Upgrade XState v6 alpha

[SandroMaglione]

Summary

• upgrade the XState v6 benchmark dependency from 6.0.0-alpha.31 to 6.0.0-alpha.36
• refresh the pnpm lockfile
• add the required patch changeset

Changeset

• Added or updated for a library or package-metadata change
• Not required because this PR does not change src/ or package.json

Validation

• pnpm check
• pnpm perf:types
• pnpm perf:runtime
• Relevant example checks, when examples changed (not applicable)
• Reviewed the automated type-performance report, when the public TypeScript API or inference changed (not applicable)
• Reviewed the automated runtime-performance report

The local runtime benchmark completed successfully with XState 6.0.0-alpha.36.

The automated base-versus-PR runtime workflow was run twice (five independent processes per revision in each run). Type instantiations were exactly unchanged, heap slopes were effectively flat, and the first run's isolated -3.5% / -3.9% throughput readings did not reproduce (-0.1% / -1.3% on confirmation). The remaining differences were within the reported shared-runner variability.

[github-actions]

Type performance

Measured with TypeScript 6.0.3 and skipLibCheck=true.

Scenario	Base	PR	Difference
Effect only	55	55	0 (0.0%)
Import effect-machine	55	55	0 (0.0%)
Machine.defineStates (3 states)	2,965	2,965	0 (0.0%)
Machine.make (3 states, 2 events)	8,715	8,715	0 (0.0%)
machine.handle (3 states, 2 transitions)	23,492	23,492	0 (0.0%)
machine.handle (depth 8)	117,075	117,075	0 (0.0%)
machine.handle (depth 12)	129,713	129,713	0 (0.0%)
machine.handle (depth 16)	145,055	145,055	0 (0.0%)
machine.handle (depth 24)	183,851	183,851	0 (0.0%)
machine.handle (wide depth 16)	214,189	214,189	0 (0.0%)
machine.handle (parallel/history/choice)	132,667	132,667	0 (0.0%)
machine.handle (4 successive calls)	128,674	128,674	0 (0.0%)
machine exact input/output/error/services	110,584	110,584	0 (0.0%)
execution adapter readiness	127,854	127,854	0 (0.0%)

Marginal instantiations are measured against the matching setup without that API call:

Scenario	Base	PR	Difference
Import effect-machine	0	0	0
Machine.defineStates (3 states)	2,910	2,910	0 (0.0%)
Machine.make (3 states, 2 events)	5,742	5,742	0 (0.0%)
machine.handle (3 states, 2 transitions)	14,777	14,777	0 (0.0%)
machine.handle (depth 8)	109,601	109,601	0 (0.0%)
machine.handle (depth 12)	121,039	121,039	0 (0.0%)
machine.handle (depth 16)	135,181	135,181	0 (0.0%)
machine.handle (depth 24)	171,577	171,577	0 (0.0%)
machine.handle (wide depth 16)	202,224	202,224	0 (0.0%)
machine.handle (parallel/history/choice)	114,331	114,331	0 (0.0%)
machine.handle (4 successive calls)	113,703	113,703	0 (0.0%)
machine exact input/output/error/services	100,670	100,670	0 (0.0%)
execution adapter readiness	102,092	102,092	0 (0.0%)

Check times (informational)

Scenario	Base	PR
Effect only	0.03s	0.03s
Import effect-machine	0.03s	0.03s
Machine.defineStates (3 states)	0.09s	0.10s
Machine.make (3 states, 2 events)	0.15s	0.15s
machine.handle (3 states, 2 transitions)	0.23s	0.21s
machine.handle (depth 8)	0.48s	0.48s
machine.handle (depth 12)	0.55s	0.52s
machine.handle (depth 16)	0.56s	0.56s
machine.handle (depth 24)	0.65s	0.66s
machine.handle (wide depth 16)	0.72s	0.72s
machine.handle (parallel/history/choice)	0.57s	0.62s
machine.handle (4 successive calls)	0.58s	0.54s
machine exact input/output/error/services	0.49s	0.49s
execution adapter readiness	0.54s	0.55s

Type instantiations are the comparison metric. Check time varies with runner load and is informational only.

[github-actions]

Runtime performance

Median of 5 independent benchmark processes on AMD EPYC 9V74 80-Core Processor with Node v24.18.0.

Pull request baseline

Scenario	Effect Machine	XState 5	XState 6 alpha
Plan counter transitions	129,345 transitions/s	138,735 transitions/s	266,222 transitions/s
Drain burst with terminal fence	513,072 increments/s	379,850 increments/s	484,661 increments/s
Drain burst with a change observer	476,311 increments/s	376,726 increments/s	479,495 increments/s
Lookup and send to one child	412,545 increments/s	373,459 increments/s	461,444 increments/s
Start and stop a machine	168,379 machines/s	181,554 machines/s	173,340 machines/s
Start and stop a parent with one child	43,020 families/s	72,727 families/s	53,311 families/s
Plan transitions through a compound state	116,846 transitions/s	—	—
Plan transitions through parallel regions	92,922 transitions/s	—	—
Drain burst through a compound state	438,024 events/s	335,466 events/s	458,996 events/s
Drain burst through two parallel regions	451,566 events/s	257,664 events/s	409,531 events/s
Drain a compound-state burst with a change observer	449,096 events/s	—	—

