How to measure time spent on socket read() method ?

Question

Hi,
I have a socket waiting for input stream from a remote host :
// method blocks until some input is available
int count = socket_host.getInputStream().read(bytes);
I want to know how much time it took to receive "count" bytes from remote host.
          t1 = System.nanoTime();
          int count = socket_host.getInputStream().read(bytes);
          t2 = System.nanoTime();
(t2-t1) of course is not the answer, because t1 needs to start when read method actually stop waiting..
I need some kind of call back, in order to know when input starts coming..
how would you do that accuratly ?
thanks for help !!

Answer 1

thanks ejp , I followed your idea :
     count1=socket_host.getInputStream().read(bytes,0,1);
     t1 = System.nanoTime();
     count2=socket_host.getInputStream().read(bytes,1,bytes.length-1);
     t2 = System.nanoTime();
     if (count1==1 && count2>0)
          count=count2+1;
     else if (count1==-1 || count2==-1)
          count=-1;After I compute speed (with t2-t1 and count given to that method)
     public static double computeSpeed(double nanosec,double nbbytes){
          if (nanosec==0)
               return 0;
          double speedkilobytespersec=nbbytes/nanosec*1000000;
          return speedkilobytespersec;
     }But speed results are very erratic and sometimes superior to 100 MBytes /sec , which is not possible with my connection.
Somehow, I have the feeling that when t1 is triggered, it is already too late, many bytes are already arrived, and results is not accurate.
It would need a lower level trigger, wouldn't it ?
thanks