promises: refactor rejection handling - #18207

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promises: refactor rejection handling#18207
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apapirovski:patch-promise-reject-refactor

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@apapirovskiapapirovski commented Jan 17, 2018

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Remove the unnecessary microTasksTickObject for scheduling microtasks and instead use TickInfo to keep track of whether promise rejections exist that need to be emitted. Consequently allow the microtasks to execute on average fewer times, in more predictable manner than previously.

Simplify unhandled & handled rejection tracking to do more in C++ to avoid needing to expose additional info in JS. Unite emitting unhandledRejection and rejectionHandled into a single function: emitPromiseRejectionWarnings, which runs after all nextTicks have executed.

When new unhandledRejections are emitted within an unhandledRejection handler, allow the event loop to proceed first instead. This means that if the end-user code handles all promise rejections on nextTick, rejections within unhandledRejection now won't spiral into an infinite loop.

On the whole, this should hopefully make reasoning about nextTick, promises and promise rejections a whole lot simpler.

Fixes: #17913

Checklist
  • make -j4 test (UNIX), or vcbuild test (Windows) passes
  • tests and/or benchmarks are included
  • commit message follows commit guidelines
Affected core subsystem(s)

process, promises, src

@apapirovskiapapirovski added c++ Issues and PRs that require attention from people who are familiar with C++. process Issues and PRs related to the process subsystem. lib / src Issues and PRs involving general changes in the lib/ or src/ directories. promises Issues and PRs related to ECMAScript promises. labels Jan 17, 2018
@nodejs-github-botnodejs-github-bot added c++ Issues and PRs that require attention from people who are familiar with C++. lib / src Issues and PRs involving general changes in the lib/ or src/ directories. labels Jan 17, 2018
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CI: https://ci.nodejs.org/job/node-test-pull-request/12580/
CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1204/

Edit: weird failures in CitGM. Investigating...

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CitGM failures unrelated to this PR but clearly something landed in the last 24 hours that completely destroyed CitGM.

@benjamingrbenjamingr self-assigned this Jan 17, 2018
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benjamingr commented Jan 17, 2018•
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I'll need a few days to digest this and run through the edge cases we had when we specified the hooks.

Pinging (no pressure to participate!) relevant parties @petkaantonov@addaleax@domenic

@joyeecheungjoyeecheung mentioned this pull request Jan 17, 2018
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Just to distill what's going on in the current loop, here's an outline:

  1. Check if any next ticks exist (C++)
    a. If none exist, run Microtasks
    b. If any ticks exist or unhandled/handled promise rejections were added, go to 2; otherwise exit
  2. Execute all currently scheduled next ticks (if any)
  3. Execute microtasks
  4. Check if any next ticks exist, if they do go to 2.
  5. Emit async handled rejections
  6. Emit all currently existing unhandled promise rejections
    a. if any unhandledRejection listeners exist or there are newly added unhandled promise rejections then go to 2
  7. Next tick loop is done (back we go to C++)

addaleax
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Comment threadtest/parallel/test-promises-unhandled-rejections.js Outdated

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I’m not sure, but, common.mustCall()? ;)

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Since it checks at exit, this would just keep looping forever until timeout is hit.

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After reading the code and testing it - I like the behavior and changes. LGTM.

@benjamingrbenjamingr removed their assignment Jan 18, 2018
@apapirovskiapapirovski added the author ready PRs with CI started, the required approvals, and no outstanding review comments. label Jan 18, 2018
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CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1213/

@apapirovski
promises: refactor rejection handling
21a2220
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
@apapirovski
apapirovskiforce-pushed the patch-promise-reject-refactor branch from 0413ebb to 21a2220CompareJanuary 19, 2018 03:55
@BridgeAR

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New CI due to some changed code (If I am not mistaken) https://ci.nodejs.org/job/node-test-pull-request/12619/

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@BridgeAR It was just rebased to make it possible to run the CitGM. But no harm in extra CI :)

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Landed in d62566e

@apapirovski
apapirovski deleted the patch-promise-reject-refactor branch January 21, 2018 17:38
apapirovski added a commit that referenced this pull request Jan 21, 2018
@apapirovski
promises: refactor rejection handling
d62566e
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: #18207Fixes: #17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@MylesBorins

MylesBorins commented Feb 20, 2018

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This does not land cleanly on v9.x, should we backport?

@apapirovski

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@MylesBorins v9.x might be missing some preceding commits, I think. I'll have time to look into it at the end of the week or the weekend, swamped with a move right now. Sorry.

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This seem to apply cleanly on v9.x now, I’m removing the label.

@addaleaxaddaleax removed backport-requested-v9.x author ready PRs with CI started, the required approvals, and no outstanding review comments. labels Feb 27, 2018
addaleax pushed a commit to addaleax/node that referenced this pull request Feb 27, 2018
@apapirovski@addaleax
promises: refactor rejection handling
b4c933d
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@addaleaxaddaleax mentioned this pull request Feb 27, 2018
Closed
MayaLekova pushed a commit to MayaLekova/node that referenced this pull request May 8, 2018
@apapirovski@MayaLekova
promises: refactor rejection handling
a84ec52
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@codebytere

codebytere commented Aug 2, 2018

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@apapirovski this doesn't land cleanly on v8.x, do you think this makes sense to backport to v8.x?

@apapirovski

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@codebytere Yeah, probably wouldn't hurt. I have a backlog of things I'm supposed to backport anyway. I'll do them all this weekend.

