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vapid cutlery posted:it's cool how tihs always happens. some company or govt body that has been doing things successfully for over 50 years shares some insight into how they do things, and goons come out of everywhere to tell them they're wrong
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# ? Aug 8, 2012 20:21 |
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# ? May 9, 2024 01:43 |
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Gazpacho posted:adaz isn't a JPL developer thank god and it's his "explanation" i'm dismissing not the jpl document that he's using as an authority, come on ahhh spiders there's no way you are this dense you didn't link to the quote so i assumed it was from the document
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# ? Aug 8, 2012 20:21 |
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so yea that guys a dumbass
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# ? Aug 8, 2012 20:22 |
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2012: year of lua in space
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# ? Aug 8, 2012 20:22 |
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Rule 14 (checking return values) The return value of non-void functions shall be checked or used by each calling function, or explicitly cast to (void) if irrelevant. [MISRA-C:2004 Rule 16.10; Power of Ten Rule 7] Rule 15 (checking parameter values) The validity of function parameters shall be checked at the start of each public function. The validity of function parameters to other functions shall be checked by either the function called or by the calling function. [MISRAC:2004 Rule 20.3; Power of Ten Rule 7] This is consistent with the principle that the use of total functions is preferable over non-total functions. A total function is setup to handle all possible input values, not just those parameter values that are expected when the software functions normally.
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# ? Aug 8, 2012 20:24 |
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Cocoa Crispies posted:Rule 14 (checking return values) So, justifying these with Therac-25: 14: "Is the return value sane? If we don't care, make it explicit." Some compilers actually enforce/bitch if you get values but never use them. If you get a return value but never use it, why are you calling the function? If it's for the side effects, is the return value telling you something you need to know and you're just ignoring it? If so, this section of code needs to be reviewed for "why." quote:The engineer had reused software from older models. These models had hardware interlocks that masked their software defects. Those hardware safeties had no way of reporting that they had been triggered, so there was no indication of the existence of faulty software commands. If the hardware was returning values and the software wasn't checking it, beep boop you just rape rayed somebody into oblivion. 15: "Make sure functions are called with valid arguments." quote:The software set a flag variable by incrementing it. Occasionally an arithmetic overflow occurred, causing the software to bypass safety checks. JPL's rules are borne out of studying critical software systems: i.e. ones where lives or expensive poo poo are at risk and not just nudie videos or xml bullshit.
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# ? Aug 8, 2012 20:32 |
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Gazpacho posted:i know crazy poo poo happens in space but if you cant even trust your ALU then you better shield that poo poo until you can Attack of the Cosmic Rays!
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# ? Aug 8, 2012 20:59 |
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i am a cowboy coder a SPACE cowboy coder
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# ? Aug 8, 2012 21:01 |
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Cocoa Crispies posted:it's actually a 32-bit powerpc just like my olde ibook i seem to recall the F-22 and F-35 using powerpc CPUs as well.
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# ? Aug 8, 2012 21:05 |
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http://www.cs.toronto.edu/~bianca/papers/sigmetrics09.pdf quote:Our data covers the majority of machines in Google’s fleet and spans nearly 2.5 years, from January 2006 to June 2008. Each machine comprises a motherboard with some proces- sors and memory DIMMs. We study 6 different hardware platforms, where a platform is defined by the motherboard and memory generation. these machines have an atmosphere, magnetosphere, buildings, and heavy cases to protect them spacecraft don't
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# ? Aug 8, 2012 21:09 |
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Star War Sex Parrot posted:serious question: why do NASA and defense contractors love these CPUs so much? the f-22 was born from the advanced tactical fighter program which started in 1990 or so, when the power architecture was hot poo poo the f-35 is also made by lockheed and probably had some engineers overlapping
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# ? Aug 8, 2012 21:10 |
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Star War Sex Parrot posted:serious question: why do NASA and defense contractors love these CPUs so much? because they love 'em, know they work well, know vxworks for ppc works well, and know that their engineers work with all of the above well
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# ? Aug 8, 2012 21:14 |
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hey what i was sayin early about adaz and jpl, that was just pay it no mind
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# ? Aug 8, 2012 21:16 |
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Nice!
