LL perf (Core): Queued threads get a lambda per frame; pause/unpause is dead #375

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opened 2026-10-04 14:09:32 +00:00 by sky_line · 0 comments

sky_line commented

2026-10-04 14:09:32 +00:00

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From the LL-origin inefficiency audit (finding C7). File/line references are from commit 0229f8872c; re-locate them before working.

Queued threads get a lambda per frame; pause/unpause is dead

Per-frame lambda: LLQueuedThread::updateQueue() posts a std::function per thread per frame to call an (usually empty) threadedUpdate() (llqueuedthread.cpp:144-162). That is a heap allocation, a mutex and a CV notify, waking idle workers.
Dead pause: checkPause() is effectively never reached under runUntilClose() (:500-527), so the background pause (llappviewer.cpp:1898-1902, 2034-2044) does nothing.
Fix: post only for overriding subclasses; delete the pause calls.
Confirmed. S.

Verify the cost (profile or timer) before and after changing it.

From the LL-origin inefficiency audit (finding C7). File/line references are from commit 0229f8872c; re-locate them before working. **Queued threads get a lambda per frame; pause/unpause is dead** - **Per-frame lambda:** `LLQueuedThread::updateQueue()` posts a `std::function` per thread per frame to call an (usually empty) `threadedUpdate()` (`llqueuedthread.cpp:144-162`). That is a heap allocation, a mutex and a CV notify, waking idle workers. - **Dead pause:** `checkPause()` is effectively never reached under `runUntilClose()` (`:500-527`), so the background pause (`llappviewer.cpp:1898-1902, 2034-2044`) does nothing. - **Fix:** post only for overriding subclasses; delete the pause calls. - Confirmed. S. Verify the cost (profile or timer) before and after changing it.

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