多线程Winpcap收包问题

Question

我用MFC做一个网络测试程序，主窗口用来获取device、ip、mac，然后分别用两个线程用Libnet和Winpcap来获取对方IP和MAC，再转到另一个对话框，但是在这个对话框中，新建的对ICMP的收包线程在收到回包后就整个死掉了，提示File:wincore.cpp Line:879的错误，请大虾帮忙！！
问题代码如下：
void op_icmp_packet_callback(u_char *argument, const struct pcap_pkthdr *packet_header, const u_char *packet_content)
{
int i=0;
    struct icmp_header *icmp_protocol;                                // ICMP协议变量     icmp_protocol = (struct icmp_header*)(packet_content + 14+20);   // 获得ICMP协议内容                // 获得ICMP类型 
    switch (icmp_protocol->icmp_type)
    {
        case 8:
            i=1;
            break;
        case 0:
            i=2;
            break;
        default:
i=0;
            break;
    } if(i==2)
{
opdlg->settim("ok");
}}
DWORD WINAPI op_send_icmp(LPVOID lpparameter)
{ sendpack.sendicmp(openapp->pdevice,openapp->pdestination_ip_str,openapp->psource_ip_str);
Sleep(200);
op_bExit=true;
TerminateThread(op_thget_icmp,0);
CloseHandle(op_thget_icmp);
return 0;
}
DWORD WINAPI op_get_icmp(LPVOID lpparameter)
{
char* s="icmp"; pcap_t *op_pcap_handle;                                  // Winpcap句柄 
    char op_error_content[PCAP_ERRBUF_SIZE];                 // 存储错误信息 
char *op_net_interface = openapp->pdevice;
    struct bpf_program op_bpf_filter;                        // BPF过滤规则 
    bpf_u_int32 op_net_mask;                                 // 掩码 
    bpf_u_int32 op_net_ip;                                   // 网路地址 
    pcap_lookupnet(op_net_interface, &op_net_ip, &op_net_mask, op_error_content);             // 获得网络地址和掩码地址 
    op_pcap_handle = pcap_open_live(op_net_interface, BUFSIZ, 1, 100, op_error_content);     // 打开网路接口 
        char *op_bpf_filter_string = s;    // 过滤规则字符串 
pcap_compile(op_pcap_handle, &op_bpf_filter, op_bpf_filter_string, 0, op_net_ip);         // 编译BPF过滤规则 
    pcap_setfilter(op_pcap_handle, &op_bpf_filter);                                     // 设置过滤规则 
    if (pcap_datalink(op_pcap_handle) != DLT_EN10MB)
        return -1;
while(1)
{
    pcap_dispatch(op_pcap_handle,-1, op_icmp_packet_callback, NULL);}   
 pcap_close(op_pcap_handle); 
return 0;
}
void opentest::Onstart() 
{
DWORD thid; // TODO: Add your control notification handler code here
switch(m_type)
{
case 0:
op_thget_icmp=CreateThread(NULL,0,op_get_icmp,NULL,0,&thid);
op_thsend_icmp=CreateThread(NULL,0,op_send_icmp,NULL,0,&thid);
break;
case 1:
op_thget_ip=CreateThread(NULL,0,op_get_ip,NULL,0,&thid);
op_thsend_ip=CreateThread(NULL,0,op_send_ip,NULL,0,&thid);
break;
default:
MessageBox("请选择类型！");
        break;
}
}