1 /* 2 * Copyright (C) 2011 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_JNI_JAVA_VM_EXT_H_ 18 #define ART_RUNTIME_JNI_JAVA_VM_EXT_H_ 19 20 #include "jni.h" 21 22 #include "base/macros.h" 23 #include "base/mutex.h" 24 #include "indirect_reference_table.h" 25 #include "obj_ptr.h" 26 #include "reference_table.h" 27 28 namespace art { 29 30 namespace mirror { 31 class Array; 32 } // namespace mirror 33 34 class ArtMethod; 35 class IsMarkedVisitor; 36 class Libraries; 37 class ParsedOptions; 38 class Runtime; 39 struct RuntimeArgumentMap; 40 class ScopedObjectAccess; 41 42 class JavaVMExt; 43 // Hook definition for runtime plugins. 44 using GetEnvHook = jint (*)(JavaVMExt* vm, /*out*/void** new_env, jint version); 45 46 class JavaVMExt : public JavaVM { 47 public: 48 // Creates a new JavaVMExt object. 49 // Returns nullptr on error, in which case error_msg is set to a message 50 // describing the error. 51 static std::unique_ptr<JavaVMExt> Create(Runtime* runtime, 52 const RuntimeArgumentMap& runtime_options, 53 std::string* error_msg); 54 55 56 ~JavaVMExt(); 57 ForceCopy()58 bool ForceCopy() const { 59 return force_copy_; 60 } 61 IsCheckJniEnabled()62 bool IsCheckJniEnabled() const { 63 return check_jni_; 64 } 65 IsTracingEnabled()66 bool IsTracingEnabled() const { 67 return tracing_enabled_; 68 } 69 GetRuntime()70 Runtime* GetRuntime() const { 71 return runtime_; 72 } 73 SetCheckJniAbortHook(void (* hook)(void *,const std::string &),void * data)74 void SetCheckJniAbortHook(void (*hook)(void*, const std::string&), void* data) { 75 check_jni_abort_hook_ = hook; 76 check_jni_abort_hook_data_ = data; 77 } 78 79 // Aborts execution unless there is an abort handler installed in which case it will return. Its 80 // therefore important that callers return after aborting as otherwise code following the abort 81 // will be executed in the abort handler case. 82 void JniAbort(const char* jni_function_name, const char* msg); 83 84 void JniAbortV(const char* jni_function_name, const char* fmt, va_list ap); 85 86 void JniAbortF(const char* jni_function_name, const char* fmt, ...) 87 __attribute__((__format__(__printf__, 3, 4))); 88 89 // If both "-Xcheck:jni" and "-Xjnitrace:" are enabled, we print trace messages 90 // when a native method that matches the -Xjnitrace argument calls a JNI function 91 // such as NewByteArray. 92 // If -verbose:third-party-jni is on, we want to log any JNI function calls 93 // made by a third-party native method. 94 bool ShouldTrace(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_); 95 96 /** 97 * Loads the given shared library. 'path' is an absolute pathname. 98 * 99 * Returns 'true' on success. On failure, sets 'error_msg' to a 100 * human-readable description of the error. 101 */ 102 bool LoadNativeLibrary(JNIEnv* env, 103 const std::string& path, 104 jobject class_loader, 105 jclass caller_class, 106 std::string* error_msg); 107 108 // Unload native libraries with cleared class loaders. 109 void UnloadNativeLibraries() 110 REQUIRES(!Locks::jni_libraries_lock_) 111 REQUIRES_SHARED(Locks::mutator_lock_); 112 113 // Unload all boot classpath native libraries. 