Reference: the CTLV specification language

Complete definition of the YAML inputs consumed by tools/ctlv.

1. Files

Path	Role
`Documentation/ctlv/ctlv-schema.yaml`	JSON Schema (draft 7) for a family specification.
`Documentation/ctlv/ctlv-registry-schema.yaml`	JSON Schema for the family registry.
`Documentation/ctlv/generated-files-schema.yaml`	JSON Schema for the output manifest.
`Documentation/ctlv/specs/<family>.yaml`	Specification of one family. The file stem is the family name.
`Documentation/ctlv/families.yaml`	Family registry.
`Documentation/ctlv/generated-files.yaml`	Output manifest.
`Documentation/ctlv/abi/<family>.yaml`	ABI snapshot of one family.
`Documentation/ctlv/abi/families.registry.yaml`	ABI baseline of the registry.
`tools/ctlv/ctlvgen/cli.py`	Validator, generator and checker entry point.
`tools/ctlv/ctlv-regen.sh`	Regenerates or checks every manifest output.
`tools/ctlv/Makefile`	Make targets.

The specification of the root family ctlv is located relative to the meta-schema (specs/ctlv.yaml beside it). The specification of every other family is located in the directory of the specification being loaded.

Every registry entry has exactly one specification and one ABI snapshot. A specification or snapshot without a registry entry is an error.

2. Document syntax

YAML subset

Each file is a single YAML document whose top level is a mapping. The loader is yaml.SafeLoader with these additional rejections:

aliases,
anchors,
merge keys,
explicit tags,
duplicate mapping keys,
more than one document.

Required first line

The first line of a specification and of a registry is a comment matching #\s*SPDX-License-Identifier:\s*(\S.*?)\s*$. The captured identifier is the license of every generated file derived from the file.

Validation order

YAML subset load.
Meta-schema validation (syntax gate).
Per-declaration normalization (spec.py).
Chain resolution and cross-declaration checks (semantics.py).
Generated-name collision check (cgen.symbols).

Every unknown key is an error at every level (additionalProperties: false).

3. Names and selectors

Kind	Pattern	Additional constraint
name	`^[a-z0-9]+(-[a-z0-9]+)*$`
family name	name	At most 63 characters.
selector	`^[a-z0-9]+(-[a-z0-9]+)(\.[a-z0-9]+(-[a-z0-9]+))?$`	At most one dot.

A dot is reserved for selectors. A name does not contain one.

Selector forms

Form	Selects
`group.attr`	The one attr `attr` of group `group`.
`name` (a group)	Every attr of the group, in declaration order, as required placements unless selected optionally.
`name` (an attr set)	The required and optional members of the set.

A selector without a dot is resolved as a group first and as an attr set second. Group names and attr set names share one namespace and are never equal. There are no tuple selectors and no family-qualified selectors.

A field typed selectors accepts one selector string or a non-empty array of selector strings.

Namespaces

Namespace	Scope	Members
Definitions	Inheritance chain	enum names and flags names, together
Groups and sets	Inheritance chain	attr group names and attr set names, together
Attrs	One group	attr names
Ops	Inheritance chain	op names
Values	One enum or flags definition	value names

Redeclaring a name in the same namespace is an error, except that a descendant declares an inherited stub attr set once to fill it (stubs).

4. family

Required. Mapping with these keys.

Key	Type	Default	Definition
`name`	family name	required	Registered name. Equals the file stem of the specification.
`inherits`	family name	none	The single direct parent.
`pre-init`	boolean	`false`	The family implements the generated pre-init callback, which translates its init information for its parent. Without it, the parent receives `NULL`.
`post-init`	boolean	`false`	The family implements the generated post-init callback, run after every family priv is initialized.
`pre-fini`	boolean	`false`	The family implements the generated pre-fini callback, run before any family priv is finalized.

Rules

The root family is named ctlv, holds family ID 0, and does not declare inherits.
Every other family declares inherits.
A family that inherits P is named P-<suffix> with a non-empty suffix.
A parent is registered at a lower index than every family inheriting it.
An inheritance cycle is an error.
The effective schema of a family is the union of the declarations of its chain, root first. Inherited definitions keep their IDs.
pre-init, post-init and pre-fini are ABI snapshot members.

