/*
* Copyright (C) 2016 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.
*/
#ifndef ART_OPENJDKJVMTI_EVENTS_H_
#define ART_OPENJDKJVMTI_EVENTS_H_
#include <bitset>
#include <unordered_map>
#include <vector>
#include <android-base/logging.h>
#include <android-base/thread_annotations.h>
#include "android-base/thread_annotations.h"
#include "base/macros.h"
#include "base/mutex.h"
#include "jvmti.h"
#include "managed_stack.h"
#include "thread.h"
namespace openjdkjvmti {
struct ArtJvmTiEnv;
class JvmtiEventAllocationListener;
class JvmtiDdmChunkListener;
class JvmtiGcPauseListener;
class JvmtiMethodTraceListener;
class JvmtiMonitorListener;
class JvmtiParkListener;
// an enum for ArtEvents. This differs from the JVMTI events only in that we distinguish between
// retransformation capable and incapable loading
enum class ArtJvmtiEvent : jint {
kMinEventTypeVal = JVMTI_MIN_EVENT_TYPE_VAL,
kVmInit = JVMTI_EVENT_VM_INIT,
kVmDeath = JVMTI_EVENT_VM_DEATH,
kThreadStart = JVMTI_EVENT_THREAD_START,
kThreadEnd = JVMTI_EVENT_THREAD_END,
kClassFileLoadHookNonRetransformable = JVMTI_EVENT_CLASS_FILE_LOAD_HOOK,
kClassLoad = JVMTI_EVENT_CLASS_LOAD,
kClassPrepare = JVMTI_EVENT_CLASS_PREPARE,
kVmStart = JVMTI_EVENT_VM_START,
kException = JVMTI_EVENT_EXCEPTION,
kExceptionCatch = JVMTI_EVENT_EXCEPTION_CATCH,
kSingleStep = JVMTI_EVENT_SINGLE_STEP,
kFramePop = JVMTI_EVENT_FRAME_POP,
kBreakpoint = JVMTI_EVENT_BREAKPOINT,
kFieldAccess = JVMTI_EVENT_FIELD_ACCESS,
kFieldModification = JVMTI_EVENT_FIELD_MODIFICATION,
kMethodEntry = JVMTI_EVENT_METHOD_ENTRY,
kMethodExit = JVMTI_EVENT_METHOD_EXIT,
kNativeMethodBind = JVMTI_EVENT_NATIVE_METHOD_BIND,
kCompiledMethodLoad = JVMTI_EVENT_COMPILED_METHOD_LOAD,
kCompiledMethodUnload = JVMTI_EVENT_COMPILED_METHOD_UNLOAD,
kDynamicCodeGenerated = JVMTI_EVENT_DYNAMIC_CODE_GENERATED,
kDataDumpRequest = JVMTI_EVENT_DATA_DUMP_REQUEST,
kMonitorWait = JVMTI_EVENT_MONITOR_WAIT,
kMonitorWaited = JVMTI_EVENT_MONITOR_WAITED,
kMonitorContendedEnter = JVMTI_EVENT_MONITOR_CONTENDED_ENTER,
kMonitorContendedEntered = JVMTI_EVENT_MONITOR_CONTENDED_ENTERED,
kResourceExhausted = JVMTI_EVENT_RESOURCE_EXHAUSTED,
kGarbageCollectionStart = JVMTI_EVENT_GARBAGE_COLLECTION_START,
kGarbageCollectionFinish = JVMTI_EVENT_GARBAGE_COLLECTION_FINISH,
kObjectFree = JVMTI_EVENT_OBJECT_FREE,
kVmObjectAlloc = JVMTI_EVENT_VM_OBJECT_ALLOC,
// Internal event to mark a ClassFileLoadHook as one created with the can_retransform_classes
// capability.
kClassFileLoadHookRetransformable = JVMTI_MAX_EVENT_TYPE_VAL + 1,
kDdmPublishChunk = JVMTI_MAX_EVENT_TYPE_VAL + 2,
kObsoleteObjectCreated = JVMTI_MAX_EVENT_TYPE_VAL + 3,
kStructuralDexFileLoadHook = JVMTI_MAX_EVENT_TYPE_VAL + 4,
kMaxNormalEventTypeVal = kStructuralDexFileLoadHook,
// All that follow are events used to implement internal JVMTI functions. They are not settable
// directly by agents.