114 void UnloadBootNativeLibraries() 115 REQUIRES(!Locks::jni_libraries_lock_) 116 REQUIRES_SHARED(Locks::mutator_lock_); 117 118 /** 119 * Returns a pointer to the code for the native method 'm', found 120 * using dlsym(3) on every native library that's been loaded so far. 121 */ 122 void* FindCodeForNativeMethod(ArtMethod* m) 123 REQUIRES_SHARED(Locks::mutator_lock_); 124 125 void DumpForSigQuit(std::ostream& os) 126 REQUIRES(!Locks::jni_libraries_lock_, 127 !Locks::jni_globals_lock_, 128 !Locks::jni_weak_globals_lock_); 129 130 void DumpReferenceTables(std::ostream& os) 131 REQUIRES_SHARED(Locks::mutator_lock_) 132 REQUIRES(!Locks::jni_globals_lock_, 133 !Locks::jni_weak_globals_lock_, 134 !Locks::alloc_tracker_lock_); 135 136 bool SetCheckJniEnabled(bool enabled); 137 138 void VisitRoots(RootVisitor* visitor) REQUIRES_SHARED(Locks::mutator_lock_) 139 REQUIRES(!Locks::jni_globals_lock_); 140 141 void DisallowNewWeakGlobals() 142 REQUIRES_SHARED(Locks::mutator_lock_) 143 REQUIRES(!Locks::jni_weak_globals_lock_); 144 void AllowNewWeakGlobals() 145 REQUIRES_SHARED(Locks::mutator_lock_) 146 REQUIRES(!Locks::jni_weak_globals_lock_); 147 void BroadcastForNewWeakGlobals() 148 REQUIRES(!Locks::jni_weak_globals_lock_); 149 150 jobject AddGlobalRef(Thread* self, ObjPtr<mirror::Object> obj) 151 REQUIRES_SHARED(Locks::mutator_lock_) 152 REQUIRES(!Locks::jni_globals_lock_); 153 154 jweak AddWeakGlobalRef(Thread* self, ObjPtr<mirror::Object> obj) 155 REQUIRES_SHARED(Locks::mutator_lock_) 156 REQUIRES(!Locks::jni_weak_globals_lock_); 157 158 void DeleteGlobalRef(Thread* self, jobject obj) REQUIRES(!Locks::jni_globals_lock_); 159 160 void DeleteWeakGlobalRef(Thread* self, jweak obj) REQUIRES(!Locks::jni_weak_globals_lock_); 161 162 void SweepJniWeakGlobals(IsMarkedVisitor* visitor) 163 REQUIRES_SHARED(Locks::mutator_lock_) 164 REQUIRES(!Locks::jni_weak_globals_lock_); 165 166 ObjPtr<mirror::Object> DecodeGlobal(IndirectRef ref) 167 REQUIRES_SHARED(Locks::mutator_lock_); 168 169 void UpdateGlobal(Thread* self, IndirectRef ref, ObjPtr<mirror::Object> result) 170 REQUIRES_SHARED(Locks::mutator_lock_) 171 REQUIRES(!Locks::jni_globals_lock_); 172 173 ObjPtr<mirror::Object> DecodeWeakGlobal(Thread* self, IndirectRef ref) 174 REQUIRES_SHARED(Locks::mutator_lock_) 175 REQUIRES(!Locks::jni_weak_globals_lock_); 176 177 ObjPtr<mirror::Object> DecodeWeakGlobalLocked(Thread* self, IndirectRef ref) 178 REQUIRES_SHARED(Locks::mutator_lock_) 179 REQUIRES(Locks::jni_weak_globals_lock_); 180 181 // Like DecodeWeakGlobal() but to be used only during a runtime shutdown where self may be 182 // null. 183 ObjPtr<mirror::Object> DecodeWeakGlobalDuringShutdown(Thread* self, IndirectRef ref) 184 REQUIRES_SHARED(Locks::mutator_lock_) 185 REQUIRES(!Locks::jni_weak_globals_lock_); 186 187 // Checks if the weak global ref has been cleared by the GC without decode (read barrier.) 