August 2007 - Darwin-dev - lists.apple.com

Question about libresolv.
by Terry Simons 25 Aug '07

25 Aug '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Hi, Are Darwin's libresolv sources available? Thanks, - Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… If so, which package does that library live in? I couldn't find "libresolv" on the darwin Intel sources page. This email sent to site_archiver(a)lists.apple.com

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Re: Questions about launchd
by Terry Lambert 25 Aug '07

25 Aug '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On Aug 25, 2007, at 4:40 AM, Finlay Dobbie wrote: On 25/08/07, Terry Lambert <tlambert(a)apple.com> wrote: Certain command conform to standards, and for those commands, we more or less say we expect that they will continue to conform to standards. Which commands? What standards? I'm aware that you're playing devil's advocate here, but I'll give you a straight answer anyway... UNIX Commands. ISO/IEC/POSIX/ANSI and other standards, the list of which may change over time, as deemed appropriate. We define our API at the top of libc, not at the user/kernel boundary. Internally, as an implementation detail, at the user/kernel boundary we occasionally use data interfaces rather than procedural interface. In technical terms, this is "a pig trick", and we can get away with it because the places we use it are very, very constrained, both by locality and by temporal relationship to us shipping new kernels. Some of these are in libraries, and some are strictly in applications, with no way to share the code, other than at a source level. For example, I shudder when anyone tries to write/use their own C libraries not derived from Apple sources, because I know that there are a number of real system calls at the user/kernel boundary that take more parameters than the ones exported by the library, and use symbol decoration in order to select between binary backward compatible interface implementations. The library actually has two (or more) implementations, and which one you get depends on who's asking for it. One of them passes one value in for that extra parameter, while the other passes a different value. I seriously doubt whether a third party could make this work reliably without using our sources as a basis for theirs. Most data interfaces implemented this way are unsupported, meaning you should be prepared for your code to break on each and every software update. Programs like "lsof" and "ps" and "netstat" and so on use these interfaces, and that's OK: we're prepared to change them every time we change a data interface, and they ship with the OS, and if the OS is revised in such a way that they would break, then the command is also revised, so that they don't break, and it ships the same time the OS does to everyone who gets the new revision of the OS, and never to people who do NOT get the new revision of the OS. Unless you also ship with every SU, or are willing to update your customers each time an SU ships AND have some magic way of detecting when this happens, without warning beforehand that something will break, OR are willing to tolerate something not working for a customer until you can get a fix out... you are discouraged from using these interfaces directly. The same way that if you are a KEXT author, you are discouraged from declaring a dependency on kernel functions not listed in one of the supported KPIs (for the same reason: if an internal kernel implementation detail changed, your KEXT would break). Clearly the best solution is a supported API ;o) Actually, no. The best solution is to not need to recreate information you had, and then "forgot" to save off for later use, and then "needing" to use it later. For example, people who have programs that rendezvous via have one program find the process ID of the other programs via "ps" (or "sysctlbyname") should instead have the program they want the rendezvous with record it's pid in a file named after the process in / var/run. That's the proper convention, and it saves the people who use it a whole lot of pain ("configd", for one, uses this convention). This email sent to site_archiver(a)lists.apple.com

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Re: Questions about launchd
by Finlay Dobbie 25 Aug '07

25 Aug '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=WjgY9wt+njmevHvr/DcIOVvT8ee4I2hdzAG1b4m2dpOfmjQDS4QQAM89XheM34AeqfguIFNeAiNe3uNkZ/jZ7NlmGrOGSl/pR8f6FfAhwzQp5lhZiAWcCicIPVbia5ypcr4YZsupgFVavClj+H+CO/pisj7jezOJ6WS9XUX4DfM= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=fBv10GDUZCOtFOugpCtne43dcxfW4tQh/578EZP87gc+mxL0jjrnTJOZU3oAhl6PcpbDBfKP7ibjaAoEQZIepWc41w3rBy78ZqqP/5zMke0sDG4lyht4PlujHZunbfptD2jZWVP+tsN4/m8usbskYRmcyyBL171HIskEnp/yqtk= On 25/08/07, Terry Lambert <tlambert(a)apple.com> wrote: > Certain command conform to standards, and for those commands, we more > or less say we expect that they will continue to conform to standards. Which commands? What standards? Clearly the best solution is a supported API ;o) -- Finlay _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Questions about launchd
by Terry Lambert 25 Aug '07

