src: remove TimerWrap #20894

apapirovski · 2018-05-22T20:07:13Z

Remove TimerWrap in favour of uv_timer_t handle stored on the Environment, more similar to how Immediates currently function. Since there's now only a single TimerWrap, it doesn't really make much sense for it to exist at all (hence this PR). In addition, the async stack from the TimerWrap is actually not desirable and every single public module that works with async hooks seems to filter it out anyway.

I've also done a quick scan of npm modules and I could not find a single use case of TimerWrap.now(), which would be the only reason to keep it publicly available. It's also currently impossible for user land to use the TimerWrap given how OnTimeout is implemented (it can only process our own internal lists).

This will make it possible to continue further improving our Timers architecture and C++ code.

Fixes: #10154

Checklist

make -j4 test (UNIX), or vcbuild test (Windows) passes
tests and/or benchmarks are included
commit message follows commit guidelines

apapirovski · 2018-05-22T20:38:10Z

CI: https://ci.nodejs.org/job/node-test-pull-request/15046/
Benchmark CI: https://ci.nodejs.org/view/Node.js%20benchmark/job/benchmark-node-micro-benchmarks/200/

addaleax

Heads up, this is going to have a minor conflict with #20884 :)

addaleax · 2018-05-22T21:08:12Z

src/env.cc

@@ -450,6 +459,59 @@ void Environment::RunAndClearNativeImmediates() {
 }


+void Environment::ScheduleTimer(int64_t duration) {


Can we add the unit of measurement to duration? E.g. duration_ms if it’s milliseconds?

addaleax · 2018-05-22T21:08:34Z

src/env.cc

+  do {
+    TryCatch try_catch(env->isolate());
+    try_catch.SetVerbose(true);
+    ret = cb->Call(env->context(), process, 1, args);


tiny style nit: arraysize(args)

addaleax · 2018-05-22T21:09:20Z

src/env.cc

+
+  if (expiry != 0) {
+    int64_t duration =
+      abs(expiry) - (uv_now(env->event_loop()) - env->timer_base());


ditto re: adding the unit to the name

(Also, why abs? Can you add a comment?)

addaleax · 2018-05-22T21:10:32Z

src/timers.cc

+  result->Set(env->context(), 1, timer_toggle_ref_function).FromJust();
+  result->Set(env->context(), 2,
+              env->immediate_info()->fields().GetJSArray()).FromJust();
+  result->Set(env->context(), 3, imm_toggle_ref_function).FromJust();


Is there a reason for not providing these directly on the binding?

I wondered about that. I don't think so?

apapirovski · 2018-05-22T21:40:21Z

Thanks @addaleax. I've cleaned up and added some detailed comments. Hope this is better :)

jasnell · 2018-05-23T00:39:28Z

src/timer_wrap.cc

-// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
-// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
-// USE OR OTHER DEALINGS IN THE SOFTWARE.
-


Is there any possibility of userland native modules depending on this? Is it safe to remove without a deprecation cycle?

/cc @bnoordhuis

I've done an extensive search and there was not a single module I could find using it. I'm not really sure why someone would want to anyway given that Timer.now() is not that different from process.hrtime() but isn't officially supported.

But also process.binding shouldn't be part of our official deprecation cycle, should it? We broke Gulp in 10.0.0 with changes to contextify and that's a huge module.

(And the TimerWrap itself is impossible to use outside of Node.js.)

jasnell · 2018-05-23T00:40:13Z

Does this need a proper deprecation cycle? /cc @nodejs/tsc

apapirovski · 2018-05-23T03:59:21Z

Here's CitGM now that it's not broken anymore: https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/1431/

CI: https://ci.nodejs.org/job/node-test-pull-request/15050/

apapirovski · 2018-05-23T04:12:30Z

test/parallel/test-inspector-tracing-domain.js

@@ -52,7 +52,7 @@ async function test() {
                        'node.perf.timerify', 'v8'],
                       categories);

-  const traceConfig = { includedCategories: ['node'] };
+  const traceConfig = { includedCategories: ['v8'] };


@eugeneo This test fails without this change. I suspect it has to do with the removal of the HandleWrap, right? Or is there something else at play? Would appreciate you having a look as the author of this test and someone with a lot of understanding of all this tracing stuff. Thanks!

