JVMTI Deoptimizing methods"), |
| uninterruptible_cause_(nullptr) { |
| deopt_->WaitForDeoptimizationToFinishLocked(self_); |
| DCHECK(!deopt->performing_deoptimization_) |
| << "Already performing deoptimization on another thread!"; |
| // Use performing_deoptimization_ to keep track of the lock. |
| deopt_->performing_deoptimization_ = true; |
| deopt_->deoptimization_status_lock_.Unlock(self_); |
| uninterruptible_cause_ = critical_section_.Enter(art::gc::kGcCauseInstrumentation, |
| art::gc::kCollectorTypeCriticalSection); |
| art::Runtime::Current()->GetThreadList()->SuspendAll("JMVTI Deoptimizing methods", |
| /*long_suspend=*/ false); |
| } |
| |
| ~ScopedDeoptimizationContext() |
| RELEASE(art::Locks::mutator_lock_) |
| RELEASE(art::Roles::uninterruptible_) { |
| // Can be suspended again. |
| critical_section_.Exit(uninterruptible_cause_); |
| // Release the mutator lock. |
| art::Runtime::Current()->GetThreadList()->ResumeAll(); |
| // Let other threads know it's fine to proceed. |
| art::MutexLock lk(self_, deopt_->deoptimization_status_lock_); |
| deopt_->performing_deoptimization_ = false; |
| deopt_->deoptimization_condition_.Broadcast(self_); |
| } |
| |
| private: |
| art::Thread* self_; |
| DeoptManager* deopt_; |
| art::gc::GCCriticalSection critical_section_; |
| const char* uninterruptible_cause_; |
| }; |
| |
| void DeoptManager::AddDeoptimizeAllMethodsLocked(art::Thread* self) { |
| global_deopt_count_++; |
| if (global_deopt_count_ == 1) { |
| PerformGlobalDeoptimization(self); |
| } else { |
| WaitForDeoptimizationToFinish(self); |
| } |
| } |
| |
| void DeoptManager::RemoveDeoptimizeAllMethodsLocked(art::Thread* self) { |
| DCHECK_GT(global_deopt_count_, 0u) << "Request to remove non-existent global deoptimization!"; |
| global_deopt_count_--; |
| if (global_deopt_count_ == 0) { |
| PerformGlobalUndeoptimization(self); |
| } else { |
| WaitForDeoptimizationToFinish(self); |
| } |
| } |
| |
| void DeoptManager::PerformLimitedDeoptimization(art::Thread* self, art::ArtMethod* method) { |
| ScopedDeoptimizationContext sdc(self, this); |
| art::Runtime::Current()->GetInstrumentation()->Deoptimize(method); |
| } |
| |
| void DeoptManager::PerformLimitedUndeoptimization(art::Thread* self, art::ArtMethod* method) { |
| ScopedDeoptimizationContext sdc(self, this); |
| art::Runtime::Current()->GetInstrumentation()->Undeoptimize(method); |
| } |
| |
| void DeoptManager::PerformGlobalDeoptimization(art::Thread* self) { |
| ScopedDeoptimizationContext sdc(self, this); |
| art::Runtime::Current()->GetInstrumentation()->DeoptimizeEverything( |
| kDeoptManagerInstrumentationKey); |
| } |
| |
| void DeoptManager::PerformGlobalUndeoptimization(art::Thread* self) { |
| ScopedDeoptimizationContext sdc(self, this); |
| art::Runtime::Current()->GetInstrumentation()->UndeoptimizeEverything( |
| kDeoptManagerInstrumentationKey); |
| } |
| |
| jvmtiError DeoptManager::AddDeoptimizeThreadMethods(art::ScopedObjectAccessUnchecked& soa, jthread jtarget) { |
| art::Locks::thread_list_lock_->ExclusiveLock(soa.Self()); |
| art::Thread* target = nullptr; |
| jvmtiError err = OK; |
| if (!ThreadUtil::GetNativeThread(jtarget, soa, &target, &err)) { |
| art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self()); |
| return err; |
| } |
| // We don't need additional locking here because we hold the Thread_list_lock_. |
| if (target->IncrementForceInterpreterCount() == 1) { |
| struct DeoptClosure : public art::Closure { |
| public: |
| explicit DeoptClosure(DeoptManager* manager) : manager_(manager) {} |
| void Run(art::Thread* self) override REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| manager_->DeoptimizeThread(self); |
| } |
| |
| private: |
| DeoptManager* manager_; |
| }; |
| DeoptClosure c(this); |
| target->RequestSynchronousCheckpoint(&c); |
| } else { |
| art::Locks::thread_list_lock_->ExclusiveUnlock(soa.Self()); |
| } |
| return OK; |
| } |
| |
| jvmtiError DeoptManager::RemoveDeoptimizeThreadMethods(art::ScopedObjectAccessUnchecked& soa, jthread jtarget) { |
| art::MutexLock mu(soa.Self(), *art::Locks::thread_list_lock_); |
| art::Thread* target = nullptr; |
| jvmtiError err = OK; |
| if (!ThreadUtil::GetNativeThread(jtarget, soa, &target, &err)) { |
| return err; |
| } |
| // We don't need additional locking here because we hold the Thread_list_lock_. |
| DCHECK_GT(target->ForceInterpreterCount(), 0u); |
| target->DecrementForceInterpreterCount(); |
| return OK; |
| } |
| |
| static constexpr const char* kInstrumentationKey = "JVMTI_DeoptRequester"; |
| |
| void DeoptManager::RemoveDeoptimizationRequester() { |
| art::Thread* self = art::Thread::Current(); |
| art::ScopedThreadStateChange sts(self, art::ThreadState::kSuspended); |
| deoptimization_status_lock_.ExclusiveLock(self); |
| DCHECK_GT(deopter_count_, 0u) << "Removing deoptimization requester without any being present"; |
| deopter_count_--; |
| if (deopter_count_ == 0) { |
| ScopedDeoptimizationContext sdc(self, this); |
| art::Runtime::Current()->GetInstrumentation()->DisableDeoptimization(kInstrumentationKey); |
| return; |
| } else { |
| deoptimization_status_lock_.ExclusiveUnlock(self); |
| } |
| } |
| |
| void DeoptManager::AddDeoptimizationRequester() { |
| art::Thread* self = art::Thread::Current(); |
| art::ScopedThreadStateChange stsc(self, art::ThreadState::kSuspended); |
| deoptimization_status_lock_.ExclusiveLock(self); |
| deopter_count_++; |
| deoptimization_status_lock_.ExclusiveUnlock(self); |
| } |
| |
| void DeoptManager::DeoptimizeThread(art::Thread* target) { |
| // We might or might not be running on the target thread (self) so get Thread::Current |
| // directly. |
| art::ScopedThreadSuspension sts(art::Thread::Current(), art::ThreadState::kSuspended); |
| art::gc::ScopedGCCriticalSection sgccs(art::Thread::Current(), |
| art::gc::GcCause::kGcCauseDebugger, |
| art::gc::CollectorType::kCollectorTypeDebugger); |
| art::ScopedSuspendAll ssa("Instrument thread stack"); |
| // Prepare the stack so methods can be deoptimized as and when required. |
| // This by itself doesn't cause any methods to deoptimize but enables |
| // deoptimization on demand. |
| art::Runtime::Current()->GetInstrumentation()->InstrumentThreadStack( |
| target, |
| /* deopt_all_frames= */ false); |
| } |
| |
| extern DeoptManager* gDeoptManager; |
| DeoptManager* DeoptManager::Get() { |
| return gDeoptManager; |
| } |
| |
| } // namespace openjdkjvmti |