Fix: Stalker disrupts exclusive access by emitting a block event.

[saicao]

Stalker generates the block event even when those blocks have exclusive access. This may disrupt the exclusive access when a user handles the block event. It seems that the default stalker event sinker uses spinlocks, which can starve the following thread.

check this issue

[oleavr]

Thanks, great catch! 🙌🏻