轮询Apache服务器无响应

Question

The apache server I am using to develop my system will not respond to request while the scripts that control the polling of messages is being run. This only happends on a domain level meaning that I can send an http request to any other apps hosted localy and get a response. When I do eventually get a response from this its about a minute later.

Here is the Js

window.fetch_messages = function ()
{
    var last_message = $("div.message:last").attr('data-ai_id');
    var last_message_status = $("p.message_status:last").text();
    var project_id = getParameterByName('project-id');

    $.ajax({
            url:'/project_messages',
            type:'POST',
            data:{ project_id:project_id, latest_message:last_message, status:last_message_status },
            timeout:50000,
            async: true,
            success:new_messages, // This upon completion also resends the request
            error:function(data){ console.log(data); setTimeout(fetch_messages(),50000); }
    });

}; // When On the page that uses this I call this function to start polling

Here is the server side code

do 
{
    // Check for status change
    $status_change = $this->mentor_model->query_status($this->project_id, $this->last_message_id, $this->last_message_status, $_SESSION['user']); 

    // Check for new messages
    $messages = $this->mentor_model->query_messages($this->project_id, $this->last_message_id); 

    // If there is a  status update or new message.
    if($messages || $status_change)
    break;

    usleep(1000000);
}
while(empty($messages) && empty($status_change));

echo json_encode(array("messages"=>$messages, "status"=>$status_change));
exit;

While this action is being run The server takes a long time to handle any request weather it be a GET, POST or another AJax request. Iv also tried changing both code sets to no avail as long as its long polling, the server will take a long time to handle.

Do I have this wrong or is there some apache setting I'm suppose to change. Using xamp on windows 8.1 also tried wamp with no change

Answer 1

Thanks to steven for this. Ansewer taken straight from the source of php manual page for session_write_close();

You can have interesting fun debugging anything with sleep() in it if you have a session still active. For example, a page that makes an ajax request, where the ajax request polls a server-side event (and may not return immediately).

If the ajax function doesn't do session_write_close(), then your outer page will appear to hang, and opening other pages in new tabs will also stall.