This command line PHP script tests algorithm times, keeping track of results in a histogram. Each time a new worst case elapsed time is found, the script will print out metrics, including user cpu time, system cpu time and context switches.

timingtest.php

<?php

declare(ticks = 1);

/*
 * This command line PHP script tests algorithm times, keeping track of results in a histogram.
 * Each time a new worst case elapsed time is found, the script will print out metrics, including
 * user cpu time, system cpu time and context switches.
 *
 * Pressing Cntrl-Z will dump the current stats.
*/

class InteruptTester
{
	const MEMORY_SIZE = 1048576; // 1MB
	const ITERATION_LIMIT = 7000;
	const SLEEP_BETWEEN_TESTS_MS = 100; // Amount of time to sleep between test runs (avoid abusing CPU)
	
	public $worstEvent = null;
	public $timeCounts = null;
	public $timeBuckets = null;
	public $worstTime = 0;
	public $eatMemory = null;
	
	protected $usageStart = null;
	protected $usageEnd = null;
	protected $tStart = 0;
	protected $tEnd = 0;
	protected $timeSum = 0;
	protected $timeAverage = 0;
	protected $iterations;
	
	public function __construct()
	{
		$this->timeBuckets = array(2,6,10,18,24,50,75,100,200,10000);
		$this->timeCounts = array(0,0,0,0,0,0,0,0,0,0);
		
		$this->eatMemory = array();
		$size = 0;
		$chunkSize = 10000;
		while ($size < self::MEMORY_SIZE)
		{
			$this->eatMemory[] = str_pad('pig', $chunkSize, uniqid());
			$size += $chunkSize;
		}
	}
	
	public function main()
	{
		$uSleep = self::SLEEP_BETWEEN_TESTS_MS * 1000;
		while(true)
		{
			$this->timetest();
			
			usleep($uSleep);
		}
	}
	
	protected function markStart()
	{
		$this->usageStart = getrusage();
		$this->tStart = microtime(true);
	}

	protected function markEnd($iterations)
	{
		$this->tEnd = microtime(true);
		$this->usageEnd = getrusage();

		$elapsed = round($this->tEnd*1000 - $this->tStart*1000);
		
		$usageDiffKeys = array('ru_nsignals' => 'signals','ru_nivcsw' =>'involSwitch', 'ru_nvcsw' =>'volSwitch',
							   'ru_minflt' =>'minFault', 'ru_majflt' =>'majFault');
		$info = array('elapsed' => $elapsed);
		
		foreach($usageDiffKeys as $key =>$val)
		{
			$info[$val] = $this->usageEnd[$key] - $this->usageStart[$key];
		}
		
		$info['userCPUTime'] = (($this->usageEnd['ru_utime.tv_sec']*1e6+$this->usageEnd['ru_utime.tv_usec']) - ($this->usageStart['ru_utime.tv_sec']*1e6+$this->usageStart['ru_utime.tv_usec']))/1000; // in ms
		$info['systemCPUTime'] = (($this->usageEnd['ru_stime.tv_sec']*1e6+$this->usageEnd['ru_stime.tv_usec']) - ($this->usageStart['ru_stime.tv_sec']*1e6+$this->usageStart['ru_stime.tv_usec']))/1000;

		$this->countTime($elapsed);
		
		if ($elapsed>$this->worstTime)
		{
			$this->logEvent($info);
			$this->worstEvent = $info;
			$this->worstTime = $elapsed;
		}
		
		return $info;

	}
	
	public function countTime($t)
	{
		$this->timeSum += $t;
		$this->iterations++;
		$this->timeAverage = $this->timeSum/$this->iterations;
		
		for($i=0;$i<count($this->timeBuckets);$i++)
		{
			if ($t<$this->timeBuckets[$i])
			{
				$this->timeCounts[$i]++;
				break;
			}
		}
	}
	


	protected function logEvent($info)
	{
		print_r($info);
		
	}
	
	public function sigint_handler($signo)
	{
		$this->showStats();
		exit();
	}
	
	public function sigstp_handler($signo)
	{
		$this->showStats();
	}
	
	public function showStats()
	{
		
		print_r($this->worstEvent);
		print("Average time: " . $this->timeAverage . "\n");
		$startRange = 0;
		for($i=0;$i<count($this->timeBuckets);$i++)
		{
			print($startRange . '-'. $this->timeBuckets[$i] . ' : ' . $this->timeCounts[$i] . "\n");
			$startRange = $this->timeBuckets[$i]+1;
		}
	}
	
	/*
	 * This is the algorithm being measured.
	 *
	 * Replaces the contents of the loop with your code.
	*/
	public function timetest()
	{
		$this->markStart();		
		
		$limit = self::ITERATION_LIMIT;
		$iterations = 0;
				
		while ($iterations < $limit)
		{
			$iterations++;
			$last=microtime(true);
		}
		
		$this->markEnd($iterations);

		
	}
}

$gInteruptTester = new InteruptTester();


pcntl_signal(SIGINT, array($gInteruptTester, 'sigint_handler'));
pcntl_signal(SIGTSTP, array($gInteruptTester, 'sigstp_handler'));

$gInteruptTester->main();


?>