kMinInternalEventTypeVal = kMaxNormalEventTypeVal + 1,
// Internal event we use to implement the ForceEarlyReturn functions.
kForceEarlyReturnUpdateReturnValue = kMinInternalEventTypeVal,
kMaxInternalEventTypeVal = kForceEarlyReturnUpdateReturnValue,
kMaxEventTypeVal = kMaxInternalEventTypeVal,
};
constexpr jint kInternalEventCount = static_cast<jint>(ArtJvmtiEvent::kMaxInternalEventTypeVal) -
static_cast<jint>(ArtJvmtiEvent::kMinInternalEventTypeVal) + 1;
using ArtJvmtiEventDdmPublishChunk = void (*)(jvmtiEnv *jvmti_env,
jint data_type,
jint data_len,
const jbyte* data);
using ArtJvmtiEventObsoleteObjectCreated = void (*)(jvmtiEnv *jvmti_env,
jlong* obsolete_tag,
jlong* new_tag);
using ArtJvmtiEventStructuralDexFileLoadHook = void (*)(jvmtiEnv *jvmti_env,
JNIEnv* jni_env,
jclass class_being_redefined,
jobject loader,
const char* name,
jobject protection_domain,
jint dex_data_len,
const unsigned char* dex_data,
jint* new_dex_data_len,
unsigned char** new_dex_data);
// It is not enough to store a Thread pointer, as these may be reused. Use the pointer and the
// thread id.
// Note: We could just use the tid like tracing does.
using UniqueThread = std::pair<art::Thread*, uint32_t>;
struct UniqueThreadHasher {
std::size_t operator()(const UniqueThread& k) const {
return std::hash<uint32_t>{}(k.second) ^ (std::hash<void*>{}(k.first) << 1);
}
};
struct ArtJvmtiEventCallbacks : jvmtiEventCallbacks {
ArtJvmtiEventCallbacks()
: DdmPublishChunk(nullptr),
ObsoleteObjectCreated(nullptr),
StructuralDexFileLoadHook(nullptr) {
memset(this, 0, sizeof(jvmtiEventCallbacks));
}
// Copies extension functions from other callback struct if it exists. There must not have been
// any modifications to this struct when it is called.
void CopyExtensionsFrom(const ArtJvmtiEventCallbacks* cb);
jvmtiError Set(jint index, jvmtiExtensionEvent cb);
ArtJvmtiEventDdmPublishChunk DdmPublishChunk;
ArtJvmtiEventObsoleteObjectCreated ObsoleteObjectCreated;
ArtJvmtiEventStructuralDexFileLoadHook StructuralDexFileLoadHook;
};
bool IsExtensionEvent(jint e);
bool IsExtensionEvent(ArtJvmtiEvent e);
// Convert a jvmtiEvent into a ArtJvmtiEvent
ALWAYS_INLINE static inline ArtJvmtiEvent GetArtJvmtiEvent(ArtJvmTiEnv* env, jvmtiEvent e);
static inline jvmtiEvent GetJvmtiEvent(ArtJvmtiEvent e) {
if (UNLIKELY(e == ArtJvmtiEvent::kClassFileLoadHookRetransformable)) {
return JVMTI_EVENT_CLASS_FILE_LOAD_HOOK;
} else {
return static_cast<jvmtiEvent>(e);
}
}
struct EventMask {
static constexpr size_t kEventsSize =
static_cast<size_t>(ArtJvmtiEvent::kMaxEventTypeVal) -
static_cast<size_t>(ArtJvmtiEvent::kMinEventTypeVal) + 1;
std::bitset<kEventsSize> bit_set;
static bool EventIsInRange(ArtJvmtiEvent event) {
return event >= ArtJvmtiEvent::kMinEventTypeVal && event <= ArtJvmtiEvent::kMaxEventTypeVal;
}
void Set(ArtJvmtiEvent event, bool value = true) {
DCHECK(EventIsInRange(event));
bit_set.set(static_cast<size_t>(event) - static_cast<size_t>(ArtJvmtiEvent::kMinEventTypeVal),
value);
}
bool Test(ArtJvmtiEvent event) const {
DCHECK(EventIsInRange(event));
return bit_set.test(
static_cast<size_t>(event) - static_cast<size_t>(ArtJvmtiEvent::kMinEventTypeVal));
}
};
struct EventMasks {
// The globally enabled events.
