getrusage

(PHP 4, PHP 5)

getrusage — Gets the current resource usages

说明

array getrusage ([ int $who = 0 ] )

This is an interface to getrusage(2). It gets data returned from the system call.

参数

who: If who is 1, getrusage will be called with RUSAGE_CHILDREN.

返回值

Returns an associative array containing the data returned from the system call. All entries are accessible by using their documented field names.

范例

Example #1 getrusage() example


<?php
$dat = getrusage();
echo $dat["ru_nswap"];         // number of swaps
echo $dat["ru_majflt"];        // number of page faults
echo $dat["ru_utime.tv_sec"];  // user time used (seconds)
echo $dat["ru_utime.tv_usec"]; // user time used (microseconds)
?>

注释

Note: 此函数未在 Windows 平台下实现。

参见

Your system's man page on getrusage(2)

PHP手册 - N: Gets the current resource usages

用户评论:

Domas Mituzas (14-Jan-2008 09:22)

getrusage() reports kernel counters that are updated only once application loses context and a switch to kernel space happens. For example on modern Linux server kernels that would mean that getrusage() calls would return information rounded at 10ms, desktop kernels - at 1ms. getrusage() isn't usable for micro-measurements at all - and getmicrotime(true) might be much more valuable resource.

php at lavrenko dot pp dot ru (20-Oct-2005 12:21)

The author of the article mentioned in the previous post says "Once I got a negative value for both times - I have absolutely no clue how that can happen.". This is because time in microseconds is not padded with zeros from the left, therefore, you cannot concatenate the two numbers. Instead, you should normalize the values and then add them up: $dat["ru_utime.tv_sec"]*1e6+$dat["ru_utime.tv_usec"];