public void UserConnected(string username,string terminalCategory,string nickname,string groupid,string groupname)
        {
            try
            {
                Terminal _TempTerminal;

                var _Users = UserManager.Instance();

               

                if (_Users.ContainsKey(username))
                {
                    var _user = _Users.SingleOrDefault(o => o.Key == username);

                    if (_user.Value.Terminals.ContainsKey(terminalCategory))
                    {
                        var _terminal = _user.Value.Terminals.SingleOrDefault(o => o.Key == terminalCategory);

                        _terminal.Value.ConnectedId= Context.ConnectionId;
                        _terminal.Value.ConnectedTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");
                        _TempTerminal = _terminal.Value;
                    }
                    else
                    {
                        var terminal = new Terminal();
                        terminal.Category = terminalCategory;
                        terminal.ConnectedId = Context.ConnectionId;
                        terminal.ConnectedTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");

                        terminal.UserName = username;
                        terminal.NickName = nickname;
                        terminal.GroupId = groupid;
                        terminal.GroupName = groupname;


                        _user.Value.Terminals.Add(terminalCategory, terminal);
                        _TempTerminal = terminal;
                    }
                 
                }
                else 
                {
                    var terminal = new Terminal();
                    terminal.Category = terminalCategory;
                    terminal.ConnectedId = Context.ConnectionId;
                    terminal.ConnectedTime = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");

                    terminal.UserName = username;
                    terminal.NickName = nickname;
                    terminal.GroupId = groupid;
                    terminal.GroupName = groupname;


                    User user = new User();
                    Dictionary<string, Terminal> terminals = new Dictionary<string, Terminal>();

                    terminals.Add(terminalCategory, terminal);
                    user.UserName = username;
                    user.Terminals = terminals;
                    user.NickName = nickname;
                    user.GroupId = groupid;
                    user.GroupName = groupname;

                    _Users.Add(username, user);

                    _TempTerminal = terminal;
                }


              

                RedisHelper RClient = new RedisHelper();
                RClient.SetEntryInHash(username, terminalCategory, JsonHelper.GetJson(_TempTerminal));

                Groups.Add(Context.ConnectionId, groupid);

                string jsonContent = "{type:'online',username:'" + username + "'}";
                Clients.Caller.OnMessage(jsonContent);
            }
            catch (Exception ex)
            {

                logger.Error("UserConnected:" + ex.ToString());
            }
          
           

        }

下面是我的类和单例

public class UserManager
    {
        private static Logger logger = LogManager.GetCurrentClassLogger();

        private static Dictionary<string, User> users = null;

        private static readonly object syncRoot = new object();

        private static readonly object syncRootRemove = new object();

        private UserManager()
        {
        }

        public static Dictionary<string, User> Instance()
        {
            if (users == null)
            {
                lock (syncRoot)
                {
                    if (users == null)
                    {
                        users = new Dictionary<string, User>();
                    }
                }
            }
            return users;
        }


        public static void RemoveUser(string ConnectionId)
        {

            lock (syncRootRemove)
            {
                foreach (var u in users)
                {
                    try
                    {
                        var t = u.Value.Terminals.Values.FirstOrDefault(o => o.ConnectedId == ConnectionId);
                        if (t != null)
                        {
                            var _tempUserName = "";

                            u.Value.Terminals.Remove(t.Category);

                            IHubContext<IClient> Context = GlobalHost.ConnectionManager.GetHubContext<MyHub, IClient>();
                            Context.Groups.Remove(ConnectionId, u.Value.GroupId);

                            RedisHelper RClient = new RedisHelper();
                            RClient.RemoveEntryFromHash(t.UserName, t.Category);

                            if (u.Value.Terminals.Count <= 0)
                            {
                                _tempUserName = u.Value.UserName;
                                users.Remove(u.Value.UserName);

                                RClient.Remove(t.UserName);
                            }

                            string jsonContent = "{type:'offline',username:'" + u.Value.UserName + "'}";
                            Context.Clients.All.OnMessage(jsonContent);

