1/* 2 * Copyright (C) 2007 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/* 18 * JNI helper functions. 19 * 20 * This file may be included by C or C++ code, which is trouble because jni.h 21 * uses different typedefs for JNIEnv in each language. 22 */ 23#ifndef NATIVEHELPER_JNIHELP_H_ 24#define NATIVEHELPER_JNIHELP_H_ 25 26#include "jni.h" 27#include "cutils/log.h" 28#include <unistd.h> 29 30#ifndef NELEM 31# define NELEM(x) ((int) (sizeof(x) / sizeof((x)[0]))) 32#endif 33 34#ifdef __cplusplus 35extern "C" { 36#endif 37 38/* 39 * Register one or more native methods with a particular class. 40 * "className" looks like "java/lang/String". Aborts on failure. 41 * TODO: fix all callers and change the return type to void. 42 */ 43int jniRegisterNativeMethods(C_JNIEnv* env, const char* className, const JNINativeMethod* gMethods, int numMethods); 44 45/* 46 * Throw an exception with the specified class and an optional message. 47 * 48 * The "className" argument will be passed directly to FindClass, which 49 * takes strings with slashes (e.g. "java/lang/Object"). 50 * 51 * If an exception is currently pending, we log a warning message and 52 * clear it. 53 * 54 * Returns 0 on success, nonzero if something failed (e.g. the exception 55 * class couldn't be found, so *an* exception will still be pending). 56 * 57 * Currently aborts the VM if it can't throw the exception. 58 */ 59int jniThrowException(C_JNIEnv* env, const char* className, const char* msg); 60 61/* 62 * Throw a java.lang.NullPointerException, with an optional message. 63 */ 64int jniThrowNullPointerException(C_JNIEnv* env, const char* msg); 65 66/* 67 * Throw a java.lang.RuntimeException, with an optional message. 68 */ 69int jniThrowRuntimeException(C_JNIEnv* env, const char* msg); 70 71/* 72 * Throw a java.io.IOException, generating the message from errno. 73 */ 74int jniThrowIOException(C_JNIEnv* env, int errnum); 75 76/* 77 * Return a pointer to a locale-dependent error string explaining errno 78 * value 'errnum'. The returned pointer may or may not be equal to 'buf'. 79 * This function is thread-safe (unlike strerror) and portable (unlike 80 * strerror_r). 81 */ 82const char* jniStrError(int errnum, char* buf, size_t buflen); 83 84/* 85 * Returns a new java.io.FileDescriptor for the given int fd. 86 */ 87jobject jniCreateFileDescriptor(C_JNIEnv* env, int fd); 88 89/* 90 * Returns the int fd from a java.io.FileDescriptor. 91 */ 92int jniGetFDFromFileDescriptor(C_JNIEnv* env, jobject fileDescriptor); 93 94/* 95 * Sets the int fd in a java.io.FileDescriptor. 96 */ 97void jniSetFileDescriptorOfFD(C_JNIEnv* env, jobject fileDescriptor, int value); 98 99/* 100 * Log a message and an exception. 101 * If exception is NULL, logs the current exception in the JNI environment. 102 */ 103void jniLogException(C_JNIEnv* env, int priority, const char* tag, jthrowable exception); 104 105#ifdef __cplusplus 106} 107#endif 108 109 110/* 111 * For C++ code, we provide inlines that map to the C functions. g++ always 112 * inlines these, even on non-optimized builds. 113 */ 114#if defined(__cplusplus) 115inline int jniRegisterNativeMethods(JNIEnv* env, const char* className, const JNINativeMethod* gMethods, int numMethods) { 116 return jniRegisterNativeMethods(&env->functions, className, gMethods, numMethods); 117} 118 119inline int jniThrowException(JNIEnv* env, const char* className, const char* msg) { 120 return jniThrowException(&env->functions, className, msg); 121} 122 123extern "C" int jniThrowExceptionFmt(C_JNIEnv* env, const char* className, const char* fmt, va_list args); 124 125/* 126 * Equivalent to jniThrowException but with a printf-like format string and 127 * variable-length argument list. This is only available in C++. 128 */ 129inline int jniThrowExceptionFmt(JNIEnv* env, const char* className, const char* fmt, ...) { 130 va_list args; 131 va_start(args, fmt); 132 return jniThrowExceptionFmt(&env->functions, className, fmt, args); 133 va_end(args); 134} 135 136inline int jniThrowNullPointerException(JNIEnv* env, const char* msg) { 137 return jniThrowNullPointerException(&env->functions, msg); 138} 139 140inline int jniThrowRuntimeException(JNIEnv* env, const char* msg) { 141 return jniThrowRuntimeException(&env->functions, msg); 142} 143 144inline int jniThrowIOException(JNIEnv* env, int errnum) { 145 return jniThrowIOException(&env->functions, errnum); 146} 147 148inline jobject jniCreateFileDescriptor(JNIEnv* env, int fd) { 149 return jniCreateFileDescriptor(&env->functions, fd); 150} 151 152inline int jniGetFDFromFileDescriptor(JNIEnv* env, jobject fileDescriptor) { 153 return jniGetFDFromFileDescriptor(&env->functions, fileDescriptor); 154} 155 156inline void jniSetFileDescriptorOfFD(JNIEnv* env, jobject fileDescriptor, int value) { 157 jniSetFileDescriptorOfFD(&env->functions, fileDescriptor, value); 158} 159 160inline void jniLogException(JNIEnv* env, int priority, const char* tag, jthrowable exception = NULL) { 161 jniLogException(&env->functions, priority, tag, exception); 162} 163#endif 164 165/* Logging macros. 166 * 167 * Logs an exception. If the exception is omitted or NULL, logs the current exception 168 * from the JNI environment, if any. 169 */ 170#define LOG_EX(env, priority, tag, ...) \ 171 IF_ALOG(priority, tag) jniLogException(env, ANDROID_##priority, tag, ##__VA_ARGS__) 172#define LOGV_EX(env, ...) LOG_EX(env, LOG_VERBOSE, LOG_TAG, ##__VA_ARGS__) 173#define LOGD_EX(env, ...) LOG_EX(env, LOG_DEBUG, LOG_TAG, ##__VA_ARGS__) 174#define LOGI_EX(env, ...) LOG_EX(env, LOG_INFO, LOG_TAG, ##__VA_ARGS__) 175#define LOGW_EX(env, ...) LOG_EX(env, LOG_WARN, LOG_TAG, ##__VA_ARGS__) 176#define LOGE_EX(env, ...) LOG_EX(env, LOG_ERROR, LOG_TAG, ##__VA_ARGS__) 177 178/* 179 * TEMP_FAILURE_RETRY is defined by some, but not all, versions of 180 * <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's 181 * not already defined, then define it here. 182 */ 183#ifndef TEMP_FAILURE_RETRY 184/* Used to retry syscalls that can return EINTR. */ 185#define TEMP_FAILURE_RETRY(exp) ({ \ 186 typeof (exp) _rc; \ 187 do { \ 188 _rc = (exp); \ 189 } while (_rc == -1 && errno == EINTR); \ 190 _rc; }) 191#endif 192 193#endif /* NATIVEHELPER_JNIHELP_H_ */ 194