Solve the problem of high CPU load caused by PHP curl_multi batch processing

The simple curl process is as follows:

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$ch = Curl_init (); curl_setopt ($ch, Curlopt_url, ' http://www.111cn.net '); curl_setopt ($ch, Curlopt_returntransfer, TRUE); $con = curl_exec ($ch); Curl_close ($ch);

Curl also provides a bulk processing session, and the following is the Curl batch processing correlation function:
curl_multi_init-returns a new Curl batch handle
curl_multi_add_handle-Add a separate curl handle to a curl batch session
curl_multi_exec-resolves a curl batch handle
curl_multi_getcontent-If the Curlopt_returntransfer is set, the text stream of the obtained output is returned
curl_multi_select-waits for active connections in all Curl batches
Curl_multi_info_read-gets the relevant transport information of the currently resolved curl
curl_multi_remove_handle-removes a handle resource from a curl batch handle resource
Curl_multi_close-closes a set of curl handles

Look at the following examples of using Curl Multi batch processing:

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<?php /** * CURL Multi Batch Processing * * @author McKee * @link http://www.111cn.net * */ $url _array = Array ( ' http://www.111cn.net/', ' Http://www.111cn.net/php/627.html ', ' Http://www.111cn.net/php/258.html ' ); $handles = $contents = Array (); Initializing Curl Multi Objects $MH = Curl_multi_init (); Add Curl Batch Session foreach ($url _array as $key => $url) { $handles [$key] = Curl_init ($url); curl_setopt ($handles [$key], Curlopt_returntransfer, 1); curl_setopt ($handles [$key], curlopt_timeout, 10); Curl_multi_add_handle ($MH, $handles [$key]); } ====================== Execute Batch handle ================================= $active = null; do { $MRC = Curl_multi_exec ($MH, $active); while ($MRC = = Curlm_call_multi_perform); while ($active and $MRC = = CURLM_OK) { if (Curl_multi_select ($mh) = = 1) { Usleep (100); } do { $MRC = Curl_multi_exec ($MH, $active); while ($MRC = = Curlm_call_multi_perform); } //==================================================================== Get Batch Content foreach ($handles as $i => $ch) { $content = Curl_multi_getcontent ($ch); $contents [$i] = Curl_errno ($ch) = = 0? $content: '; } To remove a batch handle foreach ($handles as $ch) { Curl_multi_remove_handle ($MH, $ch); } Close Batch Handle Curl_multi_close ($MH); Print_r ($contents);

The above procedure focuses on the implementation of the batch process, the normal processing:

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do {$n =curl_multi_exec ($MH, $active);} while ($active);

The

will cause the CPU loading too high, because $active to wait for all the URL data accepted to become false, so here to use the return value of curl_multi_exec to determine whether there is data, when there is time to call Curl_multi_ exec, you sleep without performing data, so you avoid CPU Loading 100%.