Each call of a typed or untyped write, writev, transform, flush, final,
construct or destroy option callback allocated a closure and a box holding
the stream for its `callback` argument. The emitted thunks now take it
from scr_stream_done_closure, which keeps the last one on the stream state and
hands it out again while the stream holds its only reference and it has
no own properties. A callback the user kept (stored, or passed to
setImmediate or a promise) is not reused: the next call gets a new
closure, and the kept one keeps its own stream reference.
The cached closure holds the stream, so the stream drops it when it
emits 'close' and traces it, which lets the cycle collector reclaim a
stream dropped before it closes.
RUNTIME_ABI_VERSION goes from 46 to 47 for scr_stream_done_closure.
A pipeline stage that arrives as an untyped value now follows Node's
stage ladder for more shapes. As the first stage, a function is a source
function: the pipeline calls it with { signal } while it is set up and
pumps its result, which must be iterable (ERR_INVALID_RETURN_VALUE
otherwise), and a { readable, writable } pair pumps its readable side.
After the first stage, the pipeline call is lowered once per combination
of its first three untyped stages being functions or not, and a typeof
test picks the branch at run time. A function stage is called with the
previous stage and { signal }; before the last stage its result must be
async iterable, and as the last stage a promise resolves the pipeline's
value and an async iterable feeds the PassThrough pipeline() returns
(SCR_PIPE_DEST_DYN). Any other value that is not a stream becomes
Duplex.from of it, which the next stage reads from without the previous
stage being piped into it, and Duplex.from's ERR_INVALID_ARG_TYPE for
the values it rejects.
An untyped stage followed by an untyped function stage hands its value to
that stage through a cell created per pipeline call, so the function
receives the previous stage's own iterator, as Node's makeAsyncIterable
answers it, instead of an async generator over it.
Untyped web streams, pairs after the first stage, and function stages
that return a stream throw the not-supported error.
RUNTIME_ABI_VERSION goes from 45 to 46 for the new stream exports.
A TCP socket's write() answered nothing in typed code and true through
untyped values, and a 'drain' listener never fired. Node 24 answers
false when the bytes the write leaves unsent reach the socket's
65536-byte high-water mark (writeOrBuffer computes it after the socket
writes), sets needDrain, and emits 'drain' when the write buffer
empties; writes to an ended or destroyed socket answer false.
The runtime's write entry points now return that answer, record
needDrain, and fire the socket's 'drain' listeners from the flush that
empties the buffer, unless the write half is ending or the socket is
gone. writableLength reads the unsent bytes and writableNeedDrain the
flag. on('drain') and once('drain') register on the typed path and
through untyped values, and socket.write() may be used as a value.
The fallback node:net declarations type write() as boolean, add the
'drain' event and both properties.
RUNTIME_ABI_VERSION goes from 43 to 44: the socket write entry points
return a boolean.
A pipeline whose first stage is a checked-dynamic value now checks it at
run time, as Node's stage ladder does: a stream is piped as before, and a
string or a value with a Symbol.asyncIterator or Symbol.iterator method is
pumped into the next stage through an async generator over its iterator.
A typed Set, Map, generator or async generator object as the first stage
takes the same path. This covers the callback and stream/promises forms,
with or without function stages and pipeline options.
A write whose callback fails synchronously no longer sets needDrain, so no
'drain' follows the error and a pumped source stops at the failed write,
as in Node.
RUNTIME_ABI_VERSION goes from 37 to 42 for scr_stream_dyn_iterable_source.
Object.freeze, Object.seal and Object.preventExtensions of a class
instance held in an untyped value threw SC2020 at run time. Node changes
the instance itself: writes through its typed references then throw the
read-only TypeError in strict mode code, adding properties through any
reference fails, and Object.isFrozen, isSealed and isExtensible report
the state through either reference.
- In a program that freezes, seals or prevents extensions of an untyped
value that is not a fresh literal, every class hierarchy that can be held
there gets the integrity word that static Object.freeze already uses, and
with it the existing write checks.
- The runtime applies the operation to the instance's checked view and
commits the view. The commit of such a hierarchy stores the view's
integrity state in the word (scr_dyn_class_view_integrity) and makes the
instance's property bag not extensible with it. A hierarchy without the
word still throws SC2020.
