How (and why) to Ramble on your goat sideways
12-21-2012, 10:08 AM
Boost Pope
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Because I build real-time systems that have to deal with the outside world, often stretching between multiple buildings across connections with variable latency. When A and B happen simultaneously (or if B follows A, but so closely that the leading edge of B occurs before the trailing edge of A), I need to be able to design in such a way that assumes that the state which results from A will occur before the state which results from B, with absolute 100% certainty.
Otherwise, parts of the system that were expecting B to follow A will be left in a hung state, and about a hundred radio stations across the US will all go silent simultaneously (give or take the delay across the satellites.)
Imagine building an enhanced MS2, where the main CPU is in Athens and the sub CPU is in Patra, and the two are connected together by both a packet-switched IP network with laggy data compression and a circuit-switched analog modem, but only one of them as active at any given time and you cannot control (or even sense) which line is active.
Otherwise, parts of the system that were expecting B to follow A will be left in a hung state, and about a hundred radio stations across the US will all go silent simultaneously (give or take the delay across the satellites.)
Imagine building an enhanced MS2, where the main CPU is in Athens and the sub CPU is in Patra, and the two are connected together by both a packet-switched IP network with laggy data compression and a circuit-switched analog modem, but only one of them as active at any given time and you cannot control (or even sense) which line is active.
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12-21-2012, 01:14 PM
Boost Pope
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Hunting down race conditions (and overflows, and other tedious, annoying, nondetermanistic events) inside the interpreter is how I spend half my time when I'm back home in the lab. The goal is 100% atomic operation for all events, regardless of user-created dependencies. And at least in this part of the system, we APPEAR to have actually achieved this.
In this particular system, we are actually using an FPGA to do all of the event handling. Based on user input via a scripting language, the uP assembles events inside the FPGA from a group of boolean primitives, and then the FPGA signals the uP when an event's conditions are met. It was a real bitch of a system to develop, but it's paying off in spades now. The language is blinding simple to use, as we actually have only one test, which is an AND with an unlimited number of inputs, where each input has a switchable inverter.
Groan...
Sidebar: there's a WFAN Store here at terminal 5 of JFK. (WFAN is the biggest sports radio station in the US, possibly in the world.) I argued with them that I deserved a discount on a shirt, however they were unreceptive to this line of reasoning. Perhaps I should have threatened to take WFAN off the air right there in front of them from my laptop...
In this particular system, we are actually using an FPGA to do all of the event handling. Based on user input via a scripting language, the uP assembles events inside the FPGA from a group of boolean primitives, and then the FPGA signals the uP when an event's conditions are met. It was a real bitch of a system to develop, but it's paying off in spades now. The language is blinding simple to use, as we actually have only one test, which is an AND with an unlimited number of inputs, where each input has a switchable inverter.
I've got some semaphore flags left from last year's party if you want them.
Sidebar: there's a WFAN Store here at terminal 5 of JFK. (WFAN is the biggest sports radio station in the US, possibly in the world.) I argued with them that I deserved a discount on a shirt, however they were unreceptive to this line of reasoning. Perhaps I should have threatened to take WFAN off the air right there in front of them from my laptop...
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12-21-2012, 01:20 PM
Sidebar: there's a WFAN Store here at terminal 5 of JFK. (WFAN is the biggest sports radio station in the US, possibly in the world.) I argued with them that I deserved a discount on a shirt, however they were unreceptive to this line of reasoning. Perhaps I should have threatened to take WFAN off the air right there in front of them from my laptop...
Do It! you're not bad!
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12-21-2012, 01:28 PM
Boost Pope
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Sometimes I actually do think about how it would take me about 30 minutes to silence about one third of all radio stations in the major markets of the US.
It scares me that such things even cross my mind.
If I ever decide to commit suicide, I think I will do that first, just to get my obituary on the front page.
It scares me that such things even cross my mind.
If I ever decide to commit suicide, I think I will do that first, just to get my obituary on the front page.
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12-21-2012, 02:28 PM
mkturbo.com
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Sometimes I actually do think about how it would take me about 30 minutes to silence about one third of all radio stations in the major markets of the US.
It scares me that such things even cross my mind.
If I ever decide to commit suicide, I think I will do that first, just to get my obituary on the front page.
It scares me that such things even cross my mind.
If I ever decide to commit suicide, I think I will do that first, just to get my obituary on the front page.
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12-21-2012, 02:59 PM
That's my favorite part of Jeopardy and Wheel of Fortune.
"Melinda, it says here that you have an unusual hobby. Can you tell us about that?"
"Pat, I know this is wacky, but I really enjoy cooking foods from different cultures. Italian, Chinese, you name it, I'm game."
"Melinda, it says here that you have an unusual hobby. Can you tell us about that?"
"Pat, I know this is wacky, but I really enjoy cooking foods from different cultures. Italian, Chinese, you name it, I'm game."
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12-21-2012, 08:06 PM
Tour de Franzia
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So, I made this "Savowood" guy have a melt-down on another forum, lol:
I wanna instruct with TDE or something - General Talk - TrackJunkies.Org
I wanna instruct with TDE or something - General Talk - TrackJunkies.Org
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