Mark Rainey: Engineers are currently debugging why the Voyager 1 spacecraft, which is 15 billions miles away, turned off its main radio and switched to a backup radio that hasn't been used in over forty years! I've had some tricky debugging issues in the past, including finding compiler bugs and debugging code with no debugger that had been burnt into prom packs for terminals, however I have huge admiration for the engineers maintaining the operation of Voyager 1. Recently they sent a command to the craft that caused it to shut off its main radio transmitter, seemingly in an effort to preserve power and protect from faults. This prompted it to switch over to the backup radio transmitter, that is lower power. Now they have regained communication they are trying to determine the cause on hardware that is nearly 50 years old. Any communication takes days. When you think you have a difficult issue to debug, spare a thought for this team.

Read more of this story at Slashdot.

Spline Technologies Corporation announces a major update to SplineTech JavaScript Debugger PRO, an independent standalone Web development tool that enables Web developers to easily edit and debug JavaScript and VBScript inside HTML and AJAX pages, without the need for any add-ons, plugins or changes of their code to handle the debugging process. Client-side JavaScript, JScript and client-side VBScript debugging languages are fully supported for simple and complex HTML, DHTML and AJAX debugging scenarios.

 SplineTech JavaScript Debugger PRO offers following main features to address the most common Web development issues:

 - Advanced form debugging for JavaScript form validation - Programmers to cause order forms to validate in clients' browser windows before they are submitted.
 - JavaScript pop-up debugging
 - Debug DHTML menus and JavaScript menus
 - Debug JavaScript and VBScript events: Debug JavaScript Pop-ups, onclick, onmouseover, onfocus and any
 other event.
 - Debug DHTML behavior
 - Debug client-side JavaScript controls: Debug calendars and any other control
 - Multi-Functional VBScript and JavaScript script editor for HTML and AJAX
 - Full Support for native VBScript and JavaScript syntax (color-coded)
 - Explicit JavaScript runtime error information
 - Execution line highlighting: Display the current line of the code to be executed

 Aside from a vast array of main features, this major update of SplineTech JavaScript Debugger PRO includes these new and unique features:
 - Pause code execution in 3, 5 or more seconds (user adjustable)
 - Reformat unreadable JavaScript and AJAX scripts (turns large one-line AJAX scripts into properly formatted readable multi-line code)
 - Step Through multiple lines of code at once (user adjustable)
 - Go back (and forth) to any step within your code
 - Call Stack enables developers to view all function names taken from function lists (since IE reports most of them as anonymous)
 - View all current variables in a dedicated Current Variables panel

 Without requiring any manual configuration or network configuration, SplineTech JavaScript Debugger PRO runs on the Windows 7/2008/2000/2003/XP and Windows Server 2008 platforms (both x86 and x64) with Microsoft Internet Explorer 6.0 or better.

 SplineTech JavaScript Debugger PRO is priced at $90 per single-user license, and is available for purchase at
 http://www.RemoteDebugger.com/javascript_debugger/javascript_debugger.asp

 Immediate online product delivery and full support is included with all Spline Technologies products.

 ABOUT:
 Spline Technologies Corporation is a growing dynamic international software development company, specializing in web development tools, with headquarters in beautiful downtown Montreal, Canada, since 1999.

Published at LXer: The upstream Linux 6.11 kernel introduced the ability to easily produce a Pacman kernel package for Arch Linux with the new "make pacman-pkg" target. With Linux 6.12 new...

We are looking for an enthusiastic software developer with understanding of Java or modern C++, to join the Arm Mobile Studio team.

The role involves collaborating with highly motivated developers from different backgrounds, and customers throughout the world, to craft the next generation of our performance analysis tools for Arm CPUs and Mali GPUs. As part of this team, you would help create new features, maintain existing ones, and support the engineering infrastructure for build, test, and continuous integration. We also help to support both internal and external customers, and contribute to our developer documentation, developer website, and community forums.

We are growing the team to help deliver features that support the full breadth of Arm's product portfolio. Our tools are used to optimize the latest smart cars, drones, mobile games, and machine learning applications, your ideas will make a difference and help to bring world-beating products to market.

Please note this is a Fixed Term Contract ending Sept 2021

We are looking for a highly skilled, technically capable senior software engineer to join the team of Arm Forge at Warwick. You will be passionate about making a difference through building great quality products.

