/**
* Removes ('pops') all child contexts chained to the given context and itself,
* then makes the parent of the given context the new active context, so this
* comes with an implicit @see SimpleTest::getContext().
*
* @param SimpleTestContext $context The context to pop. It must have been
* produced before by either
* @see SimpleTest::getContext() or
* @see SimpleTest::pushContext().
* @return SimpleTestContext The now activate context.
*/
static function popContext($ctx)
{
// see if $ctx is indeed a parent of ours ...
$child = self::$context;
while ($child && $child !== $ctx) {
$child = $child->getParent();
}
if (!$child) {
return self::getContext();
}
// ... only when it is do we 'pop' the chain of children:
self::$context = $ctx;
// ... and see whether there's a valid parent to be had:
if ($ctx = $ctx->getParent()) {
self::$context = $ctx;
}
/*
The GC should now recognize the child contexts as 'discarded'
as the parent contexts don't reference the children, it's
the other way around, so our 'self::$context' reference should
have been the only thing that kept them alive till now.
*/
return self::$context;
}