188 bool IsWeakGlobalCleared(Thread* self, IndirectRef ref) 189 REQUIRES_SHARED(Locks::mutator_lock_) 190 REQUIRES(!Locks::jni_weak_globals_lock_); 191 192 void UpdateWeakGlobal(Thread* self, IndirectRef ref, ObjPtr<mirror::Object> result) 193 REQUIRES_SHARED(Locks::mutator_lock_) 194 REQUIRES(!Locks::jni_weak_globals_lock_); 195 GetUncheckedFunctions()196 const JNIInvokeInterface* GetUncheckedFunctions() const { 197 return unchecked_functions_; 198 } 199 200 void TrimGlobals() REQUIRES_SHARED(Locks::mutator_lock_) 201 REQUIRES(!Locks::jni_globals_lock_); 202 203 jint HandleGetEnv(/*out*/void** env, jint version); 204 205 void AddEnvironmentHook(GetEnvHook hook); 206 207 static bool IsBadJniVersion(int version); 208 209 // Return the library search path for the given classloader, if the classloader is of a 210 // well-known type. The jobject will be a local reference and is expected to be managed by the 211 // caller. 212 static jstring GetLibrarySearchPath(JNIEnv* env, jobject class_loader); 213 214 private: 215 // The constructor should not be called directly. It may leave the object in 216 // an erroneous state, and the result needs to be checked. 217 JavaVMExt(Runtime* runtime, const RuntimeArgumentMap& runtime_options, std::string* error_msg); 218 219 // Return true if self can currently access weak globals. 220 bool MayAccessWeakGlobalsUnlocked(Thread* self) const REQUIRES_SHARED(Locks::mutator_lock_); 221 bool MayAccessWeakGlobals(Thread* self) const 222 REQUIRES_SHARED(Locks::mutator_lock_) 223 REQUIRES(Locks::jni_weak_globals_lock_); 224 225 void CheckGlobalRefAllocationTracking(); 226 227 Runtime* const runtime_; 228 229 // Used for testing. By default, we'll LOG(FATAL) the reason. 230 void (*check_jni_abort_hook_)(void* data, const std::string& reason); 231 void* check_jni_abort_hook_data_; 232 233 // Extra checking. 234 bool check_jni_; 235 const bool force_copy_; 236 const bool tracing_enabled_; 237 238 // Extra diagnostics. 239 const std::string trace_; 240 241 // Not guarded by globals_lock since we sometimes use SynchronizedGet in Thread::DecodeJObject. 242 IndirectReferenceTable globals_; 243 244 // No lock annotation since UnloadNativeLibraries is called on libraries_ but locks the 245 // jni_libraries_lock_ internally. 246 std::unique_ptr<Libraries> libraries_; 247 248 // Used by -Xcheck:jni. 249 const JNIInvokeInterface* const unchecked_functions_; 250 251 // Since weak_globals_ contain weak roots, be careful not to 252 // directly access the object references in it. Use Get() with the 253 // read barrier enabled. 254 // Not guarded by weak_globals_lock since we may use SynchronizedGet in DecodeWeakGlobal. 255 IndirectReferenceTable weak_globals_; 256 // Not guarded by weak_globals_lock since we may use SynchronizedGet in DecodeWeakGlobal. 257 Atomic<bool> allow_accessing_weak_globals_; 258 ConditionVariable weak_globals_add_condition_ GUARDED_BY(Locks::jni_weak_globals_lock_); 259 260 // TODO Maybe move this to Runtime. 261 std::vector<GetEnvHook> env_hooks_; 262 263 size_t enable_allocation_tracking_delta_; 264 std::atomic<bool> allocation_tracking_enabled_; 265 std::atomic<bool> old_allocation_tracking_state_; 266 267 friend IndirectReferenceTable* GetIndirectReferenceTable(ScopedObjectAccess& soa, 268 IndirectRefKind kind); 269 270 DISALLOW_COPY_AND_ASSIGN(JavaVMExt); 271 }; 272 273 } // namespace art 274 275 #endif // ART_RUNTIME_JNI_JAVA_VM_EXT_H_ 276