minutes for 2016-01-26 meeting

Author: Patrick Mueller

wg-meetings/2016-01-26.md

@@ -0,0 +1,94 @@
+January 26th 2015
+================================================================================
+
+* [YouTube recording](http://www.youtube.com/watch?v=DvQ7QSyEe64)
+* [Hangouts Event](https://plus.google.com/events/c5n1int7rfegr3lqs3ujr2707e4)
+* [issue for this meeting](https://github.com/nodejs/tracing-wg/issues/38)
+* [previous meeting](https://github.com/nodejs/tracing-wg/blob/master/wg-meetings/2015-11-19.md) - 2015-11-19
+
+
+Attendees
+================================================================================
+
+* @trevnorris - Trevor Norris
+* @thlorenz - Thorsten Lorenz
+* @watson - Thomas Watson Steen
+* @pmuellr - Patrick Mueller
+* @bripkens - Ben Ripkens
+* @AndreasMadsen - Andreas Madsen
+
+Agenda
+================================================================================
+
+* trace-event is now in V8 4.9; [#30 - next steps](https://github.com/nodejs/tracing-wg/issues/30)
+
+* need more meat / structure in the [#31 - use cases issue](https://github.com/nodejs/tracing-wg/issues/31)
+
+* AsyncWrap
+  * [node #3504 - async_wrap](https://github.com/nodejs/node/pull/3504): make native
+    API public is unlikely to land. What are the alternatives for integrating
+    native addons with AsyncWrap?
+  * Follow up on http fix and making MakeCallback reentrant:
+    * [node #4509 - Fix async wrap http](https://github.com/nodejs/node/pull/4509)
+    * [node #4507 - src: fix MakeCallback error handling](https://github.com/nodejs/node/pull/4507)
+
+
+Minutes
+================================================================================
+
+## [1:30](https://youtu.be/DvQ7QSyEe64?t=90) - agenda, previous minutes
+
+## [5:36](https://youtu.be/DvQ7QSyEe64?t=336) - trace events
+
+* node branch now available to play with - [issue comment](https://github.com/nodejs/tracing-wg/issues/38#issuecomment-174623789)
+
+* What work can we do in parallel to work Google is doing?
+  * what will Google folks be providing?
+
+* What does a trace event look like in the code, including passing data?
+
+* How do we expose the trace buffer to whoever wants to read the trace events?
+  * only via special build?
+  * provided in existing node build, via native add-on?
+
+* What trace events do we actually provide?
+  * very low overhead, and configurable, so we probably want to add a bunch
+  * grouped via categories - a grouping mechanism provided by the tracing
+    infrastructure
+
+* Probably don't want to have events themselves surface back through JavaScript,
+  kills the overhead.
+
+* But probably want to think about configuring the tracing via some kind of API;
+  start/stop tracing, configuring what trace categories are enabled, where does
+  tracing output go.  This API might be only exposed via native add-ons first,
+  and then later higher in JS if we find a nice set.
+
+* What are the constraints on the data we can add to a trace event.  Eg, presumably
+  won't be pointers to things that can move / be freed, since trace events are
+  "read" long after events occur.
+
+* Can we allow users to emit events from JavaScript?
+
+* Pat wants to create a couple of issues to focus on some of the particular
+  questions.
+
+  * how do expose trace events to the user
+  * apis to start/stop/configure tracing
+  * what are we going to put trace events around
+
+
+## [31:07](https://youtu.be/DvQ7QSyEe64?t=1867) - async wrap status
+
+* native addons integrated with AsyncWrap
+
+  * [node #3504- async_wrap: make native API public](https://github.com/nodejs/node/pull/3504)
+  * Can we do this?  Currently seems impossible | hard; because this exposes
+    some internal stuff that we wouldn't want to.  Trevor will look into some
+    techniques to do this.
+
+* http fix / MakeCallback being re-entrant
+
+  * [node #4509 - Fix async wrap http](https://github.com/nodejs/node/pull/4509)
+  * [node #4507 - src: fix MakeCallback error handling](https://github.com/nodejs/node/pull/4507)
+    * note that this PR has been merged