Performance Audit Writer Function Reference

Performance Audit Writer Function Reference (Common_PerformanceAudit)

Source-verified 2026-06-21 against master 0139a346. Paths relative to Missions/[55-2hc]warfarev2_073v48co.chernarus/ unless noted. Arma 2 OA 1.64.

Common\Functions\Common_PerformanceAudit.sqf is a self-contained 241-line local instrumentation framework (author tag "Marty") that produces the [Performance Audit] rows in each machine's RPT. It is the writer half of the perf-telemetry pipeline; the offline RPT parser that consumes these rows lives in a separate PowerShell tool documented on PerformanceAuditAnalyzer. There is no network synchronization — each client and the server writes only its own RPT (Common/Functions/Common_PerformanceAudit.sqf:5).

The file defines eight global code blocks plus a small set of module-state globals. It is loaded once via Call Compile preprocessFileLineNumbers at Common/Init/Init_Common.sqf:47, so every machine (server, clients, headless client) holds the API. The per-call accumulator (PerformanceAudit_Record) is invoked from 44 call sites across client FSMs, marker loops, cleaners, restorers, and server FSMs.

Module state and the enable gate

Everything is no-op unless PerformanceAuditEnabled is truthy. On load the file derives it from the mission parameter WFBE_C_PERFORMANCE_AUDIT_ENABLED (default 0 → disabled), but only if not already set (Common/Functions/Common_PerformanceAudit.sqf:9). The server then force-overrides the gate ON for itself only — the global param is deliberately left at 0 so clients never run the client audit (Server/Init/Init_Server.sqf:803-804, with the rationale comment at Server/Init/Init_Server.sqf:800-802).

Global	Init value	Set at	Meaning
PerformanceAuditEnabled	(WFBE_C_PERFORMANCE_AUDIT_ENABLED > 0)	Common_PerformanceAudit.sqf:9	Master no-op gate for _Record/_Flush/_Run
PerformanceAuditFlushInterval	60 (seconds)	Common_PerformanceAudit.sqf:10	_Run loop sleep between flushes
PerformanceAuditData_CLIENT	[]	Common_PerformanceAudit.sqf:11	Per-call accumulator buffer (CLIENT scope)
PerformanceAuditData_SERVER	[]	Common_PerformanceAudit.sqf:12	Per-call accumulator buffer (SERVER scope)
PerformanceAuditMarkerScripts	0	Common_PerformanceAudit.sqf:13	Active marker-script counter (snapshot field)
PerformanceAuditAARMarkerScripts	0	Common_PerformanceAudit.sqf:14	AAR marker-script counter
PerformanceAuditSessionId	Format ["%1_%2_%3", worldName, round diag_tickTime, round (random 1000000)]	Common_PerformanceAudit.sqf:16-18	Per-mission session id so appended RPT files split by game
PerformanceAuditAnchorVersion	"20260524"	Common_PerformanceAudit.sqf:19	Schema/anchor version stamped on the session anchor row

WFBE_C_PERFORMANCE_AUDIT_ENABLED is not defined in Init_CommonConstants.sqf; it is set server-local at Server/Init/Init_Server.sqf:803 and read defaulted-to-0 everywhere else. PerformanceAuditMarkerScripts is mutated externally by the marker loop (decremented on marker teardown at Common/Common_MarkerLoop.sqf:152,188) so the snapshot reflects live marker-script load.

Function family overview

Function	Lines	Role
PerformanceAudit_Round2	21-23	Helper: round a number to 2 decimals
PerformanceAudit_DataName	25-27	Helper: scope string → PerformanceAuditData_<scope> global name
PerformanceAudit_Snapshot	29-107	Build the 22-field environment record for one scope
PerformanceAudit_Log	109-149	Emit one [Performance Audit] RPT line from a snapshot + metric tuple
PerformanceAudit_SessionAnchorExtra	151-158	Build the session-anchor EXTRA string (anchor version, diag tick, frame)
PerformanceAudit_Record	160-194	Per-call stopwatch accumulator keyed by metric name
PerformanceAudit_Flush	196-220	Snapshot + emit avg/max-ms rows for the buffer, then clear it
PerformanceAudit_Run	222-241	Per-scope writer loop: session rows, then flush every interval until gameOver

PerformanceAudit_Round2 / PerformanceAudit_DataName

Function	Signature	Returns	Behavior
PerformanceAudit_Round2	_number call PerformanceAudit_Round2	Number rounded to 2 decimals	round ((_this) * 100) / 100 (Common_PerformanceAudit.sqf:21-23). Used for daytime/fog/overcast/rain in the snapshot and for ms conversions in the flush.
PerformanceAudit_DataName	_scope call PerformanceAudit_DataName	String	Format ["PerformanceAuditData_%1", _this] (Common_PerformanceAudit.sqf:25-27). Maps a scope ("SERVER"/"CLIENT") to its accumulator-buffer global variable name.

PerformanceAudit_Snapshot — the 22-field environment record

Signature: [_scope] call PerformanceAudit_Snapshot → returns a 22-element array (Common_PerformanceAudit.sqf:29-107). _scope is _this select 0 (Common_PerformanceAudit.sqf:32). The snapshot captures lightweight engine/world state so FPS can later be correlated with population, day/night, and weather.

