1/*
2 * Copyright (C) 2010 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#ifndef NET_FD_H_included
18#define NET_FD_H_included
19
20/**
21 * Wraps access to the int inside a java.io.FileDescriptor, taking care of throwing exceptions.
22 */
23class NetFd {
24public:
25    NetFd(JNIEnv* env, jobject fileDescriptor)
26        : mEnv(env), mFileDescriptor(fileDescriptor), mFd(-1)
27    {
28    }
29
30    bool isClosed() {
31        mFd = jniGetFDFromFileDescriptor(mEnv, mFileDescriptor);
32        bool closed = (mFd == -1);
33        if (closed) {
34            jniThrowException(mEnv, "java/net/SocketException", "Socket closed");
35        }
36        return closed;
37    }
38
39    int get() const {
40        return mFd;
41    }
42
43private:
44    JNIEnv* mEnv;
45    jobject mFileDescriptor;
46    int mFd;
47
48    // Disallow copy and assignment.
49    NetFd(const NetFd&);
50    void operator=(const NetFd&);
51};
52
53/**
54 * Used to retry syscalls that can return EINTR. This differs from TEMP_FAILURE_RETRY in that
55 * it also considers the case where the reason for failure is that another thread called
56 * Socket.close.
57 */
58#define NET_FAILURE_RETRY(fd, exp) ({               \
59    typeof (exp) _rc;                               \
60    do {                                            \
61        _rc = (exp);                                \
62        if (_rc == -1) {                            \
63            if (fd.isClosed() || errno != EINTR) {  \
64                break;                              \
65            }                                       \
66        }                                           \
67    } while (_rc == -1);                            \
68    _rc; })
69
70#endif // NET_FD_H_included
71