EventMask global_event_mask;
// The per-thread enabled events.
// TODO: Native thread objects are immovable, so we can use them as keys in an (unordered) map,
// if necessary.
std::vector<std::pair<UniqueThread, EventMask>> thread_event_masks;
// A union of the per-thread events, for fast-pathing.
EventMask unioned_thread_event_mask;
EventMask& GetEventMask(art::Thread* thread);
EventMask* GetEventMaskOrNull(art::Thread* thread);
// Circular dependencies mean we cannot see the definition of ArtJvmTiEnv so the mutex is simply
// asserted in the function.
// Note that the 'env' passed in must be the same env this EventMasks is associated with.
void EnableEvent(ArtJvmTiEnv* env, art::Thread* thread, ArtJvmtiEvent event);
// REQUIRES(env->event_info_mutex_);
// Circular dependencies mean we cannot see the definition of ArtJvmTiEnv so the mutex is simply
// asserted in the function.
// Note that the 'env' passed in must be the same env this EventMasks is associated with.
void DisableEvent(ArtJvmTiEnv* env, art::Thread* thread, ArtJvmtiEvent event);
// REQUIRES(env->event_info_mutex_);
bool IsEnabledAnywhere(ArtJvmtiEvent event);
// Make any changes to event masks needed for the given capability changes. If caps_added is true
// then caps is all the newly set capabilities of the jvmtiEnv. If it is false then caps is the
// set of all capabilities that were removed from the jvmtiEnv.
void HandleChangedCapabilities(const jvmtiCapabilities& caps, bool caps_added);
};
namespace impl {
template <ArtJvmtiEvent kEvent> struct EventHandlerFunc { };
} // namespace impl
// Helper class for event handling.
class EventHandler {
public:
EventHandler();
~EventHandler();
// do cleanup for the event handler.
void Shutdown();
// Register an env. It is assumed that this happens on env creation, that is, no events are
// enabled, yet.
void RegisterArtJvmTiEnv(ArtJvmTiEnv* env) REQUIRES(!envs_lock_);
// Remove an env.
void RemoveArtJvmTiEnv(ArtJvmTiEnv* env) REQUIRES(!envs_lock_);
bool IsEventEnabledAnywhere(ArtJvmtiEvent event) const {
if (!EventMask::EventIsInRange(event)) {
return false;
}
return global_mask.Test(event);
}
// Sets an internal event. Unlike normal JVMTI events internal events are not associated with any
// particular jvmtiEnv and are refcounted. This refcounting is done to allow us to easily enable
// events during functions and disable them during the requested event callback. Since these are
// used to implement various JVMTI functions these events always have a single target thread. If
// target is null the current thread is used.
jvmtiError SetInternalEvent(jthread target,
ArtJvmtiEvent event,
jvmtiEventMode mode)
REQUIRES(!envs_lock_, !art::Locks::mutator_lock_);
jvmtiError SetEvent(ArtJvmTiEnv* env,
jthread thread,
ArtJvmtiEvent event,
jvmtiEventMode mode)
REQUIRES(!envs_lock_);
// Dispatch event to all registered environments. Since this one doesn't have a JNIEnv* it doesn't
// matter if it has the mutator_lock.
template <ArtJvmtiEvent kEvent, typename ...Args>
ALWAYS_INLINE
inline void DispatchEvent(art::Thread* thread, Args... args) const
REQUIRES(!envs_lock_);
// Dispatch event to all registered environments stashing exceptions as needed. This works since
// JNIEnv* is always the second argument if it is passed to an event. Needed since C++ does not
// allow partial template function specialization.