It defaults _playerName="SERVER" / _uid="0" and overrides them with name player / getPlayerUID player only when player is non-null (Common_PerformanceAudit.sqf:50-51,57-60), so client snapshots carry the local player identity while the server snapshot stays anonymous. AI vs player population is split in one forEach allUnits pass: isPlayer units bump _players, otherwise live units bump _activeAI (Common_PerformanceAudit.sqf:67-73). Active towns are counted only if the towns global exists, summing those with wfbe_active or wfbe_active_air set (Common_PerformanceAudit.sqf:75-81).

The returned array, by index (Common_PerformanceAudit.sqf:83-106):

Idx	Field	Source
0	scope	_scope (param)
1	fps	round diag_fps
2	players	_players (isPlayer count)
3	activeAI	_activeAI (alive non-player count)
4	units	count allUnits
5	vehicles	count vehicles
6	teams	count clientTeams or -1 if nil (Common_PerformanceAudit.sqf:47)
7	townsActive	_townsActive
8	markerScripts	PerformanceAuditMarkerScripts (Common_PerformanceAudit.sqf:49)
9	playerName	name player or "SERVER"
10	uid	getPlayerUID player or "0"
11	viewDistance	viewDistance (engine)
12	profileVD	profile WFBE_PERSISTENT_CONST_VIEW_DISTANCE def -1 (Common_PerformanceAudit.sqf:63)
13	targetFPS	profile WFBE_TARGET_FPS def -1 (Common_PerformanceAudit.sqf:64)
14	terrainGrid	profile WFBE_PERSISTENT_CONST_TERRAIN_GRID def -1 (Common_PerformanceAudit.sqf:65)
15	map	worldName (Common_PerformanceAudit.sqf:36)
16	dayNightEnabled	WFBE_DAYNIGHT_ENABLED def -1 (Common_PerformanceAudit.sqf:38)
17	daytime	daytime call PerformanceAudit_Round2
18	fog	fog call PerformanceAudit_Round2
19	overcast	overcast call PerformanceAudit_Round2
20	rain	rain call PerformanceAudit_Round2
21	sessionId	PerformanceAuditSessionId def "unknown" (Common_PerformanceAudit.sqf:34)

PerformanceAudit_Log — the [Performance Audit] RPT line

Signature: [_snap, _name, _calls, _avgMs, _maxMs, _extra] call PerformanceAudit_Log (Common_PerformanceAudit.sqf:109-149). Takes a snapshot array plus a metric tuple and emits exactly one diag_log line. The format string interleaves the 22 snapshot fields with the four metric fields, and the explicit %N positional indices in the format pull the snapshot columns out of order so the human-readable line groups session/environment fields first (Common_PerformanceAudit.sqf:119-148).

Emitted line shape (Common_PerformanceAudit.sqf:120):

[Performance Audit] SID=.. MAP=.. DNC=.. DAYTIME=.. FOG=.. OVERCAST=.. RAIN=.. SCOPE=.. PLAYER=".." UID=.. VD=.. PVD=.. TFPS=.. PTG=.. NAME=.. FPS=.. PLAYERS=.. AI=.. UNITS=.. VEHICLES=.. TEAMS=.. TOWNS_ACTIVE=.. MARKERS=.. CALLS=.. AVG_MS=.. MAX_MS=.. EXTRA=..

NAME is the metric name (e.g. snapshot, session, town_activation_scan); CALLS/AVG_MS/MAX_MS/EXTRA are the per-metric stats. This is the line the offline analyzer parses (see PerformanceAuditAnalyzer).

PerformanceAudit_SessionAnchorExtra

Signature: call PerformanceAudit_SessionAnchorExtra → returns a string (Common_PerformanceAudit.sqf:151-158). Builds the EXTRA payload for the once-per-run session anchor row:

state:anchor;anchorVersion:<PerformanceAuditAnchorVersion>;realTime:unavailable_a2oa;diagTick:<diag_tickTime>;frame:<diag_frameno>

realTime is hard-coded unavailable_a2oa because Arma 2 OA exposes no wall-clock; diagTick is rounded via PerformanceAudit_Round2 and frame is diag_frameno (Common_PerformanceAudit.sqf:153-156). Consumed only by PerformanceAudit_Run (Common_PerformanceAudit.sqf:228-229).

PerformanceAudit_Record — per-call stopwatch accumulator

Signature: [_name, _elapsed, _extra, _scope] call PerformanceAudit_Record (Common_PerformanceAudit.sqf:160-194). Exits immediately if the audit is disabled (Common_PerformanceAudit.sqf:163). Parameters:

Param	Idx	Default	Meaning
_name	0	(required)	Metric key (one buffer row per distinct name)
_elapsed	1	(required)	Seconds for this call (typically diag_tickTime - _start)
_extra	2	""	Free-form key:val;… annotation string (Common_PerformanceAudit.sqf:167)
_scope	3	if (isServer && !hasInterface) then {"SERVER"} else {"CLIENT"}	Buffer selector; the default auto-detects a dedicated server / headless client (Common_PerformanceAudit.sqf:168)

It resolves the buffer via PerformanceAudit_DataName (Common_PerformanceAudit.sqf:169-170), then scans for an existing row with the same _name. On a hit it increments calls, adds to total, raises max if this call was slower, and overwrites extra only when a non-empty _extra is supplied (Common_PerformanceAudit.sqf:173-187). On a miss it appends [_name, 1, _elapsed, _elapsed, _extra] (Common_PerformanceAudit.sqf:189-191). The buffer is written back with setVariable (Common_PerformanceAudit.sqf:193).