@alexkozyalexkozy mentioned this pull request Nov 6, 2018
Closed
@hexpunkhexpunk mentioned this pull request Dec 12, 2018
Closed
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c++Issues and PRs that require attention from people who are familiar with C++.lib / srcIssues and PRs involving general changes in the lib/ or src/ directories.processIssues and PRs related to the process subsystem.promisesIssues and PRs related to ECMAScript promises.

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Successfully merging this pull request may close these issues.

unhandledRejection falls into infinite recursion

7 participants

@apapirovski@benjamingr@BridgeAR@MylesBorins@addaleax@codebytere@nodejs-github-bot
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

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promises: refactor rejection handling - #18207
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apapirovski:patch-promise-reject-refactor
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promises: refactor rejection handling#18207
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apapirovski:patch-promise-reject-refactor
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Remove the unnecessary microTasksTickObject for scheduling microtasks and instead use TickInfo to keep track of whether promise rejections exist that need to be emitted. Consequently allow the microtasks to execute on average fewer times, in more predictable manner than previously.
Simplify unhandled & handled rejection tracking to do more in C++ to avoid needing to expose additional info in JS. Unite emitting unhandledRejection and rejectionHandled into a single function: emitPromiseRejectionWarnings, which runs after all nextTicks have executed.
When new unhandledRejections are emitted within an unhandledRejection handler, allow the event loop to proceed first instead. This means that if the end-user code handles all promise rejections on nextTick, rejections within unhandledRejection now won't spiral into an infinite loop.
On the whole, this should hopefully make reasoning about nextTick, promises and promise rejections a whole lot simpler.
Fixes: #17913
Checklist
  • make -j4 test (UNIX), or vcbuild test (Windows) passes
  •  tests and/or benchmarks are included
  •  commit message follows commit guidelines
Affected core subsystem(s)
process, promises, src
@apapirovskiapapirovski
added

c++
Issues and PRs that require attention from people who are familiar with C++.
process
Issues and PRs related to the process subsystem.
lib / src
Issues and PRs involving general changes in the lib/ or src/ directories.
promises
Issues and PRs related to ECMAScript promises.
labels
Jan 17, 2018
@nodejs-github-botnodejs-github-bot
added

c++
Issues and PRs that require attention from people who are familiar with C++.
lib / src
Issues and PRs involving general changes in the lib/ or src/ directories.
labels
Jan 17, 2018
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CI: https://ci.nodejs.org/job/node-test-pull-request/12580/
CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1204/
Edit: weird failures in CitGM. Investigating...
@apapirovski
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CitGM failures unrelated to this PR but clearly something landed in the last 24 hours that completely destroyed CitGM.
@benjamingrbenjamingr
self-assigned this
Jan 17, 2018
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I'll need a few days to digest this and run through the edge cases we had when we specified the hooks.
Pinging (no pressure to participate!) relevant parties @petkaantonov@addaleax@domenic
@joyeecheungjoyeecheung
mentioned this pull request
Jan 17, 2018

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@apapirovski
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Just to distill what's going on in the current loop, here's an outline:
  1. Check if any next ticks exist (C++)
    
a. If none exist, run Microtasks
    
b. If any ticks exist or unhandled/handled promise rejections were added, go to 2; otherwise exit
  2. Execute all currently scheduled next ticks (if any)
  3. Execute microtasks
  4. Check if any next ticks exist, if they do go to 2.
  5. Emit async handled rejections
  6. Emit all currently existing unhandled promise rejections
    
a. if any unhandledRejection listeners exist or there are newly added unhandled promise rejections then go to 2
  7. Next tick loop is done (back we go to C++)
addaleax
addaleax
approved these changes
Jan 17, 2018
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Comment threadtest/parallel/test-promises-unhandled-rejections.js
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I’m not sure, but, common.mustCall()? ;)
@apapirovskiapapirovskiJan 17, 2018

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Since it checks at exit, this would just keep looping forever until timeout is hit.
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After reading the code and testing it - I like the behavior and changes. LGTM.
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CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1213/
@apapirovski
promises: refactor rejection handling
21a2220
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
@apapirovski
apapirovskiforce-pushed
the
patch-promise-reject-refactor
branch
from
0413ebb to
21a2220CompareJanuary 19, 2018 03:55
@BridgeAR
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New CI due to some changed code (If I am not mistaken) https://ci.nodejs.org/job/node-test-pull-request/12619/
@apapirovski
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Jan 19, 2018•

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@BridgeAR It was just rebased to make it possible to run the CitGM. But no harm in extra CI :)
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Landed in d62566e
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deleted the

patch-promise-reject-refactor

branch
January 21, 2018 17:38
apapirovski added a commit
that referenced
this pull request
Jan 21, 2018
@apapirovski
promises: refactor rejection handling
d62566e
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: #18207Fixes: #17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@MylesBorins
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Feb 20, 2018

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This does not land cleanly on v9.x, should we backport?
@apapirovski
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@MylesBorins v9.x might be missing some preceding commits, I think. I'll have time to look into it at the end of the week or the weekend, swamped with a move right now. Sorry.
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This seem to apply cleanly on v9.x now, I’m removing the label.
@addaleaxaddaleax
removed

backport-requested-v9.x

author ready
PRs with CI started, the required approvals, and no outstanding review comments.
labels
Feb 27, 2018
addaleax pushed a commit
to addaleax/node
that referenced
this pull request
Feb 27, 2018
@apapirovski@addaleax
promises: refactor rejection handling
b4c933d
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@addaleaxaddaleax
mentioned this pull request
Feb 27, 2018
 Closed

MayaLekova pushed a commit
to MayaLekova/node
that referenced
this pull request
May 8, 2018
@apapirovski@MayaLekova
promises: refactor rejection handling
a84ec52
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
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@apapirovski this doesn't land cleanly on v8.x, do you think this makes sense to backport to v8.x?
@apapirovski
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Aug 2, 2018

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@codebytere Yeah, probably wouldn't hurt. I have a backlog of things I'm supposed to backport anyway. I'll do them all this weekend.
@alexkozyalexkozy
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Nov 6, 2018

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@hexpunkhexpunk
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Dec 12, 2018

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c++Issues and PRs that require attention from people who are familiar with C++.lib / srcIssues and PRs involving general changes in the lib/ or src/ directories.processIssues and PRs related to the process subsystem.promisesIssues and PRs related to ECMAScript promises.

