I'm rather annoyed that Apple has chosen not to open their modifications to J2SE 1.5 and greater, since the project is now open source and can even be built on Windows by anyone that wants to... kind of ironic it can't be built on a supposedly more open operating system.
The reason I really care is that I can't use anything but Java 1.4 on our OS 10.3 systems; I have no interest in upgrading to 10.4 except for the fact that Apple refuses to port J2SE to such an old and outdated os as OS 10.3.....
Yes, here is an email my OS prof sent our class on the subject:
Subject: What really happened on Mars Rover Pathfinder
The Mars Pathfinder mission was widely proclaimed as "flawless" in the early days after its July 4th, 1997 landing on the Martian surface. Successes included its unconventional "landing" -- bouncing onto the Martian surface surrounded by airbags, deploying the Sojourner rover, and gathering and transmitting voluminous data back to Earth, including the panoramic pictures that were such a hit on the Web. But a few days into the mission, not long after Pathfinder started gathering meteorological data, the spacecraft began experiencing total system resets, each resulting in losses of data. The press reported these failures in terms such as "software glitches" and "the computer was trying to do too many things at once".
This week at the IEEE Real-Time Systems Symposium I heard a fascinating keynote address by David Wilner, Chief Technical Officer of Wind River Systems. Wind River makes VxWorks, the real-time embedded systems kernel that was used in the Mars Pathfinder mission. In his talk, he explained in detail the actual software problems that caused the total system resets of the Pathfinder spacecraft, how they were diagnosed, and how they were solved. I wanted to share his story with each of you.
VxWorks provides preemptive priority scheduling of threads. Tasks on the Pathfinder spacecraft were executed as threads with priorities that were assigned in the usual manner reflecting the relative urgency of these tasks.
Pathfinder contained an "information bus", which you can think of as a shared memory area used for passing information between different components of the spacecraft. A bus management task ran frequently with high priority to move certain kinds of data in and out of the information bus. Access to the bus was synchronized with mutual exclusion locks (mutexes).
The meteorological data gathering task ran as an infrequent, low priority thread, and used the information bus to publish its data. When publishing its data, it would acquire a mutex, do writes to the bus, and release the mutex. If an interrupt caused the information bus thread to be scheduled while this mutex was held, and if the information bus thread then attempted to acquire this same mutex in order to retrieve published data, this would cause it to block on the mutex, waiting until the meteorological thread released the mutex before it could continue. The spacecraft also contained a communications task that ran with medium priority.
Most of the time this combination worked fine. However, very infrequently it was possible for an interrupt to occur that caused the (medium priority) communications task to be scheduled during the short interval while the (high priority) information bus thread was blocked waiting for the (low priority) meteorological data thread. In this case, the long-running communications task, having higher priority than the meteorological task, would prevent it from running, consequently preventing the blocked information bus task from running. After some time had passed, a watchdog timer would go off, notice that the data bus task had not been executed for some time, conclude that something had gone drastically wrong, and initiate a total system reset.
This scenario is a classic case of priority inversion.
HOW WAS THIS DEBUGGED?
VxWorks can be run in a mode where it records a total trace of all interesting system events, including context switches, uses of synchronization objects, and interrupts. After the failure, JPL engineers spent hours and hours running the system on the exact spacecraft replica in their lab with tracing turned on, attempting to replicate the precise conditions under which they believed that the reset occurred. Early in the morning, after all but one engineer had gone
Well, I recently bought a VoodooPC (m:855 laptop) cause as the time it was the only laptop with an Athlon 64. It should have been top of the line, but unfortunately Nvidia was not an option, and even in Windows ATI's drivers suck (at least on my voodoo). On top of that, I've suffered from random power offs in windows and graphical glitches and tearing in many games, even though i have a friend with another laptop and the same ATI Radeon 9600 chipset w/o any such problems. This laptop has been nothing but a pain in the ass and the wallet:(
Has anyone made progress on hacking the nvidia drivers to work on the XBox? If so, there is software, called Chromium I belive, that can take advantage of multiple OpenGL rendering nodes, making the XBox a very cost effective platform for such a project.
Linux was running on an embedded computer soley used for communication, not to control any of the systems on board. Such a toy would hardly cause the shuttle to explode into a fireball.
You are the worst kind of fucking troll. Normally, I don't even care about trolls, or the linux zealots on the other side, but now you are using NASA's disaster as feed for your trolling with absolutely no rationalized basis for your argument.
Actually, according to something a professor told our class, men stand a 1/50 chance of having features as good as Ken's, while women stand a 1/100,000 chance of having features as good a Barbie. So, not impossible really.
There are Linux drivers for 3 different platforms intel based platforms now. There are OS X drivers for PowerPC. Why can't Nvidia merge some of that code to give us Linux/PPC Nvidia drivers. A lack of a good graphics system for Linux/PPC is the major factor holding it back. Hopefully these things will change once IBM's GPuL hits the shelves.
