iOS: bound safe_area()'s boot-path dispatch_sync to avoid a launch deadlock - #74
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iOS: bound safe_area()'s boot-path dispatch_sync to avoid a launch deadlock#74GenericJam wants to merge 1 commit into
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…adlock Mob.Screen.init/1 calls safe_area() synchronously before the first screen mounts. A plain dispatch_sync to the main queue there is a deadlock risk if the main thread hasn't reached an idle run-loop tick yet — observed via a device-family/compatibility-mode boot hang on iPad. Switch to dispatch_async + a bounded semaphore wait, falling back to zero insets on timeout, and mark the NIF dirty (IO-bound) so a slow main thread can no longer stall a regular BEAM scheduler either. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
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Summary
Mob.Screen.init/1callssafe_area()synchronously before the first screen ever mounts. A plaindispatch_syncto the main queue there is a deadlock risk if the main thread hasn't reached an idle run-loop tick yet by that point.sloppy_joe: "the app kept loading indefinitely on launch," reproduced by the reviewer on an iPad Air 11-inch (M3) / iPadOS 26.5.2. The BEAM boot thread was blocking forever inside this NIF call, so the app never finished launching.dispatch_async+ a semaphore bounded to 2s, falling back to zero insets on timeout — a screen with wrong insets once is a far smaller bug than an app that never boots. Also mark the NIF dirty (ERL_NIF_DIRTY_JOB_IO_BOUND) so a slow main thread can no longer stall a regular BEAM scheduler either.Test plan
xcrun clang-format --dry-run -Werror ios/mob_nif.m— cleansloppy_joe(pointedmob_dirat this branch): app boots correctly on both iPhone and iPad simulators, before and after forcingUIDeviceFamily=[1]on the installed bundle (mirroring the App-Store-only device-family patch)UIDeviceFamily=[1]app)🤖 Generated with Claude Code