The WSA_NOT_EMPTY error code, represented by the value 10054, signifies that a network connection was reset. This typically occurs when an attempt is made to perform an operation on a socket where data is still present in the receive buffer. Essentially, the remote endpoint detected that there was unread data and chose to reset the connection rather than allowing a new operation to proceed, which could lead to data loss or corruption.
Symbolic Constant: WSA_NOT_EMPTY
Error Value: 10054
Severity: Error
When you encounter WSA_NOT_EMPTY, consider the following steps:
Verify that your application is gracefully handling connection closures. This includes properly closing sockets after all data has been sent and received and acknowledging any incoming data before closing.
Before closing a socket or initiating a new operation that might conflict with existing data, ensure that the receive buffer is empty. You can do this by attempting to read all available data. A non-blocking read that returns EWOULDBLOCK or EAGAIN indicates that no more data is immediately available.
If possible, investigate the behavior of the remote application or system. It might be contributing to the connection resets.
If the issue is intermittent or affects multiple clients, investigate any network devices between your application and the remote endpoint.
Use appropriate socket timeouts (e.g., SO_RCVTIMEO, SO_SNDTIMEO) to detect unresponsive connections and handle them gracefully, rather than waiting indefinitely for a response that may never come, potentially leading to this error.
This example illustrates how one might attempt to clear the receive buffer before closing a socket, although robust error handling and specific socket options would be required in a real-world scenario.
#include <winsock2.h>
#pragma comment(lib, "ws2_32.lib")
// Assume socket 's' is already created and connected
// Attempt to drain the receive buffer
char buffer[1024];
int bytesRead;
DWORD timeout = 100; // Short timeout to check for data
setsockopt(s, SOL_SOCKET, SO_RCVTIMEO, (char*)&timeout, sizeof(timeout));
do {
bytesRead = recv(s, buffer, sizeof(buffer), 0);
if (bytesRead > 0) {
// Data was received, process it or simply discard if just draining
} else if (bytesRead == 0) {
// Connection gracefully closed by peer
break;
} else { // bytesRead == SOCKET_ERROR
int error = WSAGetLastError();
if (error == WSAETIMEDOUT || error == WSAEWOULDBLOCK || error == WSAEINTR) {
// No more data available within the timeout, or interrupted.
// This is the desired state to proceed with closing.
break;
} else {
// A real error occurred, handle it.
// Might be WSA_NOT_EMPTY itself or another socket error.
// Log the error or take appropriate action.
break;
}
}
} while (true);
// Now it might be safer to close the socket
// close_socket(s);