First of all, it is good to see an author using linux, especially a sci-fi author.
It seems that there is a lot of criticism of his novels here, and I agree that there is a vast quantity of sci-fi and fantasy books produced that are of very poor quality (though I have only read a few of these poorer quality books).
If you want to know if a Sci-Fi book is good, compare it to Frank Herbert's Dune series (many people say that the latter books get dull, but I say to these people all you care about is cheap action -- there are other things worth reading about).
As for Fantasy, Tolkien's works and Robert Jordan's Wheel of Time series should be the standard to hold your novels up against.
Two notes:
1) Robert Jordan seems to borrow (or perhaps integrate would be a better word) many ideas (words, peoples, plot lines, etc.) from Herbet's Dune series into Wheel of Time. The analogous nature is easy to spot, but WoT is still very good.
2) Don't copy things too much, that goes for you Terry Goodkind! While Sword of Truth is certainly pretty good (at least when I was still reading it 4 years ago, your fisrt book was your best, but you copy way too many things from Wheel of Time -- the plot lines are too similar).
Does anyone know how vp3 compares to other codecs that are already here or emerging, namely MPEG3 and DivX? Ogg is obviously making headway in the technical area of being the best lossy audio codec, and if vp3 can do the same, then hopefully this will give Free Software an edge in the media areas.
One problem here though; I suggest someone adapt the VP3 code to a GPL license, ortherwise Microsoft, Apple, or any other company could simply take VP3 and make it Free Software's worst enemy by not releasing specs on the derivative audio codec. Observe: we are just now beginning to see Sorenson codecs that are open source.
Slashdot Mirror
I'm rather annoyed that Apple has chosen not to open their modifications to J2SE 1.5 and greater, since the project is now open source and can even be built on Windows by anyone that wants to ... kind of ironic it can't be built on a supposedly more open operating system.
.....
The reason I really care is that I can't use anything but Java 1.4 on our OS 10.3 systems; I have no interest in upgrading to 10.4 except for the fact that Apple refuses to port J2SE to such an old and outdated os as OS 10.3
I never could get my Indys off ebay to work ... looks like I'm really goonna be SoL.
If it is just downloaded and not installed?
There are two kinds of people, those that read 10, and those who do not ...
But seriously, I'd say MS takes pretty good care of their employees ... but maybe someone knows more about this.
Yes, here is an email my OS prof sent our class on the subject:
Subject: What really happened on Mars Rover Pathfinder
The Mars Pathfinder mission was widely proclaimed as "flawless" in the early
days after its July 4th, 1997 landing on the Martian surface. Successes
included its unconventional "landing" -- bouncing onto the Martian surface
surrounded by airbags, deploying the Sojourner rover, and gathering and
transmitting voluminous data back to Earth, including the panoramic pictures
that were such a hit on the Web. But a few days into the mission, not long
after Pathfinder started gathering meteorological data, the spacecraft began
experiencing total system resets, each resulting in losses of data. The
press reported these failures in terms such as "software glitches" and "the
computer was trying to do too many things at once".
This week at the IEEE Real-Time Systems Symposium I heard a fascinating
keynote address by David Wilner, Chief Technical Officer of Wind River
Systems. Wind River makes VxWorks, the real-time embedded systems kernel
that was used in the Mars Pathfinder mission. In his talk, he explained in
detail the actual software problems that caused the total system resets of
the Pathfinder spacecraft, how they were diagnosed, and how they were
solved. I wanted to share his story with each of you.
VxWorks provides preemptive priority scheduling of threads. Tasks on the
Pathfinder spacecraft were executed as threads with priorities that were
assigned in the usual manner reflecting the relative urgency of these tasks.
Pathfinder contained an "information bus", which you can think of as a
shared memory area used for passing information between different components
of the spacecraft. A bus management task ran frequently with high priority
to move certain kinds of data in and out of the information bus. Access to
the bus was synchronized with mutual exclusion locks (mutexes).
The meteorological data gathering task ran as an infrequent, low priority
thread, and used the information bus to publish its data. When publishing
its data, it would acquire a mutex, do writes to the bus, and release the
mutex. If an interrupt caused the information bus thread to be scheduled
while this mutex was held, and if the information bus thread then attempted
to acquire this same mutex in order to retrieve published data, this would
cause it to block on the mutex, waiting until the meteorological thread
released the mutex before it could continue. The spacecraft also contained
a communications task that ran with medium priority.
Most of the time this combination worked fine. However, very infrequently
it was possible for an interrupt to occur that caused the (medium priority)
communications task to be scheduled during the short interval while the
(high priority) information bus thread was blocked waiting for the (low
priority) meteorological data thread. In this case, the long-running
communications task, having higher priority than the meteorological task,
would prevent it from running, consequently preventing the blocked
information bus task from running. After some time had passed, a watchdog
timer would go off, notice that the data bus task had not been executed for
some time, conclude that something had gone drastically wrong, and initiate
a total system reset.
