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 * TODO: remove C support. 24 */ 25 #ifndef NATIVEHELPER_JNIHELP_H_ 26 #define NATIVEHELPER_JNIHELP_H_ 27 28 #include "jni.h" 29 #include <unistd.h> 30 31 #ifndef NELEM 32 # define NELEM(x) ((int) (sizeof(x) / sizeof((x)[0]))) 33 #endif 34 35 // TODO: the build system doesn't ensure the standard C++ library header files are on the include 36 // path when compiling C++, and this file is included all over the place. 37 #ifdef LIBCORE_CPP_JNI_HELPERS 38 #include <string> 39 #endif // LIBCORE_CPP_JNI_HELPERS 40 41 #ifdef __cplusplus 42 extern "C" { 43 #endif 44 45 /* 46 * Register one or more native methods with a particular class. 47 * "className" looks like "java/lang/String". Aborts on failure. 48 * TODO: fix all callers and change the return type to void. 49 */ 50 int jniRegisterNativeMethods(C_JNIEnv* env, const char* className, const JNINativeMethod* gMethods, int numMethods); 51 52 /* 53 * Throw an exception with the specified class and an optional message. 54 * 55 * The "className" argument will be passed directly to FindClass, which 56 * takes strings with slashes (e.g. "java/lang/Object"). 57 * 58 * If an exception is currently pending, we log a warning message and 59 * clear it. 60 * 61 * Returns 0 on success, nonzero if something failed (e.g. the exception 62 * class couldn't be found, so *an* exception will still be pending). 63 * 64 * Currently aborts the VM if it can't throw the exception. 65 */ 66 int jniThrowException(C_JNIEnv* env, const char* className, const char* msg); 67 68 /* 69 * Throw a java.lang.NullPointerException, with an optional message. 70 */ 71 int jniThrowNullPointerException(C_JNIEnv* env, const char* msg); 72 73 /* 74 * Throw a java.lang.RuntimeException, with an optional message. 75 */ 76 int jniThrowRuntimeException(C_JNIEnv* env, const char* msg); 77 78 /* 79 * Throw a java.io.IOException, generating the message from errno. 80 */ 81 int jniThrowIOException(C_JNIEnv* env, int errnum); 82 83 /* 84 * Return a pointer to a locale-dependent error string explaining errno 85 * value 'errnum'. The returned pointer may or may not be equal to 'buf'. 86 * This function is thread-safe (unlike strerror) and portable (unlike 87 * strerror_r). 88 */ 89 const char* jniStrError(int errnum, char* buf, size_t buflen); 90 91 /* 92 * Returns a new java.io.FileDescriptor for the given int fd. 93 */ 94 jobject jniCreateFileDescriptor(C_JNIEnv* env, int fd); 95 96 /* 97 * Returns the int fd from a java.io.FileDescriptor. 98 */ 99 int jniGetFDFromFileDescriptor(C_JNIEnv* env, jobject fileDescriptor); 100 101 /* 102 * Sets the int fd in a java.io.FileDescriptor. 103 */ 104 void jniSetFileDescriptorOfFD(C_JNIEnv* env, jobject fileDescriptor, int value); 105 106 /* 107 * Returns the reference from a java.lang.ref.Reference. 108 */ 109 jobject jniGetReferent(C_JNIEnv* env, jobject ref); 110 111 /* 112 * Log a message and an exception. 113 * If exception is NULL, logs the current exception in the JNI environment. 114 */ 115 void jniLogException(C_JNIEnv* env, int priority, const char* tag, jthrowable exception); 116 117 #ifdef __cplusplus 118 } 119 #endif 120 121 122 /* 123 * For C++ code, we provide inlines that map to the C functions. g++ always 124 * inlines these, even on non-optimized builds. 125 */ 126 #if defined(__cplusplus) 127 inline int jniRegisterNativeMethods(JNIEnv* env, const char* className, const JNINativeMethod* gMethods, int numMethods) { 128 return jniRegisterNativeMethods(&env->functions, className, gMethods, numMethods); 129 } 130 131 inline int jniThrowException(JNIEnv* env, const char* className, const char* msg) { 132 return jniThrowException(&env->functions, className, msg); 133 } 134 135 extern "C" int jniThrowExceptionFmt(C_JNIEnv* env, const char* className, const char* fmt, va_list args); 136 137 /* 138 * Equivalent to jniThrowException but with a printf-like format string and 139 * variable-length argument list. This is only available in C++. 140 */ 141 inline int jniThrowExceptionFmt(JNIEnv* env, const char* className, const char* fmt, ...) { 142 va_list args; 143 va_start(args, fmt); 144 return jniThrowExceptionFmt(&env->functions, className, fmt, args); 145 va_end(args); 146 } 147 148 inline int jniThrowNullPointerException(JNIEnv* env, const char* msg) { 149 return jniThrowNullPointerException(&env->functions, msg); 150 } 151 152 inline int jniThrowRuntimeException(JNIEnv* env, const char* msg) { 153 return jniThrowRuntimeException(&env->functions, msg); 154 } 155 156 inline int jniThrowIOException(JNIEnv* env, int errnum) { 157 return jniThrowIOException(&env->functions, errnum); 158 } 159 160 inline jobject jniCreateFileDescriptor(JNIEnv* env, int fd) { 161 return jniCreateFileDescriptor(&env->functions, fd); 162 } 163 164 inline int jniGetFDFromFileDescriptor(JNIEnv* env, jobject fileDescriptor) { 165 return jniGetFDFromFileDescriptor(&env->functions, fileDescriptor); 166 } 167 168 inline void jniSetFileDescriptorOfFD(JNIEnv* env, jobject fileDescriptor, int value) { 169 jniSetFileDescriptorOfFD(&env->functions, fileDescriptor, value); 170 } 171 172 inline jobject jniGetReferent(JNIEnv* env, jobject ref) { 173 return jniGetReferent(&env->functions, ref); 174 } 175 176 inline void jniLogException(JNIEnv* env, int priority, const char* tag, jthrowable exception = NULL) { 177 jniLogException(&env->functions, priority, tag, exception); 178 } 179 180 #ifdef LIBCORE_CPP_JNI_HELPERS 181 182 extern "C" std::string jniGetStackTrace(C_JNIEnv* env, jthrowable exception); 183 184 inline std::string jniGetStackTrace(JNIEnv* env, jthrowable exception = NULL) { 185 return jniGetStackTrace(&env->functions, exception); 186 } 187 188 #endif // LIBCORE_CPP_JNI_HELPERS 189 190 #endif 191 192 /* 193 * TEMP_FAILURE_RETRY is defined by some, but not all, versions of 194 * <unistd.h>. (Alas, it is not as standard as we'd hoped!) So, if it's 195 * not already defined, then define it here. 196 */ 197 #ifndef TEMP_FAILURE_RETRY 198 /* Used to retry syscalls that can return EINTR. */ 199 #define TEMP_FAILURE_RETRY(exp) ({ \ 200 typeof (exp) _rc; \ 201 do { \ 202 _rc = (exp); \ 203 } while (_rc == -1 && errno == EINTR); \ 204 _rc; }) 205 #endif 206 207 #endif /* NATIVEHELPER_JNIHELP_H_ */ 208