@nodejs/diagnostics Perhaps some of you might have insight too? Thanks!

This test fails without this change. I suspect it has to do with the removal of the HandleWrap, right? Or is there something else at play? Would appreciate you having a look as the author of this test and someone with a lot of understanding of all this tracing stuff. Thanks!

It's because timer_wrap.cc uses AsyncWrap::MakeCallback(), which calls AsyncWrap::EmitTraceEventAfter(). Since you no longer use that method, it's not traced any more.

I personally don't feel too strongly but I guess it would be nice to keep the current behavior.

I wonder if we should do something about Immediates too in that case? But I don't know how to best handle it since there's no longer an AsyncWrap (or obviously a matching provider). All of this trace event stuff is pretty outside of my expertise as far as Node goes so I'm all ears...

Since this is semver-major (and won't land in a release for a while), perhaps we could add a TODO: or start an issue so that more qualified people can chime in (including yourself)?

I'd be okay with that. In my opinion, AsyncWrap currently conflates too much (mushes too much into a single class) and could use some decoupling.

LGTM on the test change. I haven't reviewed the rest of the PR.

bnoordhuis

LGTM modulo comments.

bnoordhuis · 2018-05-23T09:51:04Z

lib/timers.js

@@ -53,8 +58,9 @@ const kCount = 0;
 const kRefCount = 1;
 const kHasOutstanding = 2;

-const [immediateInfo, toggleImmediateRef] =
-  setupTimers(processImmediate, processTimers);
+// Call into C++ to assing callbacks that are responsible for processing


I suspect you intended to write 'assign.' :-)

bnoordhuis · 2018-05-23T09:53:16Z

lib/timers.js

    listOnTimeout(list, now);
-    ran = true;


This is a functionally null change, right?

Yeah, it's just cleaner this way since we don't assign each time.

bnoordhuis · 2018-05-23T09:55:31Z

src/env.cc

@@ -161,6 +163,9 @@ void Environment::Start(int argc,
  HandleScope handle_scope(isolate());
  Context::Scope context_scope(context());

+  uv_timer_init(event_loop(), timer_handle());


Can you CHECK_EQ(0, uv_timer_init(...));?

(Not that it can actually fail but that's why it should be CHECK'd.)

bnoordhuis · 2018-05-23T09:57:44Z

src/env.cc

+
+  Local<Function> cb = env->timers_callback_function();
+  MaybeLocal<Value> ret;
+  Local<Value> args[] = { env->GetNow() };


If you're just passing a single argument you can do Local<Value> arg = env->GetNow() and then call into JS with cb->Call(..., 1, &arg).

Not that this is wrong but it's a bit more obvious at the call site that you're just passing one arg.

bnoordhuis · 2018-05-23T09:58:38Z

src/env.cc

+    TryCatch try_catch(env->isolate());
+    try_catch.SetVerbose(true);
+    ret = cb->Call(env->context(), process, arraysize(args), args);
+  } while (ret.IsEmpty());


I realize you brought this over from timer_wrap.cc but is there a reason you can't handle exceptions in JS land?

We need to let it go to uncaughtException or domain first. I don't think there's a way to do so in JS?

bnoordhuis · 2018-05-23T10:01:55Z

src/env.cc

+
+  if (expiry_ms != 0) {
+    int64_t duration_ms =
+      abs(expiry_ms) - (uv_now(env->event_loop()) - env->timer_base());


Either check that expiry_ms fits in an int or use llabs() (or manually turn it positive.)

Ah, yeah... didn't even realize!

bnoordhuis · 2018-05-23T10:08:14Z

src/env.cc

+    }
+  } else if (has_ref) {
+    uv_unref(h);
+  }


uv_ref() and uv_unref() are idempotent, you don't need to check if the timer is ref'd or not.

bnoordhuis · 2018-05-23T10:12:20Z

src/timers.cc

+#include <stdint.h>
+
+namespace node {
+namespace timers {


You could also use an anonymous namespace here.

bnoordhuis · 2018-05-23T10:23:48Z

test/parallel/test-inspector-tracing-domain.js

@@ -52,7 +52,7 @@ async function test() {
                        'node.perf.timerify', 'v8'],
                       categories);

-  const traceConfig = { includedCategories: ['node'] };
+  const traceConfig = { includedCategories: ['v8'] };


It's because timer_wrap.cc uses AsyncWrap::MakeCallback(), which calls AsyncWrap::EmitTraceEventAfter(). Since you no longer use that method, it's not traced any more.

