March 2009 - Darwin-dev - lists.apple.com

exception not caught? (aborting)
by Ethan Tira-Thompson 27 Mar '09

27 Mar '09

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Re: Finding out the number of used file descriptors
by Thierry bultel 27 Mar '09

27 Mar '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Thunderbird 2.0.0.21 (Windows/20090302) Thierry -- Terry Hi all, So my questions are: Any help would be greatly appreciated ... Cheers, Thierry begin:vcard fn:Thierry Bultel n:Bultel;Thierry org:Atempo SA;V.O.S team adr;dom:;;+33297683688 email;internet:thierry.bultel@atempo.com title:Software engineer tel;work:+33297683688 note;quoted-printable:=0D=0A= =0D=0A= version:2.1 end:vcard _______________________________________________ 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 Terry Lambert a écrit : Number of actual open fds relative to the default administrative limit on the number of open fds is not a useful measure of overall load. Sure it is not ! Among other reasons is that we do not scale the administrative limit on the basis of hardware capability. Another is that not all types of fds consume equivalent per-fd resources, so even if the limit were scaled you couldn't trust it to be meaningful across different workload profiles.. Yes, but for the type of application I am working on, the number of fds is usually and typically the first ressource that gets exhausted (when improper setup is done by the user of application). Let's say that checking the fds usage is better than nothing, and is a first step of a more smart check. PS: Even if my questions 2) and 3) below are more general than this topic, I would really be happy to get pointers to related documentation and/or examples ... On Mar 27, 2009, at 2:22 AM, Thierry bultel <thierry.bultel(a)atempo.com> wrote: I would really appreciate if you could take some time to comment on the problems I have: In order to implement an early detection of the system load, before launching any job that would put the machine to its limits or worse ;-) , we would like to find out the current usage of file descriptors, in the entire system. If we could access that information, we would be able to compare it with the max limit and therefore decide if we continue or not, depending on a configurable threshold. I have done some investigations around sysctl (CTL_KERN + KERN_FILE) but it sounds like that part of the interface is not supported, because the matching structures of the returned buffer are not public. Notice that I am thinking about having a kind of heuristic that would determine the number of files, by only using the size of the 'struct extern_file', dividing, and forgetting the filehead, whose size is small comparing to the sum of the others. If I want to be more accurate than that, for simplicity of code, and also, performances concerns, I do not want to base it on lsof. (As I think that spawning executables and parsing output is generally a bas idea ...). Therefore I also have investigated on other ways how to possibly access the global kernel variable "nfiles", for example from a kext. Although It was relatively quick and easy to have a kind of "hello world" kernel extension, I have not been able to access the aimed variable. I guess it is not public or something of the same flavour. 1) What is your advice to get the current usage of file descriptors ? 2) As a general question: Is there a special way to access the kernel symbols from a kext ? How are (if any) public symbols declared in the kernel ? 3) Is it possible to declare a new syscall from a kext ? I have not found any examples on the web ...

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Re: Finding out the number of used file descriptors
by Terry Lambert 27 Mar '09

