apc_cas

(PECL apc >= 3.1.1)

apc_cas — Updates an old value with a new value

설명

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.

인수

key: The key of the value being updated.
old: The old value (the value currently stored).
new: The new value to update to.

반환값

성공할 경우 TRUE를, 실패할 경우 FALSE를 반환합니다.

예제

Example #1 apc_cas() example


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

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

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

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

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

위 예제의 출력 예시:

$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

참고

apc_dec() - Decrease a stored number
apc_store() - Cache a variable in the data store

add a note User Contributed Notes apc_cas

Piet Delport 09-Mar-2011 12:25


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

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