Returning a value to the calling thread
I am trying to use pthreads in PHP to speed up a series of computations that are currently maxing one cpu core in a matter of seconds. I split the calculations into multiple ranges and run each range on a parent thread:
$threads = array();
foreach($cp as $c) {
$threads[$c] = new ThreadedMatcher($params);
$threads[$c]->start();
}
Then I want array_merge
arrays created in each child thread (for each range) in the parent thread to get the value across the entire dataset.
I understand what I need to use join()
in the parent thread to wait for the thread to end, but how can I get the value from the child thread to the parent thread?
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Try the following:
This will split the payload according to your available cores, going through batches so as not to exceed the maximum Cpus threads. I use this very simple principle for many of the other Pthreads features I have tested. Simplest and most effective for me so far.
Works flawlessly with xenon servers and 80 available Cpus streams through 100M iterations over a period of hours.
$Pay_Load=array(
array('id'=>$id,'query'=>$query1,'param'=>$param1),
array('id'=>$id,'query'=>$query2,'param'=>$param2),
/*... can be hundreds...just an example...*/
)
$Nb_of_Cpus=4;
$Nb_of_threads=$Nb_of_Cpus*2;
$Batch_Works=array_chunk($Pay_Load,$Nb_of_threads);
$threads = [];
$results = array();
foreach ($Batch_Works as $batch) {
foreach ($batch as $key => $params) {
$threads[$key] = new ThreadedMatcher($params);
$threads[$key]->start();
}
foreach ($batch as $key => $params) {
$threads[$key]->join();
$returned_result=$threads[$key]->result;
$returned_id=$threads[$key]->id;
$result=array('id'=>$returned_id,'result'=>$returned_result);
array_push($results, result);
}
}
/* all returned results are now in the same array */
/* with the original Payload id as an example here */
var_dump($results);
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Complete class:
class ThreadedMatcher extends Thread {
private $query;
private $param;
public $result;
public $id;
public function __construct($params) {
$this->query = $params['query'];
$this->param = $params['param'];
$this->id= $params['id'];
}
public function run() {
/* do some stuff*/
echo ($this->query);
echo ($this->param);
$this->result = rand(100, 200);
}
}
$Pay_Load=array(
array('id'=>$id,'query'=>$query1,'param'=>$param1),
array('id'=>$id,'query'=>$query2,'param'=>$param2),
/*... can be hundreds...just an example...*/
)
$Nb_of_Cpus=4;
$Nb_of_threads=$Nb_of_Cpus*2;
$Batch_Works=array_chunk($Pay_Load,$Nb_of_threads);
$threads = [];
$results = array();
foreach ($Batch_Works as $batch) {
foreach ($batch as $key => $params) {
$threads[$key] = new ThreadedMatcher($params);
$threads[$key]->start();
}
foreach ($batch as $key => $params) {
$threads[$key]->join();
$returned_result=$threads[$key]->result;
$returned_id=$threads[$key]->id;
$result=array($returned_id=>$returned_result);
array_push($results, result);
}
}
/* all returned results are now in the same array */
/* with the original Payload id as an example here */
var_dump($results);
$results =(
1=>103,
2=>234,
3=>345,
4=>123)
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