Buffer row shape: [name, calls, total_seconds, max_seconds, extra].

Canonical call pattern at sites: capture _start = diag_tickTime before the measured work, then ["metric_name", diag_tickTime - _start, "<extra>", "<SCOPE>"] Call PerformanceAudit_Record. Call sites guard on !(isNil "PerformanceAudit_Record") and the enable flag before calling, e.g. Client/FSM/updateclient.sqf:198-200 (updateclient_afk), Client/FSM/updateclient.sqf:267-269 (updateclient_total, timed from _perfLoopStart at Client/FSM/updateclient.sqf:46), and Server/FSM/server_town_ai.sqf:124 (town_activation_scan). The marker loop records markerupdate_hq / markerupdate_unit / markerloop_tick (Common/Common_MarkerLoop.sqf:245,350,529). The server also records an antistack_state config row at startup with _elapsed=0 (Server/Init/Init_Server.sqf:824).

PerformanceAudit_Flush — emit accumulated rows and reset

Signature: [_scope] call PerformanceAudit_Flush (Common_PerformanceAudit.sqf:196-220). Exits if disabled (Common_PerformanceAudit.sqf:199). Steps:

1. Build a fresh snapshot for _scope (Common_PerformanceAudit.sqf:202) and resolve the buffer (Common_PerformanceAudit.sqf:203-204).
2. Emit one snapshot row with the EXTRA "periodic", calls=1, and zeroed ms metrics (avgMs=0, maxMs=0) (Common_PerformanceAudit.sqf:206: [_snap, "snapshot", 1, 0, 0, "periodic"] call PerformanceAudit_Log) — this is the per-flush environment heartbeat.
3. For each buffered metric with calls > 0, compute avgMs = (total/calls)*1000 and maxMs = max*1000, both rounded via PerformanceAudit_Round2, and emit a row (Common_PerformanceAudit.sqf:208-217).
4. Clear the buffer back to [] (Common_PerformanceAudit.sqf:219) so each flush window reports only its own activity.

PerformanceAudit_Run — the per-scope writer loop

Signature: [_scope] Spawn PerformanceAudit_Run (Common_PerformanceAudit.sqf:222-241). Exits if disabled (Common_PerformanceAudit.sqf:225). On entry it emits two session rows: one with the session-anchor EXTRA (Common_PerformanceAudit.sqf:228-229) and one with EXTRA "state:start" (Common_PerformanceAudit.sqf:230). It then loops: sleep PerformanceAuditFlushInterval (default 60 s), flush the scope, and break if the gameOver global exists and is true (Common_PerformanceAudit.sqf:232-238). After the loop it does one final flush so end-of-mission counters are not lost (Common_PerformanceAudit.sqf:240).

It is started once per machine inside a waitUntil {!isNil "PerformanceAudit_Run"} guard wrapper:

Scope	Start site
SERVER	Server/Init/Init_Server.sqf:807-810 (["SERVER"] Spawn PerformanceAudit_Run)
CLIENT	Client/Init/Init_Client.sqf:383-386 (["CLIENT"] Spawn PerformanceAudit_Run)

Because the server force-enables only its own gate (Server/Init/Init_Server.sqf:803) while clients keep the param default 0, in the live configuration only the server's _Run loop actually writes — the client wrapper spawns but _Run exits at its disable check (Common_PerformanceAudit.sqf:225). Re-enabling the global param would activate the client writer too.

Notes and hazards

• The disable-check default in _Record/_Flush/_Run is getVariable ["PerformanceAuditEnabled", true] (Common_PerformanceAudit.sqf:163,199,225) — i.e. if the global were somehow deleted, these would default to enabled. In practice the file always sets it on load (Common_PerformanceAudit.sqf:9).
• _scope auto-detection in _Record keys on isServer && !hasInterface, so a hosted (listen-server) host counts as CLIENT, and a dedicated server or headless client counts as SERVER (Common_PerformanceAudit.sqf:168).
• This writer is purely RPT-side and never touches publicVariable/network — it is safe to leave running and cannot create JIP or sync load.

Continue Reading

• PerformanceAuditAnalyzer — the offline PowerShell RPT parser that consumes these [Performance Audit] rows.
• AI-Headless-And-Performance — headless-client topology and where the SERVER-scope writer runs.
• Hosted-Server-FPS-Loop-Sleep — server-frame budgeting that this audit was built to measure.
• Function-And-Module-Index — index entry for the PerformanceAudit_* writer helpers.
• Bottleneck-Removal-Queue — perf findings that drive what gets instrumented with _Record.