- These commits replace and remove the bag's field entries whatever their
attributes, so a sealed or frozen view does not leave stale field values
in the bag.
- The analysis behind records and arrays now starts from these calls only,
rather than from every untyped freeze the lowering emits, such as the
frozen strings array of a tagged template.
- Programs without such calls compile as before. The runtime ABI moves to
v38.
Corpus 7407 covers freeze, seal and preventExtensions through unknown of
classes and subclasses, writes through typed and untyped references and
through methods, properties added before and after the operation, and the
integrity queries, and matches Node.
Refs #1374
Co-authored-by: blurname <50226652+blurname@users.noreply.github.com>
A checked-dynamic method call looked its name up in the method table on
every call: a strlen, a hash and a byte comparison of the name.
The compiler now gives each method-name constant an i32 slot that starts
at -1 and passes it with the call (scr_dyn_invoke_prepared_id, and the
Buffer method entries, which forward it). The first call stores the
name's id in the slot, and later calls read it. Ids stay the runtime's
own, so the slot holds whatever this runtime's table says. Names are
still matched by content on the first call, and the slot is written with
a relaxed atomic store, since every thread writes the same id.
The runtime ABI is now 28.
A 'message' listener with a typed parameter received each message as a
checked-dynamic value: the port decoded the message into dyn objects, the
listener's thunk matched the value against each union arm, read every
field again to build the record, and the dyn objects were then released.
For bench/channel-messages that was about a third of the delivery time.
- A closure registered with on, once, addListener, prependListener or
prependOnceListener for 'message' gets a typed message entry when its
parameter is a number, boolean, string, a record of those without union
fields, or a boxed union of those arms with null or undefined. The
entry builds the parameter from the message's nodes and calls the
closure.
- The entry handles a message only when it has the parameter's exact
layout: the union arm the checked conversion picks, and a record's
declared keys in declaration order with no others. Any other message
runs through the thunk on the decoded value, as before, so undeclared
keys, other orders and mismatches behave as they did.
- Ports, workers and parentPort deliver a message through the entries
when no value in it is reached twice and it holds no ports or native
handles. Listeners without an entry share one decoded value, made when
the first of them runs.
- The message readers are runtime entry points, so the runtime ABI is now
27.
Corpus 7130 and 7131 check typed listeners on MessageChannel ports, a
worker and parentPort against Node: exact layouts, extra keys, shared
values, nested records, untyped listeners beside typed ones, once
listeners and a transferred port.
Readable, Writable, Duplex, Transform and PassThrough take the
objectMode option, and a Duplex, Transform or PassThrough the
readableObjectMode and writableObjectMode options, as true or false
literals in an options object literal or in an options value. An
object-mode side holds any value that converts to a checked-dynamic
value: push, unshift, write, end, pipe, pipeline, for await, 'data'
listeners, Readable.from and the transform callback carry values in
TypeScript and JavaScript, and constructor-function streams and options
held in variables do the same. The object-mode high-water mark counts
values and defaults to 16. A readable buffer that mixes strings, Buffers
and other values holds them all, and push(undefined) and other values on
a byte-mode stream report ERR_INVALID_ARG_TYPE through 'error', as in
Node.
In typed code a write or transform callback, or a _write or _transform
method, may declare its chunk with any such type, which converts when
the callback runs. Writes pass the encoding argument to _write and
_transform as Node does: undefined when absent, null when a callback
took its place, otherwise the value unchanged. A parameter declared
string | null | undefined receives that value and one declared string
receives "" for undefined and null. write(chunk, encoding) on a
byte-mode stream encodes a string chunk with any known encoding and
throws ERR_UNKNOWN_ENCODING for an unknown one. Readable.from takes
typed Maps and Sets of any such value, and arrays that mix strings and
Buffers.
for await over a readable-only stream that will emit 'close' now ends
after 'close', as Node's eos does. Buffered writes that complete inside
clearBuffer run their callbacks in order, and 'finish' waits for a
deferred afterWrite that carries a callback, as Node's pendingcb does,
unless a _final callback schedules it.
The 'data' listener adapters take three slots and write and transform
callbacks read their chunk and encoding through runtime accessors, so
RUNTIME_ABI_VERSION is now 26.
