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amatsak at chestnutsoftware dot com ¶
18 years ago
The reason for the MySQL "Lost Connection during query" issue when forking is the fact that the child process inherits the parent's database connection. When the child exits, the connection is closed. If the parent is performing a query at this very moment, it is doing it on an already closed connection, hence the error.



An easy way to avoid this is to create a new database connection in parent immediately after forking. Don't forget to force a new connection by passing true in the 4th argument of mysql_connect():



<?php

// Create the MySQL connection

$db = mysql_connect($server, $username, $password);



$pid = pcntl_fork();

             

if ( $pid == -1 ) {        

    // Fork failed            

    exit(1);

} else if ( $pid ) {

    // We are the parent

    // Can no longer use $db because it will be closed by the child

    // Instead, make a new MySQL connection for ourselves to work with

    $db = mysql_connect($server, $username, $password, true);

} else {

    // We are the child

    // Do something with the inherited connection here

    // It will get closed upon exit

    exit(0);

?>



This way, the child will inherit the old connection, will work on it and will close upon exit. The parent won't care, because it will open a new connection for itself immediately after forking.



Hope this helps.
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