5. enums and flags

Each of enums and flags is an optional array with at least one element. An element is a mapping:

Key	Type	Definition
`name`	name	Definition name.
`values`	array of name, at least one	Value names in declaration order. Names are unique within the definition.

	enum	flags
Numbering	From 1, in declaration order. 0 is reserved.	Bit 0 upward, in declaration order.
Maximum values	4294967295	64
Payload	Unsigned 64-bit	Unsigned 64-bit mask
Mutation	Append-only.	Append-only.

An attr references a definition by name with enum or flags. The referenced definition is declared in the same family or an ancestor, and has the matching kind.

6. attr-groups

Optional array, 1 to 65535 elements per family. An element is a mapping:

Key	Type	Definition
`name`	name	Group name. Also the generated symbol prefix of its attrs.
`attrs`	array of attr, 1 to 4294967295	Attr declarations in ID order. Attr names are unique within the group.

Attr keys

An attr declares name and exactly one primary form key out of type, enum, flags, attrs, blob. Zero or more than one primary form keys is an error.

Key	Type	Applies to
`name`	name	all
`type`	`uint` \| `sint` \| `bool` \| `string` \| `binary`	primary form
`enum`	name of an enum	primary form
`flags`	name of a flags definition	primary form
`attrs`	selectors	primary form (nest)
`blob`	blob mapping	primary form
`max-occurrences`	integer 1 to 4294967295, or `unlimited`	all
`min`, `max`	integer	`uint`, `sint`
`unit`, `scale`	unit, integer	`uint`, `sint`
`length`	integer 0 to 4294967295	`binary`
`min-length`, `max-length`	integer 0 to 4294967295	`string`, `binary`
`optional-attrs`	selectors	nest
`recursive`	`true`	nest

A key that does not apply to the attr's form is an error. max-occurrences defaults to 1.

Payload forms

Form	Payload	Maximum payload length
`uint`, `sint`, `enum`, `flags`	64-bit integer	8
`bool`	One byte, 0 or 1	1
`string`	Characters and a terminating NUL	`max-length` + 1
`binary`	Bytes	`max-length`
nest	Child attrs	Sum of the children
`blob`	Descriptor nest	3 × 24 for backing `va`

Integer attrs

Key	Default	Definition
`min`	type minimum	Inclusive lower bound.
`max`	type maximum	Inclusive upper bound.
`unit`	none	One of `seconds`, `hertz`, `bytes`, `celsius`.
`scale`	`0` when `unit` is present	Decimal exponent, −128 to 127. Requires `unit`.

Type	Range
`uint`	0 to 18446744073709551615
`sint`	−9223372036854775808 to 9223372036854775807

min and max lie in the type's range, and min ≤ max.

String and binary attrs

Form	Keys
`string`	`max-length` is required. `min-length` defaults to 0. Lengths exclude the terminator. `min-length` ≤ `max-length`.
`binary`	Either `length` alone, which sets minimum and maximum to the same value, or `max-length` with an optional `min-length` (default 0). `length` is not combined with `min-length` or `max-length`. One of `length` and `max-length` is required. `min-length` ≤ `max-length`.

Nest attrs

Key	Definition
`attrs`	Selectors of the required members.
`optional-attrs`	Selectors of the optional members.
`recursive`	The nest may contain its own attr again at any depth.

A nest chain is at most 31 levels deep.
A nesting cycle through non-recursive nests is an error.

Recursive nests

attrs holds exactly one selector.
That selector names an attr set. A group name and a group.attr selector are errors.
optional-attrs is not declared.
The named attr set selects the nest's own attr, directly or through nested attrs.
A re-entry is reported by the node with reenters and no members.
Only a query reply contains a recursive nest.

Blob attrs

Key	Type	Default	Definition
`direction`	`input` \| `output` \| `inout`	required	How the family uses the described memory.
`allowed-backings`	non-empty unique array of `va`	required	Accepted backing types. `va` is the only value.
`max-length`	integer 1 to 18446744073709551615	required	Maximum external payload length. Independent of the inline message limit.
`alignment`	integer 1 to 4294967295	`1`	Required alignment of the described address or offset.

alignment is a power of two.
max-length is a multiple of alignment.
Only a request contains a blob attr.

7. attr-sets

Optional array. An element is a mapping:

Key	Type	Definition
`name`	name	Set name.
`stub`	`true`	Declares an extension point.
`attrs`	selectors	Required members.
`optional-attrs`	selectors	Optional members.

