1/*
2 * Copyright (C) 2016 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#ifndef ART_RUNTIME_OPENJDKJVMTI_EVENTS_H_
18#define ART_RUNTIME_OPENJDKJVMTI_EVENTS_H_
19
20#include <bitset>
21#include <vector>
22
23#include "base/logging.h"
24#include "jvmti.h"
25#include "thread.h"
26
27namespace openjdkjvmti {
28
29struct ArtJvmTiEnv;
30class JvmtiAllocationListener;
31class JvmtiGcPauseListener;
32
33// an enum for ArtEvents. This differs from the JVMTI events only in that we distinguish between
34// retransformation capable and incapable loading
35enum class ArtJvmtiEvent {
36    kMinEventTypeVal = JVMTI_MIN_EVENT_TYPE_VAL,
37    kVmInit = JVMTI_EVENT_VM_INIT,
38    kVmDeath = JVMTI_EVENT_VM_DEATH,
39    kThreadStart = JVMTI_EVENT_THREAD_START,
40    kThreadEnd = JVMTI_EVENT_THREAD_END,
41    kClassFileLoadHookNonRetransformable = JVMTI_EVENT_CLASS_FILE_LOAD_HOOK,
42    kClassLoad = JVMTI_EVENT_CLASS_LOAD,
43    kClassPrepare = JVMTI_EVENT_CLASS_PREPARE,
44    kVmStart = JVMTI_EVENT_VM_START,
45    kException = JVMTI_EVENT_EXCEPTION,
46    kExceptionCatch = JVMTI_EVENT_EXCEPTION_CATCH,
47    kSingleStep = JVMTI_EVENT_SINGLE_STEP,
48    kFramePop = JVMTI_EVENT_FRAME_POP,
49    kBreakpoint = JVMTI_EVENT_BREAKPOINT,
50    kFieldAccess = JVMTI_EVENT_FIELD_ACCESS,
51    kFieldModification = JVMTI_EVENT_FIELD_MODIFICATION,
52    kMethodEntry = JVMTI_EVENT_METHOD_ENTRY,
53    kMethodExit = JVMTI_EVENT_METHOD_EXIT,
54    kNativeMethodBind = JVMTI_EVENT_NATIVE_METHOD_BIND,
55    kCompiledMethodLoad = JVMTI_EVENT_COMPILED_METHOD_LOAD,
56    kCompiledMethodUnload = JVMTI_EVENT_COMPILED_METHOD_UNLOAD,
57    kDynamicCodeGenerated = JVMTI_EVENT_DYNAMIC_CODE_GENERATED,
58    kDataDumpRequest = JVMTI_EVENT_DATA_DUMP_REQUEST,
59    kMonitorWait = JVMTI_EVENT_MONITOR_WAIT,
60    kMonitorWaited = JVMTI_EVENT_MONITOR_WAITED,
61    kMonitorContendedEnter = JVMTI_EVENT_MONITOR_CONTENDED_ENTER,
62    kMonitorContendedEntered = JVMTI_EVENT_MONITOR_CONTENDED_ENTERED,
63    kResourceExhausted = JVMTI_EVENT_RESOURCE_EXHAUSTED,
64    kGarbageCollectionStart = JVMTI_EVENT_GARBAGE_COLLECTION_START,
65    kGarbageCollectionFinish = JVMTI_EVENT_GARBAGE_COLLECTION_FINISH,
66    kObjectFree = JVMTI_EVENT_OBJECT_FREE,
67    kVmObjectAlloc = JVMTI_EVENT_VM_OBJECT_ALLOC,
68    kClassFileLoadHookRetransformable = JVMTI_MAX_EVENT_TYPE_VAL + 1,
69    kMaxEventTypeVal = kClassFileLoadHookRetransformable,
70};
71
72// Convert a jvmtiEvent into a ArtJvmtiEvent
73ALWAYS_INLINE static inline ArtJvmtiEvent GetArtJvmtiEvent(ArtJvmTiEnv* env, jvmtiEvent e);
74
75static inline jvmtiEvent GetJvmtiEvent(ArtJvmtiEvent e) {
76  if (UNLIKELY(e == ArtJvmtiEvent::kClassFileLoadHookRetransformable)) {
77    return JVMTI_EVENT_CLASS_FILE_LOAD_HOOK;
78  } else {
79    return static_cast<jvmtiEvent>(e);
80  }
81}
82
83struct EventMask {
84  static constexpr size_t kEventsSize =
85      static_cast<size_t>(ArtJvmtiEvent::kMaxEventTypeVal) -
86      static_cast<size_t>(ArtJvmtiEvent::kMinEventTypeVal) + 1;
87  std::bitset<kEventsSize> bit_set;
88
89  static bool EventIsInRange(ArtJvmtiEvent event) {
90    return event >= ArtJvmtiEvent::kMinEventTypeVal && event <= ArtJvmtiEvent::kMaxEventTypeVal;
91  }
92
93  void Set(ArtJvmtiEvent event, bool value = true) {
94    DCHECK(EventIsInRange(event));
95    bit_set.set(static_cast<size_t>(event) - static_cast<size_t>(ArtJvmtiEvent::kMinEventTypeVal),
96                value);
97  }
98
99  bool Test(ArtJvmtiEvent event) const {
100    DCHECK(EventIsInRange(event));
101    return bit_set.test(
102        static_cast<size_t>(event) - static_cast<size_t>(ArtJvmtiEvent::kMinEventTypeVal));
103  }
104};
105
106struct EventMasks {
107  // The globally enabled events.
