title: why when writting more than once to socket, it blocks?
body: <p>I am facing a problem with socket and I would be glad if you could help ...<br>
  The problem is that when I send data more than once it blocks, e.g:</p>
  
  <pre><code>//--- client ---  
  //..
  send(sock, buf_1, sizeof(buf_1), 0);  
  
  for (x10){   
  //...  
  send(sock, buf_2, sizeof(buf_2), 0);    
  if (recv(sock, buf_2, sizeof(buf_2), 0)&lt;0) printf("recv_2() failed");   
  //...   
  }  
  
  for (x20){   
  //...  
  send(sock, buf_3, sizeof(buf_3), 0);     
  if (recv(sock, buf_3, sizeof(buf_3), 0)&lt;0) printf("recv_3() failed");   
  //...    
  }  
  //...          
  
  //--- server---   
  //...  
  if (recv(sock, buf_1, sizeof(buf_1), 0)&lt;0) printf("recv_1() failed"); 
  
  for (x10){     
  if (recv(sock, buf_2, sizeof(buf_2), 0)&lt;0) printf("recv_2() failed");    
  //...    
  send(sock, buf_2, sizeof(buf_2), 0);     
  }     
  
  for (x20){   
  if (recv(sock, buf_3, sizeof(buf_3), 0)&lt;0) printf("recv_3() failed");   
  //...    
  send(sock, buf_3, sizeof(buf_3), 0);     
  }     
  //...   
  </code></pre>
  
  <p>the exchange blocks just after the first <code>send()</code>, is there any idea?<br>
  Does udp support also multiple <code>sendto()</code>?</p>
  
  <p>Thanks for your answer -</p>