1 /* 2 * Copyright (C) 2013 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 LIBNATIVEHELPER_INCLUDE_NATIVEHELPER_JNIINVOCATION_H_ 18 #define LIBNATIVEHELPER_INCLUDE_NATIVEHELPER_JNIINVOCATION_H_ 19 20 #include "libnativehelper_api.h" 21 22 #ifdef __cplusplus 23 24 // JniInvocation adds a layer of indirection for applications using 25 // the JNI invocation API to allow the JNI implementation to be 26 // selected dynamically. Apps can specify a specific implementation to 27 // be used by calling InitJniInvocation. If this is not done, the 28 // library will chosen based on the value of Android system property 29 // persist.sys.dalvik.vm.lib on the device, and otherwise fall back to 30 // a hard-coded default implementation. 31 class JniInvocation final { 32 public: JniInvocation()33 JniInvocation() { 34 impl_ = JniInvocationCreate(); 35 } 36 ~JniInvocation()37 ~JniInvocation() { 38 JniInvocationDestroy(impl_); 39 } 40 41 // Initialize JNI invocation API. library should specifiy a valid 42 // shared library for opening via dlopen providing a JNI invocation 43 // implementation, or null to allow defaulting via 44 // persist.sys.dalvik.vm.lib. Init(const char * library)45 bool Init(const char* library) { 46 return JniInvocationInit(impl_, library) != 0; 47 } 48 49 // Exposes which library is actually loaded from the given name. The 50 // buffer of size PROPERTY_VALUE_MAX will be used to load the system 51 // property for the default library, if necessary. If no buffer is 52 // provided, the fallback value will be used. GetLibrary(const char * library,char * buffer)53 static const char* GetLibrary(const char* library, char* buffer) { 54 return JniInvocationGetLibrary(library, buffer); 55 } 56 57 private: 58 JniInvocation(const JniInvocation&) = delete; 59 JniInvocation& operator=(const JniInvocation&) = delete; 60 61 static const char* GetLibrary(const char* library, char* buffer, bool (*is_debuggable)(), 62 int (*get_library_system_property)(char* buffer)); 63 64 JniInvocationImpl* impl_; 65 66 friend class JNIInvocation_Debuggable_Test; 67 friend class JNIInvocation_NonDebuggable_Test; 68 }; 69 70 #endif // __cplusplus 71 72 #endif // LIBNATIVEHELPER_INCLUDE_NATIVEHELPER_JNIINVOCATION_H_ 73