I personally don't feel too strongly but I guess it would be nice to keep the current behavior.

bnoordhuis · 2018-05-23T10:31:48Z

test/parallel/test-timers-ordering.js

 const N = 30;

 let last_i = 0;
-let last_ts = 0;
+const [seconds, nanoseconds] = process.hrtime();
+let last_ts = (seconds * 1e3 + nanoseconds * 1e-6) | 0;


Not sound. process.hrtime() returns the number of nanoseconds since an unspecified point in the past. If that point is the UNIX epoch then this stops working sometime next year because seconds * 1e3 >= 2**32.

Ok, sounds like it's best to expose getLibuvNow() from internal/timers and just use that then.

apapirovski · 2018-05-23T12:07:21Z

CI after changes: https://ci.nodejs.org/job/node-test-pull-request/15053/

jasnell

LGTM! Thank you for the investigation on the semveriness :-)

apapirovski · 2018-05-26T16:33:36Z

Just an FYI, while this is marked as "author ready" and could land, I'm hoping to have @Fishrock123 review it. Please don't land until they either review or say they won't have time to do so.

Fishrock123 · 2018-05-26T19:00:17Z

I’m on Vacation. It’l have to wait until during or after JSConf.EU.

mcollina

LGTM

Unused since the excellent refactoring in 2930bd, which also removed `src/timer_wrap.cc` from `node.gyp`. If you try and get at the binding on a v11.0-pre build, you'll get an error, since the file is no longer in the GYP build. ``` Jonathans-MBP:node jon$ ./node -v v11.0.0-pre Jonathans-MBP:node jon$ ./node -e "process.binding('timer_wrap')" internal/bootstrap/loaders.js:81 mod = bindingObj[module] = getBinding(module); ^ Error: No such module: timer_wrap at process.binding (internal/bootstrap/loaders.js:81:36) at [eval]:1:9 at Script.runInThisContext (vm.js:89:20) at Object.runInThisContext (vm.js:286:38) at Object.<anonymous> ([eval]-wrapper:6:22) at Module._compile (internal/modules/cjs/loader.js:689:30) at evalScript (internal/bootstrap/node.js:562:27) at startup (internal/bootstrap/node.js:248:9) at bootstrapNodeJSCore (internal/bootstrap/node.js:595:3) ``` PR-URL: #21777 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Gus Caplan <me@gus.host> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Refs: #20894

The timers directory test, utilizing FakeTime, has not worked in quite a while and is not truly testing Node.js behaviour. If a similar test is necessary it would be better suited to libuv on which Node.js relies for timers functionality. PR-URL: nodejs#20894 Fixes: nodejs#10154 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com> Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com> Reviewed-By: Gus Caplan <me@gus.host>

The timers directory test, utilizing FakeTime, has not worked in quite a while and is not truly testing Node.js behaviour. If a similar test is necessary it would be better suited to libuv on which Node.js relies for timers functionality. PR-URL: #20894 Fixes: #10154 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com> Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com> Reviewed-By: Gus Caplan <me@gus.host> Backport-PR-URL: #22039 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Minwoo Jung <minwoo@nodesource.com>

nodejs#20894 / 2930bd1 was introduced on master which removed an offending line in this doc before linting was applied to test/ in nodejs#22221 / 56103ab. Since 20894 is semver-major, the full changes were not backported.

