vendredi 24 février 2012

Veille technologique semaine 8



Pour le bulletin de cette semaine, je vous propose les sujets suivants :
  • Le Wifi Gigabit avec une puce qui l'implémente.
  • La loi de Moore aurait-elle une limite ? Un laboratoire a réalisé un transistor avec un seul atome (de phosphore).
  • Microsoft met à jour son offre de stokage Cloud SkyDrive et propose 25Go gratuitement pour ses 100 millions d'utilisateurs inscrits.
  • Microsoft, le processeur ARM, Windows 8 et Office : la face caché de l'iceberg.
  • La spécification du langage Java et de la machine virtuelle ont été mis à jour avec la version 7.
  • Oracle viens de prolonger la date le fin de vie (EOL : End Of Life) du JDK 6 : prolongation jusqu'à novembre 2012. Plus de mise à jour gratuite au delà de cette date. Oracle recommande fortement la migartion sur le JDK 7 avant cette date. Le JDK 7 à une date de péremption en juillet 2014.
  • Les fuites mémoires avec les langages à garbage collector :  c'est un problème de l'application.
  • La programmation concurrente en Java : c'est l'application qui doit prendre en compte l'évolution des processeur multi-cores.
  • Une question théorique : quel est le type de null ? Avez vous la réponse avant de regarder le solution.

Bonne lecture.

Gigabit Wi-Fi chips emerge, will power super-fast home video streaming
The first wireless networking chips capable of powering gigabit-per-second speeds using the forthcoming IEEE 802.11ac standard are starting to emerge, with routers and other consumer networking products expected to launch in the second half of 2012. With speeds three times faster than the current generation of Wi-Fi routers, the new products will speed up synchronization between home devices and greatly improve the quality of in-home audio and video streaming, according
to Gigabit Wi-Fi vendors.

New Qualcomm chips aim to bring 1.3Gbps WiFi to one and all


La fin de Moore
La loi de Moore, tout la monde la connait sans la connaitre. On la cite souvent en disant que la puissance des processeur double tous les 18 mois, alors qu'elle concerne la densité de transistors sur une puce de silicium.


Un transistor composé d'un unique atome
Un transistor composé d'un unique atome Alors que l'on grave maintenant de manière industrielle des processeurs à la finesse de 22nm, on sait très bien que la barrière quantique n'est plus si loin et qu'il faudra totalement révolutionner la manière dont les processeurs sont fabriqués d'ici moins de 20 ans. Dans cette course à la nouveauté, des scientifiques ont réussi une prouesse, fabriquer un transistor composé d'un unique atome.


We can do no Moore: a transistor from single atom
At the center of modern technology lies the logic circuitry provided by semiconductor devices. Extending circuit logic to the realm of nanotechnology requires the construction of atomic-scale systems, which has proven challenging. Both the electric nature of individual atoms and the need to place them at specific points within a crystal lattice has kept scientists from creating atom-scale transistors until the present.


Bigger files, remote access, OpenDocument, and more coming to SkyDrive
Microsoft's SkyDrive cloud storage service is set to receive some substantial upgrades this year, according to news from both official and unofficial channels. File synchronization, secure remote access, and Windows 8 integration have been demonstrated by Microsoft, and rumored improvements include paid storage upgrades, secure storage of BitLocker keys, a new Mac client, and support for OpenDocument (ODF) files.


Windows On ARM : entre deux chaises
Après des mois de suspense, Microsoft a enfin levé le voile sur le degré de compatibilité de Windows dans sa version ARM, une question qui laissait nombre d'observateurs dubitatifs. Et la réponse est pour le moins surprenante…


JLS7 and JVMS7 online
Java Language Specification 7 and the JVM Specification 7


Updated Java 6 EOL date
The Java SE Support Roadmap reflects an updated timeline for the EOL of public support and public releases for JDK 6. The EOL date has been extended from July 2012 to November 2012, to allow some more time for the transition to JDK 7. The JRE is free software, and as is the case with most free software, users are encouraged to adopt the latest stable version.


Oracle Java SE Support Roadmap
Java SE 6 will no longer be publicly available after November 2012. Customers interested in continued access to critical bug fixes and security fixes as well as general maintenance for JDK 6 have the option to purchase Oracle Lifetime Support.


What is a memory leak?
When we talk to people about our solution for discovering memory leaks – Plumbr – we immediately get positive feedback. But when we add Java into the equation, the initial excitement is often complemented with questions: "Are there memory leaks in Java? Isn't Java a garbage-collected language?" In this post I will explain why memory leaks are in fact a common problem for Java applications.


Fork and Join: Java Can Excel at Painless Parallel Programming Too!
How do the new fork/join tasks provided by Java SE 7 make it easier to write parallel programs?
Multicore processors are now widespread across server, desktop, and laptop hardware. They are also making their way into smaller devices, such as smartphones and tablets. They open new possibilities for concurrent programming because the threads of a process can be executed on several cores in parallel. One important technique for achieving maximal performance in applications is the ability to split intensive tasks into chunks that can be performed in parallel to maximize the use of computational power.
Dealing with concurrent (parallel) programming has traditionally been difficult, because you have to deal with thread synchronization and the pitfalls of shared data. Interest in language-level support for concurrent programming on the Java platform is strong, as proven by the efforts in the Groovy (GPars), Scala, and Clojure communities. These communities all try to provide comprehensive programming models and efficient implementations that mask the pain points associated with multithreaded and distributed applications. The Java language itself should not be considered inferior in this regard. Java Platform, Standard Edition (Java SE) 5 and then Java SE 6 introduced a set of packages providing powerful concurrency building blocks.
Java SE 7 further enhanced them by adding support for parallelism The following article starts with a brief recall of concurrent programming in Java, starting with the low-level mechanisms that have existed since the early releases. It then shows the rich primitives added by the java.util.concurrent packages before presenting fork/join tasks, an essential addition provided in Java SE 7 by the fork/join framework. An example usage of the new APIs is given. Finally, a discussion on the approach precedes the conclusion.
In what follows, we assume that the reader comes from a Java SE 5 or Java SE 6 background. We present a few pragmatic language evolutions of Java SE 7 along the way.

Concurrent Programming in Java


La Classe De Null ?
La valeur null peut être affectée à toutes les références. Quel est son type ? Si null est du type Object, cela oblige à convertir toutes les valeurs null avant une affectation.

String s = (String)null;

Sans la conversion, le compilateur refuserait la compilation. Pour éviter cela, les concepteurs de Java n'ont pas donné de type à null. Le compilateur converti implicitement la valeur null dans le type du pointeur participant à l'expression. Cela fonctionne dans la majorité des situations.

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