As an experienced developer, you’ll have a methodical approach to debugging and performance analysis and understand how developers will use our tools to achieve their objectives. Working as part of a team of C++ software engineers based in Warwick you will help to develop the Arm Forge Debug and Profiling tools.

Arm Forge is used by developers to increase software performance or fix software bugs from single Linux servers right up to the largest supercomputer on the planet.  Our tools span a wide range of use cases; from C/C++/Python developers writing multithreaded server applications or ML and data analysis applications, to C/C++/Fortran/Python HPC developers scaling to millions of cores.

To learn more about our group and the products please check https://developer.arm.com/hpc.

Main Duties

We are looking for a highly skilled and motivated senior software engineer who is passionate about producing quality valuable software to join our elite team based in Warwick.

• Responsible for developing quality functionality on schedule, including specification, design, development, documentation and test.
• Drive forward major features or improvements and increase quality into the product.
• Expected to integrate with existing ARM process and infrastructure where possible and use your experience to introduce new processes where required.

Talent Acquisition Expert Joins Leadership Team to Drive Strategic Recruitment Initiatives

Detached debugging symbols for pacman

Detached debugging symbols for qtcreator

Detached debugging symbols for pacman

Detached debugging symbols for file

Detached debugging symbols for blender

Detached debugging symbols for pacman

In this episode we're talking to Andreas Zeller. about debugging. We started the discussion with an explanation of what debugging and how it works in principle. We then briefly discussed the relationship between debugging and testing. Next was the importance of the scientific method for debugging. We then looked as debugging as a search problem, leading to a discussion about delta debugging, the main topic of this discussion. We concluded the discussion by looking at the practical usability of delta debugging and the relationship to other means of automatically finding problems in software.

Donny Nadolny of PagerDuty joins Robert Blumen to tell the story of debugging an issue that PagerDuty encountered when they set up a Zookeeper cluster that spanned across two geographically separated datacenters in different regions.

Felienne talks to Diomidis Spinellis about different forms of debugging. From using print-statements to version-control systems and operating system tools. We also discuss debugging strategies for different types of programming systems.

Tim Post of echoreply.io discusses Rubber Duck Debugging, a way to wrap your head about problems and solutions. Host Felienne spoke with Post about Rubber Duck debugging, and how it can help you to find answers to complex problems.

Jim Grisanzio talks with John Spurling, a JVM engineer at Twitter, at UnVoxxed Hawaii 2020 about debugging and the mental process of solving difficult technical issues.

John Spurling, Twitter
https://twitter.com/synecdotal 

Jim Grisanzio, Java Developer Relations
https://twitter.com/jimgris 

Video on YouTube
https://youtu.be/6dwOPQSJwaI 

UnVoxxed Hawaii
https://flic.kr/s/aHsmLF23KD 
https://twitter.com/UnVoxxedHawaii 
https://www.youtube.com/playlist?list=PLX8CzqL3ArzU0APb6QgpMMTMPEz1jok5Q 

Seymour Cray
https://en.wikipedia.org/wiki/Seymour_Cray 

Make It Stick: The Science of Successful Learning 
https://www.amazon.com/Make-Stick-Science-Successful-Learning/dp/0674729013 

JavaOne 2022 Speaker Preview

In this conversation Oracle's Jim Grisanzio talks with Java developer and JavaOne 2022 speaker Mark Heckler from St. Louis. Missouri in the United States.

Mark is a software developer and developer advocate at Microsoft, a Java Champion, a conference speaker, and an author. Check out his book Spring Boot: Up and Running. In this conversation Mark previews his session at JavaOne — Das Boot: Diving into Debugging Spring Boot Applications. Mark also talks about the value of technical conferences and the community. 

JavaOne 2022 from October 17-20 in Las Vegas

• JavaOne 2022: Registration and Sessions
• JavaOne Update 1
• JavaOne Update 2

Mark Heckler, Principal Cloud Developer Advocate for Java/JVM Languages at Microsoft

• @mkheck

Java Development and Community

• OpenJDK
• Inside Java
• Dev.Java
• @java on Twitter
• Java on YouTube

Duke's Corner Podcast Host

• Jim Grisanzio, Oracle Java Developer Relations, @jimgris

Verisium Debug, the Cadence unified debug platform, offers a variety of debugging capabilities, including RTL debug, UVM testbench debug, UPF debug, and DMS debug. From IP to SoC level debug, the user can take the benefits of the rich debugging features to reduce the time for debug.