#20894 / 2930bd1 was introduced on master which removed an offending line in this doc before linting was applied to test/ in #22221 / 56103ab. Since 20894 is semver-major, the full changes were not backported. PR-URL: #22296 Reviewed-By: Rich Trott <rtrott@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: George Adams <george.adams@uk.ibm.com> Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>

Correct the output of async_hooks samples * `TIMERWRAP` has been removed in #20894 * `console.log()` doesn't issue `TTYWRAP` nor `SIGNALWRAP` I don't know which PR caused that `console.log()` is no longer using `TTYWRAP` and `SIGNALWRAP`; I think it was between 8.4.0 and 8.5.0. PR-URL: #24050 Refs: #20894 Reviewed-By: James M Snell <jasnell@gmail.com>

Correct the output of async_hooks samples * `TIMERWRAP` has been removed in nodejs#20894 * `console.log()` doesn't issue `TTYWRAP` nor `SIGNALWRAP` I don't know which PR caused that `console.log()` is no longer using `TTYWRAP` and `SIGNALWRAP`; I think it was between 8.4.0 and 8.5.0. PR-URL: nodejs#24050 Refs: nodejs#20894 Reviewed-By: James M Snell <jasnell@gmail.com>

Correct the output of async_hooks samples * `TIMERWRAP` has been removed in #20894 * `console.log()` doesn't issue `TTYWRAP` nor `SIGNALWRAP` I don't know which PR caused that `console.log()` is no longer using `TTYWRAP` and `SIGNALWRAP`; I think it was between 8.4.0 and 8.5.0. PR-URL: #24050 Refs: #20894 Reviewed-By: James M Snell <jasnell@gmail.com>

apapirovski added timers Issues and PRs related to the timers subsystem / setImmediate, setInterval, setTimeout. semver-major PRs that contain breaking changes and should be released in the next major version. labels May 22, 2018

apapirovski requested review from bnoordhuis, addaleax and Fishrock123 May 22, 2018 20:07

nodejs-github-bot added the lib / src Issues and PRs related to general changes in the lib or src directory. label May 22, 2018

apapirovski force-pushed the patch-timerwrap-refactor branch from 28a7570 to 30c54f9 Compare May 22, 2018 20:50

addaleax reviewed May 22, 2018

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addaleax approved these changes May 22, 2018

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apapirovski force-pushed the patch-timerwrap-refactor branch 2 times, most recently from a0b2f82 to dc80758 Compare May 22, 2018 22:12

jasnell reviewed May 23, 2018

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apapirovski force-pushed the patch-timerwrap-refactor branch from dc80758 to 15b2ddd Compare May 23, 2018 04:03

apapirovski commented May 23, 2018

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apapirovski force-pushed the patch-timerwrap-refactor branch 2 times, most recently from 5ab8e99 to 2b7ae97 Compare May 23, 2018 07:16

bnoordhuis approved these changes May 23, 2018

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BridgeAR added the author ready PRs that have at least one approval, no pending requests for changes, and a CI started. label May 24, 2018

mcollina approved these changes May 26, 2018

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targos mentioned this pull request Jul 31, 2018

[v10.x] test: remove outdated, non-functioning test #22039

Closed

rvagg mentioned this pull request Aug 13, 2018

Release proposal: v10.9.0 #22295

Merged

rvagg mentioned this pull request Aug 13, 2018

test,doc: fix async-hooks coverage doc for md lint (v10.x backport problem) #22296

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Flarna mentioned this pull request Nov 2, 2018

doc: correct async_hooks sample outputs #24050

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2 tasks

BenoitZugmeyer mentioned this pull request Nov 26, 2018

Timer handles not reported in Node 11 keymetrics/pm2-io-apm#213

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goto-bus-stop mentioned this pull request Dec 4, 2018

Fix native stack trace test and remove TIMERWRAP assertion in Node 11 clinicjs/node-clinic-bubbleprof#282

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richardlau mentioned this pull request Jan 30, 2019

Timer objects no longer show up in process._getActiveHandles() #25806

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mcollina mentioned this pull request May 25, 2020

Consider a timeout heap mcollina/retimer#6

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Flarna mentioned this pull request Sep 14, 2020

fix: ignore TIMERWRAP in AsyncHooksContextManager open-telemetry/opentelemetry-js#1530

Merged

		@@ -450,6 +459,59 @@ void Environment::RunAndClearNativeImmediates() {
		}


		void Environment::ScheduleTimer(int64_t duration) {

src: remove TimerWrap #20894

src: remove TimerWrap #20894

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apapirovski commented May 22, 2018

Checklist

apapirovski commented May 22, 2018 • edited

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