Missing engine startup synchronization causing 'blocker not available' message

[rjeschke]

The content blocker's underlying engine is initialized asynchronously. Now, when the content blocker needs to be restarted, because SBrowser is asking for filters, then it is possibly that engine initialization isn't finished when SBrowser asks for the filters. This results in an error message thrown by us.

Currently the engine-initialized callback is executed on the UI thread, so it is not possible to wait for initialization in the content provider callback.

We need to implement two changes to fix this issue:

1. allow the engine-initialized callback to be executed on the UI thread and a general purpose looper (possibly just a boolean for selecting which one to use)
2. wait for engine initialization in the content provider callback

[abpbot]

A commit referencing this issue has landed:
​https://hg.adblockplus.org/adblockplussbrowser/rev/7f85855c3d8f

[scheer]

• The error message below no longer occurs:

ContentBlockerContentProvider: Engine not initialized
SBrowserProxyHandler: getMDMProxy() : MDM proxy[]
System.err: java.io.FileNotFoundException: Engine not yet initialized

• The error message in Sbrowser also no longer occurs 'blocker of unwanted content not available. Please contact the developer for details.'

Adblockplussbrowser-1.0.3-20160513123700-signed
Samsung Galaxy S5, S6
Android 5.0.1
Android 6.0

[rhana@getadblock.com]

Hi @rjeschke! We have a user who is still receiving this error with ABP for Samsung Browser v1.0.3. She initially reported this to us because she was receiving the error with AdBlock for Samsung Internet (both the original version and our last update, 1.2). Yesterday we had her install ABP 1.0.3 from Google Play. The error is still occurring. Is there something more she needs to do?