为了强制执行max_execution_time限制,PHP必须跟踪特定脚本所使用的CPU时间。
是否有一种方法可以在脚本中访问它?我希望在测试中包含一些关于实际PHP中消耗了多少CPU的日志记录(当脚本等待数据库时,时间不会增加)。
我用的是Linux机顶盒。
为了强制执行max_execution_time限制,PHP必须跟踪特定脚本所使用的CPU时间。
是否有一种方法可以在脚本中访问它?我希望在测试中包含一些关于实际PHP中消耗了多少CPU的日志记录(当脚本等待数据库时,时间不会增加)。
我用的是Linux机顶盒。
当前回答
<?php
// Randomize sleeping time
usleep(mt_rand(100, 10000));
// As of PHP 5.4.0, REQUEST_TIME_FLOAT is available in the $_SERVER superglobal array.
// It contains the timestamp of the start of the request with microsecond precision.
$time = microtime(true) - $_SERVER["REQUEST_TIME_FLOAT"];
echo "Did nothing in $time seconds\n";
?>
其他回答
<?php
// Randomize sleeping time
usleep(mt_rand(100, 10000));
// As of PHP 5.4.0, REQUEST_TIME_FLOAT is available in the $_SERVER superglobal array.
// It contains the timestamp of the start of the request with microsecond precision.
$time = microtime(true) - $_SERVER["REQUEST_TIME_FLOAT"];
echo "Did nothing in $time seconds\n";
?>
我写了一个检查剩余执行时间的函数。
警告:执行时间计数在Windows和Linux平台上是不同的。
/**
* Check if more that `$miliseconds` ms remains
* to error `PHP Fatal error: Maximum execution time exceeded`
*
* @param int $miliseconds
* @return bool
*/
function isRemainingMaxExecutionTimeBiggerThan($miliseconds = 5000) {
$max_execution_time = ini_get('max_execution_time');
if ($max_execution_time === 0) {
// No script time limitation
return true;
}
if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
// On Windows: The real time is measured.
$spendMiliseconds = (microtime(true) - $_SERVER["REQUEST_TIME_FLOAT"]) * 1000;
} else {
// On Linux: Any time spent on activity that happens outside the execution
// of the script such as system calls using system(), stream operations
// database queries, etc. is not included.
// @see http://php.net/manual/en/function.set-time-limit.php
$resourceUsages = getrusage();
$spendMiliseconds = $resourceUsages['ru_utime.tv_sec'] * 1000 + $resourceUsages['ru_utime.tv_usec'] / 1000;
}
$remainingMiliseconds = $max_execution_time * 1000 - $spendMiliseconds;
return ($remainingMiliseconds >= $miliseconds);
}
使用:
while (true) {
// so something
if (!isRemainingMaxExecutionTimeBiggerThan(5000)) {
// Time to die.
// Safely close DB and done the iteration.
}
}
最便宜也是最麻烦的方法是在代码中想要进行基准测试的地方进行microtime()调用。在数据库查询之前和之后执行它,从脚本执行时间的其余部分中删除这些持续时间就很简单了。
提示:PHP执行时间很少会导致脚本超时。如果一个脚本超时,它几乎总是调用外部资源。
PHP微时间文档: http://us.php.net/microtime
您可能只想知道部分脚本的执行时间。为部分或整个脚本计时的最灵活的方法是创建3个简单的函数(这里给出了过程代码,但您可以通过在它周围放置类timer{}并进行一些调整将其转换为类)。这段代码工作,只需复制粘贴并运行:
$tstart = 0;
$tend = 0;
function timer_starts()
{
global $tstart;
$tstart=microtime(true); ;
}
function timer_ends()
{
global $tend;
$tend=microtime(true); ;
}
function timer_calc()
{
global $tstart,$tend;
return (round($tend - $tstart,2));
}
timer_starts();
file_get_contents('http://google.com');
timer_ends();
print('It took '.timer_calc().' seconds to retrieve the google page');
这里列出了几种方法。但每个人都有自己的优点和缺点。而且(在我看来)所有较长的答案的可读性都很糟糕。
所以我决定把这些都放在一个答案中,这是容易使用和阅读的。
使用
$start = get_timers();
for( $i = 0; $i < 100000; $i++ ){
// Code to check
}
$end = get_timers();
display_timer_statistics( $start, $end );
函数定义
function display_timer_statistics( $start_timers, $end_timers ){
// Settings
$key_width = '100px';
$decimals = 4;
$decimals_wallclock = $decimals;
$decimals_request_time_float = $decimals;
// Variables
$start_resource_usage_timer = $start_timers[0];
$start_wallclock = $start_timers[1];
$end_resource_usage_timer = $end_timers[0];
$end_wallclock = $end_timers[1];
// # User time
// Add seconds and microseconds for the start/end, and subtract from another
$end_user_time_seconds = $end_resource_usage_timer["ru_utime.tv_sec"]*1000;
$end_user_time_microseconds = intval($end_resource_usage_timer["ru_utime.tv_usec"]/1000);
$start_user_time_seconds = $start_resource_usage_timer["ru_utime.tv_sec"]*1000;
$start_user_time_microseconds = intval($start_resource_usage_timer["ru_utime.tv_usec"]/1000);
$total_user_time = ($end_user_time_seconds + $end_user_time_microseconds) - ($start_user_time_seconds + $start_user_time_microseconds);
// # System time
// Add seconds and microseconds for the start/end, and subtract from another
$end_system_time_seconds = $end_resource_usage_timer["ru_stime.tv_sec"]*1000;
$end_system_time_microseconds = intval($end_resource_usage_timer["ru_stime.tv_usec"]/1000);
$start_system_time_seconds = $start_resource_usage_timer["ru_stime.tv_sec"]*1000;
$start_system_time_microseconds = intval($start_resource_usage_timer["ru_stime.tv_usec"]/1000);
$total_system_time = ($end_system_time_seconds + $end_system_time_microseconds) - ($start_system_time_seconds + $start_system_time_microseconds);
// Wallclock
$total_wallclock_time = number_format( ( $end_wallclock - $start_wallclock), $decimals_wallclock );
// Server request_time_float
$request_time_float = microtime(true) - $_SERVER["REQUEST_TIME_FLOAT"];
$request_time_float = number_format( $request_time_float, $decimals_request_time_float );
// Print
$span_start = "<span style='width: $key_width; display: inline-block;'>";
$span_end = "</span>";
$output = "# RUNTIME AND TIMERS " . PHP_EOL ;
$output .= PHP_EOL;
$output .= $span_start . $total_user_time . $span_end . " User time (utime)" . PHP_EOL;
$output .= $span_start . $total_system_time . $span_end . " System time (stime)" . PHP_EOL;
$output .= PHP_EOL;
$output .= $span_start . $total_wallclock_time . $span_end . " Wallclock" . PHP_EOL;
$output .= PHP_EOL;
$output .= $span_start . $request_time_float . $span_end . " REQUEST_TIME_FLOAT" . PHP_EOL . PHP_EOL . PHP_EOL;
echo nl2br( $output );
}
function get_timers(){
return [ getrusage(), microtime( true ) ];
}
术语表
这些都是从PHP文档中获取的
挂钟=花了多长时间 ru =资源使用率 utime =用户使用的时间 stime =使用的系统时间 tv_sec =秒。 tv_usec =以微秒计。 电视= ??不知道