This scenario is a classic case of priority inversion.
HOW WAS THIS DEBUGGED?
VxWorks can be run in a mode where it records a total trace of all
interesting system events, including context switches, uses of
synchronization objects, and interrupts. After the failure, JPL engineers
spent hours and hours running the system on the exact spacecraft replica in
their lab with tracing turned on, attempting to replicate the precise
conditions under which they believed that the reset occurred. Early in the
morning, after all but one engineer had gone
But even so, I never would have seen this coming.
Well, I recently bought a VoodooPC (m:855 laptop) cause as the time it was the only laptop with an Athlon 64. It should have been top of the line, but unfortunately Nvidia was not an option, and even in Windows ATI's drivers suck (at least on my voodoo). On top of that, I've suffered from random power offs in windows and graphical glitches and tearing in many games, even though i have a friend with another laptop and the same ATI Radeon 9600 chipset w/o any such problems. This laptop has been nothing but a pain in the ass and the wallet :(
too bad the gov can't reject the patent applications because MS is a monopoly ... i think some antitrust laws need to be changed
Haha, reminds me of this, although its a little more funny since this is someone's personal comp:
l es s759.jpg
http://prycless.orsm.net/prycless38/images/pryc
Just because i like cheeseburgers more than steak doesn't mean i like windows more than linux ... sheesh
Has anyone made progress on hacking the nvidia drivers to work on the XBox? If so, there is software, called Chromium I belive, that can take advantage of multiple OpenGL rendering nodes, making the XBox a very cost effective platform for such a project.
All of us are still using 2.2 kernels, whether we like it or not.
I wasn't saying that you were flaming, just a disclaimer that he shouldn't be flamed because his style can be ... derogatory and blatant at times.
Don't flame this guy; he is way smarter than we will ever be (I'm serious): check his site out at http://maddox.xmission.com/
Read some of the content on his site and see if you agree that the parent is in fact maddox.
The parent has some good points. Has NASA really done anything all that great recently? Maybe this disaster will help clean up NASA, but probably not.
Is that you, Maddox?
You dumbass.
Linux was running on an embedded computer soley used for communication, not to control any of the systems on board. Such a toy would hardly cause the shuttle to explode into a fireball.
You are the worst kind of fucking troll. Normally, I don't even care about trolls, or the linux zealots on the other side, but now you are using NASA's disaster as feed for your trolling with absolutely no rationalized basis for your argument.
Dipshit.
Actually, according to something a professor told our class, men stand a 1/50 chance of having features as good as Ken's, while women stand a 1/100,000 chance of having features as good a Barbie. So, not impossible really.
There are Linux drivers for 3 different platforms intel based platforms now. There are OS X drivers for PowerPC. Why can't Nvidia merge some of that code to give us Linux/PPC Nvidia drivers. A lack of a good graphics system for Linux/PPC is the major factor holding it back. Hopefully these things will change once IBM's GPuL hits the shelves.
aren't really funny, except in the way that they make me really angry when I hear them.
You may want to take a look at using Trolltech's QT for the GUI; it is very portable and already has nice support for OpenGL.
Indeed, if we do experience a short "ice age" then many people will think globabl warming was a bunch of hogwash and say it is ok to pollute.
Does anyone know if it is possible to use some sort of toolchain with Kylix to cross-compile software for architectures other than x86?
First of all, it is good to see an author using linux, especially a sci-fi author.
It seems that there is a lot of criticism of his novels here, and I agree that there is a vast quantity of sci-fi and fantasy books produced that are of very poor quality (though I have only read a few of these poorer quality books).
If you want to know if a Sci-Fi book is good, compare it to Frank Herbert's Dune series (many people say that the latter books get dull, but I say to these people all you care about is cheap action -- there are other things worth reading about).
As for Fantasy, Tolkien's works and Robert Jordan's Wheel of Time series should be the standard to hold your novels up against.
Two notes:
1) Robert Jordan seems to borrow (or perhaps integrate would be a better word) many ideas (words, peoples, plot lines, etc.) from Herbet's Dune series into Wheel of Time. The analogous nature is easy to spot, but WoT is still very good.
2) Don't copy things too much, that goes for you Terry Goodkind! While Sword of Truth is certainly pretty good (at least when I was still reading it 4 years ago, your fisrt book was your best, but you copy way too many things from Wheel of Time -- the plot lines are too similar).
Does anyone know how vp3 compares to other codecs that are already here or emerging, namely MPEG3 and DivX? Ogg is obviously making headway in the technical area of being the best lossy audio codec, and if vp3 can do the same, then hopefully this will give Free Software an edge in the media areas.
One problem here though; I suggest someone adapt the VP3 code to a GPL license, ortherwise Microsoft, Apple, or any other company could simply take VP3 and make it Free Software's worst enemy by not releasing specs on the derivative audio codec. Observe: we are just now beginning to see Sorenson codecs that are open source.