PSR cache interfaces have the same problem: they don't consider race condition when a cache is stale and a process starts updating cache when another process is already doing it. This proposal make this problem solving be incapsulated into a cache object while keeping it simple.

PHP cache proposal.php

<?php

$cache = new Cache(); // A cache implementation

/* Basic usage */

/*
    This method returns a cached value.
    If the value needs to be recalculated, the function from the second argument is called.
    The $cache object makes this function not to be called too often in any race conditions by setting locks, updating before expiration or any other method. 
    
    Arguments:
     - cache key;
     - value calculating function (returns the value to cache);
     - cache life time (seconds or a DateTimeInterface object).
*/
$value = $cache->get('keyName', function() {
    // Do some long calculations that should be cached
    $stuff = calculateSomethingForLongTime();
    return $stuff;
}, 3600);

echo "Cached value: $value.";

/* "Advanced" usage */
$cache->delete('keyName');
$cache->clean();