licenses.ini was hit on every heartbeat -- 5s x clients x ~8 SetStr per
auth -- with no concurrency protection. Two consequences:
1. 100 concurrent online would saturate the file (~160 writes/sec,
full-file rewrite each via WritePrivateProfileString).
2. Concurrent SetPendingRenewal / DecrementPendingQuota with no lock
occasionally clobbered freshly-set renewal quotas (reported by
user as "preset renewal silently disappears").
Add LicensesIniMutex() (Meyers singleton recursive_mutex, exposed in
CPasswordDlg.h so both CPasswordDlg.cpp and CLicenseDlg.cpp share it)
and wrap all 15 functions that touch licenses.ini.
Rewrite UpdateLicenseActivity around g_activityCache (in-memory state
keyed by "SN|IP|machine"): skip the entire write path when nothing
changed and the 30s LastActiveTime throttle window hasn't expired.
Passcode/HMAC are only flushed on actual change (renewal path); IP
list is only rewritten when the yyMMdd timestamp would roll a day.
Measured impact (local 2-client baseline):
before: 0.60 writes/sec (4 writes per heartbeat cluster)
after: 0.07 writes/sec (one write per client per 30s throttle)
Extrapolated to the 100-online target:
before: ~160 writes/sec (saturation)
after: ~3.3 writes/sec (100 clients / 30s throttle window)
Race elimination is the more important win: PendingQuota's
read-modify-write is now atomic, so the "preset renewal disappears"
race is closed.
Notes from audit (these landed during the same iteration):
- Cache key is (SN, IP, machine), not SN alone. A single SN can be
shared by 100+ end machines in bulk-license deployments, so a
per-SN cache flips on every heartbeat and defeats suppression.
Per-(SN, IP, machine) throttling is what makes the 100/30 model
actually hold; an SN-only key reproduced the original ~0.7 writes/s.
- DeleteLicense invalidates the per-SN activity cache via
InvalidateLicenseActivityCache() (prefix scan since one SN maps to
many cache entries). Without this, cache hits after delete would
skip the auto-recreate path and leave the section permanently
missing.
- OnLicenseViewIPs: m_ListLicense.SetItemText moved outside the lock
so the critical section only covers disk I/O.
740ec8baf3