fix: replace Windows input busy-poll with WaitForSingleObject#120
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…dows The Windows streamData implementation uses PeekConsoleInput + time.Sleep(10ms) in a tight loop, polling at 100Hz even when idle. This causes noticeable CPU usage for all TUI applications on Windows. Replace the busy-poll with WaitForSingleObject on the console input handle, which blocks in the kernel until input is available (zero CPU). A 1s timeout ensures cancellation is detected promptly. Also pre-allocate the peek buffer to avoid repeated 80KB allocations per poll.
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Problem
The Windows
streamDataimplementation interminal_reader_windows.gousesPeekConsoleInput+time.Sleep(10ms)in a tight loop. SincePeekConsoleInputis non-blocking and returns immediately when no input is available, this creates a 100Hz polling loop even when the TUI application is completely idle.This causes noticeable CPU usage for all TUI applications on Windows that use ultraviolet for input handling.
Solution
Replace the busy-poll with
WaitForSingleObjecton the console input handle (conin), which blocks in the kernel until input events are available — zero CPU when idle.A 1-second timeout ensures cancellation is detected promptly.
Additionally, pre-allocate the peek buffer (
peekBuf) and reuse it across iterations viapeekNConsoleInputsInto(), eliminating repeated ~80KB allocations per poll cycle.Changes
time.Sleep(10ms)polling withWaitForSingleObject(conin, 1000)peekNConsoleInputsInto()to reuse pre-allocated buffer"time"importImpact
Testing
Built and tested on Windows 11. Idle CPU dropped from noticeable usage to 0%.