Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Make sure to propagate a promise job's snapshot when handling abrupt completions #41

Merged
merged 4 commits into from
Jan 23, 2024
Merged

Make sure to propagate a promise job's snapshot when handling abrupt completions #41

Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
43f5711
Make sure to propagate a promise job's snapshot when handling abrupt …
andreubotella Mar 17, 2023
68bab19
Wrap resolve call in `AsyncContextSwap` as well
andreubotella Mar 20, 2023
17eb330
Update spec.html
jridgewell Jan 20, 2024
b4d5c28
Remove extra AsyncContextSwap
jridgewell Jan 20, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
115 changes: 83 additions & 32 deletions spec.html
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -206,38 +206,7 @@ <h1>
</emu-alg>
<p>ECMAScript hosts that are not web browsers must use the default implementation of HostMakeJobCallback.</p>
<emu-note>
<p>HostMakeJobCallback snapshots the current AsyncContext global state. HostCallJobCallback restores the snapshot.</p>
</emu-note>
</emu-clause>

<emu-clause id="sec-hostcalljobcallback" type="host-defined abstract operation">
<h1>
HostCallJobCallback (
_jobCallback_: a JobCallback Record,
_V_: an ECMAScript language value,
_argumentsList_: a List of ECMAScript language values,
): either a normal completion containing an ECMAScript language value or a throw completion
</h1>
<dl class="header">
</dl>
<p>An implementation of HostCallJobCallback must conform to the following requirements:</p>
<ul>
<li><ins>It must perform AsyncContextSwap(_jobCallback_.[[AsyncContextSnapshot]]) before the call,</ins></li>
<li>It must perform and return the result of Call(_jobCallback_.[[Callback]], _V_, _argumentsList_),</li>
<li><ins>It must perform AsyncContextSwap after the call, with the result of the earlier AsyncContextSwap operation.</ins></li>
</ul>
<p>The default implementation of HostCallJobCallback performs the following steps when called:</p>
<emu-alg>
1. Assert: IsCallable(_jobCallback_.[[Callback]]) is *true*.
1. <del>Return ? Call(_jobCallback_.[[Callback]], _V_, _argumentsList_).</del>
1. <ins>Let _previousContextMapping_ be AsyncContextSwap(_jobCallback_.[[AsyncContextSnapshot]]).</ins>
1. <ins>Let _result_ be Completion(Call(_jobCallback_.[[Callback]], _V_, _argumentsList_)).</ins>
1. <ins>AsyncContextSwap(_previousContextMapping_).</ins>
1. <ins>Return _result_.</ins>
</emu-alg>
<p>ECMAScript hosts that are not web browsers must use the default implementation of HostCallJobCallback.</p>
<emu-note>
<p>HostCallJobCallback restores the snapshot saved in HostMakeJobCallback when calling the _jobCallback_.[[Callback]].</p>
<p>HostMakeJobCallback snapshots the current AsyncContext global state. The snapshot is restored before calling HostCallJobCallback in NewPromiseReactionJob and NewPromiseResolveThenableJob.</p>
</emu-note>
</emu-clause>
</emu-clause>
Expand Down Expand Up @@ -333,6 +302,88 @@ <h1>
</ins>
</emu-clause>
</emu-clause>

