使用 2016 年 5 月 9 日发布的 iOS 10 和 Google IMA，我们看到它有时会阻塞主线程，而不是它声称需要的 1-2 秒。
这样做的行是：
adsLoader = IMAAdsLoader(settings: nil)
它锁定了主线程，我们完成了。
这并非一直如此，等等。我们正在研究这个以尝试获取更多信息。
#0 0x000000018770e8e8 in __ulock_wait ()
#1 0x0000000100f27320 in _dispatch_ulock_wait ()
#2 0x0000000100f27448 in _dispatch_thread_event_wait_slow ()
#3 0x0000000100f0e354 in _dispatch_sync_f_slow ()
#4 0x000000018a165a0c in -[_LSQueryCache cachedQueryResultsForQueries:] ()
#5 0x000000018a16207c in -[_LSQueryContext(Internal) _resolveQueries:cachingStrategy:synchronously:XPCConnection:completionHandler:] ()
#6 0x000000018a161e08 in -[_LSQueryContext(SynchronousResolution) resolveQueries:cachingStrategy:error:] ()
#7 0x000000018a1aa758 in -[_UTTypeQuery resolve] ()
#8 0x000000018a1ba7b8 in UTTypeCopyAllTagsWithClass ()
#9 0x000000018a1ba710 in UTTypeCopyPreferredTagWithClass ()
#10 0x000000018d1e46b0 in WebCore::MIMETypeForImageSourceType(WTF::String const&) ()
#11 0x000000018d1e3eec in WebCore::initializeMIMETypeRegistry() ()
#12 0x000000018dc4afbc in WebCore::MIMETypeRegistry::getPDFMIMETypes() ()
#13 0x0000000191c84c2c in -[WKWebViewContentProviderRegistry init] ()
#14 0x0000000191c84230 in -[WKWebViewConfiguration _contentProviderRegistry] ()
#15 0x0000000191c83b58 in -[WKWebViewConfiguration copyWithZone:] ()
#16 0x0000000191c762f0 in -[WKWebView _initializeWithConfiguration:] ()
#17 0x0000000191c777e4 in -[WKWebView initWithFrame:configuration:] ()
#18 0x00000001003e6c4c in -[IMAWKWebView initWithFrame:] at /Users/sanils/Documents/ios2/google3/googlemac/iPhone/interactivemedia/GoogleIMA3/Display/IMAWebView.m:256
#19 0x00000001003e82c8 in +[IMAWebViewFactory webViewWithFrame:backgroundPlaybackEnabled:] at /Users/sanils/Documents/ios2/google3/googlemac/iPhone/interactivemedia/GoogleIMA3/Display/IMAWebView.m:415
#20 0x00000001003b9ca0 in -[IMAJavascriptBridge initWithSettings:] at /Users/sanils/Documents/ios2/google3/googlemac/iPhone/interactivemedia/GoogleIMA3/Bridge/IMAJavascriptBridge.m:59
#21 0x00000001003c0dd0 in -[IMAAdsLoader initWithSettings:] at /Users/sanils/Documents/ios2/google3/googlemac/iPhone/interactivemedia/GoogleIMA3/Common/IMAAdsLoader.m:119