/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include <stdint.h> #include <sys/types.h> #include <unistd.h> #include <fcntl.h> #include <utils/Errors.h> #include <binder/Parcel.h> #include <gui/BitTube.h> namespace android { // ---------------------------------------------------------------------------- BitTube::BitTube() : mSendFd(-1), mReceiveFd(-1) { int fds[2]; if (pipe(fds) == 0) { mReceiveFd = fds[0]; mSendFd = fds[1]; fcntl(mReceiveFd, F_SETFL, O_NONBLOCK); fcntl(mSendFd, F_SETFL, O_NONBLOCK); } else { mReceiveFd = -errno; ALOGE("BitTube: pipe creation failed (%s)", strerror(-mReceiveFd)); } } BitTube::BitTube(const Parcel& data) : mSendFd(-1), mReceiveFd(-1) { mReceiveFd = dup(data.readFileDescriptor()); if (mReceiveFd >= 0) { fcntl(mReceiveFd, F_SETFL, O_NONBLOCK); } else { mReceiveFd = -errno; ALOGE("BitTube(Parcel): can't dup filedescriptor (%s)", strerror(-mReceiveFd)); } } BitTube::~BitTube() { if (mSendFd >= 0) close(mSendFd); if (mReceiveFd >= 0) close(mReceiveFd); } status_t BitTube::initCheck() const { if (mReceiveFd < 0) { return status_t(mReceiveFd); } return NO_ERROR; } int BitTube::getFd() const { return mReceiveFd; } ssize_t BitTube::write(void const* vaddr, size_t size) { ssize_t err, len; do { len = ::write(mSendFd, vaddr, size); err = len < 0 ? errno : 0; } while (err == EINTR); return err == 0 ? len : -err; } ssize_t BitTube::read(void* vaddr, size_t size) { ssize_t err, len; do { len = ::read(mReceiveFd, vaddr, size); err = len < 0 ? errno : 0; } while (err == EINTR); if (err == EAGAIN || err == EWOULDBLOCK) { // EAGAIN means that we have non-blocking I/O but there was // no data to be read. Nothing the client should care about. return 0; } return err == 0 ? len : -err; } status_t BitTube::writeToParcel(Parcel* reply) const { if (mReceiveFd < 0) return -EINVAL; status_t result = reply->writeDupFileDescriptor(mReceiveFd); close(mReceiveFd); mReceiveFd = -1; return result; } // ---------------------------------------------------------------------------- }; // namespace android