<emu-clause id="sec-promise-jobs">
<h1>Promise Jobs</h1>
<emu-clause id="sec-newpromisereactionjob" type="abstract operation" oldids="sec-promisereactionjob">
<h1>
NewPromiseReactionJob (
_reaction_: a PromiseReaction Record,
_argument_: an ECMAScript language value,
): a Record with fields [[Job]] (a Job Abstract Closure) and [[Realm]] (a Realm Record or *null*)
</h1>
<dl class="header">
<dt>description</dt>
<dd>It returns a new Job Abstract Closure that applies the appropriate handler to the incoming value, and uses the handler's return value to resolve or reject the derived promise associated with that handler.</dd>
</dl>
<emu-alg>
1. Let _job_ be a new Job Abstract Closure with no parameters that captures _reaction_ and _argument_ and performs the following steps when called:
1. Let _promiseCapability_ be _reaction_.[[Capability]].
1. Let _type_ be _reaction_.[[Type]].
1. Let _handler_ be _reaction_.[[Handler]].
1. <ins>Let _previousContextMapping_ be AsyncContextSwap(_handler_.[[AsyncContextSnapshot]]).</ins>
1. If _handler_ is ~empty~, then
1. If _type_ is ~Fulfill~, let _handlerResult_ be NormalCompletion(_argument_).
1. Else,
1. Assert: _type_ is ~Reject~.
1. Let _handlerResult_ be ThrowCompletion(_argument_).
1. Else, let _handlerResult_ be Completion(HostCallJobCallback(_handler_, *undefined*, « _argument_ »)).
1. If _promiseCapability_ is *undefined*, then
1. Assert: _handlerResult_ is not an abrupt completion.
1. <ins>AsyncContextSwap(_previousContextMapping_).</ins>
1. Return ~empty~.
1. Assert: _promiseCapability_ is a PromiseCapability Record.
1. If _handlerResult_ is an abrupt completion, then
1. <del>Return ? Call(_promiseCapability_.[[Reject]], *undefined*, « _handlerResult_.[[Value]] »).</del>
1. <ins>Let _resolvingFunctionResult_ be Completion(Call(_promiseCapability_.[[Reject]], *undefined*, « _handlerResult_.[[Value]] »)).</ins>
1. Else,
1. <del>Return ? Call(_promiseCapability_.[[Resolve]], *undefined*, « _handlerResult_.[[Value]] »).</del>
1. <ins>Let _resolvingFunctionResult_ be Completion(Call(_promiseCapability_.[[Resolve]], *undefined*, « _handlerResult_.[[Value]] »)).</ins>
1. <ins>AsyncContextSwap(_previousContextMapping_).</ins>
1. <ins>Return _resolvingFunctionResult_.</ins>
1. Let _handlerRealm_ be *null*.
1. If _reaction_.[[Handler]] is not ~empty~, then
1. Let _getHandlerRealmResult_ be Completion(GetFunctionRealm(_reaction_.[[Handler]].[[Callback]])).
1. If _getHandlerRealmResult_ is a normal completion, set _handlerRealm_ to _getHandlerRealmResult_.[[Value]].
1. Else, set _handlerRealm_ to the current Realm Record.
1. NOTE: _handlerRealm_ is never *null* unless the handler is *undefined*. When the handler is a revoked Proxy and no ECMAScript code runs, _handlerRealm_ is used to create error objects.
1. Return the Record { [[Job]]: _job_, [[Realm]]: _handlerRealm_ }.
</emu-alg>
</emu-clause>

<emu-clause id="sec-newpromiseresolvethenablejob" type="abstract operation" oldids="sec-promiseresolvethenablejob">
<h1>
NewPromiseResolveThenableJob (
_promiseToResolve_: a Promise,
_thenable_: an Object,
_then_: a JobCallback Record,
): a Record with fields [[Job]] (a Job Abstract Closure) and [[Realm]] (a Realm Record)
</h1>
<dl class="header">
</dl>
<emu-alg>
1. Let _job_ be a new Job Abstract Closure with no parameters that captures _promiseToResolve_, _thenable_, and _then_ and performs the following steps when called:
1. Let _resolvingFunctions_ be CreateResolvingFunctions(_promiseToResolve_).
1. <ins>Let _previousContextMapping_ be AsyncContextSwap(_then_.[[AsyncContextSnapshot]]).</ins>
1. Let _thenCallResult_ be Completion(HostCallJobCallback(_then_, _thenable_, « _resolvingFunctions_.[[Resolve]], _resolvingFunctions_.[[Reject]] »)).
1. If _thenCallResult_ is an abrupt completion, then
1. <del>Return ? Call(_resolvingFunctions_.[[Reject]], *undefined*, « _thenCallResult_.[[Value]] »).</del>
1. <ins>Let _rejectResult_ be Completion(Call(_resolvingFunctions_.[[Reject]], *undefined*, « _thenCallResult_.[[Value]] »)).</ins>
1. <ins>AsyncContextSwap(_previousContextMapping_).</ins>
1. <ins>Return _rejectResult_.</ins>
1. <ins>AsyncContextSwap(_previousContextMapping_).</ins>
1. Return ? _thenCallResult_.
1. Let _getThenRealmResult_ be Completion(GetFunctionRealm(_then_.[[Callback]])).
1. If _getThenRealmResult_ is a normal completion, let _thenRealm_ be _getThenRealmResult_.[[Value]].
1. Else, let _thenRealm_ be the current Realm Record.
1. NOTE: _thenRealm_ is never *null*. When _then_.[[Callback]] is a revoked Proxy and no code runs, _thenRealm_ is used to create error objects.
1. Return the Record { [[Job]]: _job_, [[Realm]]: _thenRealm_ }.
</emu-alg>
<emu-note>
<p>This Job uses the supplied thenable and its `then` method to resolve the given promise. This process must take place as a Job to ensure that the evaluation of the `then` method occurs after evaluation of any surrounding code has completed.</p>
</emu-note>
</emu-clause>
</emu-clause>
</emu-clause>

<emu-clause id="sec-generator-objects">
Expand Down