Not only the common and advanced debug features, Verisium Debug also provides Python-based interface API, which enables capabilities allowing users to customize functions with Verisium Debug Python API to access from design, waveform databases and add functions to Verisium Debug’s GUI for visualization purposes. With Verisium Debug’s Python API, users can turn repetitive works into automatic programs or reduce efforts to create in-house utilities with well-established infrastructure from Verisium Debug.

Here is an example of how the user uses Python API to create a customized function. Users can write a Python program to extract signals in a specific design scope and report the values of the extracted signals. From Fig 1., you can understand the procedure of the traversal steps.

1. Import Python library in Verisium Debug package.
2. Setup the database for traversal.
3. Search the scope with the hierarchy information in the design DB.
4. Query the signal list and the values of the signals.
5. Print out the results.

Fig 1. Procedure of Verisium Debug Python Program

The result from the Verisium Debug Python App can be used for post-process design checking or fed into other utilities in the design flow.

The concept is very straightforward. With Verisium Debug and the Python API environment enabled, you can easily query any information that is stored in the databases of Verisium Debug. The result can be outputted in text format, or you can also use the API to display the results back to Verisium Debug’s GUI.

The Verisium Debug Python API is an important capability and resource for Verisium Debug users. To make Verisium Debug Python API easier to access, from Verisium Debug 24.10 release, Verisium Debug introduced the new Verisium Debug Python App Store.

Fig 2. Verisium Debug App Store

The Python App Store includes ready-to-use Python App examples with the availabilities of original source code documents, which help the user to understand how to start writing an app that fits their use case.

Fig 3. Example apps in Verisium Debug App Store

The Verisium Debug Python App Store can also be used by a team as an app management system. App creators can share the developed apps across teams within their companies. The in-house created apps will become easy to manage, and engineers can easily access the apps from the central location, which makes it possible for users to see the updated available Verisium Debug Apps from the Verisium Debug App Store.

Check the following videos for more information about Verisium Debug Python API:

Customize Verisium Debug with Python API

Verisium Debug Customized Apps with Python API

Cadence Protium prototyping platforms rapidly bring up an SoC or system prototype and provide a pre-silicon platform for early software development, SoC verification, system validation, and hardware regressions. In this Training W ebinar, we will explore debugging using Save/Restart on Protium X2 . This feature saves execution time and lets you focus on actual debugging. The system state can be saved before the bug appears and restartS directly from there without spending time in initial execution. We’ll cover key concepts and applications, explore Save/Restart performance metrics, and provide examples to help you understand the concepts. Agenda: The key concepts of debugging using save/restart Capabilities, limitations, and performance metrics Some examples to enable and use save/restart on the Protium X2 system Date and Time Thursday, November 7, 2024 07:00 PST San Jose / 10:00 EST New York / 15:00 GMT London / 16:00 CET Munich / 17:00 IST Jerusalem / 20:30 IST Bangalore / 23:00 CST Beijing REGISTER To register for this webinar, sign in with your Cadence Support account (email ID and password) to log in to the Learning and Support System*. Then select Enrol to register for the session. Once registered, you’ll receive a confirmation email containing all login details. A quick reminder: If you haven’t received a registration confirmation within 1 hour of registering, please check your spam folder and ensure your pop-up blockers are off and cookies are enabled. For issues with registration or other inquiries, reach out to eur_training_webinars@cadence.com . Want to See More Webinars? You can find recordings of all past webinars here Like This Topic? Take this opportunity and register for the free online course related to this webinar topic: Protium Introduction Training The course includes slides with audio and downloadable lab exercises designed to emphasize the topics covered in the lecture. There is also a Digital Badge available for the training. Want to share this and other great Cadence learning opportunities with someone else? Tell them to subscribe . Hungry for Training? Choose the Cadence Training Menu that’s right for you. To view our complete training offerings, visit the Cadence Training website . Related Courses Protium Introduction Training Course | Cadence Palladium Introduction Training Course | Cadence Related Blogs Training Insights – A New Free Online Course on the Protium System for Beginner and Advanced Users Training Insights – Palladium Emulation Course for Beginner and Advanced Users Related Training Bytes Protium Flow Steps for Running Design on Protium System ICE and IXCOM mode comparison ICE compile flow IXCOM compile flow PATH settings for using Protium System Please see the course learning maps for a visual representation of courses and course relationships. Regional course catalogs may be viewed here

