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codemastr
Idler
Joined: 05 Feb 2004
Posts: 345
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 Posted: Jan 10, 2005 9:36pm Post subject: |
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| Quote: | | What i meant to say was, threads are annoying. Yeah that's it. |
They can be, but they don't have to be. In C they are difficult because C makes you do everything. In other languages, this is not the case. For example, in C, to "protect" a variable, you must create a mutex (lets assume Pthreads). So you create your mutex_t. Before you access theVar you request the mutex, then when you are done accessing it, you release it. If you forget to request and/or release it, you have a race condition (not good). The old example of this is that a guy has $50 in his bank account, he withdraws $50 from two ATMs at the same time, and the bank erroneously gives him $100, rather than informing him that the account is empty since both threads saw currentBalance == 50.00 and said "there are sufficient funds." Java, on the other hand, does this for you. In Java, I just add the keyword "synchronized" to the member I want to be protected, and Java handles all the mutex stuff for me. Java allows you to use synchronized more broadly to create virtually any critical section you need. Other languages go even further providing tools such as monitors. Threads are only complex in C because C is designed to be as efficient as possible. All these "extras" may make things safer and easier, but they also make things slower. C was designed for speed, not for safety. |
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aquanight
Lurker
Joined: 14 Jun 2004
Posts: 116
Location: Boise, ID
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| Posted: Jan 11, 2005 12:27am Post subject: |
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My operating systems teacher gave us another example of that: where you have $50 in a bank, and you have a $25 paycheck being deposited or a $30 college bill (  ) withdrawn at the same time, and either way you end up with the wrong amount of cash . But yeah, another thing about threads are those nice things called deadlocks which are REALLY fun :/ . Unfortunaly I don't know of any languages that can help you bail out, but if you're watchful of how you manage your locks, you can easily avoid setting yourself up for those. |
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w00t
Eleet
Joined: 09 Jun 2004
Posts: 698
Location: Nowra, Australia
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| Posted: Jan 11, 2005 6:20pm Post subject: |
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To clarify something: What I meant was, you can't read async without threading or some other method that code outlined (he'd know, having gone to university or whatever). Without some method to execute OUTSIDE the current scope, it'd be synchronous and would go back to the whole recipe idea
ie:
do_1();
do_2();
do_3();
would get executed in order, unless one of them was async, in which case, it finishes when it finishes.
Am I getting anywhere yet? |
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EqualSlashed_Brian
Lurker
Joined: 29 Aug 2004
Posts: 221
Location: IRC
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| Posted: Jan 11, 2005 6:51pm Post subject: |
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| Asynchronous programs do not use threads. Period. |
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braindigitalis
Idler
Joined: 22 Sep 2003
Posts: 443
Location: IRC
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| Posted: Jan 12, 2005 6:29pm Post subject: |
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| EqualSlashed_Brian wrote: | | Asynchronous programs do not use threads. Period. |
What you really mean is:
"Asynchronous programs do not explicitly use threads, although black-boxed system calls that they trigger may indeed spawn threads implicitly, that the developer of the program really doesnt need to know about or care about, so long as it works"  |
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Cobi
Lurker
Joined: 30 Dec 2003
Posts: 120
Location: IRC
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| Posted: Jan 15, 2005 12:01am Post subject: |
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| squirrel wrote: | | geez, i wrote a 12,000 line PHP bot that runs on the server along side the ircd, just does goofy stuff really. |
would you mind sending me the source? cobi@winbots.org |
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codemastr
Idler
Joined: 05 Feb 2004
Posts: 345
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| Posted: Jan 15, 2005 11:08am Post subject: |
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| EqualSlashed_Brian wrote: | | Asynchronous programs do not use threads. Period. |
On this forum, it says your rank is "newbie." I guess this applies to your rank as a programmer as well, because you are dead wrong. |
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Robert-E-Lee
Idler
Joined: 22 Nov 2004
Posts: 314
Location: IRC
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| Posted: Jan 15, 2005 12:00pm Post subject: |
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| Moderator's Note: Off-Topic. |
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aquanight
Lurker
Joined: 14 Jun 2004
Posts: 116
Location: Boise, ID
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| Posted: Jan 20, 2005 12:02am Post subject: |
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| You already established that unreal does not use threads. Ok fine. But Unreal DOES use asynchronous DNS resolution (duh). So if aysnchronous does not mean threads, then tell me why Task Manager tells me wircd.exe has 2 threads. |
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EqualSlashed_Brian
Lurker
Joined: 29 Aug 2004
Posts: 221
Location: IRC
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| Posted: Jan 20, 2005 9:11am Post subject: |
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Leave me alone I only code in Python and not well! I just want to fit in. *cries*  |
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zeke
Idler
Joined: 04 Oct 2003
Posts: 334
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| Posted: Jan 20, 2005 2:17pm Post subject: |
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lol EqualSlashed_Brian
I'm a PHPer...and I'm n00b PHPer at that....I'm just as lost as the next guy... |
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[DiMENSiON]
Eleet
Joined: 06 Sep 2003
Posts: 670
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| Posted: Jan 20, 2005 2:39pm Post subject: |
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| I don't code.. 'cos i suck :P .. yeh so sue me.. |
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codemastr
Idler
Joined: 05 Feb 2004
Posts: 345
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| Posted: Jan 22, 2005 7:34pm Post subject: |
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| aquanight wrote: | | You already established that unreal does not use threads. Ok fine. But Unreal DOES use asynchronous DNS resolution (duh). So if aysnchronous does not mean threads, then tell me why Task Manager tells me wircd.exe has 2 threads. |
That has absolutely nothing to do with DNS at all. Unreal for Windows has 1 thread for the GUI, and 1 thread for the rest of the IRCd. Unreal does not create threads for asynchronous DNS. All of that is handled internally by the winsock library. |
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aquanight
Lurker
Joined: 14 Jun 2004
Posts: 116
Location: Boise, ID
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| Posted: Jan 26, 2005 11:00am Post subject: |
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| Erm, why would it have a GUI thread if I'm running it as an NT Service? |
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Digital_Assassin
none
Joined: 20 Mar 2005
Posts: 4
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| Posted: Mar 20, 2005 12:31am Post subject: |
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Ive been working on writing a C# ircd for about a yr. now, i just did a restart on a lot of the project because ive learned better ways of doin things too get the ircd too run the way i want, basically it runs like this ...
Theres 1 main server loop, and everything is basically asyncronous. The server loops through all clients/servers, and calls poll with a 0 timeout. If poll returns read ready, then it goes into an async read method, and reads all data from the client, the loop also checks bans, checks for ping timeouts ... I was gonna make it async read all together, but then id have too make a seperate timer for ping reply's, and checking the ban's ... Right now the ircd doesnt run ive been fixing up a lot of the code, but when i did have it running a while back it ran pretty stable. If anyone would like too help out with the project a bit, feel free too email bmyatt99@msn.com, or send me a msn msg! |
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