Cipheriv and Decipheriv values are Transforms, as in Node: they can be
written and ended, piped into, used as pipeline() and stream/promises
pipeline stages, composed, read, iterated with for await, read by
stream/consumers, passed to finished(), and listened to, and their stream
properties read as in Node. Each chunk goes through the cipher's
update(), and the end pushes final() or reports its error through
'error'; writing after final() throws out of write(). The stream unit
builds a cipher's Transform on its first stream use from operations the
cipher's handle provides (ScrDynHandleOps.transform), so programs that
use ciphers without streams link as before. The cipher is a
collector-headered object behind a traced handle: its Transform's steps
hold it, and the pair is reclaimed as a cycle. Through untyped values, in
a program that uses streams, a cipher's stream properties and its on,
once, off, pipe, unpipe, read, pause, resume, setEncoding, write, end,
destroy, cork and uncork members run on its Transform; other stream
members throw a coded SC2020 error.
A Transform holds a write's callback while its readable side is at the
high-water mark and runs it at the next read, and runs it on a tick once
the readable side has ended, as Transform._write does. write() on a
PassThrough, a Transform, a Hash or a cipher used to return true however
much the readable side buffered. zlib streams applied the rule already
and keep their timing.
pipeline() accepts function stages anywhere among its streams, so runs of
async generator stages can sit on both sides of a stream. A stage can be
named by a function declaration, or a const bound to a function
expression, that nothing reassigns; its body lowers again at the
pipeline with its source typed by the pipeline. The source can also be
an array, a string, a synchronous generator object, or a synchronous
generator function without parameters: an async generator steps the
source's iterator and yields each element, and the next stage receives
each element on the same tick as with Node's for await over the source.
The runtime's function-stage entry points take a bitmask of the function
positions and one (next, read, return) helper triple for each generator
pumped into a stream, so RUNTIME_ABI_VERSION is now 25. In JavaScript,
the chunks a stage receives from the previous stage's generator read as
the strings or Buffers it yields, so their string and Buffer methods
compile.
Corpus 7055-7059 cover cipher streams in TypeScript and JavaScript, their
errors, close order and backpressure, the pipeline stages and sources
with their tick order, and Transform backpressure.
ScrArr stores len and cap as 32-bit fields and no longer stores the
state pointer. The dense states share the values' allocation and run
backward from its end: the state of slot i is at
data + cap * (slot width + 1) - 1 - i. Removing slots from the front
(shift, splice(0, n)) advances data and lowers cap, which leaves every
remaining state at its address; the head room size, needed only to free
or reallocate the block, is kept in the vacated slot before data. On
64-bit targets the header goes from 64 to 48 bytes, and from 36 to 32
bytes on wasm32. Array lengths were already limited to 2^32 - 1.
The emitted code loads len and cap as i32 and zero-extends them, and
computes state addresses from data and cap. Runtime loops compute the
end of the states once per call. Local array reads load data once for
both the state and value paths. A local or strict element read whose
index is a loop's induction variable reads slots above the hole-free
prefix through the runtime: an inline state check there makes LLVM keep
-1 - i as a second induction variable, which costs a register in the
loop.
Bulk operations do not read back states they just wrote: an append to
an array whose hole-free prefix reaches its length moves the prefix bound
to the new length, a copy from below the source's prefix writes value
states without reading the source's, and releasing a string array skips
the state checks below the prefix. Copies of up to eight slots and of
short state runs use overlapping word moves instead of a call. Emitted
element access computes the state address only on the state-checked
path. Without these, programs that build many small arrays with split or
slice ran 2-4% slower than with the separate state pointer.
Integer loops over an array's length compare the counter with the i32
length field in 32 bits; the counter never exceeds 2^32 - 1 there. The
array-length stability proof accepts Map and Set reads (get, has, size)
and checked union extractions (`x!`), which run no user code, so loops
that look up maps keep the dense fast copy, which tests the hole-free
prefix once before the loop.
Small constructions with the small allocator request 6 slots, so their
blocks stay 112 bytes, now with 7 inline slots (6 after a collector
header). With 96-byte blocks of 5 slots, programs that free and reuse
many small arrays ran 15-20% slower.
RUNTIME_ABI_VERSION goes from 22 to 23.
