delta/node-new.git/src/node_messaging.h, branch sam-github-tsc

worker: allow passing JS wrapper objects via postMessage

2020-06-14T12:53:39+00:00

Enable JS wrapper objects to be used as transferable or cloneable
objects in `postMessage()` calls, by having them extend a C++-backed
class.

This requires a few internal changes:
- This commit adds the possibility for transferred objects to
  read/write JS values at the end of the serialization/deserialization
  phases.
- This commit adds the possibility for transferred objects to list
  sub-transferables, e.g. typically the public JS wrapper class
  would list its C++ handle in there.
- This commit adds usage of `BaseObject` in a few more places, because
  now during deserialization weakly held objects can also be involved,
  in addition to `MessagePort`s.

PR-URL: https://github.com/nodejs/node/pull/33772
Reviewed-By: Benjamin Gruenbaum

worker: allow transferring/cloning generic BaseObjects

2020-06-14T12:53:38+00:00

Extend support for transferring objects à la `MessagePort` to other
types of `BaseObject` subclasses, as well as implement cloning
support for cases in which destructive transferring is not needed
or optional.

PR-URL: https://github.com/nodejs/node/pull/33772
Reviewed-By: Benjamin Gruenbaum

worker: improve MessagePort performance

2020-02-07T21:01:59+00:00

Use a JS function as the single entry point for emitting `.onmessage()`
calls, avoiding the overhead of manually constructing each message
event object in C++.

                                                                             confidence improvement accuracy (*)   (**)  (***)
    worker/echo.js n=100000 sendsPerBroadcast=1 payload='object' workers=1         ***     16.34 %       ±1.16% ±1.54% ±1.99%
    worker/echo.js n=100000 sendsPerBroadcast=1 payload='string' workers=1         ***     24.41 %       ±1.50% ±1.99% ±2.58%
    worker/echo.js n=100000 sendsPerBroadcast=10 payload='object' workers=1        ***     26.66 %       ±1.54% ±2.05% ±2.65%
    worker/echo.js n=100000 sendsPerBroadcast=10 payload='string' workers=1        ***     32.72 %       ±1.60% ±2.11% ±2.73%
    worker/messageport.js n=1000000 payload='object'                               ***     40.28 %       ±1.48% ±1.95% ±2.52%
    worker/messageport.js n=1000000 payload='string'                               ***     76.95 %       ±2.19% ±2.90% ±3.75%

Also fix handling exceptions returned from `MessagePort::New`.

PR-URL: https://github.com/nodejs/node/pull/31605
Reviewed-By: James M Snell 
Reviewed-By: Denys Otrishko 
Reviewed-By: Rich Trott

src: move MemoryInfo() for worker code to .cc files

2020-01-21T22:51:37+00:00

This is a) the right thing to do anyway because these functions
can not be inlined by the compiler and b) avoids compilation warnings
in the following commit.

PR-URL: https://github.com/nodejs/node/pull/31386
Refs: https://github.com/openjs-foundation/summit/pull/240
Reviewed-By: Gireesh Punathil 
Reviewed-By: James M Snell 
Reviewed-By: Colin Ihrig 
Reviewed-By: Rich Trott

src: remove uses of deprecated wasm TransferrableModule

2019-11-08T22:25:01+00:00

WasmModuleObject::TransferrableModule is deprecated and will be removed
in V8 v8.0. Replace all uses by CompiledWasmModule.

Refs: https://github.com/v8/node/pull/101

PR-URL: https://github.com/nodejs/node/pull/30026
Reviewed-By: Gus Caplan 
Reviewed-By: Michaël Zasso 
Reviewed-By: James M Snell 
Reviewed-By: Gireesh Punathil 
Reviewed-By: Colin Ihrig 
Reviewed-By: David Carlier

src: remove custom tracking for SharedArrayBuffers

2019-11-08T14:53:36+00:00

Remove custom tracking for `SharedArrayBuffer`s and their allocators
and instead let V8 do the tracking of both. This is required starting
in V8 7.9, because lifetime management for `ArrayBuffer::Allocator`s
differs from what was performed previously (i.e. it is no longer
easily possible for one Isolate to release an `ArrayBuffer` and another
to accept it into its own allocator), and the alternative would
have been adapting the `SharedArrayBuffer` tracking logic to also
apply to regular `ArrayBuffer` instances.

Refs: https://github.com/nodejs/node/pull/30044

PR-URL: https://github.com/nodejs/node/pull/30020
Reviewed-By: Colin Ihrig 
Reviewed-By: Jiawen Geng 
Reviewed-By: Anna Henningsen 
Reviewed-By: Matteo Collina

worker: make transfer list behave like web MessagePort

2019-09-06T04:12:47+00:00

Allow generic iterables as transfer list arguments, as well
as an options object with a `transfer` option, for web compatibility.

PR-URL: https://github.com/nodejs/node/pull/29319
Refs: https://github.com/nodejs/node/pull/28033#discussion_r289964991
Reviewed-By: James M Snell

worker: make MessagePort constructor non-callable

2019-06-13T03:56:44+00:00

Refactor the C++ code for creating `MessagePort`s to skip calling the
constructor and instead directly instantiating the `InstanceTemplate`,
and always throw an error from the `MessagePort` constructor.

This aligns behaviour with the web, and creating single `MessagePort`s
does not make sense anyway.

PR-URL: https://github.com/nodejs/node/pull/28032
Reviewed-By: Rich Trott 
Reviewed-By: Tiancheng "Timothy" Gu 
Reviewed-By: James M Snell

worker: add ability to unshift message from MessagePort

2019-05-19T20:01:34+00:00

In combination with Atomics, this makes it possible to implement
generic synchronous functionality, e.g. `importScript()`, in Workers
purely by communicating with other threads.

This is a continuation of https://github.com/nodejs/node/pull/26686,
where a preference for a solution was voiced that allowed reading
individual messages, rather than emitting all messages through events.

PR-URL: https://github.com/nodejs/node/pull/27294
Reviewed-By: Benjamin Gruenbaum 
Reviewed-By: James M Snell 
Reviewed-By: Gus Caplan 
Reviewed-By: Ruben Bridgewater

worker: use special message as MessagePort close command

2019-05-17T12:01:27+00:00

When a `MessagePort` connected to another `MessagePort` closes, the
latter `MessagePort` will be closed as well. Until now, this is done
by testing whether the ports are still entangled after processing
messages. This leaves open a race condition window in which messages
sent just before the closure can be lost when timing is unfortunate.
(A description of the timing is in the test file.)

This can be addressed by using a special message instead, which is
the last message received by a `MessagePort`. This way, all previously
sent messages are processed first.

Fixes: https://github.com/nodejs/node/issues/22762
PR-URL: https://github.com/nodejs/node/pull/27705
Reviewed-By: Rich Trott 
Reviewed-By: Colin Ihrig