Home | History | Annotate | Download | only in native 
      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:
     27     NetFd(JNIEnv* env, jobject fileDescriptor)
     28         : mEnv(env), mFileDescriptor(fileDescriptor), mFd(-1)
     29     {
     30     }
     31 
     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 
     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