Re: jni link error
--On Tuesday, May 15, 2001 09:34:50 -0700 Nathan Meyers <[EMAIL PROTECTED]> wrote: > Zhihong Pan wrote: > >> I need jni in my java application. I created a shared library, and set >> my library path (export LD_LIBRARY=/home/mydir/), but I still get the >> following error message:java.lang.UnsatisfiedLinkError: no java_gsapi in >> java.library.path. Could anybody help me ? > > You need LD_LIBRARY_PATH instead of LD_LIBRARY. Can anyone explain to me why having the file in the path set in ld.so.conf shouldn't be enough? --Chris -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Signals, JNI and sigtimedwait()...
Okay, I'm writing some JNI code for some stuff using RT signals. I need to do some sigtimedwaits, which then post as IO events to the JVM. My original design was to have Java threads invoke something like waitForIO(), which was a native method which did the sigtimedwait(). Unfortunately, this seems like to cause problems for the JVM's GC. Is the only solution to use native threads, have them "join" the VM to post events, and then have them "leave" the VM before invoking sigtimedwait() again? That seems just really slow and painful. --Chris -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Java/Linux at JavaOne
Took a quick look at the JavaOne schedule and saw two major Linux related talks: The Java 2 Platform, Standard Edition (J2SE) on Linux Sun telling us what's up http://servlet.java.sun.com/javaone/conf/sessions/1641/0-sf2001.jsp Tuesday June 5, 2:45 PM - 3:45 PM The Penguin Gets Pumped Up . . . Turning Linux into a High-Powered Java Technology-Based Application Server Java/Linux performance talk http://servlet.java.sun.com/javaone/conf/sessions/934/0-sf2001.jsp Friday June 8, 8:30 AM - 9:30 AM The JavaTM 2 Platform on Linux Caldera and Blackdown folks, BoF http://servlet.java.sun.com/javaone/conf/bofs/1745/0-sf2001.jsp Monday June 4, 10:30 PM - 11:20 PM [EMAIL PROTECTED] . . . .. . . . http://www.media.mit.edu/~nelson/ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: jni link error
On Tue, 29 May 2001, Christopher Smith wrote: > > Can anyone explain to me why having the file in the path set in ld.so.conf > shouldn't be enough? Heh. Try getting the security nazis to agree to THAT for a user application. I'm not sure, but I don't think the JVM uses ld to load its stuff. Otherwise why would it keel over when the shared library still has unresolved references? -- Joi EllisSoftware Engineer Aravox Technologies [EMAIL PROTECTED], [EMAIL PROTECTED] No matter what we think of Linux versus FreeBSD, etc., the one thing I really like about Linux is that it has Microsoft worried. Anything that kicks a monopoly in the pants has got to be good for something. - Chris Johnson -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: jni link error
--On Tuesday, May 29, 2001 17:21:41 -0500 Joi Ellis <[EMAIL PROTECTED]> wrote: > On Tue, 29 May 2001, Christopher Smith wrote: > >> >> Can anyone explain to me why having the file in the path set in >> ld.so.conf shouldn't be enough? > > Heh. Try getting the security nazis to agree to THAT for a user > application. Umm... on most systems ld.so.conf can only be modified by root, and normally you only set it to include "safe" directories. I mean, if I can load in fake shared libraries into ld.so.conf, I can hose your system regardless (through libc for example). --Chris -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Java/Linux at JavaOne
--On Tuesday, May 29, 2001 15:01:25 -0700 Nelson Minar <[EMAIL PROTECTED]> wrote: > The Penguin Gets Pumped Up . . . Turning Linux into a High-Powered > Java Technology-Based Application Server > Java/Linux performance talk > http://servlet.java.sun.com/javaone/conf/sessions/934/0-sf2001.jsp > Friday June 8, 8:30 AM - 9:30 AM That's mine. It should be fun. We're mostly going to focus on the scalability issue, which appears to be the major question on everyone's mind. If anyone thinks there are other things I should be speaking to, say it now. ;-) --Chris -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: jni link error
