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 35 extern "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 */ 43 int 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 */ 59 int jniThrowException(C_JNIEnv* env, const char* className, const char* msg); 60 61 /* 62 * Throw a java.lang.NullPointerException, with an optional message. 63 */ 64 int jniThrowNullPointerException(C_JNIEnv* env, const char* msg); 65 66 /* 67 * Throw a java.lang.RuntimeException, with an optional message. 68 */ 69 int jniThrowRuntimeException(C_JNIEnv* env, const char* msg); 70 71 /* 72 * Throw a java.io.IOException, generating the message from errno. 73 */ 74 int 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 */ 82 const char* jniStrError(int errnum, char* buf, size_t buflen); 83 84 /* 85 * Returns a new java.io.FileDescriptor for the given int fd. 86 */ 87 jobject jniCreateFileDescriptor(C_JNIEnv* env, int fd); 88 89 /* 90 * Returns the int fd from a java.io.FileDescriptor. 91 */ 92 int jniGetFDFromFileDescriptor(C_JNIEnv* env, jobject fileDescriptor); 93 94 /* 95 * Sets the int fd in a java.io.FileDescriptor. 96 */ 97 void jniSetFileDescriptorOfFD(C_JNIEnv* env, jobject fileDescriptor, int value); 98 99 /* 100 * Returns the reference from a java.lang.ref.Reference. 101 */ 102 jobject jniGetReferent(C_JNIEnv* env, jobject ref); 103 104 /* 105 * Log a message and an exception. 106 * If exception is NULL, logs the current exception in the JNI environment. 107 */ 108 void jniLogException(C_JNIEnv* env, int priority, const char* tag, jthrowable exception); 109 110 #ifdef __cplusplus 111 } 112 #endif 113 114 115 /* 116 * For C++ code, we provide inlines that map to the C functions. g++ always 117 * inlines these, even on non-optimized builds. 118 */ 119 #if defined(__cplusplus) 120 inline int jniRegisterNativeMethods(JNIEnv* env, const char* className, const JNINativeMethod* gMethods, int numMethods) { 121 return jniRegisterNativeMethods(&env->functions, className, gMethods, numMethods); 122 } 123 124 inline int jniThrowException(JNIEnv* env, const char* className, const char* msg) { 125 return jniThrowException(&env->functions, className, msg); 126 } 127 128 extern "C" int jniThrowExceptionFmt(C_JNIEnv* env, const char* className, const char* fmt, va_list args); 129 130 /* 131 * Equivalent to jniThrowException but with a printf-like format string and 132 * variable-length argument list. This is only available in C++. 133 */ 134 inline int jniThrowExceptionFmt(JNIEnv* env, const char* className, const char* fmt, ...) { 135 va_list args; 136 va_start(args, fmt); 137 return jniThrowExceptionFmt(&env->functions, className, fmt, args); 138 va_end(args); 139 } 140 141 inline int jniThrowNullPointerException(JNIEnv* env, const char* msg) { 142 return jniThrowNullPointerException(&env->functions, msg); 143 } 144 145 inline int jniThrowRuntimeException(JNIEnv* env, const char* msg) { 146 return jniThrowRuntimeException(&env->functions, msg); 147 } 148 149 inline int jniThrowIOException(JNIEnv* env, int errnum) { 150 return jniThrowIOException(&env->functions, errnum); 151 } 152 153 inline jobject jniCreateFileDescriptor(JNIEnv* env, int fd) { 154 return jniCreateFileDescriptor(&env->functions, fd); 155 } 156 157 inline int jniGetFDFromFileDescriptor(JNIEnv* env, jobject fileDescriptor) { 158 return jniGetFDFromFileDescriptor(&env->functions, fileDescriptor); 159 } 160 161 inline void jniSetFileDescriptorOfFD(JNIEnv* env, jobject fileDescriptor, int value) { 162 jniSetFileDescriptorOfFD(&env->functions, fileDescriptor, value); 163 } 164 165 inline jobject jniGetReferent(JNIEnv* env, jobject ref) { 166 return jniGetReferent(&env->functions, ref); 167 } 168 169 inline void jniLogException(JNIEnv* env, int priority, const char* tag, jthrowable exception = NULL) { 170 jniLogException(&env->functions, priority, tag, exception); 171 } 172 #endif 173 174 /* Logging macros. 175 * 176 * Logs an exception. If the exception is omitted or NULL, logs the current exception 177 * from the JNI environment, if any. 178 */ 179 #define LOG_EX(env, priority, tag, ...) \ 180 IF_ALOG(priority, tag) jniLogException(env, ANDROID_##priority, tag, ##__VA_ARGS__) 181 #define LOGV_EX(env, ...) LOG_EX(env, LOG_VERBOSE, LOG_TAG, ##__VA_ARGS__) 182 #define LOGD_EX(env, ...) LOG_EX(env, LOG_DEBUG, LOG_TAG, ##__VA_ARGS__) 183 #define LOGI_EX(env, ...) LOG_EX(env, LOG_INFO, LOG_TAG, ##__VA_ARGS__) 184 #define LOGW_EX(env, ...) LOG_EX(env, LOG_WARN, LOG_TAG, ##__VA_ARGS__) 185 #define LOGE_EX(env, ...) LOG_EX(env, LOG_ERROR, LOG_TAG, ##__VA_ARGS__) 186 187 /* 188 * TEMP_FAILURE_RETRY is defined by some, but not all, versions of 189 * <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's 190 * not already defined, then define it here. 191 */ 192 #ifndef TEMP_FAILURE_RETRY 193 /* Used to retry syscalls that can return EINTR. */ 194 #define TEMP_FAILURE_RETRY(exp) ({ \ 195 typeof (exp) _rc; \ 196 do { \ 197 _rc = (exp); \ 198 } while (_rc == -1 && errno == EINTR); \ 199 _rc; }) 200 #endif 201 202 #endif /* NATIVEHELPER_JNIHELP_H_ */ 203