25 Aug '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com However, I'm fairly sure you don't provide any guarantees that the arguments or output of the tool will remain the same across releases, so surely this is just moving the fragility to a different layer? - char *proc_name = "launchd"; pid_t proc_pid = 1; /* * load format string from plist... * use "%1$d" for proc_pid parameter * use "%2$s" for proc_name parameter */ ... /* * build command line using positional parameter format strings * to let us pick and choose which parameters we want to pass * to the actual command we're going to use to get the data. */ sprintf(cmdbuf, fmtstring, proc_pid, proc_name); ...pretty trivial. -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On Aug 25, 2007, at 2:10 AM, Finlay Dobbie wrote: On 25/08/07, Terry Lambert <tlambert(a)apple.com> wrote: The point of forcing you to write wrappers around standard tools instead of doing what the tool does is to ensure you that when the system is updated, you are guaranteed that the tools are updated at the same time that the kernel and other system components are updated, so your code will continue working, even if we change the system interface used by the tool. Certain command conform to standards, and for those commands, we more or less say we expect that they will continue to conform to standards. For the "ps" example I gave, that means that the "-p" and "-o" arguments will be supported, and they will behave as written, so long as there is no overriding reason for that to stay true. So even if the default display output changes, there are command line options to get you output in the same format each time that most likely won't. If you really find this concerning in more than a "We Fear Change" sort of way, then all you need to do is support putting a command format string with arguments in your plist file, along with a command parsing format string, and a line number in the output (or a regex, etc.). For the output formatting of your command, you include everything you thing is relevant as arguments to the sprintf() that creates the command string to the popen(), and then use the positional argument qualifiers to select which one(s) to include, e.g.: If you're looking for me to guarantee thing won't change, well, you're looking to the wrong person. But if I had to guess, I'd guess on the side of commands that have to conform to standards changing a lot less often the data interfaces to kernel data that could change on every software update. Obviously, the best possible scenario for the original question would be to remember whether or not you opened the file in the first place, rather than depending on being able to ask the system if you called open earlier in your own operation. This email sent to site_archiver(a)lists.apple.com

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Re: Questions about launchd
by Finlay Dobbie 25 Aug '07

25 Aug '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=KRctMRcGSEsFmoEbhaQJMGX+JL1hsXXRpVf8mjTPcYBLbS9s4W5d/CXTHLKqXsVtALS/FzfkFrUSWikRdjHpuLtHMWks3vXY/af54wMEoHIOSj8uRHzorlDum0r/0NGLHja5gwhZ5QQNQCHWchXLIok3Oo2aNK9VlqXs1oXRtxY= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=NsZJRbaDtosEAw6go3o9wakXbcC14Ny45Q9WszH/HLWrLFcgtroHRggO4LzUVOk/WErrkgmcpEtFGaRlNlkKQWx+GRnQ3evz9xD1oD1VTl4rX9ib1UnFJ2rZtj7YIG0PysVhXGaQfkkbiXSu8sQz7QYyXcuhKWepB9kWyIR9FTI= On 25/08/07, Terry Lambert <tlambert(a)apple.com> wrote: > The point of forcing you to write wrappers around standard tools > instead of doing what the tool does is to ensure you that when the > system is updated, you are guaranteed that the tools are updated at > the same time that the kernel and other system components are updated, > so your code will continue working, even if we change the system > interface used by the tool. However, I'm fairly sure you don't provide any guarantees that the arguments or output of the tool will remain the same across releases, so surely this is just moving the fragility to a different layer? -- Finlay _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Re: Questions about launchd
by Terry Lambert 25 Aug '07

25 Aug '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com /* NB: returns signed int; not suitable for processes with > 2TB RSS */ int getrss(pid_t pid) { FILE *fp; char buf[128]; int rss; snprintf(buf, sizeof(buf), "/bin/ps -p %d -o rsz=", pid); if ((fp = popen(buf, "r")) == NULL) { return (-1); } if (!fscanf(fp, "%d", &rss)) { return(-2); } fclose(fp); return(rss); } -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On Aug 24, 2007, at 7:47 AM, Dave Zarzycki wrote: On Aug 22, 2007, at 6:38 PM, Michal Taurich wrote: I did it in my script with checking "lsof" if the file is used or not. Isn't there any other way directly in launchd or Lingon ? Unfortunately, there are no facilities in the OS for knowing whether a file is open or not. popen of lsof will work, assuming you use the output format specifiers to prevent it from changing output format on you, or simply look at the found/not fond return value. The point of forcing you to write wrappers around standard tools instead of doing what the tool does is to ensure you that when the system is updated, you are guaranteed that the tools are updated at the same time that the kernel and other system components are updated, so your code will continue working, even if we change the system interface used by the tool. For example, here's a function that takes a pid and returns the resident set size of a process (limited to 32 bits because I implemented it quickly) or < 0 on error: This function will remain operational so long as ps remains operational, and the standards do not change, despite software updates. Of course, you could also write a kauth kext and keep track of this information yourself, too. This email sent to site_archiver(a)lists.apple.com

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Problem with shutting down.
by Draichis 25 Aug '07