108  EventMask global_event_mask;
109
110  // The per-thread enabled events.
111
112  // It is not enough to store a Thread pointer, as these may be reused. Use the pointer and the
113  // thread id.
114  // Note: We could just use the tid like tracing does.
115  using UniqueThread = std::pair<art::Thread*, uint32_t>;
116  // TODO: Native thread objects are immovable, so we can use them as keys in an (unordered) map,
117  //       if necessary.
118  std::vector<std::pair<UniqueThread, EventMask>> thread_event_masks;
119
120  // A union of the per-thread events, for fast-pathing.
121  EventMask unioned_thread_event_mask;
122
123  EventMask& GetEventMask(art::Thread* thread);
124  EventMask* GetEventMaskOrNull(art::Thread* thread);
125  void EnableEvent(art::Thread* thread, ArtJvmtiEvent event);
126  void DisableEvent(art::Thread* thread, ArtJvmtiEvent event);
127  bool IsEnabledAnywhere(ArtJvmtiEvent event);
128  // Make any changes to event masks needed for the given capability changes. If caps_added is true
129  // then caps is all the newly set capabilities of the jvmtiEnv. If it is false then caps is the
130  // set of all capabilities that were removed from the jvmtiEnv.
131  void HandleChangedCapabilities(const jvmtiCapabilities& caps, bool caps_added);
132};
133
134// Helper class for event handling.
135class EventHandler {
136 public:
137  EventHandler();
138  ~EventHandler();
139
140  // Register an env. It is assumed that this happens on env creation, that is, no events are
141  // enabled, yet.
142  void RegisterArtJvmTiEnv(ArtJvmTiEnv* env);
143
144  // Remove an env.
145  void RemoveArtJvmTiEnv(ArtJvmTiEnv* env);
146
147  bool IsEventEnabledAnywhere(ArtJvmtiEvent event) const {
148    if (!EventMask::EventIsInRange(event)) {
149      return false;
150    }
151    return global_mask.Test(event);
152  }
153
154  jvmtiError SetEvent(ArtJvmTiEnv* env,
155                      art::Thread* thread,
156                      ArtJvmtiEvent event,
157                      jvmtiEventMode mode);
158
159  // Dispatch event to all registered environments.
160  template <ArtJvmtiEvent kEvent, typename ...Args>
161  ALWAYS_INLINE
162  inline void DispatchEvent(art::Thread* thread, Args... args) const;
163  // Dispatch event to the given environment, only.
164  template <ArtJvmtiEvent kEvent, typename ...Args>
165  ALWAYS_INLINE
166  inline void DispatchEvent(ArtJvmTiEnv* env, art::Thread* thread, Args... args) const;
167
168  // Tell the event handler capabilities were added/lost so it can adjust the sent events.If
169  // caps_added is true then caps is all the newly set capabilities of the jvmtiEnv. If it is false
170  // then caps is the set of all capabilities that were removed from the jvmtiEnv.
171  ALWAYS_INLINE
172  inline void HandleChangedCapabilities(ArtJvmTiEnv* env,
173                                        const jvmtiCapabilities& caps,
174                                        bool added);
175
176 private:
177  template <ArtJvmtiEvent kEvent>
178  ALWAYS_INLINE
179  static inline bool ShouldDispatch(ArtJvmTiEnv* env, art::Thread* thread);
180
181  ALWAYS_INLINE
182  inline bool NeedsEventUpdate(ArtJvmTiEnv* env,
183                               const jvmtiCapabilities& caps,
184                               bool added);
185
186  // Recalculates the event mask for the given event.
187  ALWAYS_INLINE
188  inline void RecalculateGlobalEventMask(ArtJvmtiEvent event);
189
190  template <ArtJvmtiEvent kEvent>
191  ALWAYS_INLINE inline void DispatchClassFileLoadHookEvent(art::Thread* thread,
192                                                           JNIEnv* jnienv,
193                                                           jclass class_being_redefined,
194                                                           jobject loader,
195                                                           const char* name,
196                                                           jobject protection_domain,
197                                                           jint class_data_len,
198                                                           const unsigned char* class_data,
199                                                           jint* new_class_data_len,
200                                                           unsigned char** new_class_data) const;
201
202  void HandleEventType(ArtJvmtiEvent event, bool enable);
203
204  // List of all JvmTiEnv objects that have been created, in their creation order.
205  // NB Some elements might be null representing envs that have been deleted. They should be skipped
206  // anytime this list is used.
207  std::vector<ArtJvmTiEnv*> envs;
208
209  // A union of all enabled events, anywhere.
210  EventMask global_mask;
211
212  std::unique_ptr<JvmtiAllocationListener> alloc_listener_;
213  std::unique_ptr<JvmtiGcPauseListener> gc_pause_listener_;
214};
215
216}  // namespace openjdkjvmti
217
218#endif  // ART_RUNTIME_OPENJDKJVMTI_EVENTS_H_
219