void Socket::handleSendError(int ret, const char* context) {
#if defined(_WIN32)
const int mongo_errno = WSAGetLastError();
if ( mongo_errno == WSAETIMEDOUT && _timeout != 0 ) {
#else
const int mongo_errno = errno;
if ( ( mongo_errno == EAGAIN || mongo_errno == EWOULDBLOCK ) && _timeout != 0 ) {
#endif
LOG(_logLevel) << "Socket " << context <<
" send() timed out " << remoteString() << endl;
throw SocketException(SocketException::SEND_TIMEOUT , remoteString());
}
else {
LOG(_logLevel) << "Socket " << context << " send() "
<< errnoWithDescription(mongo_errno) << ' ' << remoteString() << endl;
throw SocketException(SocketException::SEND_ERROR , remoteString());
}
}
void Socket::handleRecvError(int ret, int len) {
if (ret == 0) {
LOG(3) << "Socket recv() conn closed? " << remoteString() << endl;
throw SocketException(SocketException::CLOSED , remoteString());
}
// ret < 0
#if defined(_WIN32)
int e = WSAGetLastError();
#else
int e = errno;
# if defined(EINTR)
if (e == EINTR) {
LOG(_logLevel) << "EINTR returned from recv(), retrying";
return;
}
# endif
#endif
#if defined(_WIN32)
// Windows
if ((e == EAGAIN || e == WSAETIMEDOUT) && _timeout > 0) {
#else
if (e == EAGAIN && _timeout > 0) {
#endif
// this is a timeout
LOG(_logLevel) << "Socket recv() timeout " << remoteString() <<endl;
throw SocketException(SocketException::RECV_TIMEOUT, remoteString());
}
LOG(_logLevel) << "Socket recv() " <<
errnoWithDescription(e) << " " << remoteString() <<endl;
throw SocketException(SocketException::RECV_ERROR , remoteString());
}
void Socket::setTimeout( double secs ) {
setSockTimeouts( _fd, secs );
}
// TODO: allow modification?
//
// <positive value> : secs to wait between stillConnected checks
// 0 : always check
// -1 : never check
const int Socket::errorPollIntervalSecs( 5 );
// Patch to allow better tolerance of flaky network connections that get broken
// while we aren't looking.
// TODO: Remove when better async changes come.
//
// isStillConnected() polls the socket at max every Socket::errorPollIntervalSecs to determine
// if any disconnection-type events have happened on the socket.
bool Socket::isStillConnected() {
if (_fd == -1) {
// According to the man page, poll will respond with POLLVNAL for invalid or
// unopened descriptors, but it doesn't seem to be properly implemented in
// some platforms - it can return 0 events and 0 for revent. Hence this workaround.
return false;
}
if ( errorPollIntervalSecs < 0 ) return true;
if ( ! isPollSupported() ) return true; // nothing we can do
time_t now = time( 0 );
time_t idleTimeSecs = now - _lastValidityCheckAtSecs;
// Only check once every 5 secs
if ( idleTimeSecs < errorPollIntervalSecs ) return true;
// Reset our timer, we're checking the connection
_lastValidityCheckAtSecs = now;
// It's been long enough, poll to see if our socket is still connected
pollfd pollInfo;
pollInfo.fd = _fd;
// We only care about reading the EOF message on clean close (and errors)
pollInfo.events = POLLIN;
// Poll( info[], size, timeout ) - timeout == 0 => nonblocking
int nEvents = socketPoll( &pollInfo, 1, 0 );
LOG( 2 ) << "polling for status of connection to " << remoteString()
<< ", " << ( nEvents == 0 ? "no events" :
nEvents == -1 ? "error detected" :
"event detected" ) << endl;
if ( nEvents == 0 ) {
// No events incoming, return still connected AFAWK
return true;
}
else if ( nEvents < 0 ) {
// Poll itself failed, this is weird, warn and log errno
warning() << "Socket poll() failed during connectivity check"
<< " (idle " << idleTimeSecs << " secs,"
<< " remote host " << remoteString() << ")"
<< causedBy(errnoWithDescription()) << endl;
// Return true since it's not clear that we're disconnected.
return true;
}
dassert( nEvents == 1 );
dassert( pollInfo.revents > 0 );
// Return false at this point, some event happened on the socket, but log what the
// actual event was.
if ( pollInfo.revents & POLLIN ) {
// There shouldn't really be any data to recv here, so make sure this
// is a clean hangup.
const int testBufLength = 1024;
char testBuf[testBufLength];
int recvd = ::recv( _fd, testBuf, testBufLength, portRecvFlags );
if ( recvd < 0 ) {
// An error occurred during recv, warn and log errno
warning() << "Socket recv() failed during connectivity check"
<< " (idle " << idleTimeSecs << " secs,"
<< " remote host " << remoteString() << ")"
<< causedBy(errnoWithDescription()) << endl;
}
else if ( recvd > 0 ) {
// We got nonzero data from this socket, very weird?
// Log and warn at runtime, log and abort at devtime
// TODO: Dump the data to the log somehow?
error() << "Socket found pending " << recvd
<< " bytes of data during connectivity check"
<< " (idle " << idleTimeSecs << " secs,"
<< " remote host " << remoteString() << ")" << endl;
DEV {
std::string hex = hexdump(testBuf, recvd);
error() << "Hex dump of stale log data: " << hex << endl;
}
dassert( false );
}
else {
// recvd == 0, socket closed remotely, just return false
LOG( 0 ) << "Socket closed remotely, no longer connected"
<< " (idle " << idleTimeSecs << " secs,"
<< " remote host " << remoteString() << ")" << endl;
}
}
int socketPoll( pollfd* fdarray, unsigned long nfds, int timeout ) {
fassert(17185, isPollSupported());
return wsaPollFunction(fdarray, nfds, timeout);
}