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Successfully merging this pull request may close these issues.

unhandledRejection falls into infinite recursion


7 participants

@apapirovski@benjamingr@BridgeAR@MylesBorins@addaleax@codebytere@nodejs-github-bot

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
promises: refactor rejection handling - #18207
Closed
apapirovski wants to merge 1 commit into
nodejs:masterfrom 
apapirovski:patch-promise-reject-refactor
Closed
promises: refactor rejection handling#18207
apapirovski wants to merge 1 commit into
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Remove the unnecessary microTasksTickObject for scheduling microtasks and instead use TickInfo to keep track of whether promise rejections exist that need to be emitted. Consequently allow the microtasks to execute on average fewer times, in more predictable manner than previously.
Simplify unhandled & handled rejection tracking to do more in C++ to avoid needing to expose additional info in JS. Unite emitting unhandledRejection and rejectionHandled into a single function: emitPromiseRejectionWarnings, which runs after all nextTicks have executed.
When new unhandledRejections are emitted within an unhandledRejection handler, allow the event loop to proceed first instead. This means that if the end-user code handles all promise rejections on nextTick, rejections within unhandledRejection now won't spiral into an infinite loop.
On the whole, this should hopefully make reasoning about nextTick, promises and promise rejections a whole lot simpler.
Fixes: #17913
Checklist
  • make -j4 test (UNIX), or vcbuild test (Windows) passes
  •  tests and/or benchmarks are included
  •  commit message follows commit guidelines
Affected core subsystem(s)
process, promises, src
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CI: https://ci.nodejs.org/job/node-test-pull-request/12580/
CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1204/
Edit: weird failures in CitGM. Investigating...
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CitGM failures unrelated to this PR but clearly something landed in the last 24 hours that completely destroyed CitGM.
@benjamingrbenjamingr
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I'll need a few days to digest this and run through the edge cases we had when we specified the hooks.
Pinging (no pressure to participate!) relevant parties @petkaantonov@addaleax@domenic
@joyeecheungjoyeecheung
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Just to distill what's going on in the current loop, here's an outline:
  1. Check if any next ticks exist (C++)
    
a. If none exist, run Microtasks
    
b. If any ticks exist or unhandled/handled promise rejections were added, go to 2; otherwise exit
  2. Execute all currently scheduled next ticks (if any)
  3. Execute microtasks
  4. Check if any next ticks exist, if they do go to 2.
  5. Emit async handled rejections
  6. Emit all currently existing unhandled promise rejections
    
a. if any unhandledRejection listeners exist or there are newly added unhandled promise rejections then go to 2
  7. Next tick loop is done (back we go to C++)
addaleax
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Comment threadtest/parallel/test-promises-unhandled-rejections.js
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I’m not sure, but, common.mustCall()? ;)
@apapirovskiapapirovskiJan 17, 2018

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Since it checks at exit, this would just keep looping forever until timeout is hit.
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After reading the code and testing it - I like the behavior and changes. LGTM.
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CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1213/
@apapirovski
promises: refactor rejection handling
21a2220
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
@apapirovski
apapirovskiforce-pushed
the
patch-promise-reject-refactor
branch
from
0413ebb to
21a2220CompareJanuary 19, 2018 03:55
@BridgeAR
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New CI due to some changed code (If I am not mistaken) https://ci.nodejs.org/job/node-test-pull-request/12619/
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@BridgeAR It was just rebased to make it possible to run the CitGM. But no harm in extra CI :)
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Landed in d62566e
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deleted the

patch-promise-reject-refactor

branch
January 21, 2018 17:38
apapirovski added a commit
that referenced
this pull request
Jan 21, 2018
@apapirovski
promises: refactor rejection handling
d62566e
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: #18207Fixes: #17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@MylesBorins
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Feb 20, 2018

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This does not land cleanly on v9.x, should we backport?
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@MylesBorins v9.x might be missing some preceding commits, I think. I'll have time to look into it at the end of the week or the weekend, swamped with a move right now. Sorry.
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Feb 27, 2018

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This seem to apply cleanly on v9.x now, I’m removing the label.
@addaleaxaddaleax
removed

backport-requested-v9.x

author ready
PRs with CI started, the required approvals, and no outstanding review comments.
labels
Feb 27, 2018
addaleax pushed a commit
to addaleax/node
that referenced
this pull request
Feb 27, 2018
@apapirovski@addaleax
promises: refactor rejection handling
b4c933d
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@addaleaxaddaleax
mentioned this pull request
Feb 27, 2018
 Closed

MayaLekova pushed a commit
to MayaLekova/node
that referenced
this pull request
May 8, 2018
@apapirovski@MayaLekova
promises: refactor rejection handling
a84ec52
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@codebytere
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Aug 2, 2018

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@apapirovski this doesn't land cleanly on v8.x, do you think this makes sense to backport to v8.x?
@apapirovski
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@codebytere Yeah, probably wouldn't hurt. I have a backlog of things I'm supposed to backport anyway. I'll do them all this weekend.
@alexkozyalexkozy
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Nov 6, 2018

Closed

@hexpunkhexpunk
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Dec 12, 2018

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c++Issues and PRs that require attention from people who are familiar with C++.lib / srcIssues and PRs involving general changes in the lib/ or src/ directories.processIssues and PRs related to the process subsystem.promisesIssues and PRs related to ECMAScript promises.