As a verification engineer, you’re surely looking for ways to automate the debugging process. Have you developed your own scripts to ease specific debugging steps that tools don’t offer? Working with scripts locally and manually is challenging—so is reusing and organizing them. What if there was a way to create your own app with the required functionality and register it with the tool? The answer to that question is “Yes!” The Verisium Debug Python App Store lets you instantly add additional features and capabilities to your Verisium Debug Application using Python Apps that interact with Verisium Debug via the Python API. Join me, Principal Education Application Engineer Bhairava Prasad, for this Training Webinar and discover the Verisium Debug Python App Store. The app store allows you to search for existing apps, learn about them, install or uninstall them, and even customize existing apps. Date and Time Wednesday, November 20, 2024 07:00 PST San Jose / 10:00 EST New York / 15:00 GMT London / 16:00 CET Munich / 17:00 IST Jerusalem / 20:30 IST Bangalore / 23:00 CST Beijing REGISTER To register for this webinar, sign in with your Cadence Support account (email ID and password) to log in to the Learning and Support System*. Then select Enroll to register for the session. Once registered, you’ll receive a confirmation email containing all login details. A quick reminder: If you haven’t received a registration confirmation within one hour of registering, please check your spam folder and ensure your pop-up blockers are off and cookies are enabled. For issues with registration or other inquiries, reach out to eur_training_webinars@cadence.com . Like this topic? Take this opportunity and register for the free online course related to this webinar topic: Verisium Debug Training To view our complete training offerings, visit the Cadence Training website Want to share this and other great Cadence learning opportunities with someone else? Tell them to subscribe . Hungry for Training? Choose the Cadence Training Menu that’s right for you. Related Courses Xcelium Simulator Training Course | Cadence Related Blogs Unveiling the Capabilities of Verisium Manager for Optimized Operations - Verification - Cadence Blogs - Cadence Community Verisium SimAI: SoC Verification with Unprecedented Coverage Maximization - Corporate News - Cadence Blogs - Cadence Community Verisium SimAI: Maximizing Coverage, Minimizing Bugs, Unlocking Peak Throughput - Verification - Cadence Blogs - Cadence Community Related Training Bytes Introducing Verisium Debug (Video) (cadence.com) Introduction to UVM Debug of Verisium Debug (Video) (cadence.com) Verisium Debug Customized Apps with Python API Please see course learning maps a visual representation of courses and course relationships. Regional course catalogs may be viewed here . *If you don’t have a Cadence Support account, go to Cadence User Registration and complete the requested information. Or visit Registration Help .

Hi,

i am compiling firmware under Windows transfer the binaries and the sources to Linux to simulate/debug there. The problem is that the paths in the DWARF debug info of the .elf file are the absolute Windows paths as set by the compiler so they are useless under Linux. Is it possible to configure mappings of these paths to the Linux paths when simulating/debugging like with e.g. GDB (https://sourceware.org/gdb/current/onlinedocs/gdb/Source-Path.html#index-set-substitute_002dpath)?

thx,

Peter

Hello,


I would like to use the simulation software xrun/simvision that comes with XCELIUM. We are currently using classroom licenses and want to disable all ip addresses on the student pcs except the license server ip. We want to make sure that students cannot copy confidential data from the Cadence tools.


Problem:

When I launch the xrun simulation while all ip addresses are blocked, it starts but the performance is very slow. The GUI starts after 5 minutes and the simulation is ready after 10 minutes. The interesting thing is that when I enable all blocked ip addresses, everything works at a reasonable speed.

Terminal Output (execution without internet connection):

xrun -gui design.vhd

waiting for SimVision/Verisium Debug to connect...


Is there a way to run the simulation tools without an Internet connection? Or can you give me the ip addresses that are used by the simulation tools so that I can enable only those specific ips?


Regards,

Max

Hello,

I am aware of command script .svcf file that saves signals and loads them in while opening Simvision.

I am wondering, if there is a way for saving signals while we are in an interactive session and loading them next time when we open Simvision interactively.

Any ideas on how to do this?

Thank you in advance.

Swetha. C

This blog introduces you to an efficient way to debug interface elements or connect modules in a mixed-signal simulation.(read more)

This Metasploit module exploits sendmail's well-known historical debug mode to escape to a shell and execute commands in the SMTP RCPT TO command. This vulnerability was exploited by the Morris worm in 1988-11-02. Cliff Stoll reports on the worm in the epilogue of The Cuckoo's Egg. Currently only cmd/unix/reverse and cmd/unix/generic are supported.

