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 #include <sensor/BitTube.h> 18 19 #include <stdint.h> 20 #include <sys/types.h> 21 #include <sys/socket.h> 22 23 #include <fcntl.h> 24 #include <unistd.h> 25 26 #include <binder/Parcel.h> 27 28 namespace android { 29 // ---------------------------------------------------------------------------- 30 31 // Socket buffer size. The default is typically about 128KB, which is much larger than 32 // we really need. So we make it smaller. 33 static const size_t DEFAULT_SOCKET_BUFFER_SIZE = 4 * 1024; 34 35 36 BitTube::BitTube() 37 : mSendFd(-1), mReceiveFd(-1) 38 { 39 init(DEFAULT_SOCKET_BUFFER_SIZE, DEFAULT_SOCKET_BUFFER_SIZE); 40 } 41 42 BitTube::BitTube(size_t bufsize) 43 : mSendFd(-1), mReceiveFd(-1) 44 { 45 init(bufsize, bufsize); 46 } 47 48 BitTube::BitTube(const Parcel& data) 49 : mSendFd(-1), mReceiveFd(-1) 50 { 51 mReceiveFd = dup(data.readFileDescriptor()); 52 if (mReceiveFd < 0) { 53 mReceiveFd = -errno; 54 ALOGE("BitTube(Parcel): can't dup filedescriptor (%s)", 55 strerror(-mReceiveFd)); 56 } 57 } 58 59 BitTube::~BitTube() 60 { 61 if (mSendFd >= 0) 62 close(mSendFd); 63 64 if (mReceiveFd >= 0) 65 close(mReceiveFd); 66 } 67 68 void BitTube::init(size_t rcvbuf, size_t sndbuf) { 69 int sockets[2]; 70 if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets) == 0) { 71 size_t size = DEFAULT_SOCKET_BUFFER_SIZE; 72 setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &rcvbuf, sizeof(rcvbuf)); 73 setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &sndbuf, sizeof(sndbuf)); 74 // sine we don't use the "return channel", we keep it small... 75 setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &size, sizeof(size)); 76 setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &size, sizeof(size)); 77 fcntl(sockets[0], F_SETFL, O_NONBLOCK); 78 fcntl(sockets[1], F_SETFL, O_NONBLOCK); 79 mReceiveFd = sockets[0]; 80 mSendFd = sockets[1]; 81 } else { 82 mReceiveFd = -errno; 83 ALOGE("BitTube: pipe creation failed (%s)", strerror(-mReceiveFd)); 84 } 85 } 86 87 status_t BitTube::initCheck() const 88 { 89 if (mReceiveFd < 0) { 90 return status_t(mReceiveFd); 91 } 92 return NO_ERROR; 93 } 94 95 int BitTube::getFd() const 96 { 97 return mReceiveFd; 98 } 99 100 int BitTube::getSendFd() const 101 { 102 return mSendFd; 103 } 104 105 ssize_t BitTube::write(void const* vaddr, size_t size) 106 { 107 ssize_t err, len; 108 do { 109 len = ::send(mSendFd, vaddr, size, MSG_DONTWAIT | MSG_NOSIGNAL); 110 // cannot return less than size, since we're using SOCK_SEQPACKET 111 err = len < 0 ? errno : 0; 112 } while (err == EINTR); 113 return err == 0 ? len : -err; 114 } 115 116 ssize_t BitTube::read(void* vaddr, size_t size) 117 { 118 ssize_t err, len; 119 do { 120 len = ::recv(mReceiveFd, vaddr, size, MSG_DONTWAIT); 121 err = len < 0 ? errno : 0; 122 } while (err == EINTR); 123 if (err == EAGAIN || err == EWOULDBLOCK) { 124 // EAGAIN means that we have non-blocking I/O but there was 125 // no data to be read. Nothing the client should care about. 126 return 0; 127 } 128 return err == 0 ? len : -err; 129 } 130 131 status_t BitTube::writeToParcel(Parcel* reply) const 132 { 133 if (mReceiveFd < 0) 134 return -EINVAL; 135 136 status_t result = reply->writeDupFileDescriptor(mReceiveFd); 137 close(mReceiveFd); 138 mReceiveFd = -1; 139 return result; 140 } 141 142 143 ssize_t BitTube::sendObjects(const sp<BitTube>& tube, 144 void const* events, size_t count, size_t objSize) 145 { 146 const char* vaddr = reinterpret_cast<const char*>(events); 147 ssize_t size = tube->write(vaddr, count*objSize); 148 149 // should never happen because of SOCK_SEQPACKET 150 LOG_ALWAYS_FATAL_IF((size >= 0) && (size % static_cast<ssize_t>(objSize)), 151 "BitTube::sendObjects(count=%zu, size=%zu), res=%zd (partial events were sent!)", 152 count, objSize, size); 153 154 //ALOGE_IF(size<0, "error %d sending %d events", size, count); 155 return size < 0 ? size : size / static_cast<ssize_t>(objSize); 156 } 157 158 ssize_t BitTube::recvObjects(const sp<BitTube>& tube, 159 void* events, size_t count, size_t objSize) 160 { 161 char* vaddr = reinterpret_cast<char*>(events); 162 ssize_t size = tube->read(vaddr, count*objSize); 163 164 // should never happen because of SOCK_SEQPACKET 165 LOG_ALWAYS_FATAL_IF((size >= 0) && (size % static_cast<ssize_t>(objSize)), 166 "BitTube::recvObjects(count=%zu, size=%zu), res=%zd (partial events were received!)", 167 count, objSize, size); 168 169 //ALOGE_IF(size<0, "error %d receiving %d events", size, count); 170 return size < 0 ? size : size / static_cast<ssize_t>(objSize); 171 } 172 173 // ---------------------------------------------------------------------------- 174 }; // namespace android 175
