| /* |
| * Copyright (C) 2013 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #pragma once |
| |
| #include <sys/cdefs.h> |
| |
| #include <stdbool.h> |
| |
| __BEGIN_DECLS |
| |
| /* |
| * The JNI invocation API exists to allow a choice of library responsible for managing virtual |
| * machines. |
| */ |
| |
| /* |
| * Opaque structure used to hold JNI invocation internal state. |
| */ |
| struct JniInvocationImpl; |
| |
| /* |
| * Creates an instance of a JniInvocationImpl. |
| */ |
| struct JniInvocationImpl* JniInvocationCreate(); |
| |
| /* |
| * Associates a library with a JniInvocationImpl instance. The library should export C symbols for |
| * JNI_GetDefaultJavaVMInitArgs, JNI_CreateJavaVM and JNI_GetDefaultJavaVMInitArgs. |
| * |
| * The specified |library| should be the filename of a shared library. The |library| is opened with |
| * dlopen(3). |
| * |
| * If there is an error opening the specified |library|, then function will fallback to the |
| * default library "libart.so". If the fallback library is successfully used then a warning is |
| * written to the Android log buffer. Use of the fallback library is not considered an error. |
| * |
| * If the fallback library cannot be opened or the expected symbols are not found in the library |
| * opened, then an error message is written to the Android log buffer and the function returns 0. |
| * |
| * Returns true on success, false otherwise. |
| */ |
| bool JniInvocationInit(struct JniInvocationImpl* instance, const char* library); |
| |
| /* |
| * Release resources associated with JniInvocationImpl instance. |
| */ |
| void JniInvocationDestroy(struct JniInvocationImpl* instance); |
| |
| /* |
| * Gets the default library for JNI invocation. The default library is "libart.so". This value may |
| * be overridden for debuggable builds using the persist.sys.dalvik.vm.lib.2 system property. |
| * |
| * The |library| argument is the preferred library to use on debuggable builds (when |
| * ro.debuggable=1). If the |library| argument is nullptr, then the system preferred value will be |
| * queried from persist.sys.dalvik.vm.lib.2 if the caller has provided |buffer| argument. |
| * |
| * The |buffer| argument is used for reading system properties in debuggable builds. It is |
| * optional, but should be provisioned to be PROP_VALUE_MAX bytes if provided to ensure it is |
| * large enough to hold a system property. |
| * |
| * Returns the filename of the invocation library determined from the inputs and system |
| * properties. The returned value may be |library|, |buffer|, or a pointer to a string constant |
| * "libart.so". |
| */ |
| const char* JniInvocationGetLibrary(const char* library, char* buffer); |
| |
| __END_DECLS |
| |
| #ifdef __cplusplus |
| |
| // JniInvocation adds a layer of indirection for applications using |
| // the JNI invocation API to allow the JNI implementation to be |
| // selected dynamically. Apps can specify a specific implementation to |
| // be used by calling InitJniInvocation. If this is not done, the |
| // library will chosen based on the value of Android system property |
| // persist.sys.dalvik.vm.lib on the device, and otherwise fall back to |
| // a hard-coded default implementation. |
| class JniInvocation final { |
| public: |
| JniInvocation() { |
| impl_ = JniInvocationCreate(); |
| } |
| |
| ~JniInvocation() { |
| JniInvocationDestroy(impl_); |
| } |
| |
| // Initialize JNI invocation API. library should specify a valid |
| // shared library for opening via dlopen providing a JNI invocation |
| // implementation, or null to allow defaulting via |
| // persist.sys.dalvik.vm.lib. |
| bool Init(const char* library) { |
| return JniInvocationInit(impl_, library) != 0; |
| } |
| |
| // Exposes which library is actually loaded from the given name. The |
| // buffer of size PROPERTY_VALUE_MAX will be used to load the system |
| // property for the default library, if necessary. If no buffer is |
| // provided, the fallback value will be used. |
| static const char* GetLibrary(const char* library, char* buffer) { |
| return JniInvocationGetLibrary(library, buffer); |
| } |
| |
| private: |
| JniInvocation(const JniInvocation&) = delete; |
| JniInvocation& operator=(const JniInvocation&) = delete; |
| |
| JniInvocationImpl* impl_; |
| }; |
| |
| #endif // __cplusplus |