JNIHelp.h revision 519e0b931c5c7fa927059c588898ec46d0b19c90 
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
29#ifndef NELEM
30# define NELEM(x) ((int) (sizeof(x) / sizeof((x)[0])))
31#endif
32
33#ifdef __cplusplus
34extern "C" {
35#endif
36
37/*
38 * Register one or more native methods with a particular class.
39 */
40int jniRegisterNativeMethods(C_JNIEnv* env, const char* className,
41    const JNINativeMethod* gMethods, int numMethods);
42
43/*
44 * Throw an exception with the specified class and an optional message.
45 * The "className" argument will be passed directly to FindClass, which
46 * takes strings with slashes (e.g. "java/lang/Object").
47 *
48 * Returns 0 on success, nonzero if something failed (e.g. the exception
49 * class couldn't be found).
50 *
51 * Currently aborts the VM if it can't throw the exception.
52 */
53int jniThrowException(C_JNIEnv* env, const char* className, const char* msg);
54
55/*
56 * Throw a java.IO.IOException, generating the message from errno.
57 */
58int jniThrowIOException(C_JNIEnv* env, int errnum);
59
60/*
61 * Create a java.io.FileDescriptor given an integer fd
62 */
63jobject jniCreateFileDescriptor(C_JNIEnv* env, int fd);
64
65/*
66 * Get an int file descriptor from a java.io.FileDescriptor
67 */
68int jniGetFDFromFileDescriptor(C_JNIEnv* env, jobject fileDescriptor);
69
70/*
71 * Set an int file descriptor to a java.io.FileDescriptor
72 */
73void jniSetFileDescriptorOfFD(C_JNIEnv* env, jobject fileDescriptor, int value);
74
75#ifdef __cplusplus
76}
77#endif
78
79
80/*
81 * For C++ code, we provide inlines that map to the C functions.  g++ always
82 * inlines these, even on non-optimized builds.
83 */
84#if defined(__cplusplus) && !defined(JNI_FORCE_C)
85inline int jniRegisterNativeMethods(JNIEnv* env, const char* className,
86    const JNINativeMethod* gMethods, int numMethods)
87{
88    return jniRegisterNativeMethods(&env->functions, className, gMethods,
89        numMethods);
90}
91inline int jniThrowException(JNIEnv* env, const char* className,
92    const char* msg)
93{
94    return jniThrowException(&env->functions, className, msg);
95}
96inline int jniThrowIOException(JNIEnv* env, int errnum)
97{
98    return jniThrowIOException(&env->functions, errnum);
99}
100inline jobject jniCreateFileDescriptor(JNIEnv* env, int fd)
101{
102    return jniCreateFileDescriptor(&env->functions, fd);
103}
104inline int jniGetFDFromFileDescriptor(JNIEnv* env, jobject fileDescriptor)
105{
106    return jniGetFDFromFileDescriptor(&env->functions, fileDescriptor);
107}
108inline void jniSetFileDescriptorOfFD(JNIEnv* env, jobject fileDescriptor,
109    int value)
110{
111    return jniSetFileDescriptorOfFD(&env->functions, fileDescriptor, value);
112}
113#endif
114
115#endif /*_NATIVEHELPER_JNIHELP_H*/
116