Notes about asynchronous programing in Dart. In this article I test and learn about two variants of writing asynchronous code in Dart: async/await and Future-based.

Welcome in a new series of articles about Dart programming language.

It is not a beginner tutorial. I focus mainly on features that may be surprising and/or interesting for a Java(Script) developer.

Slides

Slide notes are available here.

The resources:

Start with these:…

1. https://dart.dev/guides/language/language-tour (language overview)
2. https://dartpad.dev/ (write & run in online editor)
3. https://dart.dev/guides/language/spec (language specification page, current spec pdf: 2.10)
4. https://dart.dev/guides/language/effective-dart (good practices)

Basics

… or look below:

Java predictions

Predictions by authors of Java JVM Trends focus on faster adoption of new Java features and long-term releases

• frameworks (Helidon, Vert.x etx.) start providing Virtual Threads programming models, so the usage of this language/platform feature would grow
• native Java could become more visible due to Project Leyden (back to life in 2022) and focus on ease of use for Spring developers
• migration from MicroProfile Metrics to metrics and tracing by Micrometer.
• frameworks set the baseline to Java 17 (Spring)
• Java 11 takes over Java 8 (market): needs modernization of old stacks (libs, dependencies), challenge for many Java developers
• adoption of Java 17 is faster than Java 11
• Java as a language is strong (Jetbrains dev ecosystem research from 2021, waiting for 2022 one)

Resources

• https://www.infoq.com/articles/java-jvm-trends-2022/
• https://newrelic.com/resources/report/2022-state-of-java-ecosystem
• https://www.jetbrains.com/lp/devecosystem-2021/
• https://openjdk.org/projects/leyden/notes/01-beginnings

IT predictions

• more focus on security
• recognition for core value of IT Ops / Dev Ops
• Amazon (or: Cloud) rising even more
• optimization of development, processes, libraries in the direction of
  • containers
  • CI/CD
• more impact of developers and engeneers on company-level decision making
• no-code is not a threat for developers
• GPT-4 would be a game-changer; robotics will go mainstream expected adoption of self-driving cars
• buzzing in social platforms (Twitter, Tik-Tok), possible further content-moderation regulatory actions (esp. in Europe)
• new trends: IoB (Internet of Behaviour) - analysis of human behaviour with analytics (security issues) and prediction of futire behavior

Resources

• https://www.ipsos.com/en/ipsos-global-predictions-2023
• https://enterprisersproject.com/article/2022/12/tech-predictions-2023
• https://www.forbes.com/sites/robtoews/2022/12/20/10-ai-predictions-for-2023/
• https://www.theverge.com/2022/12/16/23512588/tech-platform-predictions-2023-facebook-twitter-moderation
• https://trojanczyk.eu/internet-of-behaviour-iob-what-it-is-data-predictions-and-benefits-for-business-and-threats-to-private-life/

What I think

I’m reading about the trends in IT and expected directions for companies, inverstors and business in IT world and one theme comes again and again as a common denominator of all the predictions. This theme is: the client. But we as individuals are not “the client”: we are “the revenue stream”. The real client (the one who gives money to software companies) wants the information and needs software professionals to dig that information in order to know:

In this article I’m going to explore what an API is, why we might want to change it, how to do it and how to do it safely.

Java na szybko

Załóżmy, że potrzebujesz “na szybko” napisać jakiś program w Javie. Jakiego edytora użyjesz? Myślę, że większość Javowców, nawet jeśli są wyznania Vim-owego albo wyznawcami Kościoła Emacs, ucieknie się do uruchomienia grubego IDE takiego jak Eclipse, IntellijIdea lub - szczególnie ostatnimi laty - VSCode.

Przynam się, że ja też jakś czas temu zainstalowałam VSCode (zdaje się, że przy okazji nauki języka Go). Wciąż się docieramy (ja i VSCode) - mimo możliwości “podpięcia” sktótów klawiszowych z innych IDE wciąż staram się nauczyć sktótów właściwych dla VSCode i zrozumieć “filozofię” tego edytora.

Nowy hosting?

Ten wpis to krótka notka do siebie samej na temat użycia scp i rsync do synchronizacij katalogów.

Testuję właśnie  hosting na smarthost.pl (i jestem bardzo zadowolona - choć nie można wykluczyć, że parametry podczas testowania są sztucznie “podkręcane” - przy czym na hostingach i ich parametrach nie znam się zbytnio). Przede wszystkim ucieszył mnie zawarty w “najmniejszym” pakiecie hostingowym dostęp przez ssh.

Użycie scp

Próbowałam sobie przypomnieć, jaka jest składnia polecenia scp do “uploadu” plików na serwer. I dopiero po chwili odkryłam, że ssh działa na niestandardowym numerze portu, więc konieczna byłam opcja -P:

Task appropriate for the job

• high parallelization : use fork-join pool and and parallel streams for highly CPU-bound calculations
• high interactivity: high concurrency and a need to keep a lot of IO-bound tasks on single CPU: use Future (Completable Future) or Flow API

Problems and solutions

Threads problems

• map 1:1 to OS threads (expensive to create and of limited number)
• much higher number than hardware threads (cores? well, it seems a core is more complex)

CPUs like the Intel i7-6900K have multiple hardware threads per core, so the CPU can execute useful instructions even for short delays such as a cache miss.