Why does session_start cause a timeout when one script calls another script using curl

Question

I have two PHP scripts, both using the same session by calling session_name(\'MySessID\').

When the first script calls the second script using curl, the

Answer 1

I got bitten by this as well. I fixed it thanks to the info provided in stackoverflow.

I had two pages, both had "session_start()" at the top and the first was calling the second with curl so I could POST variables to the second script after validation. The webserver was hanging until I added "session_write_close()".

Code sample follows:

// IMPORTANT (OR ELSE INFINITE LOOP) - close current sessions or the next page will wait FOREVER for a write lock.
session_write_close();

// We can't use GET because we can't display the password in the URL.
$host = $_SERVER['HTTP_HOST'];
$uri  = rtrim(dirname($_SERVER['PHP_SELF']), '/\\');
$url  = "http://$host$uri/formPage2.php?";

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$url); //append URL
curl_setopt($ch, CURLOPT_POST,TRUE);//We are using method POST
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($_REQUEST, '', "&"));//append parameters    

curl_exec($ch); // results will be outputted to the browser directly
curl_close($ch);
exit();