perf(process_manager): batch process enumeration, cache SID lookup#198
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HetCreep wants to merge 1 commit into
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perf(process_manager): batch process enumeration, cache SID lookup#198HetCreep wants to merge 1 commit into
HetCreep wants to merge 1 commit into
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ProcessIdManager built its snapshot by calling x.exe() on every process returned by process_iter() — one syscall per process, on a list rebuilt each time new_process() diffs before/after a launch. Switch to process_iter(attrs=["pid", "exe"]), which fetches both fields in one pass and yields None for exe on AccessDenied (same result as the old try/except wrapper), markedly faster on machines with many processes. Also cache get_sid() with lru_cache(maxsize=1): the current user's SID is constant for the process lifetime, so the win32 lookup need not repeat on every scheduled-task operation. No behavioural change.
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Summary
Two small, behaviour-preserving performance tweaks in
lib/process_manager.py.1. Batch process enumeration
ProcessIdManager.__init__calledx.exe()for every process fromprocess_iter()- one syscall per process. Sincenew_process()builds a fresh snapshot before and after each launch to diff them, this runs on the full process table repeatedly.process_iter(attrs=["pid", "exe"])fetches both fields in a single pass and storesNoneforexewhen access is denied - the same result the oldtry/exceptwrapper produced - without the per-process call. This is the pattern the psutil docs recommend.2. Cache the SID lookup
get_sid()performs a win32LookupAccountName+ConvertSidToStringSidon every call, but the current user's SID is constant for the process lifetime.functools.lru_cache(maxsize=1)makes repeatedSchtasksoperations reuse the first result.Notes
No behavioural change; output is identical. Net
+8 / -7.