Look at the following code snippet

$fh=pfsockopen('localhost', 12345, &$err_no, &$err_str, 30);
fputs($fh, "GETTSTUFF\r\n");

$stuff=fgets($fh, 256);
print strlen($stuff);
print $stuff;

Now, when I run in for the first time, everything works fine and my perl-server returns the desired value to php. When I hit reload, the connection is reused (it's really the same one, same host/port), and the server receives the request, and responses with a single line, but PHP is no longer able to read from the socket. It returns FALSE. I already tried to flush the socket or set it to non-blocking, neither works. The symptom remains the same: server gets request, replies to it, but PHP doesn't read anything.

PHP was compiled as a module, as a cgi version, statically or as dso, with or without socket support, nearly all combinations have been checked out (on Debian and FreeBSD).