/**
* wait for ANY of the given promises to resolve
*
* Once the first promise is resolved, this will try to cancel() all
* remaining promises and return whatever the first promise resolves to.
*
* If ALL promises fail to resolve, this will fail and throw an Exception.
*
* @param array $promises
* @param LoopInterface $loop
* @return mixed returns whatever the first promise resolves to
* @throws Exception if ALL promises are rejected
*/
function awaitAny(array $promises, LoopInterface $loop)
{
try {
// Promise\any() does not cope with an empty input array, so reject this here
if (!$promises) {
throw new UnderflowException('Empty input array');
}
$ret = await(Promise\any($promises)->then(null, function () {
// rejects with an array of rejection reasons => reject with Exception instead
throw new Exception('All promises rejected');
}), $loop);
} catch (Exception $e) {
// if the above throws, then ALL promises are already rejected
// (attention: this does not apply once timeout comes into play)
throw new UnderflowException('No promise could resolve', 0, $e);
}
// if we reach this, then ANY of the given promises resolved
// => try to cancel all promises (settled ones will be ignored anyway)
_cancelAllPromises($promises);
return $ret;
}
public function create($host, $port)
{
$all = array();
foreach ($this->managers as $connector) {
/* @var $connection Connector */
$all[] = $connector->create($host, $port);
}
return Promise\any($all)->then(function ($conn) use($all) {
// a connection attempt succeeded
// => cancel all pending connection attempts
foreach ($all as $promise) {
if ($promise instanceof CancellablePromiseInterface) {
$promise->cancel();
}
// if promise resolves despite cancellation, immediately close stream
$promise->then(function ($stream) use($conn) {
if ($stream !== $conn) {
$stream->close();
}
});
}
return $conn;
});
}