> I'm not sure, but I don't think the JVM uses ld to load its stuff. If the JVM uses anything other than the standard dlsym() I think it'd really be asking for trouble ... why would it want to do that, anyway? -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Java/Linux at JavaOne
Chris, It might be helpful and may even spawn other suggestions if you were to flesh out in a post some of the aspects, as you articulate them, of scaling Java on Linux. Perhaps a kind of pre-BoF statement of the topic to be discussed? Thanks, Ed Phillips Christopher Smith wrote: > --On Tuesday, May 29, 2001 15:01:25 -0700 Nelson Minar <[EMAIL PROTECTED]> > wrote: > > The Penguin Gets Pumped Up . . . Turning Linux into a High-Powered > > Java Technology-Based Application Server > > Java/Linux performance talk > > http://servlet.java.sun.com/javaone/conf/sessions/934/0-sf2001.jsp > > Friday June 8, 8:30 AM - 9:30 AM > > That's mine. It should be fun. We're mostly going to focus on the > scalability issue, which appears to be the major question on everyone's > mind. If anyone thinks there are other things I should be speaking to, say > it now. ;-) > > --Chris > > -- > To UNSUBSCRIBE, email to [EMAIL PROTECTED] > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Java/Linux at JavaOne
Excuse me, It is a session not a BoF, but the question still might be helpful pre-session. Christopher Smith wrote: > --On Tuesday, May 29, 2001 15:01:25 -0700 Nelson Minar <[EMAIL PROTECTED]> > wrote: > > The Penguin Gets Pumped Up . . . Turning Linux into a High-Powered > > Java Technology-Based Application Server > > Java/Linux performance talk > > http://servlet.java.sun.com/javaone/conf/sessions/934/0-sf2001.jsp > > Friday June 8, 8:30 AM - 9:30 AM > > That's mine. It should be fun. We're mostly going to focus on the > scalability issue, which appears to be the major question on everyone's > mind. If anyone thinks there are other things I should be speaking to, say > it now. ;-) > > --Chris > > -- > To UNSUBSCRIBE, email to [EMAIL PROTECTED] > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: Java/Linux at JavaOne
--On Tuesday, May 29, 2001 21:25:20 -0700 ed phillips <[EMAIL PROTECTED]> wrote: > It might be helpful and may even spawn other suggestions if > you were to flesh out in a post some of the aspects, as you articulate > them, of scaling Java on Linux. Perhaps a kind of pre-BoF statement of > the topic to be discussed? That's a good suggestion. Here goes: The biggest problem with scaling Java on Linux are threads. No question about it. Linux 2.4.x is very scalable to even as many as 16 processors, with excellent network, memory, and disk performance (particularly now with XFS & ReiserFS). In my experience, most Java applications won't push the kernel's capabilities in these areas even on a $2000 1U server with a single processor, and those that do will find Linux scales just as well as everyone else. So, the thread issue is a nasty one, particularly if you're say hosting servlets on Linux. 90% of the reason you need all these threads is due to the thread-per-IO model in standard Java I/O. Unfortunately, this doesn't map too efficiently to the 1-1 thread model found in most Linux JVM's. There are a few strategies for coping with this: 1) Use green threads (people don't normally think of this as an OK solution for an application server) 2) Have a C or other application multiplex the I/O either over sockets or JMS. 3) Use lots of boxes & tweak the kernel to allow as many threads as possible. 4) Use JNI to use Linux's various asynch I/O API's. The good news is Linux's thread model is moving in a direction to better support Java's approach to I/O (IBM's next generation pthreads implementation), and Java's approach to I/O (NIO) is moving closer to the efficient way to do I/O with Linux. Indeed, we're working on some benchmarks right now for #4 and also using NIO to see just how far Linux will go. My bet is Linux is actually going to prove very cost-effective in terms of scalability with this stuff. --Chris -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