27 Mar '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com -- Terry Hi all, So my questions are: Any help would be greatly appreciated ... Cheers, Thierry _______________________________________________ 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… Number of actual open fds relative to the default administrative limit on the number of open fds is not a useful measure of overall load. Among other reasons is that we do not scale the administrative limit on the basis of hardware capability. Another is that not all types of fds consume equivalent per-fd resources, so even if the limit were scaled you couldn't trust it to be meaningful across different workload profiles.. On Mar 27, 2009, at 2:22 AM, Thierry bultel <thierry.bultel(a)atempo.com> wrote: I would really appreciate if you could take some time to comment on the problems I have: In order to implement an early detection of the system load, before launching any job that would put the machine to its limits or worse ;-) , we would like to find out the current usage of file descriptors, in the entire system. If we could access that information, we would be able to compare it with the max limit and therefore decide if we continue or not, depending on a configurable threshold. I have done some investigations around sysctl (CTL_KERN + KERN_FILE) but it sounds like that part of the interface is not supported, because the matching structures of the returned buffer are not public. Notice that I am thinking about having a kind of heuristic that would determine the number of files, by only using the size of the 'struct extern_file', dividing, and forgetting the filehead, whose size is small comparing to the sum of the others. If I want to be more accurate than that, for simplicity of code, and also, performances concerns, I do not want to base it on lsof. (As I think that spawning executables and parsing output is generally a bas idea ...). Therefore I also have investigated on other ways how to possibly access the global kernel variable "nfiles", for example from a kext. Although It was relatively quick and easy to have a kind of "hello world" kernel extension, I have not been able to access the aimed variable. I guess it is not public or something of the same flavour. 1) What is your advice to get the current usage of file descriptors ? 2) As a general question: Is there a special way to access the kernel symbols from a kext ? How are (if any) public symbols declared in the kernel ? 3) Is it possible to declare a new syscall from a kext ? I have not found any examples on the web ... This email sent to site_archiver(a)lists.apple.com

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Re: seg.fault in pthread library
by Jason Coco 27 Mar '09

27 Mar '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:cc:message-id:from:to :in-reply-to:content-type:content-transfer-encoding:mime-version :subject:date:references:x-mailer; bh=CQLldd3JQAsEZqnY8W9xmC0fAHD8QY/22dnePvZHXh4=; b=utG+oQ8KWgedp09z9jE7SniBrgUeAaX9B9/bzPv21nWS7KELo3ysV1rer0CDB5oCJE qRC8xEY1ASlQkS0EFeskzIaI+Apzrmt64D2sfj7KiI5NVujDeiU1/tsAhF7Ju7Xyy77k tV33N9Xi9pjm3xlJ+3eWLeKj7q/73/KUZHCzI= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=cc:message-id:from:to:in-reply-to:content-type :content-transfer-encoding:mime-version:subject:date:references :x-mailer; b=X+lTIVNz52D6AWOmqiYww/skh04uA7IRFManbZ81FPvhBlJoKa7wyUg0X3t7PJ82H2 RWHshnbH7hwoM/vp4bV684QcqPoZxM15w1gWE9YA29rx2uEkKLZyxznKBi93R/ziaODu h7soR9pohH666ceby68AyjhWubawMStNQY+o8= man pthread_testcancel see Cancellation Points :-) On Mar 26, 2009, at 18:24 , Stefan Solbrig wrote: best regards, Stefan _______________________________________________ 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/jason.coco%40gmail.com _______________________________________________ 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… Hi, thanks for the help! So I have to be more careful with pthread_cancel(). But this brings me to another question: is there a list which functions are cancellation points? It is not legal POSIX to cancel a thread which has already been joined, since its local state information has potentially been destroyed and/or freed back to the system. It's morally equivalent to freeing memory and then dereferencing the pointer that used to point to it and hoping it still lives in your address space. This email sent to jason.coco(a)gmail.com This email sent to site_archiver(a)lists.apple.com

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Re: Finding out the number of used file descriptors
by Tim Murison 27 Mar '09

27 Mar '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Thread-index: Acmu5z2LKIxVoIMtsEaZyLT7DBv3lw== Thread-topic: Finding out the number of used file descriptors User-agent: Microsoft-Entourage/12.15.0.081119 > 1) What is your advice to get the current usage of file descriptors ? libproc.h has functions that can retrieve a set of structs with all the open FDs for a given PID. *********************************************************************** This e-mail and its attachments are confidential, legally privileged, may be subject to copyright and sent solely for the attention of the addressee(s). Any unauthorized use or disclosure is prohibited. Statements and opinions expressed in this e-mail may not represent those of Radialpoint. Le contenu de ce courriel est confidentiel, privilégié et peut être soumis à des droits d'auteur. Il est envoyé à l'intention exclusive de son ou de ses destinataires. Il est interdit de l'utiliser ou de le divulguer sans autorisation. Les opinions exprimées dans le présent courriel peuvent diverger de celles de Radialpoint. _______________________________________________ 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: seg.fault in pthread library
by Terry Lambert 27 Mar '09

