(PHP 5, PHP 7)
curl_multi_select — Wait for activity on any curl_multi connection
$timeout= 1.0 ] ) : int
Blocks until there is activity on any of the curl_multi connections.
A cURL multi handle returned by curl_multi_init().
Time, in seconds, to wait for a response.
On success, returns the number of descriptors contained in the descriptor sets. This may be 0 if there was no activity on any of the descriptors. On failure, this function will return -1 on a select failure (from the underlying select system call).