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Successfully merging this pull request may close these issues.

unhandledRejection falls into infinite recursion


7 participants

@apapirovski@benjamingr@BridgeAR@MylesBorins@addaleax@codebytere@nodejs-github-bot

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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promises: refactor rejection handling - #18207
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apapirovski:patch-promise-reject-refactor
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promises: refactor rejection handling#18207
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apapirovski:patch-promise-reject-refactor
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Remove the unnecessary microTasksTickObject for scheduling microtasks and instead use TickInfo to keep track of whether promise rejections exist that need to be emitted. Consequently allow the microtasks to execute on average fewer times, in more predictable manner than previously.
Simplify unhandled & handled rejection tracking to do more in C++ to avoid needing to expose additional info in JS. Unite emitting unhandledRejection and rejectionHandled into a single function: emitPromiseRejectionWarnings, which runs after all nextTicks have executed.
When new unhandledRejections are emitted within an unhandledRejection handler, allow the event loop to proceed first instead. This means that if the end-user code handles all promise rejections on nextTick, rejections within unhandledRejection now won't spiral into an infinite loop.
On the whole, this should hopefully make reasoning about nextTick, promises and promise rejections a whole lot simpler.
Fixes: #17913
Checklist
  • make -j4 test (UNIX), or vcbuild test (Windows) passes
  •  tests and/or benchmarks are included
  •  commit message follows commit guidelines
Affected core subsystem(s)
process, promises, src
@apapirovskiapapirovski
added

c++
Issues and PRs that require attention from people who are familiar with C++.
process
Issues and PRs related to the process subsystem.
lib / src
Issues and PRs involving general changes in the lib/ or src/ directories.
promises
Issues and PRs related to ECMAScript promises.
labels
Jan 17, 2018
@nodejs-github-botnodejs-github-bot
added

c++
Issues and PRs that require attention from people who are familiar with C++.
lib / src
Issues and PRs involving general changes in the lib/ or src/ directories.
labels
Jan 17, 2018
@apapirovski
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Jan 17, 2018•

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CI: https://ci.nodejs.org/job/node-test-pull-request/12580/
CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1204/
Edit: weird failures in CitGM. Investigating...
@apapirovski
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Jan 17, 2018

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CitGM failures unrelated to this PR but clearly something landed in the last 24 hours that completely destroyed CitGM.
@benjamingrbenjamingr
self-assigned this
Jan 17, 2018
@benjamingr
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Jan 17, 2018•

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I'll need a few days to digest this and run through the edge cases we had when we specified the hooks.
Pinging (no pressure to participate!) relevant parties @petkaantonov@addaleax@domenic
@joyeecheungjoyeecheung
mentioned this pull request
Jan 17, 2018

Closed

@apapirovski
apapirovski
commented
Jan 17, 2018•

edited

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Just to distill what's going on in the current loop, here's an outline:
  1. Check if any next ticks exist (C++)
    
a. If none exist, run Microtasks
    
b. If any ticks exist or unhandled/handled promise rejections were added, go to 2; otherwise exit
  2. Execute all currently scheduled next ticks (if any)
  3. Execute microtasks
  4. Check if any next ticks exist, if they do go to 2.
  5. Emit async handled rejections
  6. Emit all currently existing unhandled promise rejections
    
a. if any unhandledRejection listeners exist or there are newly added unhandled promise rejections then go to 2
  7. Next tick loop is done (back we go to C++)
addaleax
addaleax
approved these changes
Jan 17, 2018
View reviewed changes
Comment threadtest/parallel/test-promises-unhandled-rejections.js
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I’m not sure, but, common.mustCall()? ;)
@apapirovskiapapirovskiJan 17, 2018

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Since it checks at exit, this would just keep looping forever until timeout is hit.
benjamingr
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Jan 17, 2018
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After reading the code and testing it - I like the behavior and changes. LGTM.
@benjamingrbenjamingr
removed their assignment
Jan 18, 2018
@apapirovskiapapirovski
added
the 
author ready
PRs with CI started, the required approvals, and no outstanding review comments.
label
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Jan 19, 2018•

edited

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CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1213/
@apapirovski
promises: refactor rejection handling
21a2220
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
@apapirovski
apapirovskiforce-pushed
the
patch-promise-reject-refactor
branch
from
0413ebb to
21a2220CompareJanuary 19, 2018 03:55
@BridgeAR
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Jan 19, 2018

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New CI due to some changed code (If I am not mistaken) https://ci.nodejs.org/job/node-test-pull-request/12619/
@apapirovski
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Jan 19, 2018•

edited

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@BridgeAR It was just rebased to make it possible to run the CitGM. But no harm in extra CI :)
@apapirovski
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Jan 21, 2018

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Landed in d62566e
@apapirovski
apapirovski
deleted the

patch-promise-reject-refactor

branch
January 21, 2018 17:38
apapirovski added a commit
that referenced
this pull request
Jan 21, 2018
@apapirovski
promises: refactor rejection handling
d62566e
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: #18207Fixes: #17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@MylesBorins
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Feb 20, 2018