25 Aug '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:user-agent:mime-version:to:subject:references:in-reply-to:content-type:content-transfer-encoding; b=XGp3WZVkf8HMyigkj9u/ase6kl6Zn7MamkhQDivCZ1iVgKORS3wSLxEvJ4Tav7LRvJZP/08Z/CiP/aFsMGA89lMrxjOMAEJjA5rhnVeTphiHQ99tXvgZgXU5f5oEgVE7GfQQgUdam+eYPF0tDkWwfPz+0r8YJ8qMJYp5JhYn/iM= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:user-agent:mime-version:to:subject:references:in-reply-to:content-type:content-transfer-encoding; b=CJlM6gfBAXCvxh8TlVbNBcYHo/Ljiq0o72EYFWlnkS48qOV6mSVKmsUefXeyE2xayFFbFje4pREbrgEkdplFbH6+6pVLPlcLmAdkPhZaAgmqeBH5SG1syn/acWabXGVC8XimUspLOxs+DoAkiyzj5fE2C2c5+18aSqwDrzCkArM= User-agent: Thunderbird 1.5.0.10 (Macintosh/20070221) Thanks _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… Hello all, I have a problem shutting down/rebooting/logging out from the Apple display menu. I've tried to rotate the cron logs, and rebuild launchd in any attempt of fixing this. No avail. Could anyone give me any suggestions? This email sent to site_archiver(a)lists.apple.com

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Re: Hardware drivers (CD/DVD specifically) and anychrony
by Graham J Lee 24 Aug '07

24 Aug '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On 24 Aug 2007, at 19:45, Shawn Erickson wrote: Very simple (or perhaps not) question, which might be more appropriate for an IOKit list: Is there a technical reason why *certain* phases of the actions of hardware, ... cannot be performed synchronously, and thus not block the entire system? I think you mean asynchronously in the above, anyway... The system, as a whole, isn't stopping to spin up the disk, etc.. It likely is upper level software (or a framework it depends on) sending out a synchronous IO request for data that cannot be satisfied until the disk is spun up and read. This blocks that thread until the IO request is satisfied. Cheers, Graham. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… On 8/24/07, Jim Witte <jswitte(a)bloomington.in.us> wrote: Aye, the SBOD more-or-less means that the thread in an app (and without being rude, I'm guessing it's The Fine Finder) responsible for dealing with the event loop is blocked. In this case it's not the system but the app which needs fixing. This email sent to site_archiver(a)lists.apple.com

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Re: Hardware drivers (CD/DVD specifically) and anychrony
by Shawn Erickson 24 Aug '07

24 Aug '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: a=rsa-sha1; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=iaO1nCxdNxLNKgdTMwSOnHcz6dMZe54zejVEU0nMmdzDPrLmdBHfQh1jIkfXISjl2W5omJKI18W/+HBzUQ7EGw2EKIiffoBDEfr8jWN2AT7FYq4KOa3p4n+VJ0wSXh6FG9uyMTS5C2PbiS+i8Vlp5BeoiOZlQ0sBx4/cRePGjjw= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=T6n1CajMZuCUmnldMbh2nFYOXe1KKClyMhnLVmcwSV8JSJd2tuG1gVig/kkapswIT2L0U0UZssjePaNe1Z0TG6fpYmDDoNAK0SvOYH2CExV194T0sO+qzex9brpGsgeUDl9gRxoTC0GMTQ2iomqDYFQA+ZvTcQ3GAuqGWCZYMMc= On 8/24/07, Jim Witte <jswitte(a)bloomington.in.us> wrote: > Very simple (or perhaps not) question, which might be more > appropriate for an IOKit list: Is there a technical reason why > *certain* phases of the actions of hardware, ... cannot be > performed synchronously, and thus not block the entire system? I think you mean asynchronously in the above, anyway... The system, as a whole, isn't stopping to spin up the disk, etc.. It likely is upper level software (or a framework it depends on) sending out a synchronous IO request for data that cannot be satisfied until the disk is spun up and read. This blocks that thread until the IO request is satisfied. -Shawn _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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Hardware drivers (CD/DVD specifically) and anychrony
by Jim Witte 24 Aug '07

24 Aug '07

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Very simple (or perhaps not) question, which might be more appropriate for an IOKit list: Is there a technical reason why *certain* phases of the actions of hardware, such as disk spin-up, spin-down, eject, and insertion (while the drive is positioning the head and such, before it begins to read I presume) cannot be performed synchronously, and thus not block the entire system? My Macbook (Core Duo) is set to require the password on wake, and I notice a lot that I just get the SBOD, *while the drive* is spinning up. I suppose it's reading something in order to allow the OS to 'reset' the FS connection to the device so that it can be read like a normal device, hence the system block. But simply displaying a dialog and checking a password should not require any of that - although things that happen *after* the password is entered correctly might - but I doubt it would have anything to do (immediately) with the DVD drive, although the drive may somehow block the ATAPI chain affecting HDD access. I'm not sure if there are any drivers that will block the entire system for significant amounts of time because of (necessarily) slow hardware, but I wonder if the drivers and/or firmware could be modified to make certain parts of the processes able to execute synchronously. This might require the kernel to be able to somehow determine that some things (like resetting file pointers or whatever it does on wake with a mounted DVD) to be 'delayed' while other tasks can complete. This might or might not be possible, or feasible.. (INTOSC - "I've never taken an OS class") :) But it might be something to think about for Darwin (Tiger version) +5 or something.. _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev(a)lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.app… This email sent to site_archiver(a)lists.apple.com

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