Fix macOS threading deadlock in _event_generator (issue #61)#314
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copernicusjones wants to merge 1 commit into
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Fix macOS threading deadlock in _event_generator (issue #61)#314copernicusjones wants to merge 1 commit into
copernicusjones wants to merge 1 commit into
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Replace blocking mpv_wait_event(handle, -1) with a pipe-based wakeup mechanism to prevent deadlocks on macOS where Cocoa requires the main thread for its event loop. - Create a self-pipe for wakeup signaling - Register mpv_set_wakeup_callback to write to the pipe when events arrive - Use select.select() on the pipe fd with 100ms timeout instead of blocking forever on mpv_wait_event - Drain events with mpv_wait_event(handle, 0) (non-blocking) after each wakeup or timeout - Clean up pipe and unregister callback in finally block This resolves the deadlock where wait_for_playback() would hang forever on macOS because: 1. Main thread blocks on result.result() waiting for end_file event 2. Event thread blocks on mpv_wait_event(handle, -1) 3. Cocoa needs the main thread to process events, but it's blocked 4. No events are ever delivered → deadlock Closes jaseg#61
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Summary
Fixes the deadlock described in issue #61 where
wait_for_playback()hangs forever on macOS.Root Cause
On macOS, mpv's Cocoa backend requires the main thread for its event loop. The previous code used
mpv_wait_event(handle, -1)(infinite timeout) in a background Python thread, which caused a deadlock:result.result()waiting for theend_fileeventmpv_wait_event(handle, -1)Fix
Replace the blocking event loop with a pipe-based wakeup mechanism:
mpv_set_wakeup_callbackto write to the pipe when events arriveselect.select()on the pipe fd with 100ms timeout instead of blocking forevermpv_wait_event(handle, 0)(non-blocking) after each wakeupfinallyblockTesting
python3 -m py_compile mpv.pypassesCloses #61