• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 #include <nativehelper/JNIHelp.h>
21 
22 /**
23  * Wraps access to the int inside a java.io.FileDescriptor, taking care of throwing exceptions.
24  */
25 class NetFd {
26 public:
NetFd(JNIEnv * env,jobject fileDescriptor)27     NetFd(JNIEnv* env, jobject fileDescriptor)
28         : mEnv(env), mFileDescriptor(fileDescriptor), mFd(-1)
29     {
30     }
31 
isClosed()32     bool isClosed() {
33         mFd = jniGetFDFromFileDescriptor(mEnv, mFileDescriptor);
34         bool closed = (mFd == -1);
35         if (closed) {
36             jniThrowException(mEnv, "java/net/SocketException", "Socket closed");
37         }
38         return closed;
39     }
40 
get()41     int get() const {
42         return mFd;
43     }
44 
45 private:
46     JNIEnv* mEnv;
47     jobject mFileDescriptor;
48     int mFd;
49 
50     // Disallow copy and assignment.
51     NetFd(const NetFd&);
52     void operator=(const NetFd&);
53 };
54 
55 /**
56  * Used to retry syscalls that can return EINTR. This differs from TEMP_FAILURE_RETRY in that
57  * it also considers the case where the reason for failure is that another thread called
58  * Socket.close.
59  */
60 #define NET_FAILURE_RETRY(fd, exp) ({               \
61     typeof (exp) _rc;                               \
62     do {                                            \
63         _rc = (exp);                                \
64         if (_rc == -1) {                            \
65             if (fd.isClosed() || errno != EINTR) {  \
66                 break;                              \
67             }                                       \
68         }                                           \
69     } while (_rc == -1);                            \
70     _rc; })
71 
72 #endif // NET_FD_H_included
73