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_TI_AGENT_H_ 18 #define ART_RUNTIME_TI_AGENT_H_ 19 20 #include <dlfcn.h> 21 #include <jni.h> // for jint, JavaVM* etc declarations 22 23 #include "runtime.h" 24 #include "utils.h" 25 26 namespace art { 27 namespace ti { 28 29 using AgentOnLoadFunction = jint (*)(JavaVM*, const char*, void*); 30 using AgentOnUnloadFunction = void (*)(JavaVM*); 31 32 // Agents are native libraries that will be loaded by the runtime for the purpose of 33 // instrumentation. They will be entered by Agent_OnLoad or Agent_OnAttach depending on whether the 34 // agent is being attached during runtime startup or later. 35 // 36 // The agent's Agent_OnUnload function will be called during runtime shutdown. 37 // 38 // TODO: consider splitting ti::Agent into command line, agent and shared library handler classes 39 // TODO Support native-bridge. Currently agents can only be the actual runtime ISA of the device. 40 class Agent { 41 public: 42 enum LoadError { 43 kNoError, // No error occurred.. 44 kAlreadyStarted, // The agent has already been loaded. 45 kLoadingError, // dlopen or dlsym returned an error. 46 kInitializationError, // The entrypoint did not return 0. This might require an abort. 47 }; 48 49 bool IsStarted() const { 50 return dlopen_handle_ != nullptr; 51 } 52 53 const std::string& GetName() const { 54 return name_; 55 } 56 57 const std::string& GetArgs() const { 58 return args_; 59 } 60 61 bool HasArgs() const { 62 return !GetArgs().empty(); 63 } 64 65 void* FindSymbol(const std::string& name) const; 66 67 LoadError Load(/*out*/jint* call_res, /*out*/std::string* error_msg) { 68 VLOG(agents) << "Loading agent: " << name_ << " " << args_; 69 return DoLoadHelper(false, call_res, error_msg); 70 } 71 72 // TODO We need to acquire some locks probably. 73 void Unload(); 74 75 // Tries to attach the agent using its OnAttach method. Returns true on success. 76 LoadError Attach(/*out*/jint* call_res, /*out*/std::string* error_msg) { 77 VLOG(agents) << "Attaching agent: " << name_ << " " << args_; 78 return DoLoadHelper(true, call_res, error_msg); 79 } 80 81 explicit Agent(std::string arg); 82 83 Agent(const Agent& other); 84 Agent& operator=(const Agent& other); 85 86 Agent(Agent&& other); 87 Agent& operator=(Agent&& other); 88 89 ~Agent(); 90 91 private: 92 LoadError DoDlOpen(/*out*/std::string* error_msg); 93 94 LoadError DoLoadHelper(bool attaching, 95 /*out*/jint* call_res, 96 /*out*/std::string* error_msg); 97 98 std::string name_; 99 std::string args_; 100 void* dlopen_handle_; 101 102 // The entrypoints. 103 AgentOnLoadFunction onload_; 104 AgentOnLoadFunction onattach_; 105 AgentOnUnloadFunction onunload_; 106 107 friend std::ostream& operator<<(std::ostream &os, Agent const& m); 108 }; 109 110 std::ostream& operator<<(std::ostream &os, Agent const& m); 111 std::ostream& operator<<(std::ostream &os, const Agent* m); 112 113 } // namespace ti 114 } // namespace art 115 116 #endif // ART_RUNTIME_TI_AGENT_H_ 117 118
