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 ANDROID_HIDL_INTERNAL_H
18 #define ANDROID_HIDL_INTERNAL_H
19
20 #include <cstdint>
21 #include <dirent.h>
22 #include <functional>
23 #include <string>
24 #include <vector>
25 #include <utility>
26
27 namespace android {
28 namespace hardware {
29 namespace details {
30
31 // tag for pure interfaces (e.x. IFoo)
32 struct i_tag {};
33
34 // tag for server interfaces (e.x. BnHwFoo)
35 struct bnhw_tag {};
36
37 // tag for proxy interfaces (e.x. BpHwFoo)
38 struct bphw_tag {};
39
40 // tag for passthrough interfaces (e.x. BsFoo)
41 struct bs_tag {};
42
43 //Templated classes can use the below method
44 //to avoid creating dependencies on liblog.
45 void logAlwaysFatal(const char *message);
46
47 // Returns VNDK-SP hw path according to "ro.vndk.version"
48 #if defined(__LP64__)
49 std::string getVndkSpHwPath(const char* lib = "lib64");
50 #else
51 std::string getVndkSpHwPath(const char* lib = "lib");
52 #endif
53
54 // Explicitly invokes the parameterized element's destructor;
55 // intended to be used alongside the placement new operator.
56 template<typename T>
destructElement(T * element)57 void destructElement(T* element) {
58 if (element != nullptr) {
59 element->~T();
60 }
61 }
62
63 // HIDL client/server code should *NOT* use this class.
64 //
65 // hidl_pointer wraps a pointer without taking ownership,
66 // and stores it in a union with a uint64_t. This ensures
67 // that we always have enough space to store a pointer,
68 // regardless of whether we're running in a 32-bit or 64-bit
69 // process.
70 template<typename T>
71 struct hidl_pointer {
hidl_pointerhidl_pointer72 hidl_pointer()
73 : _pad(0) {
74 static_assert(sizeof(*this) == 8, "wrong size");
75 }
hidl_pointerhidl_pointer76 hidl_pointer(T* ptr) : hidl_pointer() { mPointer = ptr; }
hidl_pointerhidl_pointer77 hidl_pointer(const hidl_pointer<T>& other) : hidl_pointer() { mPointer = other.mPointer; }
hidl_pointerhidl_pointer78 hidl_pointer(hidl_pointer<T>&& other) noexcept : hidl_pointer() { *this = std::move(other); }
79
80 hidl_pointer &operator=(const hidl_pointer<T>& other) {
81 mPointer = other.mPointer;
82 return *this;
83 }
84 hidl_pointer& operator=(hidl_pointer<T>&& other) noexcept {
85 mPointer = other.mPointer;
86 other.mPointer = nullptr;
87 return *this;
88 }
89 hidl_pointer &operator=(T* ptr) {
90 mPointer = ptr;
91 return *this;
92 }
93
94 operator T*() const {
95 return mPointer;
96 }
97 explicit operator void*() const { // requires explicit cast to avoid ambiguity
98 return mPointer;
99 }
100 T& operator*() const {
101 return *mPointer;
102 }
103 T* operator->() const {
104 return mPointer;
105 }
106 T &operator[](size_t index) {
107 return mPointer[index];
108 }
109 const T &operator[](size_t index) const {
110 return mPointer[index];
111 }
112
113 private:
114 union {
115 T* mPointer;
116 uint64_t _pad;
117 };
118 };
119
120 #define HAL_LIBRARY_PATH_SYSTEM_64BIT "/system/lib64/hw/"
121 #define HAL_LIBRARY_PATH_VENDOR_64BIT "/vendor/lib64/hw/"
122 #define HAL_LIBRARY_PATH_ODM_64BIT "/odm/lib64/hw/"
123 #define HAL_LIBRARY_PATH_SYSTEM_32BIT "/system/lib/hw/"
124 #define HAL_LIBRARY_PATH_VENDOR_32BIT "/vendor/lib/hw/"
125 #define HAL_LIBRARY_PATH_ODM_32BIT "/odm/lib/hw/"
126
127 #if defined(__LP64__)
128 #define HAL_LIBRARY_PATH_SYSTEM HAL_LIBRARY_PATH_SYSTEM_64BIT
129 #define HAL_LIBRARY_PATH_VENDOR HAL_LIBRARY_PATH_VENDOR_64BIT
130 #define HAL_LIBRARY_PATH_ODM HAL_LIBRARY_PATH_ODM_64BIT
131 #else
132 #define HAL_LIBRARY_PATH_SYSTEM HAL_LIBRARY_PATH_SYSTEM_32BIT
133 #define HAL_LIBRARY_PATH_VENDOR HAL_LIBRARY_PATH_VENDOR_32BIT
134 #define HAL_LIBRARY_PATH_ODM HAL_LIBRARY_PATH_ODM_32BIT
135 #endif
136
137 // ----------------------------------------------------------------------
138 // Class that provides Hidl instrumentation utilities.
