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