In case anyone is puzzled by the function name, "cas" refers to http://en.wikipedia.org/wiki/Compare-and-swap
(PECL apc >= 3.1.1)
apc_cas — Updates an old value with a new value
$key
, int $old
, int $new
)
apc_cas() updates an already existing integer value if the
old
parameter matches the currently stored value
with the value of the new
parameter.
key
The key of the value being updated.
old
The old value (the value currently stored).
new
The new value to update to.
성공 시 TRUE
를, 실패 시 FALSE
를 반환합니다.
Example #1 apc_cas() example
<?php
apc_store('foobar', 2);
echo '$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
In case anyone is puzzled by the function name, "cas" refers to http://en.wikipedia.org/wiki/Compare-and-swap