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 <stdint.h> 18 #include <sys/types.h> 19 #include <sys/socket.h> 20 21 #include <fcntl.h> 22 #include <unistd.h> 23 24 #include <utils/Errors.h> 25 26 #include <binder/Parcel.h> 27 28 #include <gui/BitTube.h> 29 30 namespace android { 31 // ---------------------------------------------------------------------------- 32 33 // Socket buffer size. The default is typically about 128KB, which is much larger than 34 // we really need. So we make it smaller. 35 static const size_t DEFAULT_SOCKET_BUFFER_SIZE = 4 * 1024; 36 37 38 BitTube::BitTube() 39 : mSendFd(-1), mReceiveFd(-1) 40 { 41 init(DEFAULT_SOCKET_BUFFER_SIZE, DEFAULT_SOCKET_BUFFER_SIZE); 42 } 43 44 BitTube::BitTube(size_t bufsize) 45 : mSendFd(-1), mReceiveFd(-1) 46 { 47 init(bufsize, bufsize); 48 } 49 50 BitTube::BitTube(const Parcel& data) 51 : mSendFd(-1), mReceiveFd(-1) 52 { 53 mReceiveFd = dup(data.readFileDescriptor()); 54 if (mReceiveFd < 0) { 55 mReceiveFd = -errno; 56 ALOGE("BitTube(Parcel): can't dup filedescriptor (%s)", 57 strerror(-mReceiveFd)); 58 } 59 } 60 61 BitTube::~BitTube() 62 { 63 if (mSendFd >= 0) 64 close(mSendFd); 65 66 if (mReceiveFd >= 0) 67 close(mReceiveFd); 68 } 69 70 void BitTube::init(size_t rcvbuf, size_t sndbuf) { 71 int sockets[2]; 72 if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets) == 0) { 73 size_t size = DEFAULT_SOCKET_BUFFER_SIZE; 74 setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &rcvbuf, sizeof(rcvbuf)); 75 setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &sndbuf, sizeof(sndbuf)); 76 // sine we don't use the "return channel", we keep it small... 77 setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &size, sizeof(size)); 78 setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &size, sizeof(size)); 79 fcntl(sockets[0], F_SETFL, O_NONBLOCK); 80 fcntl(sockets[1], F_SETFL, O_NONBLOCK); 81 mReceiveFd = sockets[0]; 82 mSendFd = sockets[1]; 83 } else { 84 mReceiveFd = -errno; 85 ALOGE("BitTube: pipe creation failed (%s)", strerror(-mReceiveFd)); 86 } 87 } 88 89 status_t BitTube::initCheck() const 90 { 91 if (mReceiveFd < 0) { 92 return status_t(mReceiveFd); 93 } 94 return NO_ERROR; 95 } 96 97 int BitTube::getFd() const 98 { 99 return mReceiveFd; 100 } 101 102 int BitTube::getSendFd() const 103 { 104 return mSendFd; 105 } 106 107 ssize_t BitTube::write(void const* vaddr, size_t size) 108 { 109 ssize_t err, len; 110 do { 111 len = ::send(mSendFd, vaddr, size, MSG_DONTWAIT | MSG_NOSIGNAL); 112 // cannot return less than size, since we're using SOCK_SEQPACKET 113 err = len < 0 ? errno : 0; 114 } while (err == EINTR); 115 return err == 0 ? len : -err; 116 } 117 118 ssize_t BitTube::read(void* vaddr, size_t size) 119 { 120 ssize_t err, len; 121 do { 122 len = ::recv(mReceiveFd, vaddr, size, MSG_DONTWAIT); 123 err = len < 0 ? errno : 0; 124 } while (err == EINTR); 125 if (err == EAGAIN || err == EWOULDBLOCK) { 126 // EAGAIN means that we have non-blocking I/O but there was 127 // no data to be read. Nothing the client should care about. 128 return 0; 129 } 130 return err == 0 ? len : -err; 131 } 132 133 status_t BitTube::writeToParcel(Parcel* reply) const 134 { 135 if (mReceiveFd < 0) 136 return -EINVAL; 137 138 status_t result = reply->writeDupFileDescriptor(mReceiveFd); 139 close(mReceiveFd); 140 mReceiveFd = -1; 141 return result; 142 } 143 144 145 ssize_t BitTube::sendObjects(const sp<BitTube>& tube, 146 void const* events, size_t count, size_t objSize) 147 { 148 const char* vaddr = reinterpret_cast<const char*>(events); 149 ssize_t size = tube->write(vaddr, count*objSize); 150 151 // should never happen because of SOCK_SEQPACKET 152 LOG_ALWAYS_FATAL_IF((size >= 0) && (size % objSize), 153 "BitTube::sendObjects(count=%zu, size=%zu), res=%zd (partial events were sent!)", 154 count, objSize, size); 155 156 //ALOGE_IF(size<0, "error %d sending %d events", size, count); 157 return size < 0 ? size : size / objSize; 158 } 159 160 ssize_t BitTube::recvObjects(const sp<BitTube>& tube, 161 void* events, size_t count, size_t objSize) 162 { 163 char* vaddr = reinterpret_cast<char*>(events); 164 ssize_t size = tube->read(vaddr, count*objSize); 165 166 // should never happen because of SOCK_SEQPACKET 167 LOG_ALWAYS_FATAL_IF((size >= 0) && (size % objSize), 168 "BitTube::recvObjects(count=%zu, size=%zu), res=%zd (partial events were received!)", 169 count, objSize, size); 170 171 //ALOGE_IF(size<0, "error %d receiving %d events", size, count); 172 return size < 0 ? size : size / objSize; 173 } 174 175 // ---------------------------------------------------------------------------- 176 }; // namespace android 177