A set is either a stub with no members, or has at least one member in attrs or optional-attrs.
A set selecting itself, directly or through other sets, is an error.
Every set is expanded and checked whether or not an op selects it.
Set IDs are assigned from 1 per family, in declaration order, counting only sets not filling an inherited stub.

Stubs

A stub has no members and expands to nothing until filled.
A descendant fills an inherited stub by declaring an attr set with the same name and at least one member.
A fill is made at most once in an inheritance chain.
A fill is not itself a stub.
Only a stub is filled. A name already declared as a non-stub set by an ancestor is an error.
The filled set keeps the ID given by the family that declared the stub.
A fill contains no recursive attr.
An attr set that a message root built by the core uses does not select a stub.
A query reply that selects a stub does not also contain a re-entry.

8. ops

Optional array, at most 4294967295 elements per family. An element is a mapping:

Key	Type	Default	Applies to	Definition
`name`	name	required	all	Op name.
`type`	`action` \| `query` \| `event`	required	all	An action is invoked once and does not fragment. A query may fragment its reply. An event is an unsolicited reply-only message.
`fd-access`	`read` \| `read-write`	`read-write`	action, query	`read` is executable through an observation fd. `read-write` requires a full-control fd. Events are always readable.
`availability`	`fixed` \| `dynamic`	`fixed`	action, query	`dynamic` permits the family to enable and disable the op per device. Every device starts with a dynamic op enabled. A disabled op remains in introspection and returns `-EOPNOTSUPP`.
`optional`	boolean	`false`	action, query	When true, the op exists on a device only if family initialization opts in before publication. An op not opted in is absent from introspection.
`pre-post`	boolean	`false`	action, query	The op has a generated pre/post hook pair implemented by its declaring family. Kernel implementation metadata, absent from UAPI and introspection.
`request`	placements	root with no children	action, query	Request root.
`reply`	placements	see below	all	Reply root.
`suggested-reply-length`	integer 1 to 1048576	see lengths	query	Initial reply buffer length.

Placements

A mapping with at least one of the keys attrs and optional-attrs, each holding selectors. An empty mapping is an error.

Per-type rules

	action	query	event
`request`	allowed	allowed	not allowed
`reply` omitted	acknowledgement only	not allowed	root with no children
`fd-access`	allowed	allowed	not allowed
`availability`	allowed	allowed	not allowed
`optional`	allowed	allowed	not allowed
`pre-post`	allowed	allowed	not allowed
`suggested-reply-length`	not allowed	allowed	not allowed

Message contexts

Construct	request	action reply	query reply	event
`max-occurrences: unlimited`	no	no	yes	no
re-entry of a recursive nest	no	no	yes	no
blob attr	yes	no	no	no

9. Composition rules

Expansion of a selection

A selection in attrs yields required placements. A selection in optional-attrs yields optional placements.
When an attr set or group is selected optionally, every member becomes optional.
When one attr is selected more than once at one level, the selections merge into one placement. A required selection takes precedence over an optional one.
Selecting one attr both through a filled stub set and outside it at one level is an error.
After fills are composed, every attr ID at one nesting level has exactly one placement. A second placement is an error.

Stub selection

A stub selected optionally makes every member of its fill optional.
One reference is kept per stub selected at a level. A required reference takes precedence over an optional one.

Structural checks

A selector that matches no attr, group or set is an error.
The per-op request tree and reply tree are checked individually.
The composed tree of each op (fills spliced in) is checked against the limits of section 12.

10. Identifiers

Identifier	Value
Family ID	Zero-based index of the family name in `families.yaml`.
Group ID	1-based position of the group in the family's `attr-groups`.
Local attr ID	1-based position of the attr in its group.
Attr ID	(family ID << 48) \| (group ID << 32) \| local attr ID
Local op ID	1-based position of the op in the family's `ops`.
Op ID	(family ID << 48) \| local op ID
Set ID	1-based counter per family; see attr-sets.
Enum value	1-based position in `values`.
Flag bit	0-based position in `values`.

An ID is part of the ABI for the life of the family.

11. Lengths

Constants

Name	Value
Alignment (`CTLV_ALIGNTO`)	8
Attr header length	16
Event record header length	24
`CTLV_MAX_INLINE_MESSAGE_LEN`	0x100000
`CTLV_MAX_ERROR_LEN`	0x4000
`CTLV_MAX_NEST_DEPTH`	32
`CTLV_DEFAULT_QUERY_REPLY_LEN`	0x10000
`CTLV_MAX_EVENT_QUEUE_LEN`	0x1000000

The declared nest depth limit is CTLV_MAX_NEST_DEPTH − 1 = 31.

