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