void AsyncPipeReader::failRead(const AsyncSocketException& ex) {
VLOG(5) << "AsyncPipeReader(this=" << this << ", fd=" << fd_
<< "): failed while reading: " << ex.what();
DCHECK(readCallback_ != nullptr);
AsyncReader::ReadCallback* callback = readCallback_;
readCallback_ = nullptr;
callback->readErr(ex);
close();
}
void AsyncPipeReader::handlerReady(uint16_t events) noexcept {
DestructorGuard dg(this);
CHECK(events & EventHandler::READ);
VLOG(5) << "AsyncPipeReader::handlerReady() this=" << this << ", fd=" << fd_;
assert(readCallback_ != nullptr);
while (readCallback_) {
// - What API does callback support?
const auto movable = readCallback_->isBufferMovable(); // noexcept
// Get the buffer to read into.
void* buf = nullptr;
size_t buflen = 0;
std::unique_ptr<IOBuf> ioBuf;
if (movable) {
ioBuf = IOBuf::create(readCallback_->maxBufferSize());
buf = ioBuf->writableBuffer();
buflen = ioBuf->capacity();
} else {
try {
readCallback_->getReadBuffer(&buf, &buflen);
} catch (const std::exception& ex) {
AsyncSocketException aex(
AsyncSocketException::BAD_ARGS,
string("ReadCallback::getReadBuffer() "
"threw exception: ") +
ex.what());
failRead(aex);
return;
} catch (...) {
AsyncSocketException aex(
AsyncSocketException::BAD_ARGS,
string("ReadCallback::getReadBuffer() "
"threw non-exception type"));
failRead(aex);
return;
}
if (buf == nullptr || buflen == 0) {
AsyncSocketException aex(
AsyncSocketException::INVALID_STATE,
string("ReadCallback::getReadBuffer() "
"returned empty buffer"));
failRead(aex);
return;
}
}
// Perform the read
#if _WIN32
// On Windows you can't call read on a socket, so call recv instead.
ssize_t bytesRead =
folly::fileutil_detail::wrapNoInt(recv_internal, fd_, buf, buflen);
#else
ssize_t bytesRead = folly::readNoInt(fd_.toFd(), buf, buflen);
#endif
if (bytesRead > 0) {
if (movable) {
ioBuf->append(std::size_t(bytesRead));
readCallback_->readBufferAvailable(std::move(ioBuf));
} else {
readCallback_->readDataAvailable(size_t(bytesRead));
}
// Fall through and continue around the loop if the read
// completely filled the available buffer.
// Note that readCallback_ may have been uninstalled or changed inside
// readDataAvailable().
if (static_cast<size_t>(bytesRead) < buflen) {
return;
}
} else if (bytesRead < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
// No more data to read right now.
return;
} else if (bytesRead < 0) {
AsyncSocketException ex(
AsyncSocketException::INVALID_STATE, "read failed", errno);
failRead(ex);
return;
} else {
assert(bytesRead == 0);
// EOF
unregisterHandler();
AsyncReader::ReadCallback* callback = readCallback_;
readCallback_ = nullptr;
callback->readEOF();
return;
}
// Max reads per loop?
}
}
void AsyncPipeReader::handlerReady(uint16_t events) noexcept {
DestructorGuard dg(this);
CHECK(events & EventHandler::READ);
VLOG(5) << "AsyncPipeReader::handlerReady() this=" << this << ", fd=" << fd_;
assert(readCallback_ != nullptr);
while (readCallback_) {
// Get the buffer to read into.
void* buf = nullptr;
size_t buflen = 0;
try {
readCallback_->getReadBuffer(&buf, &buflen);
} catch (const std::exception& ex) {
AsyncSocketException aex(AsyncSocketException::BAD_ARGS,
string("ReadCallback::getReadBuffer() "
"threw exception: ") + ex.what());
failRead(aex);
return;
} catch (...) {
AsyncSocketException ex(AsyncSocketException::BAD_ARGS,
string("ReadCallback::getReadBuffer() "
"threw non-exception type"));
failRead(ex);
return;
}
if (buf == nullptr || buflen == 0) {
AsyncSocketException ex(AsyncSocketException::INVALID_STATE,
string("ReadCallback::getReadBuffer() "
"returned empty buffer"));
failRead(ex);
return;
}
// Perform the read
ssize_t bytesRead = folly::readNoInt(fd_, buf, buflen);
if (bytesRead > 0) {
readCallback_->readDataAvailable(bytesRead);
// Fall through and continue around the loop if the read
// completely filled the available buffer.
// Note that readCallback_ may have been uninstalled or changed inside
// readDataAvailable().
if (static_cast<size_t>(bytesRead) < buflen) {
return;
}
} else if (bytesRead < 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
// No more data to read right now.
return;
} else if (bytesRead < 0) {
AsyncSocketException ex(AsyncSocketException::INVALID_STATE,
"read failed", errno);
failRead(ex);
return;
} else {
assert(bytesRead == 0);
// EOF
unregisterHandler();
AsyncReader::ReadCallback* callback = readCallback_;
readCallback_ = nullptr;
callback->readEOF();
return;
}
// Max reads per loop?
}
}