27 Mar '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com You wwant section 2.9.5. -- 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… <http://www.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_09.html > THe only place you can depend on cancellation working portably is a limited set of functions where it's specifically required ("Cancellation points shall occur..."), rather than where it's allowed ("A cancellation may also occur...") but not guaranteed. You are guaranteed that they aren't upported anywhere else: An implementation shall not introduce cancellation points into any other functions specified in this volume of IEEE Std 1003.1-2001. On Mar 26, 2009, at 3:24 PM, Stefan Solbrig wrote: Hi, thanks for the help! So I have to be more careful with pthread_cancel(). But this brings me to another question: is there a list which functions are cancellation points? It is not legal POSIX to cancel a thread which has already been joined, since its local state information has potentially been destroyed and/or freed back to the system. It's morally equivalent to freeing memory and then dereferencing the pointer that used to point to it and hoping it still lives in your address space. This email sent to site_archiver(a)lists.apple.com

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Finding out the number of used file descriptors
by Thierry bultel 27 Mar '09

27 Mar '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com User-agent: Thunderbird 2.0.0.21 (Windows/20090302) Hi all, So my questions are: Any help would be greatly appreciated ... Cheers, Thierry begin:vcard fn:Thierry Bultel n:Bultel;Thierry org:Atempo SA;V.O.S team adr;dom:;;+33297683688 email;internet:thierry.bultel@atempo.com title:Software engineer tel;work:+33297683688 note;quoted-printable:=0D=0A= =0D=0A= version:2.1 end:vcard _______________________________________________ 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 I would really appreciate if you could take some time to comment on the problems I have: In order to implement an early detection of the system load, before launching any job that would put the machine to its limits or worse ;-) , we would like to find out the current usage of file descriptors, in the entire system. If we could access that information, we would be able to compare it with the max limit and therefore decide if we continue or not, depending on a configurable threshold. I have done some investigations around sysctl (CTL_KERN + KERN_FILE) but it sounds like that part of the interface is not supported, because the matching structures of the returned buffer are not public. Notice that I am thinking about having a kind of heuristic that would determine the number of files, by only using the size of the 'struct extern_file', dividing, and forgetting the filehead, whose size is small comparing to the sum of the others. If I want to be more accurate than that, for simplicity of code, and also, performances concerns, I do not want to base it on lsof. (As I think that spawning executables and parsing output is generally a bas idea ...). Therefore I also have investigated on other ways how to possibly access the global kernel variable "nfiles", for example from a kext. Although It was relatively quick and easy to have a kind of "hello world" kernel extension, I have not been able to access the aimed variable. I guess it is not public or something of the same flavour. 1) What is your advice to get the current usage of file descriptors ? 2) As a general question: Is there a special way to access the kernel symbols from a kext ? How are (if any) public symbols declared in the kernel ? 3) Is it possible to declare a new syscall from a kext ? I have not found any examples on the web ...

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Re: seg.fault in pthread library
by Stefan Solbrig 26 Mar '09

26 Mar '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com best regards, Stefan _______________________________________________ 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… Hi, thanks for the help! So I have to be more careful with pthread_cancel(). But this brings me to another question: is there a list which functions are cancellation points? It is not legal POSIX to cancel a thread which has already been joined, since its local state information has potentially been destroyed and/or freed back to the system. It's morally equivalent to freeing memory and then dereferencing the pointer that used to point to it and hoping it still lives in your address space. This email sent to site_archiver(a)lists.apple.com

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Re: How to find the architecture for a mach-o file?
by Stuart Crook 26 Mar '09