Formulas

align(n) rounds n up to a multiple of 8.

Quantity	Definition
Attr maximum length	16 + payload maximum length
Root maximum length	16 + sum of children
Children sum	Σ `max-occurrences` × `align`(attr maximum length) over members
Blob payload maximum length	(largest descriptor attr count over `allowed-backings`) × `align`(24); `va` counts 3
`request-max-len`	Root maximum length of the request.
`action-reply-max-len`	Root maximum length of the reply of an action with a reply.
`event-record-max-len`	24 + `align`(root maximum length of the event reply)
`query-reply-min-len`	Maximum over the leaves of the reply tree of 16 × (number of ancestors including the root) + `align`(leaf attr maximum length). A tree that contains a re-entry uses 33 × 16 + `align`(attr maximum length) of the largest non-nest placement.
`query-reply-suggested-len`	With `suggested-reply-length` declared: that value. Otherwise the larger of `CTLV_DEFAULT_QUERY_REPLY_LEN` and `query-reply-min-len`. For a composed family, the larger of the declared value and the composed minimum.

Checks

Each of request-max-len, action-reply-max-len, the event payload maximum length and query-reply-min-len is at most CTLV_MAX_INLINE_MESSAGE_LEN.
A declared suggested-reply-length is at least query-reply-min-len and at most CTLV_MAX_INLINE_MESSAGE_LEN.
event-record-max-len is at most CTLV_MAX_EVENT_QUEUE_LEN.
A core-built message root has a maximum length of at most its limit (error-info: CTLV_MAX_ERROR_LEN).

12. Limits

Item	Limit
Family name length	63 characters
Registry entries	65536 (family IDs 0 to 65535)
Attr groups per family	65535
Attrs per group	4294967295
Attr sets per family	4294967295 new sets
Ops per family	4294967295
Effective ops of a chain	4294967295
Enum values	4294967295
Flag bits	64
`max-occurrences`	4294967295
Declared nest depth	31
Composed required attrs per level	4294967295
Composed optional attrs per level	4294967295
Schema nodes per tree	4294967295
Stub references per tree	4294967295
Composed schema nodes per op (request plus reply)	4294967295
Stub fills per family	4294967295
`suggested-reply-length`	1 to 1048576

13. Family registry

Documentation/ctlv/families.yaml. Top-level key families: an array of 1 to 65536 elements.

Element form	Meaning
name string (at most 63 characters, name pattern)	A registered family.
mapping with `name` and `deprecated: true`	A deprecated family. Its ID stays reserved.

The array index is the family ID.
The first entry is ctlv and is not deprecated.
Each family appears after the family it inherits.
Names are unique.
Entries are never reordered, removed, renamed or reused.
Every entry has a specification and a snapshot.

14. Output manifest

Documentation/ctlv/generated-files.yaml. Root keys, all required:

Key	Type	Definition
`version`	`1`	Manifest version.
`registry`	mapping	`source` (path of the registry) and `outputs.uapi-header` (path, required).
`families`	array, at least one	One mapping per generated family.

A families element:

Key	Required	Definition
`name`	yes	Family name.
`source`	yes	Path of the specification.
`outputs`	yes	Mapping with at least one of `uapi-header`, `kernel-header`, `kernel-source`.

Paths are non-empty, relative to the kernel tree root, and do not begin with /.

15. ABI snapshots

A snapshot records one family's own declarations: family flags, ID and parent; definitions with value numbers; groups with attr IDs and constraints; sets; stub fills; and ops with their request and reply trees. It is written by --abi-update and compared by --abi-check.

Compared members

Declaration	Rule
Family	Name, ID, parent, `pre-init`, `post-init`, `pre-fini` are unchanged.
Enum, flags	Not removed. Kind unchanged. Each existing value remains present with the same number.
Attr group	Not removed. Group ID unchanged.
Attr	Not removed. Local ID, kind, referenced definition, `unit` and `scale` unchanged.
Attr bounds	`min` and `min-length` do not increase. `max` and `max-length` do not decrease.
`max-occurrences`	Does not decrease, and does not change from `unlimited` to a finite value.
Blob	`direction` and `alignment` unchanged. No `allowed-backings` removed. `max-length` does not decrease.
Attr set	Not removed. Set ID and `stub` unchanged.
Stub fill	Not removed. Compared as a node list.
Op	Not removed. `op-id`, `type`, `fd-access`, `availability`, `optional` and `pre-post` unchanged.
Op request, reply	Present schema not removed. An action without a reply does not gain one. Compared as a node list.
Node list	No node removed. No node changes from optional to required. `reenters` unchanged. A node added since the snapshot is optional.

