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 SOCKET_BUFFER_SIZE = 4 * 1024;
36
37
BitTube()38 BitTube::BitTube()
39 : mSendFd(-1), mReceiveFd(-1)
40 {
41 int sockets[2];
42 if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets) == 0) {
43 int size = SOCKET_BUFFER_SIZE;
44 setsockopt(sockets[0], SOL_SOCKET, SO_SNDBUF, &size, sizeof(size));
45 setsockopt(sockets[0], SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
46 setsockopt(sockets[1], SOL_SOCKET, SO_SNDBUF, &size, sizeof(size));
47 setsockopt(sockets[1], SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
48 fcntl(sockets[0], F_SETFL, O_NONBLOCK);
49 fcntl(sockets[1], F_SETFL, O_NONBLOCK);
50 mReceiveFd = sockets[0];
51 mSendFd = sockets[1];
52 } else {
53 mReceiveFd = -errno;
54 ALOGE("BitTube: pipe creation failed (%s)", strerror(-mReceiveFd));
55 }
56 }
57
BitTube(const Parcel & data)58 BitTube::BitTube(const Parcel& data)
59 : mSendFd(-1), mReceiveFd(-1)
60 {
61 mReceiveFd = dup(data.readFileDescriptor());
62 if (mReceiveFd >= 0) {
63 int size = SOCKET_BUFFER_SIZE;
64 setsockopt(mReceiveFd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size));
65 setsockopt(mReceiveFd, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
66 fcntl(mReceiveFd, F_SETFL, O_NONBLOCK);
67 } else {
68 mReceiveFd = -errno;
69 ALOGE("BitTube(Parcel): can't dup filedescriptor (%s)",
70 strerror(-mReceiveFd));
71 }
72 }
73
~BitTube()74 BitTube::~BitTube()
75 {
76 if (mSendFd >= 0)
77 close(mSendFd);
78
79 if (mReceiveFd >= 0)
80 close(mReceiveFd);
81 }
82
initCheck() const83 status_t BitTube::initCheck() const
84 {
85 if (mReceiveFd < 0) {
86 return status_t(mReceiveFd);
87 }
88 return NO_ERROR;
89 }
90
getFd() const91 int BitTube::getFd() const
92 {
93 return mReceiveFd;
94 }
95
write(void const * vaddr,size_t size)96 ssize_t BitTube::write(void const* vaddr, size_t size)
97 {
98 ssize_t err, len;
99 do {
100 len = ::send(mSendFd, vaddr, size, MSG_DONTWAIT | MSG_NOSIGNAL);
101 err = len < 0 ? errno : 0;
102 } while (err == EINTR);
103 return err == 0 ? len : -err;
104
105 }
106
read(void * vaddr,size_t size)107 ssize_t BitTube::read(void* vaddr, size_t size)
108 {
109 ssize_t err, len;
110 do {
111 len = ::recv(mReceiveFd, vaddr, size, MSG_DONTWAIT);
112 err = len < 0 ? errno : 0;
113 } while (err == EINTR);
114 if (err == EAGAIN || err == EWOULDBLOCK) {
115 // EAGAIN means that we have non-blocking I/O but there was
116 // no data to be read. Nothing the client should care about.
117 return 0;
118 }
119 return err == 0 ? len : -err;
120 }
121
writeToParcel(Parcel * reply) const122 status_t BitTube::writeToParcel(Parcel* reply) const
123 {
124 if (mReceiveFd < 0)
125 return -EINVAL;
126
127 status_t result = reply->writeDupFileDescriptor(mReceiveFd);
128 close(mReceiveFd);
129 mReceiveFd = -1;
130 return result;
131 }
132
133
sendObjects(const sp<BitTube> & tube,void const * events,size_t count,size_t objSize)134 ssize_t BitTube::sendObjects(const sp<BitTube>& tube,
135 void const* events, size_t count, size_t objSize)
136 {
137 ssize_t numObjects = 0;
138 for (size_t i=0 ; i<count ; i++) {
139 const char* vaddr = reinterpret_cast<const char*>(events) + objSize * i;
140 ssize_t size = tube->write(vaddr, objSize);
141 if (size < 0) {
142 // error occurred
143 return size;
144 } else if (size == 0) {
145 // no more space
146 break;
147 }
148 numObjects++;
149 }
150 return numObjects;
151 }
152
recvObjects(const sp<BitTube> & tube,void * events,size_t count,size_t objSize)153 ssize_t BitTube::recvObjects(const sp<BitTube>& tube,
154 void* events, size_t count, size_t objSize)
155 {
156 ssize_t numObjects = 0;
157 for (size_t i=0 ; i<count ; i++) {
158 char* vaddr = reinterpret_cast<char*>(events) + objSize * i;
159 ssize_t size = tube->read(vaddr, objSize);
160 if (size < 0) {
161 // error occurred
162 return size;
163 } else if (size == 0) {
164 // no more messages
165 break;
166 }
167 numObjects++;
168 }
169 return numObjects;
170 }
171
172 // ----------------------------------------------------------------------------
173 }; // namespace android
174