110 lines
3.8 KiB
C++
110 lines
3.8 KiB
C++
/*
|
|
* Copyright (C) 2022 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.
|
|
*/
|
|
#pragma once
|
|
|
|
#include <android-base/unique_fd.h>
|
|
#include <poll.h>
|
|
|
|
#include "FdTrigger.h"
|
|
#include "RpcState.h"
|
|
|
|
namespace android {
|
|
|
|
template <typename SendOrReceive>
|
|
status_t interruptableReadOrWrite(
|
|
const android::RpcTransportFd& socket, FdTrigger* fdTrigger, iovec* iovs, int niovs,
|
|
SendOrReceive sendOrReceiveFun, const char* funName, int16_t event,
|
|
const std::optional<android::base::function_ref<status_t()>>& altPoll) {
|
|
MAYBE_WAIT_IN_FLAKE_MODE;
|
|
|
|
if (niovs < 0) {
|
|
return BAD_VALUE;
|
|
}
|
|
|
|
// Since we didn't poll, we need to manually check to see if it was triggered. Otherwise, we
|
|
// may never know we should be shutting down.
|
|
if (fdTrigger->isTriggered()) {
|
|
return DEAD_OBJECT;
|
|
}
|
|
|
|
// If iovs has one or more empty vectors at the end and
|
|
// we somehow advance past all the preceding vectors and
|
|
// pass some or all of the empty ones to sendmsg/recvmsg,
|
|
// the call will return processSize == 0. In that case
|
|
// we should be returning OK but instead return DEAD_OBJECT.
|
|
// To avoid this problem, we make sure here that the last
|
|
// vector at iovs[niovs - 1] has a non-zero length.
|
|
while (niovs > 0 && iovs[niovs - 1].iov_len == 0) {
|
|
niovs--;
|
|
}
|
|
if (niovs == 0) {
|
|
// The vectors are all empty, so we have nothing to send.
|
|
return OK;
|
|
}
|
|
|
|
bool havePolled = false;
|
|
while (true) {
|
|
ssize_t processSize = sendOrReceiveFun(iovs, niovs);
|
|
if (processSize < 0) {
|
|
int savedErrno = errno;
|
|
|
|
// Still return the error on later passes, since it would expose
|
|
// a problem with polling
|
|
if (havePolled || (savedErrno != EAGAIN && savedErrno != EWOULDBLOCK)) {
|
|
LOG_RPC_DETAIL("RpcTransport %s(): %s", funName, strerror(savedErrno));
|
|
return -savedErrno;
|
|
}
|
|
} else if (processSize == 0) {
|
|
return DEAD_OBJECT;
|
|
} else {
|
|
while (processSize > 0 && niovs > 0) {
|
|
auto& iov = iovs[0];
|
|
if (static_cast<size_t>(processSize) < iov.iov_len) {
|
|
// Advance the base of the current iovec
|
|
iov.iov_base = reinterpret_cast<char*>(iov.iov_base) + processSize;
|
|
iov.iov_len -= processSize;
|
|
break;
|
|
}
|
|
|
|
// The current iovec was fully written
|
|
processSize -= iov.iov_len;
|
|
iovs++;
|
|
niovs--;
|
|
}
|
|
if (niovs == 0) {
|
|
LOG_ALWAYS_FATAL_IF(processSize > 0,
|
|
"Reached the end of iovecs "
|
|
"with %zd bytes remaining",
|
|
processSize);
|
|
return OK;
|
|
}
|
|
}
|
|
|
|
if (altPoll) {
|
|
if (status_t status = (*altPoll)(); status != OK) return status;
|
|
if (fdTrigger->isTriggered()) {
|
|
return DEAD_OBJECT;
|
|
}
|
|
} else {
|
|
if (status_t status = fdTrigger->triggerablePoll(socket, event); status != OK)
|
|
return status;
|
|
if (!havePolled) havePolled = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
} // namespace android
|