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