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This does not land cleanly on v9.x, should we backport?
@apapirovski
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Feb 20, 2018

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@MylesBorins v9.x might be missing some preceding commits, I think. I'll have time to look into it at the end of the week or the weekend, swamped with a move right now. Sorry.
@addaleax
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Feb 27, 2018

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This seem to apply cleanly on v9.x now, I’m removing the label.
@addaleaxaddaleax
removed

backport-requested-v9.x

author ready
PRs with CI started, the required approvals, and no outstanding review comments.
labels
Feb 27, 2018
addaleax pushed a commit
to addaleax/node
that referenced
this pull request
Feb 27, 2018
@apapirovski@addaleax
promises: refactor rejection handling
b4c933d
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@addaleaxaddaleax
mentioned this pull request
Feb 27, 2018
 Closed

MayaLekova pushed a commit
to MayaLekova/node
that referenced
this pull request
May 8, 2018
@apapirovski@MayaLekova
promises: refactor rejection handling
a84ec52
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@codebytere
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Aug 2, 2018

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@apapirovski this doesn't land cleanly on v8.x, do you think this makes sense to backport to v8.x?
@apapirovski
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Aug 2, 2018

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@codebytere Yeah, probably wouldn't hurt. I have a backlog of things I'm supposed to backport anyway. I'll do them all this weekend.
@alexkozyalexkozy
mentioned this pull request
Nov 6, 2018

Closed

@hexpunkhexpunk
mentioned this pull request
Dec 12, 2018

Closed

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c++Issues and PRs that require attention from people who are familiar with C++.lib / srcIssues and PRs involving general changes in the lib/ or src/ directories.processIssues and PRs related to the process subsystem.promisesIssues and PRs related to ECMAScript promises.

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Successfully merging this pull request may close these issues.

unhandledRejection falls into infinite recursion


7 participants

@apapirovski@benjamingr@BridgeAR@MylesBorins@addaleax@codebytere@nodejs-github-bot

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
promises: refactor rejection handling - #18207
Closed
apapirovski wants to merge 1 commit into
nodejs:masterfrom 
apapirovski:patch-promise-reject-refactor
Closed
promises: refactor rejection handling#18207
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Remove the unnecessary microTasksTickObject for scheduling microtasks and instead use TickInfo to keep track of whether promise rejections exist that need to be emitted. Consequently allow the microtasks to execute on average fewer times, in more predictable manner than previously.
Simplify unhandled & handled rejection tracking to do more in C++ to avoid needing to expose additional info in JS. Unite emitting unhandledRejection and rejectionHandled into a single function: emitPromiseRejectionWarnings, which runs after all nextTicks have executed.
When new unhandledRejections are emitted within an unhandledRejection handler, allow the event loop to proceed first instead. This means that if the end-user code handles all promise rejections on nextTick, rejections within unhandledRejection now won't spiral into an infinite loop.
On the whole, this should hopefully make reasoning about nextTick, promises and promise rejections a whole lot simpler.
Fixes: #17913
Checklist
  • make -j4 test (UNIX), or vcbuild test (Windows) passes
  •  tests and/or benchmarks are included
  •  commit message follows commit guidelines
Affected core subsystem(s)
process, promises, src
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CI: https://ci.nodejs.org/job/node-test-pull-request/12580/
CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1204/
Edit: weird failures in CitGM. Investigating...
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CitGM failures unrelated to this PR but clearly something landed in the last 24 hours that completely destroyed CitGM.
@benjamingrbenjamingr
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Jan 17, 2018
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I'll need a few days to digest this and run through the edge cases we had when we specified the hooks.
Pinging (no pressure to participate!) relevant parties @petkaantonov@addaleax@domenic
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Just to distill what's going on in the current loop, here's an outline:
  1. Check if any next ticks exist (C++)
    
a. If none exist, run Microtasks
    
b. If any ticks exist or unhandled/handled promise rejections were added, go to 2; otherwise exit
  2. Execute all currently scheduled next ticks (if any)
  3. Execute microtasks
  4. Check if any next ticks exist, if they do go to 2.
  5. Emit async handled rejections
  6. Emit all currently existing unhandled promise rejections
    
a. if any unhandledRejection listeners exist or there are newly added unhandled promise rejections then go to 2
  7. Next tick loop is done (back we go to C++)
addaleax
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Comment threadtest/parallel/test-promises-unhandled-rejections.js
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I’m not sure, but, common.mustCall()? ;)
@apapirovskiapapirovskiJan 17, 2018

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Since it checks at exit, this would just keep looping forever until timeout is hit.
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After reading the code and testing it - I like the behavior and changes. LGTM.
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CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1213/
@apapirovski
promises: refactor rejection handling
21a2220
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
@apapirovski
apapirovskiforce-pushed
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patch-promise-reject-refactor
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0413ebb to
21a2220CompareJanuary 19, 2018 03:55
@BridgeAR
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New CI due to some changed code (If I am not mistaken) https://ci.nodejs.org/job/node-test-pull-request/12619/
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@BridgeAR It was just rebased to make it possible to run the CitGM. But no harm in extra CI :)
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Landed in d62566e
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Jan 21, 2018
@apapirovski
promises: refactor rejection handling
d62566e
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: #18207Fixes: #17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@MylesBorins
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This does not land cleanly on v9.x, should we backport?
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@MylesBorins v9.x might be missing some preceding commits, I think. I'll have time to look into it at the end of the week or the weekend, swamped with a move right now. Sorry.
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This seem to apply cleanly on v9.x now, I’m removing the label.
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backport-requested-v9.x

author ready
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addaleax pushed a commit
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Feb 27, 2018
@apapirovski@addaleax
promises: refactor rejection handling
b4c933d
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@addaleaxaddaleax
mentioned this pull request
Feb 27, 2018
 Closed