//
// We need both of these since we want to make sure to push a stack frame when it is possible for
// the event to allocate local references.
template <ArtJvmtiEvent kEvent, typename ...Args>
ALWAYS_INLINE
inline void DispatchEvent(art::Thread* thread, JNIEnv* jnienv, Args... args) const
REQUIRES(!envs_lock_);
// Tell the event handler capabilities were added/lost so it can adjust the sent events.If
// caps_added is true then caps is all the newly set capabilities of the jvmtiEnv. If it is false
// then caps is the set of all capabilities that were removed from the jvmtiEnv.
ALWAYS_INLINE
inline void HandleChangedCapabilities(ArtJvmTiEnv* env,
const jvmtiCapabilities& caps,
bool added)
REQUIRES(!envs_lock_);
// Dispatch event to the given environment, only.
template <ArtJvmtiEvent kEvent, typename ...Args>
ALWAYS_INLINE
inline void DispatchEventOnEnv(ArtJvmTiEnv* env,
art::Thread* thread,
JNIEnv* jnienv,
Args... args) const
REQUIRES(!envs_lock_);
// Dispatch event to the given environment, only.
template <ArtJvmtiEvent kEvent, typename ...Args>
ALWAYS_INLINE
inline void DispatchEventOnEnv(ArtJvmTiEnv* env, art::Thread* thread, Args... args) const
REQUIRES(!envs_lock_);
void AddDelayedNonStandardExitEvent(const art::ShadowFrame* frame, bool is_object, jvalue val)
REQUIRES_SHARED(art::Locks::mutator_lock_)
REQUIRES(art::Locks::user_code_suspension_lock_, art::Locks::thread_list_lock_);
template<typename Visitor>
void ForEachEnv(art::Thread* self, Visitor v) REQUIRES(!envs_lock_) {
art::ReaderMutexLock mu(self, envs_lock_);
for (ArtJvmTiEnv* e : envs) {
if (e != nullptr) {
v(e);
}
}
}
private:
void SetupTraceListener(JvmtiMethodTraceListener* listener, ArtJvmtiEvent event, bool enable);
uint32_t GetInstrumentationEventsFor(ArtJvmtiEvent event);
// Specifically handle the FramePop event which it might not always be possible to turn off.
void SetupFramePopTraceListener(bool enable);
template <ArtJvmtiEvent kEvent, typename ...Args>
ALWAYS_INLINE
inline std::vector<impl::EventHandlerFunc<kEvent>> CollectEvents(art::Thread* thread,
Args... args) const
REQUIRES(!envs_lock_);
template <ArtJvmtiEvent kEvent>
ALWAYS_INLINE
inline bool ShouldDispatchOnThread(ArtJvmTiEnv* env, art::Thread* thread) const;
template <ArtJvmtiEvent kEvent, typename ...Args>
ALWAYS_INLINE
static inline void ExecuteCallback(impl::EventHandlerFunc<kEvent> handler,
JNIEnv* env,
Args... args)
REQUIRES(!envs_lock_);
template <ArtJvmtiEvent kEvent, typename ...Args>
ALWAYS_INLINE
static inline void ExecuteCallback(impl::EventHandlerFunc<kEvent> handler, Args... args)
REQUIRES(!envs_lock_);
// Public for use to collect dispatches
template <ArtJvmtiEvent kEvent, typename ...Args>
ALWAYS_INLINE
inline bool ShouldDispatch(ArtJvmTiEnv* env, art::Thread* thread, Args... args) const;
ALWAYS_INLINE
inline bool NeedsEventUpdate(ArtJvmTiEnv* env,
const jvmtiCapabilities& caps,
bool added);
// Recalculates the event mask for the given event.
ALWAYS_INLINE
inline void RecalculateGlobalEventMask(ArtJvmtiEvent event) REQUIRES(!envs_lock_);
ALWAYS_INLINE
inline void RecalculateGlobalEventMaskLocked(ArtJvmtiEvent event) REQUIRES_SHARED(envs_lock_);
// Returns whether there are any active requests for the given event on the given thread. This
// should only be used while modifying the events for a thread.