LLVM's WebAssembly pass that gives multiple-entry loops a single entry
first records, for every block, every block it can reach. Its time and
memory grow with the square of a function's block count even when the
function has no such loop. In the three.js nodes fixture a module
initializer of 40,000 blocks spent four minutes and 22 GB in it, which
set the helper's peak and most of its wall time.
The helper now runs the pass only on functions whose control flow graph
is irreducible, and WebAssembly object emission leaves out the module
pass that collects external symbols for assembly declarations, so each
function's machine code is freed once it is printed. Optimized
partitions are compiled through the thin backend's pre-codegen hook to
use the same pipeline. Objects are unchanged.
Release builds now emit the string retain and the dyn retain and release
fast paths inline. The dyn release decides the cases scr_dyn_release
decides by kind and calls scr_dyn_release_survivor for capsules and
handles. String releases and the other families stay runtime calls, as
string-heavy programs have many release sites. The speed posture keeps
every fast path and gains the dyn release. The runtime ABI version moves
to 21 because program objects call the new runtime entry point.
Every SCR_ELEM_REF array stored its element type's retain, release and trace entry points in its own header (24 bytes), so ScrArr was 80 bytes: an 80-byte block for arrays of acyclic elements and a 96-byte block for cycle-capable ones. The three pointers now live in one constant ScrArrOps descriptor per element type, which the compiler emits once per module (@sc_arrops.*) and the runtime keeps static, and the header holds a pointer to it plus a 4-byte `cyc` flag beside `elem` that the inline RC fast paths test. ScrArr is 64 bytes: arrays take 64- and 80-byte blocks.
scr_arr_new_ref(retain, release, trace, cap) becomes scr_arr_new_ops(ops, cap); scr_set_to_arr_ref takes the result's descriptor from its caller instead of building an array from the set's key adapters. The backend names the %ScrArr fields in SCR_ARR_FIELD. The layout change bumps the runtime ABI marker to scr_runtime_abi_v13.
Nearly every long-lived object becomes a cycle candidate once, soon after
it is built: the constructing frame's release leaves it held only by the
structure it was stored into. A nursery pass then walks it (about 75 ns per
object), it survives, and it is re-buffered for the mature level, whose
next pass walks it again. In tsc-ts single-threaded, nursery passes walked
6.0M objects on Excalidraw and 36.5M on Sentry and freed 7%; 99% of what
they walked was promoted. Most of that walking goes to types whose objects
never die in a young cycle: SymbolLinks, NodeLinks and Symbol were 2.0M of
Excalidraw's candidates and the collector freed none of them, while young
garbage comes from a few types (inference contexts and mappers, closures,
some arrays). Types with a collector yield under 0.5% are 42-55% of what
nursery passes walk.
So the collector now keeps per-thread statistics per type and level. Each
ScrCycType gains a `kind` index: emitted descriptors number themselves from
32 (FIRST_EMITTED_CYC_KIND / SCR_CYC_KIND_EMITTED), the runtime's own
families have fixed kinds below that, 0 keeps no statistics. For the
nursery and mature levels, a pass counts the candidates of each kind it
walks and the objects of each kind it frees. After every 8192 walked
candidates a kind bypasses that level for the next window if fewer than 1
in 128 of them were freed. A release that buffers an object at a level its
type bypasses promotes it past the level first, and a nursery pass that
re-buffers a survivor into a bypassed mature level moves it to the old
level. One candidate in 16 stays put, so the yield keeps being measured
and a type whose objects start dying young again is walked again after
one window.
Only the generation an object is judged in changes. Any assignment is
sound (a restricted pass counts edges from older objects as external), a
bypassing candidate stays buffered, and full passes walk everything they
did before, so the old level's bounds hold unchanged. Cyclic garbage made
only of objects of a bypassing type waits for the next pass at an older
level. Programs that never complete a window (8192 walked candidates of one
type) are collected exactly as before.
The descriptor layout is part of the emitted-code/runtime ABI, so the
program-object marker moves to scr_runtime_abi_v12.