Methods and apparatus for output of high-bandwidth debug data/traces in electronic devices using embedded high-speed debug port(s). Debug data is received from multiple blocks and buffered in a buffer. The buffer's output is operatively coupled to one or more high-speed serial I/O interfaces via muxing logic during debug test operations. The buffered data is encoded as serialized data and sent over the one or more high-speed serial I/O interfaces to a logic device that receives serialized data and de-serializes it to generate parallel debug data that is provided to a debugger. The buffer may be configured as a bandwidth-adapting buffer that facilitates transfer of debug data that is received at a variable combined data rate outbound via the one or more high-speed serial I/O interfaces at a data rate corresponding to the bandwidth of the serial I/O interfaces.

A method of monitoring thread execution within a multicore processor architecture which comprises a plurality of interconnected processor elements for processing the threads, the method comprising receiving a plurality of thread parameter indicators of one or more parameters relating to the function and/or identity and/or execution location of a thread or threads, comparing at least one of the thread parameter indicators with a first plurality of predefined criteria each representative of an indicator of interest, and generating an output consequential upon thread parameter indicators which have been identified to be of interest as a result of the said comparison.

A plurality of Field Programmable Gate Arrays (FPGA), high performance transceivers, and memory devices provide a verification module for timing and state debugging of electronic circuit designs. Signal value compression circuits and gigabit transceivers embedded in each FPGA increase the fanout of each FPGA. Ethernet communication ports enable remote software debugging of processor instructions.

Embedded logic is implemented in a partially reconfigurable programmable logic device (PLD), thus allowing debugging of implemented instantiations of logic after partial reconfiguration. Several instantiations of logic are received at the PLD. One instantiation of logic is implemented in a reconfigurable region of logic within the PLD. The instantiation of logic includes a port that provides a constant interface between the reconfigurable region of logic and a fixed region of logic within the PLD. The port may receive signals from probe points implemented within the reconfigurable region of logic. The port may provide the signals to a signal interface implemented within a fixed region of logic. Furthermore, an embedded logic analyzer may be implemented in either the reconfigurable region of logic or the fixed region of logic. The embedded logic analyzer receives signals from the probe points and provides signal visibility to an external computing system.

According to example embodiments of the present invention, an object to be monitored is determined, the object being associated with a variable in a code snippet including a plurality of statements. The object is monitored in execution of the plurality of statements. If a plurality of updates of the object are detected in the execution of the plurality of statements, a snapshot associated with each of the updates of the object is created. The snapshot includes a current value of the object and a memory address for the current value of the object.

Xdebug is an indispensable tool for every PHP developer. PHP’s favorite real-time debugger, it supports breakpoints, more detailed debug output, and deeper introspection of PHP code to determine just what it’s doing (and what it’s doing wrong). Sadly, it comes at a huge cost in performance, though, making it unsuitable for production. Not on Platform.sh, though. Xdebug is now available on all Grid environments, secure and without a performance loss.

Truncated by Planet PHP, read more at the original (another 720 bytes)

This SAS Note provides instructions about how to enable SAS Workflow Studio log generation and debugging in order to troubleshoot a problem in SAS Workflow Studio. On the client machine where&

Martin Mincey of SAS Technical Support shows you how to debug when listing registered SAS fonts, registering new fonts, getting SAS SG procedures to use a new font and more.

How to debug 5 common SAS® software font issues was published on SAS Users.

Martin Mincey of SAS Technical Support shows you how to debug when listing registered SAS fonts, registering new fonts, getting SAS SG procedures to use a new font and more.

How to debug 5 common SAS® software font issues was published on SAS Users.

  When developing an Android* application, you usually need to test, optimize, and debug on many different platforms. While basically every hardware and chip manufacturer provides a set of custom tools...

   Debugging Android* NDK apps with Eclipse* and gdb Eclipse* with ADT plugin and CDT, all part of the ADT bundle, support the Android* NDK quite well. You can even use gdb integration to debug yo...

Hi All,

I'm trying to understand checkpoint concept. When I found save and restart concept in cdnshelp, There is just describing about "$save" and "xrun -r "~~~".

and I found also the below link about save restart and it saves your time.