26 Mar '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com _sjc_ On 26 Mar 2009, at 21:18, Eli Bach wrote: On Mar 26, 2009, at 1:41 PM, Karan, Cem (Civ, ARL/CISD) wrote: Thanks, Cem Karan The version of expat on my system is listed as this: ls /usr/lib | grep expat Eli _______________________________________________ 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/stuart%40echus.demon.co.uk _______________________________________________ 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… There's also a binary of the corresponding Darwin project build at code.google.com/p/puredarwin in the svn under Roots/9G55pd1, in case you've misplaced your DVD. OK, so somewhere in the mess of installing various bits, I messed up my libexpat. Rebuilding from scratch isn't working, so how do I reinstall it? Can I pull it off the Leopard DVD, or is it a Darwin project somewhere that I can download? I would suggest Pacifist & pulling it off the leopard DVD, and not building it yourself, as it is non-trivial to ensure you use the same options to build expat that Apple did (as Apple hasn't made their build system available to developers, only a semi-functional copy? of it). -rwxr-xr-x 1 root wheel 651248 Sep 23 2007 libexpat. 1.5.0.dylib lrwxr-xr-x 1 root wheel 20 Nov 18 2007 libexpat.1.dylib - > libexpat.1.5.0.dylib lrwxr-xr-x 1 root wheel 20 Nov 18 2007 libexpat.dylib -> libexpat.1.5.0.dylib -rwxr-xr-x 1 root wheel 805 Feb 19 2008 libexpat.la so most likely you can get expat off any install dvd, as it doesn't appear to have been updated from when 10.5 was released. This email sent to stuart(a)echus.demon.co.uk This email sent to site_archiver(a)lists.apple.com

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Re: How to find the architecture for a mach-o file?
by Eli Bach 26 Mar '09

26 Mar '09

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:from:to :in-reply-to:content-type:content-transfer-encoding:subject :mime-version:date:references:x-mailer; bh=Kbnd0ddLIeKUYo7WhPAnoxqbwlI49ADhZ5/MDqswBB8=; b=SyLt/Sga1TQn+d0vkXp3dqSiRdpPa5iLs4PetmNBHDrncFcO4R2IWdlC0mQyOzlA5I +FZ5HVdEmm41OPaovtfIRK2n0P88Eo2HWM46e0+qe9VYU8m6G2trHdoT5CETpqVTkoXU eEpmD2TcETH2FZZc9KssfjgCbMTTAoI+Eqn8g= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:from:to:in-reply-to:content-type :content-transfer-encoding:subject:mime-version:date:references :x-mailer; b=GY9SJoztoAdYCyKZl4IAR5eYD48IV2ID2LgPY7ZOFNnPLcgSE0RjG44vm6FRTj9zxw mIggChjhNfKb4JtVaL1m+rRF2urBZ6pm3AdNJ+FOoU15zKhCwcVDd7Rv/Ovy3UNI8my8 4SOp5fICuH8GYHq7tmQtj5YWRhS+hK/BEf2Y4= On Mar 26, 2009, at 1:41 PM, Karan, Cem (Civ, ARL/CISD) wrote: Thanks, Cem Karan The version of expat on my system is listed as this: ls /usr/lib | grep expat Eli _______________________________________________ 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… OK, so somewhere in the mess of installing various bits, I messed up my libexpat. Rebuilding from scratch isn't working, so how do I reinstall it? Can I pull it off the Leopard DVD, or is it a Darwin project somewhere that I can download? I would suggest Pacifist & pulling it off the leopard DVD, and not building it yourself, as it is non-trivial to ensure you use the same options to build expat that Apple did (as Apple hasn't made their build system available to developers, only a semi-functional copy? of it). -rwxr-xr-x 1 root wheel 651248 Sep 23 2007 libexpat.1.5.0.dylib lrwxr-xr-x 1 root wheel 20 Nov 18 2007 libexpat.1.dylib -> libexpat.1.5.0.dylib lrwxr-xr-x 1 root wheel 20 Nov 18 2007 libexpat.dylib -> libexpat.1.5.0.dylib -rwxr-xr-x 1 root wheel 805 Feb 19 2008 libexpat.la so most likely you can get expat off any install dvd, as it doesn't appear to have been updated from when 10.5 was released. This email sent to site_archiver(a)lists.apple.com

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