Pass log (instrumented build, single-threaded, one run each, with the
preceding null-slot change): all collector passes Excalidraw 606 -> 313 ms
(nursery 435 -> 153), TypeORM 629 -> 383 ms, tsc-ts self-check 377 -> 215
ms, Sentry 7.61 -> 5.75 s (nursery 2.92 -> 1.04 s, mature 1.17 -> 1.02 s;
the full pass is unchanged at 3.6 s).
tsc-ts (Linux sandbox, interleaved, medians; 10 rounds, Sentry 5 rounds
pinned to 8 CPUs; both changes against int/best-v6): single-threaded
Excalidraw -8.0%, TypeORM -4.2%, self-check -4.3%, Sentry -5.3%;
--checkers 8 -12.2%, -0.8%, -2.3%, -1.6%. Peak RSS -0.8% to +0.6%.
Diagnostics identical.
Tests: test_cycle gains check_nursery_bypass, check_mature_bypass and
check_rebuffer_past_mature (a test-only entry point, scr_cyc_pass_at under
SCR_CYC_TESTING, runs passes at exact levels); each fails under the
corresponding mutation (no bypass, a sticky decision, no sampling, no freed
or walked counts, a bypassing candidate left unbuffered, survivors
re-buffered into a bypassed level). Corpus 4690 builds a long-lived
declaration graph large enough for both levels to bypass and lets objects
of the same classes die in cycles; under --sanitize the exit RC audit
proves they are reclaimed.
Every ScrArr carried sixteen words, seven of them (sparse slots, their
length and capacity, noncanonical numeric properties with length and
capacity, and match-result metadata) used only by sparse arrays, arrays
with numeric non-index properties and regex match results. They now live in
a ScrArrExt the array points at, allocated on first use: a dense array
shrinks from 128 to 80 bytes, and a cycle-capable one (with its 16-byte
collector header) from 144 to 96.
Runtime readers go through a shared empty ext; writers allocate it. The
backend mirror loses the seven fields, tagged-template arrays are emitted
with a NULL ext, live stream commits swap the ext pointer (which swapped all
seven fields before), and the cached typed-view refresh swaps sparse slots
and properties through scr_arr_swap_indexed_ext, keeping each array's
metadata as before. The program-object ABI marker moves to
scr_runtime_abi_v11.
A corpus program (4610-array-ext-dyn-refresh.ts, with its order baseline) pins numeric non-index properties of a dynamically typed array through its refreshed typed view, sparse slots written directly and through a live reference, truncation, and regex match metadata read directly, through `any` and after a copy.
Every cycle-capable object carried a 32-byte header: trace and teardown function pointers, a 32-bit color, the buffered flag, the generation and a 64-bit candidate index. The two function pointers are the same for every object of a type, so the header now points at one constant ScrCycType { trace, free_fn } descriptor per type, and the remaining fields pack into the second word: u8 color, u8 gen, u16 buffered, u32 buf_index (candidate buffers stop at 2^31 entries). wasm32 pads before the descriptor, so every object-relative offset is the same on all targets.
Emitted shapes define their descriptor next to the trace and teardown functions; inline allocation stores one header word; the inline release reads buffered at obj-6 and the inline free reads the generation as an i8 at obj-7. Runtime families allocate with static descriptors. The program-object ABI marker moves to scr_runtime_abi_v10.
tsc-ts (interleaved, 5 rounds): peak RSS -8% to -11% on every app and mode; single-threaded wall -0.3% to -5.5% on top of the typed-rest-spread change.
- Synchronize published packages and the compiler surface manifest at v0.2.8, and bump the runtime ABI marker to v9.
- Add release notes for worker graph sharing, catchable deep recursion, parallel code generation, runtime performance, and compatibility fixes.
- Preserve callback identity, receiver binding, and class references across unions and collections.
- Track record field presence independently of undefined values and improve native runtime behavior.
- Expand differential coverage and streamline CI bootstrap and compiler rebuild checks.
- Add native worker execution with isolated module state, structured messages, and lifecycle controls.
- Support shared buffers and integer atomics with coordinated runtime ownership and cancellation.
- Extend compiler, runtime-pack, differential, and compatibility coverage for native concurrency.
- Enforce oxlint and oxfmt for owned JavaScript and TypeScript with independent CI checks.
- Preserve compiler import boundaries and protected fixtures while cleaning up lint findings.
- Standardize source formatting and validate import, fixture, and embedded-source protections.
Chris Tate