Adding an attr, group, set, op, enum value or flag bit, or making a required placement optional, is compatible.

Registry baseline

abi/families.registry.yaml records the ordered registry. The check fails when:

an entry of the baseline is missing from the registry,
the name at an index differs,
a deprecated entry is no longer deprecated,
the registry differs from the baseline in any other way (--abi-check and --outputs-check), which requires updating the baseline.

16. Generated names

Let F be the family name with dashes replaced by underscores (upper case in macros), and X-Y a YAML name rendered as X_Y.

Declaration	Name
Family number	`CTLV_FAMILY_<S>`, where `S` is the family name without a leading `ctlv-`; `CTLV_FAMILY_ROOT` for `ctlv`
Group	`<F>_GROUP_<GROUP>`
Attr	`<F>_ATTR_<GROUP>_<ATTR>` (complete ID)
Set	`<F>_SET_<SET>`
Op	`<F>_OP_<OP>` (complete ID)
Enum value	`<F>_<ENUM>_<VALUE>`
Flag bit	`<F>_<FLAGS>_<VALUE>_BIT`
Flag mask	`<F>_<FLAGS>_<VALUE>` and `<F>_<FLAGS>_MASK`

In the root family, F is CTLV.

Two declarations that generate the same C name are an error, as is a collision with a lifecycle API symbol or a symbol of an ancestor family.
A generated UAPI header includes the UAPI header of its parent.
Each generated file begins with the license of its specification and a marker naming the specification it is generated from.

17. Tooling

Dependencies: pyyaml 6.*, jsonschema 4.*.

Make targets

Run as make -C tools/ctlv <target>.

Target	Action
`all`	`validate` and `abi-check`.
`validate`	Validates every specification in `specs/`.
`abi-check`	Checks every specification against its snapshot.
`abi-update`	Rewrites every snapshot.
`regen`	Runs `ctlv-regen.sh`, which writes every manifest output.
`check-regen`	Fails when a checked-in output differs from generator output. Writes nothing.
`lint`	Runs yamllint, pycodestyle and pyflakes.
`clean`	Removes Python caches and build directories.

`cli.py` options

--spec PATH is required. Exactly one action is required.

Option	Definition
`--spec PATH`	Specification to load.
`--schema PATH`	Meta-schema. Default: `ctlv-schema.yaml` beside `specs/`.
`--registry PATH`	Registry. Default: `families.yaml` beside `specs/`.
`--abi DIR`	Snapshot directory. Default: `abi/` beside `specs/`.
`--validate`	Validates the specification and its chain, and the generated-name check.
`--abi-check`	Checks the registry baseline and the family snapshot.
`--abi-update`	Rewrites the family snapshot.
`--tree-check`	Checks registry, specifications, snapshots and manifest coverage.
`--tree-check-update`	Checks whole-tree inputs before an ABI update. Snapshots for appended registry entries may be missing.
`--registry-abi-update`	Rewrites the registry baseline. Requires complete snapshots.
`--outputs-check`	Checks every manifest output.
`--outputs-update`	Regenerates every manifest output.
`--mode uapi\|kernel`	Generates one file. Requires `--header` or `--source`.
`--header`, `--source`	Selects the file kind of `--mode`. Mutually exclusive.
`--schema-only`	With `--mode kernel`, omits the family API.
`-o, --output PATH`	Writes to a file instead of standard output. Requires `--mode`.
`--cmp-out`	Leaves an unchanged output file untouched. Requires `--mode` and `--output`.
`--output-root DIR`	Alternate destination root. Requires `--outputs-check` or `--outputs-update`. Not empty.

Exit status is 0 on success and 1 on a reported error. Each error is printed as ctlvgen: <location>: <message>.

`ctlv-regen.sh`

Option	Definition
`-f`	Accepted and ignored.
`-c`	Writes nothing and fails on any difference.
`-p DIR`	Uses DIR as the output root. Not empty.

Whole-tree coverage

Every registry entry has specs/<name>.yaml. A file without an entry is an error.
Every registry entry has abi/<name>.yaml. A file without an entry is an error.
The registry satisfies its baseline.
The output manifest loads and satisfies its schema.