bool GetThreadEventState(ArtJvmtiEvent event, art::Thread* thread)
REQUIRES(envs_lock_, art::Locks::thread_list_lock_);
template <ArtJvmtiEvent kEvent>
ALWAYS_INLINE inline void DispatchClassFileLoadHookEvent(art::Thread* thread,
JNIEnv* jnienv,
jclass class_being_redefined,
jobject loader,
const char* name,
jobject protection_domain,
jint class_data_len,
const unsigned char* class_data,
jint* new_class_data_len,
unsigned char** new_class_data) const
REQUIRES(!envs_lock_);
template <ArtJvmtiEvent kEvent>
ALWAYS_INLINE inline void DispatchClassLoadOrPrepareEvent(art::Thread* thread,
JNIEnv* jnienv,
jthread jni_thread,
jclass klass) const
REQUIRES(!envs_lock_);
// Sets up the global state needed for the first/last enable of an event across all threads
void HandleEventType(ArtJvmtiEvent event, bool enable);
// Perform deopts required for enabling the event on the given thread. Null thread indicates
// global event enabled.
jvmtiError HandleEventDeopt(ArtJvmtiEvent event, jthread thread, bool enable);
void HandleLocalAccessCapabilityAdded();
void HandleBreakpointEventsChanged(bool enable);
bool OtherMonitorEventsEnabledAnywhere(ArtJvmtiEvent event);
int32_t GetInternalEventRefcount(ArtJvmtiEvent event) const REQUIRES(envs_lock_);
// Increment internal event refcount for the given event and return the new count.
int32_t IncrInternalEventRefcount(ArtJvmtiEvent event) REQUIRES(envs_lock_);
// Decrement internal event refcount for the given event and return the new count.
int32_t DecrInternalEventRefcount(ArtJvmtiEvent event) REQUIRES(envs_lock_);
int32_t& GetInternalEventThreadRefcount(ArtJvmtiEvent event, art::Thread* target)
REQUIRES(envs_lock_, art::Locks::thread_list_lock_);
// Increment internal event refcount for the given event and return the new count.
int32_t IncrInternalEventThreadRefcount(ArtJvmtiEvent event, art::Thread* target)
REQUIRES(envs_lock_, art::Locks::thread_list_lock_);
// Decrement internal event refcount for the given event and return the new count.
int32_t DecrInternalEventThreadRefcount(ArtJvmtiEvent event, art::Thread* target)
REQUIRES(envs_lock_, art::Locks::thread_list_lock_);
// List of all JvmTiEnv objects that have been created, in their creation order. It is a std::list
// since we mostly access it by iterating over the entire thing, only ever append to the end, and
// need to be able to remove arbitrary elements from it.
std::list<ArtJvmTiEnv*> envs GUARDED_BY(envs_lock_);
// Close to top level lock. Nothing should be held when we lock this (except for mutator_lock_
// which is needed when setting new events).
mutable art::ReaderWriterMutex envs_lock_ ACQUIRED_AFTER(art::Locks::mutator_lock_);
// A union of all enabled events, anywhere.
EventMask global_mask;
std::unique_ptr<JvmtiEventAllocationListener> alloc_listener_;
std::unique_ptr<JvmtiDdmChunkListener> ddm_listener_;
std::unique_ptr<JvmtiGcPauseListener> gc_pause_listener_;
std::unique_ptr<JvmtiMethodTraceListener> method_trace_listener_;
std::unique_ptr<JvmtiMonitorListener> monitor_listener_;
std::unique_ptr<JvmtiParkListener> park_listener_;
// True if frame pop has ever been enabled. Since we store pointers to stack frames we need to
// continue to listen to this event even if it has been disabled.
// TODO We could remove the listeners once all jvmtiEnvs have drained their shadow-frame vectors.
bool frame_pop_enabled;
// The overall refcount for each internal event across all threads.
std::array<int32_t, kInternalEventCount> internal_event_refcount_ GUARDED_BY(envs_lock_);
// The refcount for each thread for each internal event.
// TODO We should clean both this and the normal EventMask lists up when threads end.
std::array<std::unordered_map<UniqueThread, int32_t, UniqueThreadHasher>, kInternalEventCount>
internal_event_thread_refcount_
GUARDED_BY(envs_lock_) GUARDED_BY(art::Locks::thread_list_lock_);
friend class JvmtiMethodTraceListener;
};
} // namespace openjdkjvmti
#endif // ART_OPENJDKJVMTI_EVENTS_H_