MayaLekova pushed a commit
to MayaLekova/node
that referenced
this pull request
May 8, 2018
@apapirovski@MayaLekova
promises: refactor rejection handling
a84ec52
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
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@apapirovski this doesn't land cleanly on v8.x, do you think this makes sense to backport to v8.x?
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@codebytere Yeah, probably wouldn't hurt. I have a backlog of things I'm supposed to backport anyway. I'll do them all this weekend.
@alexkozyalexkozy
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unhandledRejection falls into infinite recursion


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
promises: refactor rejection handling - #18207
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promises: refactor rejection handling#18207
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Remove the unnecessary microTasksTickObject for scheduling microtasks and instead use TickInfo to keep track of whether promise rejections exist that need to be emitted. Consequently allow the microtasks to execute on average fewer times, in more predictable manner than previously.
Simplify unhandled & handled rejection tracking to do more in C++ to avoid needing to expose additional info in JS. Unite emitting unhandledRejection and rejectionHandled into a single function: emitPromiseRejectionWarnings, which runs after all nextTicks have executed.
When new unhandledRejections are emitted within an unhandledRejection handler, allow the event loop to proceed first instead. This means that if the end-user code handles all promise rejections on nextTick, rejections within unhandledRejection now won't spiral into an infinite loop.
On the whole, this should hopefully make reasoning about nextTick, promises and promise rejections a whole lot simpler.
Fixes: #17913
Checklist
  • make -j4 test (UNIX), or vcbuild test (Windows) passes
  •  tests and/or benchmarks are included
  •  commit message follows commit guidelines
Affected core subsystem(s)
process, promises, src
@apapirovskiapapirovski
added

c++
Issues and PRs that require attention from people who are familiar with C++.
process
Issues and PRs related to the process subsystem.
lib / src
Issues and PRs involving general changes in the lib/ or src/ directories.
promises
Issues and PRs related to ECMAScript promises.
labels
Jan 17, 2018
@nodejs-github-botnodejs-github-bot
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Issues and PRs that require attention from people who are familiar with C++.
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CI: https://ci.nodejs.org/job/node-test-pull-request/12580/
CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1204/
Edit: weird failures in CitGM. Investigating...
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CitGM failures unrelated to this PR but clearly something landed in the last 24 hours that completely destroyed CitGM.
@benjamingrbenjamingr
self-assigned this
Jan 17, 2018
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I'll need a few days to digest this and run through the edge cases we had when we specified the hooks.
Pinging (no pressure to participate!) relevant parties @petkaantonov@addaleax@domenic
@joyeecheungjoyeecheung
mentioned this pull request
Jan 17, 2018

Closed

@apapirovski
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Just to distill what's going on in the current loop, here's an outline:
  1. Check if any next ticks exist (C++)
    
a. If none exist, run Microtasks
    
b. If any ticks exist or unhandled/handled promise rejections were added, go to 2; otherwise exit
  2. Execute all currently scheduled next ticks (if any)
  3. Execute microtasks
  4. Check if any next ticks exist, if they do go to 2.
  5. Emit async handled rejections
  6. Emit all currently existing unhandled promise rejections
    
a. if any unhandledRejection listeners exist or there are newly added unhandled promise rejections then go to 2
  7. Next tick loop is done (back we go to C++)
addaleax
addaleax
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Jan 17, 2018
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Comment threadtest/parallel/test-promises-unhandled-rejections.js
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I’m not sure, but, common.mustCall()? ;)
@apapirovskiapapirovskiJan 17, 2018

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Since it checks at exit, this would just keep looping forever until timeout is hit.
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After reading the code and testing it - I like the behavior and changes. LGTM.
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CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1213/
@apapirovski
promises: refactor rejection handling
21a2220
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
@apapirovski
apapirovskiforce-pushed
the
patch-promise-reject-refactor
branch
from
0413ebb to
21a2220CompareJanuary 19, 2018 03:55
@BridgeAR
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New CI due to some changed code (If I am not mistaken) https://ci.nodejs.org/job/node-test-pull-request/12619/
@apapirovski
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@BridgeAR It was just rebased to make it possible to run the CitGM. But no harm in extra CI :)
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Landed in d62566e
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patch-promise-reject-refactor

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January 21, 2018 17:38
apapirovski added a commit
that referenced
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Jan 21, 2018
@apapirovski
promises: refactor rejection handling
d62566e
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: #18207Fixes: #17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@MylesBorins
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Feb 20, 2018

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This does not land cleanly on v9.x, should we backport?
@apapirovski
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@MylesBorins v9.x might be missing some preceding commits, I think. I'll have time to look into it at the end of the week or the weekend, swamped with a move right now. Sorry.
@addaleax
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This seem to apply cleanly on v9.x now, I’m removing the label.
@addaleaxaddaleax
removed

backport-requested-v9.x

author ready
PRs with CI started, the required approvals, and no outstanding review comments.
labels
Feb 27, 2018
addaleax pushed a commit
to addaleax/node
that referenced
this pull request
Feb 27, 2018
@apapirovski@addaleax
promises: refactor rejection handling
b4c933d
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@addaleaxaddaleax
mentioned this pull request
Feb 27, 2018
 Closed