18. Root family

Family ctlv, family ID 0, specified in specs/ctlv.yaml. Its operations are inherited by every family. Its attr groups are placed inside the messages of other families.

Requirements on the root specification

It declares the attr set error-info.
Entry counts of these root enums are bounded: op-type, op-availability, op-fd-access, blob-direction at most 255; blob-type at most 15.

Enums

Enum	Values (1, 2, …)
`op-type`	`action`, `query`, `event`
`op-availability`	`fixed`, `dynamic`
`blob-type`	`va`
`blob-direction`	`input`, `output`, `inout`
`validation-reason`	`malformed-message`, `unknown-attr`, `unknown-flag`, `nesting-too-deep`, `missing-attr`, `too-many-occurrences`, `value-out-of-range`, `bad-length`, `bad-string`, `bad-blob-descriptor`, `stale-generation`, `noncontiguous-attr`
`op-fd-access`	`read`, `read-write`

Attr groups

Group	Attrs
`family` (1)	`id`, `name` (string, max-length 63), `entry` (nest of set `family-entry`, unlimited)
`blob` (2)	`type` (enum `blob-type`), `address`, `fd` (max 2147483647), `offset`, `length` (min 1)
`error` (3)	`reason` (enum `validation-reason`), `message` (string, max-length 255), `bad-attr-offset`, `nest-offset`, `missing-attr-id`, `expected-generation`, `current-generation`
`op` (4)	`id` (min 1), `type`, `availability`, `disabled` (bool), `request-max-len`, `action-reply-max-len`, `query-reply-min-len`, `query-reply-suggested-len`, `event-record-max-len`, `state-generation`, `entry` (nest of `op-entry`, unlimited), `fd-access`
`schema` (5)	`attr-id`, `kind`, `max-occurrences`, `min`, `max`, `min-length`, `max-length`, `flags-mask`, `unit`, `scale` (sint), `blob-direction`, `blob-backings`, `blob-max-length`, `blob-alignment`, `reenters` (min 1), `attrs` and `optional-attrs` (recursive nests of `schema-node`, unlimited), `request`, `reply` (nests of `schema-node`)
`event` (6)	`op-id` (min 1, max-occurrences 256), `queue-len` (unit bytes, 1 to 16777216), `queue-used` (unit bytes), `first-sequence`, `last-sequence`, `dropped-count`

Unless noted, an attr is an unsigned integer (uint) with no bounds.

Attr sets

Set	Required	Optional
`family-entry`	`family.id`, `family.name`
`op-entry`	`op.id`, `op.type`	`op.availability`, `op.disabled`, `op.request-max-len`, `op.action-reply-max-len`, `op.query-reply-min-len`, `op.query-reply-suggested-len`, `op.event-record-max-len`, `op.fd-access`
`op-schema-request`	`op.id`
`schema-node`	`schema.attr-id`, `schema.kind`, `schema.max-occurrences`	`schema.min`, `schema.max`, `schema.min-length`, `schema.max-length`, `schema.flags-mask`, `schema.unit`, `schema.scale`, `schema.blob-direction`, `schema.blob-backings`, `schema.blob-max-length`, `schema.blob-alignment`, `schema.reenters`, `schema.attrs`, `schema.optional-attrs`
`op-schema-info`		`schema.request`, `schema.reply`
`op-change-info`	`op.id`, `op.disabled`, `op.state-generation`
`error-info`		every `error.*` attr
`event-subscription`	`event.op-id`
`event-queue-limit`	`event.queue-len`
`event-queue-state`	`event.queue-len`, `event.queue-used`
`event-overflow-info`	`event.first-sequence`, `event.last-sequence`, `event.dropped-count`

Ops

ID	Op	Type	fd-access	Request	Reply
1	`families-dump`	query	read		`family.entry`
2	`ops-dump`	query	read		`op.entry`
3	`op-schema-get`	query	read	`op-schema-request`	`op-schema-info`
4	`subscriptions-add`	action	read	`event-subscription`	acknowledgement
5	`subscriptions-remove`	action	read	`event-subscription`	acknowledgement
6	`event-queue-get`	query	read		`event-queue-state`
7	`event-queue-set`	action	read	`event-queue-limit`	acknowledgement
8	`op-changed`	event			`op-change-info`
9	`event-overflow`	event			`event-overflow-info`
10	`device-removed`	event			no children