public function testMergeFailDelayed()
{
/*
* Test concurrent merges by forking this process, if:
* - not manually called with --use-bagostuff
* - pcntl_fork is supported by the system
* - cache type will correctly support calls over forks
*/
$fork = (bool) $this->getCliArg('use-bagostuff');
$fork &= function_exists('pcntl_fork');
$fork &= !$this->cache instanceof HashBagOStuff;
$fork &= !$this->cache instanceof EmptyBagOStuff;
$fork &= !$this->cache instanceof MultiWriteBagOStuff;
if (!$fork) {
$this->markTestSkipped("Unable to fork, can't test merge");
}
$this->cache->set('key', 'value');
$callback = function (\BagOStuff $cache, $key, $value) {
// prepend merged to whatever is in cache
return 'merged-' . (string) $value;
};
$this->bufferedCache->merge('key', $callback, 0, 1);
// callback should take awhile now so that we can test concurrent merge attempts
$pid = pcntl_fork();
if ($pid == -1) {
// can't fork, ignore this test...
} elseif ($pid) {
// wait a little, making sure that the child process is calling merge
usleep(3000);
// attempt a merge - this should fail to persist to real cache
$this->bufferedCache->commit();
// make sure the child's merge is completed and verify
usleep(3000);
// check that the values failed to merge
$this->assertEquals(false, $this->bufferedCache->get('key'));
$this->assertEquals(false, $this->cache->get('key'));
} else {
$this->bufferedCache->commit();
// before exiting, tear down - MediaWikiTestCase will check for it
// on destruct & throw an exception if it wasn't called
$this->tearDown();
// Note: I'm not even going to check if the merge worked, I'll
// compare values in the parent process to test if this merge worked.
// I'm just going to exit this child process, since I don't want the
// child to output any test results (would be rather confusing to
// have test output twice)
exit;
}
}
/**
* @param string $key
* @param Closure $callback
* @param int $attempts
* @return bool
*/
public function merge($key, Closure $callback, $attempts = 10)
{
return $this->cache->merge($key, $callback, $this->exptime, $attempts);
}
