APC 函数
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apc_cas

(PECL apc >= 3.1.1)

apc_casUpdates an old value with a new value

说明

bool apc_cas ( string $key , int $old , int $new )

apc_cas() updates an already existing integer value if the old parameter matches the currently stored value with the value of the new parameter.

参数

key

The key of the value being updated.

old

The old value (the value currently stored).

new

The new value to update to.

返回值

成功时返回 TRUE, 或者在失败时返回 FALSE

范例

Example #1 apc_cas() example

<?php
apc_store
('foobar'2);
echo 
'$foobar = 2'PHP_EOL;
echo 
'$foobar == 1 ? 2 : 1 = ', (apc_cas('foobar'12) ? 'ok' 'fail'), PHP_EOL;
echo 
'$foobar == 2 ? 1 : 2 = ', (apc_cas('foobar'21) ? 'ok' 'fail'), PHP_EOL;

echo 
'$foobar = 'apc_fetch('foobar'), PHP_EOL;

echo 
'$f__bar == 1 ? 2 : 1 = ', (apc_cas('f__bar'12) ? 'ok' 'fail'), PHP_EOL;

apc_store('perfection''xyz');
echo 
'$perfection == 2 ? 1 : 2 = ', (apc_cas('perfection'21) ? 'ok' 'epic fail'), PHP_EOL;

echo 
'$foobar = 'apc_fetch('foobar'), PHP_EOL;
?>

以上例程的输出类似于:

$foobar = 2
$foobar == 1 ? 2 : 1 = fail
$foobar == 2 ? 1 : 2 = ok
$foobar = 1
$f__bar == 1 ? 2 : 1 = fail
$perfection == 2 ? 1 : 2 = epic fail
$foobar = 1

参见


APC 函数
在线手册:中文  英文

用户评论:

Piet Delport (2011-03-09 12:25:40)

In case anyone is puzzled by the function name, "cas" refers to http://en.wikipedia.org/wiki/Compare-and-swap

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