I am very new to Java and also Real Time Program. I am trying to run some real time code using Eclipse or Netbeans in Windows, however, I face same problem for both IDE which I could not import the javax.realtime package.
I had googled for several hours just to get this package, but I came across quite a lot resources pointing to Java real time virtual machine. Is it not possible to have the real time features in Windows? If yes, can I get some help here for me to run those real time program in Ubuntu running from a VM?
Any feedback is highly appreciated...
Thank you very much...
The answer looks like no.
Over at Java RTS is says the requirements are:
Real-Time OS:
Solaris 10 (Update 6, Update 7)
SUSE Linux Enterprise Real Time 10 Service Pack 2 (SP2) update 6 (2.6.22.19-0.22-rt kernel)
Red Hat Enterprise MRG 1.1
--note--
I was going to edit/comment on someone else's post but it looks like it has disappeared :(
Related
I wrote a client server java project using Netbeans on Windows platform. When I profile it on windows it shows 8 threads running but when I run it on Ubuntu, htop shows 21 processes(threads) attached to it. Does anyone know why?
Yes. The numbers mean different things. In Windows there are process and threads. In contrast, Linux uses a 1-1 threading model.
I am running a simple script in Groovy on an Ubuntu 11.10 machine, which takes key/value pairs and adds them to a JDBM map in a loop. Every ~3 minutes the script hangs for a couple of minutes and then resumes. When I look at the resource monitor I see that there is no CPU or Memory activity and the process is in futex_wait_queue_me().
Please suggest means to overcome this, on a Windows machine by the way the application runs without the hangs.
Could this be an OS issue? (found many similar threads about similar futex_wait_queue_me() problems in Ubuntu0
Thanks
Please check the version of the kernel. I ran into a similar problem (java and other multithreaded applications) on Centos6 and upgrading the kernel to version 2.6.32-504.16.2.el6.x86_64 solved the issue.
See the centos bug report: https://bugs.centos.org/view.php?id=8703 which contains this pointer to an explanation of the problem:
https://github.com/torvalds/linux/commit/76835b0ebf8a7fe85beb03c75121419a7dec52f0 [^]
My stacktrace was:
cat /proc/23199/stack
[<ffffffff810b226a>] futex_wait_queue_me+0xba/0xf0
[<ffffffff810b33a0>] futex_wait+0x1c0/0x310
[<ffffffff810b4c91>] do_futex+0x121/0xae0
[<ffffffff810b56cb>] sys_futex+0x7b/0x170
[<ffffffff8100b072>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff
For anyone interested I used those parameters when running java:
-Xms16384M -Xmx16384M
You can find additional GC optimization tips at http://randomlyrr.blogspot.it/2012/03/java-tuning-in-nutshell-part-1.html
I am thinking about buying an Apple Powerbook 1.5 GHz machine. While my primary focus for that machine would be internet, I may also do some programming on that machine since it would be the machine I would be taking to college...
What I wanted to know if there would be any major difference in context with the compilers used etc? Would I have to setup a completely different environment for the Power PC?
To be fairly clear, my primary categories of work include:
* Python {i know mac supports this right out of the box}
* PHP/MySQL
* HTML/CSS
* Javascript
* Java - I will be starting to learn Java, do this is pretty significant.
I am a complete n00b as far as Mac OS is concerned. Any and every help is appreciated.
PS: If this falls in the wrong category, I apologise.
Keep in mind that, with the latest recent release of OS X, 10.6 or Snow Leopard, Apple has pulled the plug on Power PC Macs: 10.6 does not run on any PPC Mac. Based on its past support policies, you can expect that Apple will continue to provide security updates and, possibly some bug fixes and minor features, for 10.5 (Leopard) until the next release of OS X (as yet, unannounced). But you can also expect that more and more things will be released by Apple or third-parties that are Intel-only, like the things already mentioned. Of the list you mentioned, it would seem that the only immediate concern is Java 1.6; Python and the rest will be no problem for a long-time to come.
By the way, you might want to check out MacPorts and Fink, two independent projects that tailor and package for OS X hundreds of popular open source packages. If it isn't already shipped with OS X or you need a newer version, you may find something you need there.
The Powerbook can't do Java 1.6. That might be a problem for you. You also can't do iPhone development on it. Other than that, once it's maxed out on RAM it's a pretty decent development environment.