Effect runtime reference points

Scenario	Effect Machine	Effect runtime primitives
Start and stop a raw generic process	24,661 processes/s	—
Start and stop a raw compiled process	71,073 processes/s	—
Start and interrupt a suspended fiber	—	162,101 fibers/s
Start and stop a queue worker	—	118,455 workers/s
Start and stop an actor shell	—	109,733 actors/s
Start and stop two actor shells	—	69,152 families/s
Update an owner-only mutable snapshot	—	312,012,480 updates/s
Update a synchronized snapshot	—	1,676,409 updates/s
Create, resolve, and await a terminal latch	—	1,675,648 latches/s

Memory profile	Effect Machine	XState 5	XState 6 alpha	Effect runtime primitives
Idle machine	1.5 KiB	3.8 KiB	1.5 KiB	—
Raw generic managed process	12.7 KiB	—	—	—
Raw compiled process	2.8 KiB	—	—	—
Two independent idle machines	2.9 KiB	7.3 KiB	2.7 KiB	—
Idle parent with one child	4.8 KiB	5.5 KiB	3.4 KiB	—
Parent with observed child registry	9.0 KiB	—	—	—
Parent with observed invoked child snapshots	5.0 KiB	—	—	—
Suspended Effect fiber	—	—	—	0.6 KiB
Effect queue with waiting fiber	—	—	—	2.8 KiB
Effect mailbox actor shell	—	—	—	3.2 KiB
Two Effect actor shells	—	—	—	6.8 KiB

Effect Machine change from base

Metric	Base	Base variability	PR	PR variability	Difference
Plan counter transitions	129,531 transitions/s	0.6% MAD	129,345 transitions/s	0.9% MAD	-0.1%
Drain burst with terminal fence	519,781 increments/s	0.3% MAD	513,072 increments/s	2.2% MAD	-1.3%
Drain burst with a change observer	476,202 increments/s	0.8% MAD	476,311 increments/s	3.1% MAD	+0.0%
Lookup and send to one child	422,331 increments/s	0.6% MAD	412,545 increments/s	2.4% MAD	-2.3%
Start and stop a machine	169,520 machines/s	1.3% MAD	168,379 machines/s	1.0% MAD	-0.7%
Start and stop a parent with one child	42,946 families/s	0.3% MAD	43,020 families/s	1.8% MAD	+0.2%
Plan transitions through a compound state	117,219 transitions/s	0.7% MAD	116,846 transitions/s	0.9% MAD	-0.3%
Plan transitions through parallel regions	92,262 transitions/s	0.7% MAD	92,922 transitions/s	1.0% MAD	+0.7%
Drain burst through a compound state	455,936 events/s	8.9% MAD	438,024 events/s	8.3% MAD	-3.9%
Drain burst through two parallel regions	450,880 events/s	1.3% MAD	451,566 events/s	3.2% MAD	+0.2%
Drain a compound-state burst with a change observer	455,671 events/s	1.1% MAD	449,096 events/s	4.3% MAD	-1.4%
Idle machine heap per unit	1.5 KiB	0.1% MAD	1.5 KiB	0.1% MAD	-0.1%
Raw generic managed process heap per unit	12.7 KiB	0.0% MAD	12.7 KiB	0.0% MAD	-0.0%
Raw compiled process heap per unit	2.8 KiB	0.3% MAD	2.8 KiB	0.2% MAD	-0.9%
Two independent idle machines heap per unit	2.9 KiB	0.0% MAD	2.9 KiB	0.0% MAD	+0.0%
Idle parent with one child heap per unit	4.8 KiB	0.0% MAD	4.8 KiB	0.0% MAD	-0.0%
Parent with observed child registry heap per unit	9.0 KiB	0.0% MAD	9.0 KiB	0.0% MAD	+0.0%
Parent with observed invoked child snapshots heap per unit	5.0 KiB	0.2% MAD	5.0 KiB	0.1% MAD	-0.2%

Effect runtime reference change from base

Metric	Base	Base variability	PR	PR variability	Difference
Start and stop a raw generic process	25,070 processes/s	1.6% MAD	24,661 processes/s	1.6% MAD	-1.6%
Start and stop a raw compiled process	71,174 processes/s	0.7% MAD	71,073 processes/s	0.5% MAD	-0.1%
Start and interrupt a suspended fiber	160,282 fibers/s	0.2% MAD	162,101 fibers/s	1.4% MAD	+1.1%
Start and stop a queue worker	117,897 workers/s	0.6% MAD	118,455 workers/s	0.4% MAD	+0.5%
Start and stop an actor shell	109,004 actors/s	0.9% MAD	109,733 actors/s	0.9% MAD	+0.7%
Start and stop two actor shells	68,719 families/s	0.3% MAD	69,152 families/s	0.7% MAD	+0.6%
Update an owner-only mutable snapshot	312,012,480 updates/s	0.0% MAD	312,012,480 updates/s	0.0% MAD	0.0%
Update a synchronized snapshot	1,662,870 updates/s	0.4% MAD	1,676,409 updates/s	1.4% MAD	+0.8%
Create, resolve, and await a terminal latch	1,633,277 latches/s	1.0% MAD	1,675,648 latches/s	0.9% MAD	+2.6%

Versions and interpretation

• Effect Machine: 0.5.1
• XState 5: 5.32.5
• XState 6 alpha: 6.0.0-alpha.36
• Effect runtime primitives: 4.0.0-beta.107

Higher throughput is better; lower heap is better. Variability is the median absolute deviation across independent processes, relative to their median. Runtime measurements on shared GitHub-hosted hardware remain informational, so small differences should be confirmed across multiple workflow runs.