But I can't find any benefits from my experiment from save&restart article( I fully agree..the article)

Ok, So I'v got some experiment  Here.

1. I declared $save and got the below result as I expected within the simple UVM code.

In UVM code...

$display("TEST1");
$display("TEST2");
$save("SAVE_TEST");
$display("TEST3");
$display("TEST4");

And I restart at "SAVE_TEST" point by xrun -r "SAVE_TEST", I've got the below log

xcelium> run
TEST3
TEST4

Ok, It's Good what I expected.(The concept of Save and Restore is simple: instead of re-initializing your simulation every time you want to run a test, only initialize it once. Then you can save the simulation as a “snapshot” and re-run it from that point to avoid hours of initialization times. It used to be inconvenient. I agree..)

2. But The Problem is that I can't restart with modified code. Let's see the below example.

I just modified TEST5 instead of "TEST3"

$display("TEST1");
$display("TEST2");
$save("SAVE_TEST");
$display("TEST5"); //$display("TEST3");
$display("TEST4");

and I rerun with xrun -r "SAVE_TEST", then I've got the same log

xcelium> run
TEST3
TEST4

There is no "TEST5". Actually I expected "TEST5" in the log.From here We know $save can't support partially modified code after $save. 

Actually, through this, we can approach to our goal about saving developing time. 

So I want to know Is there any possible way that instead of re-initializing our simulation every time we want to run a test, only initialize it once and keep developing(debugging) our code ?

If we do, Could you let me know the simple example?

113 bytes small Linux/x64 anti-debug trick (INT3 trap) with execve("/bin/sh") shellcode that is NULL free.

MPLAB PICkit4 In-Circuit Debugger User's Guide

MPLAB PICkit 4 In-Circuit Debugger Quick Start Guide

Hayden Library - QA76.9.W65 C6 2014

JavaScript debugging the hard way Marcin Szczepanski, Principal Developer Atlassian Error on line 1, column 6532112 of bundle.js? Out of memory error trying to load a CPU profile into the Chrome debugger? Two minutes to see wait and see if a change you made fixed a bug? While upgrading our complex web application from Webpack […]

The post Web Directions Code ’20 session spotlight–JavaScript debugging the hard way appeared first on Web Directions.

Hayden Library - GV1469.3.D43 2016

Episode Summary

Todd Gardner is a software developer, podcaster on the show Script and Style, startup founder,  and comedy host for Pub Conf, a ‘comedy after party for developers’. Since he was last on the show 6 years ago, he has seen his startup TrackJS become quite successful. TrackJS is a JavaScript error monitoring service which gives you visibility into your client side experience. It’s different from other tools because focused on simplicity, so you’ll never need a guy on your team dedicated solely to TrackJS because everyone can use it.

The panel begins by talking about debugging methods and tools. Some rely solely on the debugger built into their platform while others prefer to use a third party service. They discuss the necessity of using a third party debugger and if there are better solutions than just the built in debugger. 

They then discuss what to do after you’ve fixed a bug, such as if it is necessary to write a test to make sure it was completely fixed They talk about things to do to make debugging more effective. Todd and Aimee believe that code needs to begin by being designed for debug-ability. 

The panel discusses issues with invisible boundaries encountered while debugging, such as running out of memory. They talk about ways to mitigate issues that happen outside of your code base. Todd talks about the dangers of ad-blockers, and the panel agrees that it is important to consider how your website will be crippled by the user’s own technology. The end user in a production environment will have a different experience than you did writing it on a professional computer. 

Todd talks about the difference between debugging for the web versus a mobile application. Todd has encountered particular problems with debugging on a remote device, and he talks about how he solved the issue. The show concludes with Todd giving a quick elevator pitch for TrackJS

Panelists

• Chris Ferdinandi

• Christopher Buecheler

• Aimee Knight

• Charles Max Wood

• Steve Emmrich

With special guest: Todd Gardner

Sponsors

• Adventures in Blockchain

• Sentry use the code “devchat” for 2 months free on Sentry’s small plan

• React Round Up

Links

• Track JS (free trial available)

• Script and Style podcast

• PubConf

• Console.log

• Blackbox for Firefox and Chrome

• Redux lager

• Remote JS 

Follow DevChat on Facebook and Twitter

Picks

Christopher Buecheler:

• React/TypeScript cheat sheet 

Chris Ferdinandi:

• Pokemon Brawl 

• Space Invaders game

• Gomakethings.com newsletter

Aimee Knight:

• TechLead Youtube channel

Charles Max Wood:

• Atomic Habits

• Getting up at 4 am

Steve Emmrich:

• Trello

• Babushkas and grandmas to help you with your newborn

Todd Gardner:

• PubConf

• Follow Todd @toddhgardner or todd.mn

Valeri Karpov is a maintainer on Mongoose, has started a few companies, and works for a company called Booster Fuels. Today’s topic debugging with Async/Await. The panel talks about some of the challenges of debugging with Async. AJ, however, has never encountered the same problems, so he shares his debugging method. 