139 struct HidlInstrumentor {
140 // Event that triggers the instrumentation. e.g. enter of an API call on
141 // the server/client side, exit of an API call on the server/client side
142 // etc.
143 enum InstrumentationEvent {
144 SERVER_API_ENTRY = 0,
145 SERVER_API_EXIT,
146 CLIENT_API_ENTRY,
147 CLIENT_API_EXIT,
148 SYNC_CALLBACK_ENTRY,
149 SYNC_CALLBACK_EXIT,
150 ASYNC_CALLBACK_ENTRY,
151 ASYNC_CALLBACK_EXIT,
152 PASSTHROUGH_ENTRY,
153 PASSTHROUGH_EXIT,
154 };
155
156 // Signature of the instrumentation callback function.
157 using InstrumentationCallback = std::function<void(
158 const InstrumentationEvent event,
159 const char *package,
160 const char *version,
161 const char *interface,
162 const char *method,
163 std::vector<void *> *args)>;
164
165 explicit HidlInstrumentor(
166 const std::string &package,
167 const std::string &insterface);
168 virtual ~HidlInstrumentor();
169
170 public:
getInstrumentationCallbacksHidlInstrumentor171 const std::vector<InstrumentationCallback>& getInstrumentationCallbacks() {
172 return mInstrumentationCallbacks;
173 }
isInstrumentationEnabledHidlInstrumentor174 bool isInstrumentationEnabled() { return mEnableInstrumentation; }
175
176 protected:
177 // Set mEnableInstrumentation based on system property
178 // hal.instrumentation.enable, register/de-register instrumentation
179 // callbacks if mEnableInstrumentation is true/false.
180 void configureInstrumentation(bool log=true);
181 // Function that lookup and dynamically loads the hidl instrumentation
182 // libraries and registers the instrumentation callback functions.
183 //
184 // The instrumentation libraries should be stored under any of the following
185 // directories: HAL_LIBRARY_PATH_SYSTEM, HAL_LIBRARY_PATH_VNDK_SP,
186 // HAL_LIBRARY_PATH_VENDOR and HAL_LIBRARY_PATH_ODM.
187 // The name of instrumentation libraries should follow pattern:
188 // ^profilerPrefix(.*).profiler.so$
189 //
190 // Each instrumentation library is expected to implement the instrumentation
191 // function called HIDL_INSTRUMENTATION_FUNCTION.
192 //
193 // A no-op for user build.
194 void registerInstrumentationCallbacks(
195 std::vector<InstrumentationCallback> *instrumentationCallbacks);
196
197 // Utility function to determine whether a give file is a instrumentation
198 // library (i.e. the file name follow the expected pattern).
199 bool isInstrumentationLib(const dirent *file);
200
201 // A list of registered instrumentation callbacks.
202 std::vector<InstrumentationCallback> mInstrumentationCallbacks;
203 // Flag whether to enable instrumentation.
204 union {
205 bool mEnableInstrumentation;
206 void* mReserved0;
207 };
208 // Prefix to lookup the instrumentation libraries.
209 std::string mInstrumentationLibPackage;
210 // Used for dlsym to load the profiling method for given interface.
211 std::string mInterfaceName;
212
213 };
214
215 #ifdef __LP64__
216 static_assert(sizeof(HidlInstrumentor) == 88, "HidlInstrumentor size frozen by prebuilts");
217 #else
218 static_assert(sizeof(HidlInstrumentor) == 44, "HidlInstrumentor size frozen by prebuilts");
219 #endif
220
221 } // namespace details
222 } // namespace hardware
223 } // namespace android
224
225 #endif // ANDROID_HIDL_INTERNAL_H
226