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# ? Aug 8, 2012 21:19 |
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Star War Sex Parrot posted:serious question: why do NASA and defense contractors love these CPUs so much? they know about the megahertz myth
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# ? Aug 8, 2012 21:43 |
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hm, I thought they might somehow be more reliable/resilient in adverse conditions i guess it just has more to do with the fact that these projects take decades to finish
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# ? Aug 8, 2012 21:44 |
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Cocoa Crispies posted:because they love 'em, know they work well, know vxworks for ppc works well, and know that their engineers work with all of the above well also the only rad-hardened x86 cpu intel produced until recently was a 386 variant
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# ? Aug 8, 2012 21:45 |
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Star War Sex Parrot posted:serious question: why do NASA and defense contractors love these CPUs so much? non-commodity hardware is more expensive which makes padding budgets easier. "we gotta have these arcane procs because of magic so no price is too much"
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# ? Aug 8, 2012 21:45 |
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Star War Sex Parrot posted:hm, I thought they might somehow be more reliable/resilient in adverse conditions Nomnom Cookie posted:also the only rad-hardened x86 cpu intel produced until recently was a 386 variant and then they quit making 386 variants and now don't make any or didn't make any when these projects were started
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# ? Aug 8, 2012 21:48 |
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Cocoa Crispies posted:they are, because they can get radiation hardened ones, because nobody bought anyone else's radiation hardened chips nah they've made 386s for fuckin ever and just stopped a couple years ago. now there's a new one that's probably sandy bridge or something
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# ? Aug 8, 2012 21:51 |
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Star War Sex Parrot posted:hm, I thought they might somehow be more reliable/resilient in adverse conditions they use radiation hardened chips
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# ? Aug 8, 2012 21:52 |
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my motherboard is military grade
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# ? Aug 8, 2012 21:52 |
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http://www.baesystems.com/product/BAES_028145/rad750-family-of-products
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# ? Aug 8, 2012 21:53 |
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i spray painted camo onto my keyboard so that should count for something
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# ? Aug 8, 2012 21:55 |
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tef posted:they use radiation hardened chips
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# ? Aug 8, 2012 21:56 |
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Nomnom Cookie posted:nah they've made 386s for fuckin ever and just stopped a couple years ago. now there's a new one that's probably sandy bridge or something yeah that's what i said but sandy bridge wasn't around when they started curiosity and you don't switch CPUs in the middle of a project especially if it's a new unproven one and your project is already hella over budget
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# ? Aug 8, 2012 21:56 |
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can i get a rad hardened billy bass?
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# ? Aug 8, 2012 21:56 |
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my keyboard is black so its already space camo
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# ? Aug 8, 2012 21:56 |
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rad-hardened parts are going to be the next crazy in high end gaming rigs
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# ? Aug 8, 2012 21:58 |
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Cocoa Crispies posted:yeah that's what i said ah i thought you meant the f-22 and f-35. yeah i expect it'll be a little while before anyone thinks about shooting sandy bridge into space
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# ? Aug 8, 2012 21:59 |
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Otto Skorzeny posted:good luck not doing any dynamic allocation in java! here's some java that does very little dynamic allocation: Java code:
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# ? Aug 8, 2012 21:59 |
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fwiw, yeah the coding standards are mostly about having total coverage from static analysis. reminds me of what a PhD told me in passing "turing complete is overrated". there are some other notes about how they do failure handling in software and hardware elsewhere. and how much code is auto generated from specifications of state machines apparently depends on the flight director. as much as I think the jpl standards are neat for lifting C into a mission critical language, I think in the future, languages like 'rust' could be a better tool for these sorts of systems.
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# ? Aug 8, 2012 22:00 |
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Win8 Hetro Experie posted:here's some java that does very little dynamic allocation: get real
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# ? Aug 8, 2012 22:01 |
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tef posted:fwiw, yeah the coding standards are mostly about having total coverage from static analysis. reminds me of what a PhD told me in passing "turing complete is overrated". do you think it's realistic for any language that's not C to be adopted by aerospace types? maybe once the olds die off
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# ? Aug 8, 2012 22:02 |
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Panic! At The cisco posted:can i get a rad hardened billy bass? rad hardened tofu bass
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# ? Aug 8, 2012 22:02 |
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tef posted:fwiw, yeah the coding standards are mostly about having total coverage from static analysis. reminds me of what a PhD told me in passing "turing complete is overrated". i doubt anyone is going to bother porting rust to whatever janky isa satellite cpus use and going through the hell of getting their compiler certified to generate Space Binaries
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# ? Aug 8, 2012 22:06 |
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vapid cutlery posted:rad-hardened parts are going to be the next crazy in high end gaming rigs lol you think gamers can afford that
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# ? Aug 8, 2012 22:24 |
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Cocoa Crispies posted:lol you think gamers can afford that it will just be some fake bullshit like my military grade motherboard
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# ? Aug 8, 2012 22:26 |
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vapid cutlery posted:do you think it's realistic for any language that's not C to be adopted by aerospace types? maybe once the olds die off http://en.wikipedia.org/wiki/Ada_(programming_language)
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# ? Aug 8, 2012 22:27 |
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# ? May 9, 2024 01:43 |
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vapid cutlery posted:it will just be some fake bullshit like my military grade motherboard that't not "rad-hardened" and you can see how well ECC rams have taken off with gamers
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# ? Aug 8, 2012 22:28 |