                            break;
                        }

                    }
                    catch (Exception ex)
                    {

                        logger.Error("RemoveUser" + ex.ToString());
                    }


                }
            }

        }
    }


    public class User
    {
        public string UserName { get; set; }

        public string NickName { get; set; }

        public string GroupId { get; set; }

        public string GroupName { get; set; }

        public Dictionary<string,Terminal> Terminals { get; set; }
    }


    public class Terminal
    {
        public string UserName { get; set; }

        public string NickName { get; set; }

        public string GroupId { get; set; }

        public string GroupName { get; set; }


        public string Category { get; set; }

        public string ConnectedTime { get; set; }

        public string ConnectedId { get; set; }

    }

使用的是微软的SignalR 

内存池
线程池
连接池
……

有时不将“调用函数名字＋各参数值，进入函数后各参数值，中间变量值，退出函数前准备返回的值，返回函数到调用处后函数名字＋各参数值＋返回值”这些信息写日志到文件中是无论如何也发现不了问题在哪里的，包括捕获各种异常、写日志到屏幕、单步或设断点或生成core或dmp文件、……这些方法都不行！ 写日志到文件参考下面：

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#ifdef _MSC_VER

    #pragma warning(disable:4996)

    #include <windows.h>

    #include <io.h>

#else

    #include <unistd.h>

    #include <sys/time.h>

    #include <pthread.h>

    #define  CRITICAL_SECTION   pthread_mutex_t

    #define  _vsnprintf         vsnprintf

#endif

//Log{

#define MAXLOGSIZE 20000000

#define MAXLINSIZE 16000

#include <time.h>

#include <sys/timeb.h>

#include <stdarg.h>

char logfilename1[]="MyLog1.log";

char logfilename2[]="MyLog2.log";

static char logstr[MAXLINSIZE+1];

char datestr[16];

char timestr[16];

char mss[4];

CRITICAL_SECTION cs_log;

FILE *flog;

#ifdef _MSC_VER

void Lock(CRITICAL_SECTION *l) {

    EnterCriticalSection(l);

}

void Unlock(CRITICAL_SECTION *l) {

    LeaveCriticalSection(l);

}

#else

void Lock(CRITICAL_SECTION *l) {

    pthread_mutex_lock(l);

}

void Unlock(CRITICAL_SECTION *l) {

    pthread_mutex_unlock(l);

}

#endif

void LogV(const char *pszFmt,va_list argp) {

    struct tm *now;

    struct timeb tb;



    if (NULL==pszFmt||0==pszFmt[0]) return;

    _vsnprintf(logstr,MAXLINSIZE,pszFmt,argp);

    ftime(&tb);

    now=localtime(&tb.time);

    sprintf(datestr,"%04d-%02d-%02d",now->tm_year+1900,now->tm_mon+1,now->tm_mday);

    sprintf(timestr,"%02d:%02d:%02d",now->tm_hour     ,now->tm_min  ,now->tm_sec );

    sprintf(mss,"%03d",tb.millitm);

    printf("%s %s.%s %s",datestr,timestr,mss,logstr);

    flog=fopen(logfilename1,"a");

    if (NULL!=flog) {

        fprintf(flog,"%s %s.%s %s",datestr,timestr,mss,logstr);

        if (ftell(flog)>MAXLOGSIZE) {

            fclose(flog);

            if (rename(logfilename1,logfilename2)) {

                remove(logfilename2);

                rename(logfilename1,logfilename2);

            }

        } else {

            fclose(flog);

        }

    }

}

void Log(const char *pszFmt,...) {

    va_list argp;



    Lock(&cs_log);

    va_start(argp,pszFmt);

    LogV(pszFmt,argp);

    va_end(argp);

    Unlock(&cs_log);

}

//Log}

int main(int argc,char * argv[]) {

    int i;

#ifdef _MSC_VER

    InitializeCriticalSection(&cs_log);

#else

    pthread_mutex_init(&cs_log,NULL);

#endif

    for (i=0;i<10000;i++) {

        Log("This is a Log %04d from FILE:%s LINE:%d\n",i, __FILE__, __LINE__);

    }

#ifdef _MSC_VER

    DeleteCriticalSection(&cs_log);

#else

    pthread_mutex_destroy(&cs_log);

#endif

    return 0;

}

//1-79行添加到你带main的.c或.cpp的那个文件的最前面

//81-86行添加到你的main函数开头

//90-94行添加到你的main函数结束前

//在要写LOG的地方仿照第88行的写法写LOG到文件MyLog1.log中

我就是单纯的顺序执行 他也会少 而且没有异常抛出，这和写不写日志 没什么关系吧