为什么pcap_next_ex在Window上始终返回0？

Question

I'm using winpcap to implement a sniffer, I keep polling the following readpacket function but randomly (some times after 1 minute some times after 5 hours) my program get stuck in this procedure's while since rc keep being equal 0. Why is this happening? What am I missing?

Relevant configuration:

    pcap_set_snaplen (_pPCapHandle, 65535);
    pcap_set_promisc (_pPCapHandle, 1);
    pcap_set_timeout (_pPCapHandle, msPacketValid); //msPacketValid = 0

int PCapInterface::readPacket (uint8 *pui8Buf, uint16 ui16BufSize)
{
    struct pcap_pkthdr *pPacketHeader;
    const u_char *pPacketData;
    while (true) {
        int rc = pcap_next_ex (_pPCapHandle, &pPacketHeader, &pPacketData);

        if (rc > 0) {

            uint32 ui32PacketSize = ui16BufSize < pPacketHeader->caplen ? ui16BufSize : pPacketHeader->caplen;
            memcpy (pui8Buf, pPacketData, ui32PacketSize);

            return ui32PacketSize;
        }
        else if (rc == 0) {
            printf("read rc = 0...\n");
            if (_bIsTerminationRequested) {

                return 0;
            }
        }
        else if (rc < 0) 
        {
            checkAndLogMsg ("PCapInterface::readPacket", Logger::L_MildError, "pcap_next_ex() returned %d\n", rc);
            return -1;
        }
    }
}

Answer 1

I discovered that the reason why the function was not working was because the polling function was too slow. Now that I'm using a thread just for the reading phase the problem is not present anymore.