I own a MacBook (intel core 2 duo processor) myself and would strongly discourage you to get an older model than that if you want to get reasonably up-to-date java support. (Java 1.6 does not work on older models as far as I know) I really like my macbook and it is a great development machine for me, but I have strong doubts on the java support (See for example http://stuffthathappens.com/blog/2007/10/28/os-x-java-definitive-timeline/).
I have an 12" 1.5 Ghz, 1.25GB ram G4 Powerbook and I wouldn't recommend it for java development due to the fact that running an IDE (Eclipse or NetBeans) will be painfully slow. Also expect to buy a new battery for an old laptop.
If 10.5 is not enough for you, you may want to consider installing Linux since the StuffIt you mention is easy to install with e.g. Ubuntu.
I'd like to install Java on a Psion 5MX with GNU/Linux 16MB RAM machine, will it be possible?
Unfortunatly, "KVM must be installed by the manufacturer".
What I want is to be able to is to write basic Java code, test and sketch simple algorithms.
Important notes: I don't need the graphic part since I'll only use the console (no graphic server) but this will be inside a Debian.
There is a List of Java virtual machines on Wikipedia, with a number of them open source and targeting embed devices. Like Mika which seems quite small and portable.
Please give us more details about the machine, besides the OS and the memory. Also give us details on what you hope to accomplish with Java on such an underpowered machine (Java has some big overhead in embedded places as compared to writing native code).
The answer is maybe. I've seen Java running on a machine with 4MB of RAM, but it was not running Linux (in fact there was no OS at all). Link: Java on the Nintendo DS
The Squawk virtual machine is designed for small devices. It's probably got sub-par performance though since most of it is in java.
Probably a little late but I'd also suggest Squawk. It runs on sun spot devices which have 160k of membory (or something in that area). 160mhz CPU. The whole JVM is open source so you can try to re-write it for your own devices :)
I just get the beach ball all day long (it's been doing nothing for hours). It's not taking CPU, not reading from disk, not using the network.
I'm using Java 1.6 on Mac OS X 10.5.4. It worked once, now even restarts of the computer won't help. Activity Monitor says it's "(Not Responding)". Only thing that I can do is kill -9 that sucker.
When I sample the process I see this:
mach_msg_trap 16620
read 831
semaphore_wait_trap 831
An acceptable answer that doesn't fix this would include a url for a decent free Oracle client for the Mac.
Edit:
#Mark Harrison sadly this happens every time I start it up, it's not an old connection. I'll like to avoid running Windows on my laptop. I'm giving some plugins for my IDE a whirl, but still no solution for me.
#Matthew Schinckel Navicat seems to only have a non-commercial Oracle product...I need a commercial friendly one (even if it costs money).
I get the same problem after there's been an active connection sitting idle for a while. I solve it by restarting sql developer every once in a while.
I also have Toad for Oracle running on a vmware XP session, and it works great. If you don't mind the money, try that.
The company Navicat has released an Oracle client for Mac (and they do a Windows version too).
It's not free, but I think you can get a 30 day demo.
Have you looked at http://www.aquafold.com/? They have a very JDBC/java Mac-friendly utility, Aqua Data Studio (ADS) that you can try for I think 30 days. It's not free, but...
Excellent support via Yahoo groups. VERY responsive re bugs or enhancement requests.
No affiliation with them - just a fan.
Squirrel is a nice database agonstic application development client. No Oracle specific features, but runs well on the mac
I use SQLDeveloper on the Mac and have had problems where it becomes unresponsive. Usually, I can fix this by going into the Activity Monitor and killing the process. However, this doesn't always work to end the process. When that happens, I go to the Terminal and find the process id and send it a SIGKILL and then the next time it will work correctly.
However, more importantly I evaluated SQLGrinder at one point. I didn't end up buying the software, largely because I have a Mac laptop and a windows desktop. Therefore, I more often use Toad on the windows desktop and it wasn't worth purchasing SQLGrinder for me.
Use RazorSQL. Do yourself a favor and spend the 60 bucks. It will pay for itself in the first hour or two of use. You may even be able to get 60 days for free out of it.
The latest version of SQL Developer is very good and I have experienced no problems with it on my Mac Pro. DB Solo 3 is also quite good.