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  <title>PHPCrawl webcrawler library for PHP - Multiprocessing modes</title>
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        <h1 style="margin: 0px; float: left;">PHPCrawl webcrawler library/framework</h1>
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        <h3>Multiprocessing modes</h3><br />
        
        PHPCrawl supports two different types of multiprocessing.<br /><br />
        
        The first one and the default is "<b>MPMODE_PARENT_EXECUTES_USERCODE</b>". When running this mode, the overridable function handleDocumentInfo() containing
        usercode always gets executed by the main-process of the crawler. This means that the code provided by the user never gets executed simultaneously and so you
        don't have to care about concurrent file/database/handle-accesses or similar things. This is the <b>recommended</b> multiprocessing-mode.<br /><br />
        
        Example of starting the crawler in this mode:<br />
        
        <p id ="code">
        <span style="color: #000000">
        <span style="color: #0000BB">
        $crawler</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">goMultiProcessed</span><span style="color: #007700">(</span><span style="color: #0000BB">5</span><span style="color: #007700">,<br /></span><span style="color: #0000BB">PHPCrawlerMultiProcessModes</span><span style="color: #007700">::</span><span style="color: #0000BB">MPMODE_PARENT_EXECUTES_USERCODE</span><span style="color: #007700">);
        <br /></span>
        </span>
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        or simply
        
        <p id ="code">
        <span style="color: #000000">
        <span style="color: #0000BB">$crawler</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">goMultiProcessed</span><span style="color: #007700">(</span><span style="color: #0000BB">5</span><span style="color: #007700">);
        <br /></span>
        </span>
        </p>
        
        <br />
        
        The second one is "<b>MPMODE_CHILDS_EXECUTES_USERCODE</b>".<br />
        In this mode all used child-processes are calling the function handleDocumentInfo() directly from their process-context, so the code you provided to the overridden
        method handleDocumentInfo() probably will be executed simultaneously by the different child-processes. This may result in a better performance, but you always should take care
        of concurrent file/data/handle-accesses and all other typical things to take care of when using parallel-computing.<br /><br />
        
        When using the "MPMODE_CHILDS_EXECUTES_USERCODE" mode and you use any handles like database-connections or filestreams in your extended crawler-class, you should open
        them within the overridden mehtod <a href="classreferences/PHPCrawler/method_detail_tpl_method_initChildProcess.htm" target="blank">initChildProcess()</a> instead of opening them from the constructor.
        For more details see the documentation of the <a href="classreferences/PHPCrawler/method_detail_tpl_method_initChildProcess.htm" target="blank">initChildProcess()</a>-method.<br /><br />

        Example of starting the crawler in this mode:<br />
        <p id ="code">
        <span style="color: #000000">
        <span style="color: #0000BB">
        $crawler</span><span style="color: #007700">-&gt;</span><span style="color: #0000BB">goMultiProcessed</span><span style="color: #007700">(</span><span style="color: #0000BB">5</span><span style="color: #007700">,<br /></span><span style="color: #0000BB">PHPCrawlerMultiProcessModes</span><span style="color: #007700">::</span><span style="color: #0000BB">MPMODE_CHILDS_EXECUTES_USERCODE</span><span style="color: #007700">);
        <br /></span>
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