MayaLekova pushed a commit
to MayaLekova/node
that referenced
this pull request
May 8, 2018
@apapirovski@MayaLekova
promises: refactor rejection handling
a84ec52
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
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@apapirovski this doesn't land cleanly on v8.x, do you think this makes sense to backport to v8.x?
@apapirovski
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@codebytere Yeah, probably wouldn't hurt. I have a backlog of things I'm supposed to backport anyway. I'll do them all this weekend.
@alexkozyalexkozy
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Nov 6, 2018

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@hexpunkhexpunk
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Dec 12, 2018

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Successfully merging this pull request may close these issues.

unhandledRejection falls into infinite recursion


7 participants

@apapirovski@benjamingr@BridgeAR@MylesBorins@addaleax@codebytere@nodejs-github-bot

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
promises: refactor rejection handling - #18207
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apapirovski wants to merge 1 commit into
nodejs:masterfrom 
apapirovski:patch-promise-reject-refactor
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promises: refactor rejection handling#18207
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Remove the unnecessary microTasksTickObject for scheduling microtasks and instead use TickInfo to keep track of whether promise rejections exist that need to be emitted. Consequently allow the microtasks to execute on average fewer times, in more predictable manner than previously.
Simplify unhandled & handled rejection tracking to do more in C++ to avoid needing to expose additional info in JS. Unite emitting unhandledRejection and rejectionHandled into a single function: emitPromiseRejectionWarnings, which runs after all nextTicks have executed.
When new unhandledRejections are emitted within an unhandledRejection handler, allow the event loop to proceed first instead. This means that if the end-user code handles all promise rejections on nextTick, rejections within unhandledRejection now won't spiral into an infinite loop.
On the whole, this should hopefully make reasoning about nextTick, promises and promise rejections a whole lot simpler.
Fixes: #17913
Checklist
  • make -j4 test (UNIX), or vcbuild test (Windows) passes
  •  tests and/or benchmarks are included
  •  commit message follows commit guidelines
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CI: https://ci.nodejs.org/job/node-test-pull-request/12580/
CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1204/
Edit: weird failures in CitGM. Investigating...
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CitGM failures unrelated to this PR but clearly something landed in the last 24 hours that completely destroyed CitGM.
@benjamingrbenjamingr
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I'll need a few days to digest this and run through the edge cases we had when we specified the hooks.
Pinging (no pressure to participate!) relevant parties @petkaantonov@addaleax@domenic
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Just to distill what's going on in the current loop, here's an outline:
  1. Check if any next ticks exist (C++)
    
a. If none exist, run Microtasks
    
b. If any ticks exist or unhandled/handled promise rejections were added, go to 2; otherwise exit
  2. Execute all currently scheduled next ticks (if any)
  3. Execute microtasks
  4. Check if any next ticks exist, if they do go to 2.
  5. Emit async handled rejections
  6. Emit all currently existing unhandled promise rejections
    
a. if any unhandledRejection listeners exist or there are newly added unhandled promise rejections then go to 2
  7. Next tick loop is done (back we go to C++)
addaleax
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Comment threadtest/parallel/test-promises-unhandled-rejections.js
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I’m not sure, but, common.mustCall()? ;)
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Since it checks at exit, this would just keep looping forever until timeout is hit.
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After reading the code and testing it - I like the behavior and changes. LGTM.
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CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1213/
@apapirovski
promises: refactor rejection handling
21a2220
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
@apapirovski
apapirovskiforce-pushed
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patch-promise-reject-refactor
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from
0413ebb to
21a2220CompareJanuary 19, 2018 03:55
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New CI due to some changed code (If I am not mistaken) https://ci.nodejs.org/job/node-test-pull-request/12619/
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@BridgeAR It was just rebased to make it possible to run the CitGM. But no harm in extra CI :)
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Landed in d62566e
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Jan 21, 2018
@apapirovski
promises: refactor rejection handling
d62566e
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: #18207Fixes: #17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@MylesBorins
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This does not land cleanly on v9.x, should we backport?
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@MylesBorins v9.x might be missing some preceding commits, I think. I'll have time to look into it at the end of the week or the weekend, swamped with a move right now. Sorry.
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This seem to apply cleanly on v9.x now, I’m removing the label.
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Feb 27, 2018
@apapirovski@addaleax
promises: refactor rejection handling
b4c933d
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@addaleaxaddaleax
mentioned this pull request
Feb 27, 2018
 Closed

MayaLekova pushed a commit
to MayaLekova/node
that referenced
this pull request
May 8, 2018
@apapirovski@MayaLekova
promises: refactor rejection handling
a84ec52
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
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@apapirovski this doesn't land cleanly on v8.x, do you think this makes sense to backport to v8.x?
@apapirovski
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@codebytere Yeah, probably wouldn't hurt. I have a backlog of things I'm supposed to backport anyway. I'll do them all this weekend.
@alexkozyalexkozy
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Successfully merging this pull request may close these issues.

unhandledRejection falls into infinite recursion


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@apapirovski@benjamingr@BridgeAR@MylesBorins@addaleax@codebytere@nodejs-github-bot

