c++ - Weird behavior in an HTTP request with Winsock2 -

i'm trying implement http request in c++ using winsock 2.

after connecting http://stackoverflow.com, here's im sending:

send(_socket, "get / http/1.1\r\nhost: www.stackoverflow.com\r\n\r\n", (the length ), 0); 

and reading response:

std::string s; char buffer[buffer_length]; int bytes = 0;  {     zeromemory(buffer, buffer_length);     bytes = recv(_socket, buffer, buffer_length, 0);     s.append(buffer); } while (bytes == buffer_length);  return s; 

by way: #define buffer_length 512

here's come weird part, when run program response's headers part:

http/1.1 200 ok  cache-control: public, max-age=34  content-type: text/html; charset=utf-8  expires: wed, 04 sep 2013 08:14:00 gmt  last-modified: wed, 04 sep 2013 08:13:00 gmt  vary: *  x-frame-options: sameorigin  date: wed, 04 sep 2013 08:13:26 gmt  content-length: 193288 

but when debug read function step step response including content. if put breakpoint on zeromemory() function , continue execute code pressing f10 key (step over) advances 1 "command" @ time, loop goes on few times exists , returns full response, both headers , content. if put breakpoint after recv() function (s.append(buffer)) loop exists (after 1 execution of loop performed) , retruns headers.

someone can explain me behavior?

what assume there kind of timed delay between sending headers , content, when stop before recv() debugger server have enough time send , recv() can read all, when put after, server had enough time send headers , recv() function reads what's arrived , return less 512 bytes read, , loop exists. right?

thanks in advance!

the assumption right, mentioned in comment can less buffer size if data has not arrived yet. should in loop use knowledge of http , example \r\n\r\n know when headers have arrived, lookup content length , try read amount of data content. or alternatively, since on winsock2 use methods httpsendrequest (http://msdn.microsoft.com/en-us/library/windows/desktop/aa384247(v=vs.85).aspx) , friends - less issues if want send requests.