Valeri differentiates between .catch vs try...catch, and talks about why he prefers .catch. There are two ways to handle all errors in an async function without leading to an unhandled promise rejection. The first is to wrap the entire body of the async function in a try...catch, has some limitations. Calling an async function always returns a promise, so the other approach is calling .catch on the promise to handle any errors that occur in that function body. One of the key differences is if you return a promise within an async function, and that return promise is wrapped in a try...catch, the catch block won’t get called if that promise is rejected, whereas if you call .catch on the promise that the function returns, you’ll actually catch that error. There are rare instances where this can get tricky and unintuitive, such as where you have to call new promise and have resolve and reject, and you can get unexpected behavior.

The panel discusses Valeri’s current favorite JS interview question, which is,  “Given a stream, implement a function called ‘stream to promise’ that, given a stream, returns a promise that resolves to the concatenation of all the data chunks emitted by the stream, or rejects if the stream emits an error event.” It’s really simple to get this qustion right, and really simple to get it wrong, and the difference can be catastrophic. AJ cautions listeners to never use the data event except in the cases Val was talking about, only use the readable event.

The conversation turns to the function of a readable event. Since data always pushes data, when you get a readable event, it’s up to you to call read inside the function handler, and then you get back a chunk of data, call read again and again until the read returns null. When you use readable, you are in control and you avoid piling functions into RAM. In addition, the right function will return true or false to let you know if the buffer is full or not. This is a way to mix imperative style into a stream.

The next discussion topics are the differences between imperative style and reactive style and how a waits and promises work in a normal four loop. A wait suspends the execution of a function until the promise is resolved. Does a wait actually stop the loop or is it just transpiling like a promise and it doesn’t stop the loop. AJ wrote a module called Batch Async to be not as greedy as promise.all but not as limited as other options.

The JavaScript panelists talk about different async iterators they’ve used, such as Babel. They discuss the merits of Babel, especially since baseline Android phones (which a significant portion of the population of the world uses) run UC Browser that doesn’t support Babel, and so a significant chunk of the population of the world. On the other hand, if you want to target a large audience, you need to use Babel.

Since frameworks in general don’t handle async very well, the panel discusses ways to mitigate this. They talk about different frameworks like Vue, React, and Express and how they support async functions. They discuss why there is no way for you to actually cancel an async option in an actual case, how complex canceling is, and what you are really trying to solve for in the cancellation process. 

Canceling something is a complex problem. Valeri talks about his one case where he had a specific bug that required non-generic engineering to solve, and cancelling actually solved something. When AJ has come across cancellation issues, it’s very specific to that use case. The rest of the panelists talk about their experiences with having to cancel something. 

Finally, they talk about their experience with async generator functions. A generator is a function that lets you enter into the function later. This makes sense for very large or long running data sets, but when you have a bounded items, don’t complicate your code this way. When an async generator function yields, you explicitly need to call next in order for it to pick up again. If you don’t call ‘next’, it’s essentially cancelled. Remember that object.keys and object.values are your friends. 

Panelists

• Christopher Buecheler

• AJ O’Neal

• Charles Max Wood

With special guest: Valeri Karpov

Sponsors

• The DevEd Podcast

• Sentry use the code “devchat” for 2 months free on Sentry’s small plan

• Adventures in DevOps

Links

• Mongoose

• Express 5

• Node Streams

• Pull Streams

• Masteringjs.io

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• How to Write Batch Async Functions

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Picks

AJ O’Neal:

• Ethan Garofolo YouTube

Christopher Buecheler:

• Functional Design Patterns for Express.js

Charles Max Wood:

• Microsoft Ignite

• Maxcoders.io

Valeri Karpov:

• Follow Valeri on Twitter @code_barbarian and Github @vkarpov15

• Masteringjs.io

• Jurassic Park: A Novel