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

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promises: refactor rejection handling - #18207
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Remove the unnecessary microTasksTickObject for scheduling microtasks and instead use TickInfo to keep track of whether promise rejections exist that need to be emitted. Consequently allow the microtasks to execute on average fewer times, in more predictable manner than previously.
Simplify unhandled & handled rejection tracking to do more in C++ to avoid needing to expose additional info in JS. Unite emitting unhandledRejection and rejectionHandled into a single function: emitPromiseRejectionWarnings, which runs after all nextTicks have executed.
When new unhandledRejections are emitted within an unhandledRejection handler, allow the event loop to proceed first instead. This means that if the end-user code handles all promise rejections on nextTick, rejections within unhandledRejection now won't spiral into an infinite loop.
On the whole, this should hopefully make reasoning about nextTick, promises and promise rejections a whole lot simpler.
Fixes: #17913
Checklist
  • make -j4 test (UNIX), or vcbuild test (Windows) passes
  •  tests and/or benchmarks are included
  •  commit message follows commit guidelines
Affected core subsystem(s)
process, promises, src
@apapirovskiapapirovski
added

c++
Issues and PRs that require attention from people who are familiar with C++.
process
Issues and PRs related to the process subsystem.
lib / src
Issues and PRs involving general changes in the lib/ or src/ directories.
promises
Issues and PRs related to ECMAScript promises.
labels
Jan 17, 2018
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CI: https://ci.nodejs.org/job/node-test-pull-request/12580/
CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1204/
Edit: weird failures in CitGM. Investigating...
@apapirovski
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CitGM failures unrelated to this PR but clearly something landed in the last 24 hours that completely destroyed CitGM.
@benjamingrbenjamingr
self-assigned this
Jan 17, 2018
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I'll need a few days to digest this and run through the edge cases we had when we specified the hooks.
Pinging (no pressure to participate!) relevant parties @petkaantonov@addaleax@domenic
@joyeecheungjoyeecheung
mentioned this pull request
Jan 17, 2018

Closed

@apapirovski
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Just to distill what's going on in the current loop, here's an outline:
  1. Check if any next ticks exist (C++)
    
a. If none exist, run Microtasks
    
b. If any ticks exist or unhandled/handled promise rejections were added, go to 2; otherwise exit
  2. Execute all currently scheduled next ticks (if any)
  3. Execute microtasks
  4. Check if any next ticks exist, if they do go to 2.
  5. Emit async handled rejections
  6. Emit all currently existing unhandled promise rejections
    
a. if any unhandledRejection listeners exist or there are newly added unhandled promise rejections then go to 2
  7. Next tick loop is done (back we go to C++)
addaleax
addaleax
approved these changes
Jan 17, 2018
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Comment threadtest/parallel/test-promises-unhandled-rejections.js
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I’m not sure, but, common.mustCall()? ;)
@apapirovskiapapirovskiJan 17, 2018

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Since it checks at exit, this would just keep looping forever until timeout is hit.
benjamingr
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After reading the code and testing it - I like the behavior and changes. LGTM.
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CitGM: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1213/
@apapirovski
promises: refactor rejection handling
21a2220
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
@apapirovski
apapirovskiforce-pushed
the
patch-promise-reject-refactor
branch
from
0413ebb to
21a2220CompareJanuary 19, 2018 03:55
@BridgeAR
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New CI due to some changed code (If I am not mistaken) https://ci.nodejs.org/job/node-test-pull-request/12619/
@apapirovski
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@BridgeAR It was just rebased to make it possible to run the CitGM. But no harm in extra CI :)
@apapirovski
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Landed in d62566e
@apapirovski
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deleted the

patch-promise-reject-refactor

branch
January 21, 2018 17:38
apapirovski added a commit
that referenced
this pull request
Jan 21, 2018
@apapirovski
promises: refactor rejection handling
d62566e
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: #18207Fixes: #17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@MylesBorins
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Feb 20, 2018

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This does not land cleanly on v9.x, should we backport?
@apapirovski
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@MylesBorins v9.x might be missing some preceding commits, I think. I'll have time to look into it at the end of the week or the weekend, swamped with a move right now. Sorry.
@addaleax
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This seem to apply cleanly on v9.x now, I’m removing the label.
@addaleaxaddaleax
removed

backport-requested-v9.x

author ready
PRs with CI started, the required approvals, and no outstanding review comments.
labels
Feb 27, 2018
addaleax pushed a commit
to addaleax/node
that referenced
this pull request
Feb 27, 2018
@apapirovski@addaleax
promises: refactor rejection handling
b4c933d
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
@addaleaxaddaleax
mentioned this pull request
Feb 27, 2018
 Closed

MayaLekova pushed a commit
to MayaLekova/node
that referenced
this pull request
May 8, 2018
@apapirovski@MayaLekova
promises: refactor rejection handling
a84ec52
Remove the unnecessary microTasksTickObject for scheduling microtasks
and instead use TickInfo to keep track of whether promise rejections
exist that need to be emitted. Consequently allow the microtasks to
execute on average fewer times, in more predictable manner than
previously.
Simplify unhandled & handled rejection tracking to do more in C++ to
avoid needing to expose additional info in JS.
When new unhandledRejections are emitted within an unhandledRejection
handler, allow the event loop to proceed first instead. This means
that if the end-user code handles all promise rejections on nextTick,
rejections within unhandledRejection now won't spiral into an infinite
loop.
PR-URL: nodejs#18207Fixes: nodejs#17913
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
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@apapirovski this doesn't land cleanly on v8.x, do you think this makes sense to backport to v8.x?
@apapirovski
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@codebytere Yeah, probably wouldn't hurt. I have a backlog of things I'm supposed to backport anyway. I'll do them all this weekend.
@alexkozyalexkozy
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Nov 6, 2018

Closed

@hexpunkhexpunk
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Dec 12, 2018

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Successfully merging this pull request may close these issues.

unhandledRejection falls into infinite recursion


7 participants

@apapirovski@benjamingr@BridgeAR@MylesBorins@addaleax@codebytere@nodejs-github-bot