August 2006 - Darwin-dev - lists.apple.com

Re: How can I find out what predefined symbols the compiler is using?
by Greg Parker 31 Aug '06

31 Aug '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Try this in a terminal: % touch empty.c % cc empty.c -E -dM -o - | sort #define _ARCH_PPC 1 #define _BIG_ENDIAN 1 #define __APPLE_CC__ 5419 #define __APPLE__ 1 #define __BIG_ENDIAN__ 1 #define __CHAR_BIT__ 8 #define __DBL_DENORM_MIN__ 4.9406564584124654e-324 ... Compiler flags and source language can change the built-in definitions. -- Greg Parker gparker(a)apple.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… What I would like to know is how do you determine what the choices are for these types of #defines? The compiler obviously knows about __GNUC__, and maybe __MWERKS__, but is there a way for me to query the compiler about which ones of these it has defined? (And, what is the proper terminology for these symbols? I would happily google for this info if I knew what to call it.) They're "preprocessor macros" or "preprocessor defines" (not symbols). "built-in" might also be a useful search term. This email sent to site_archiver(a)lists.apple.com

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How can I find out what predefined symbols the compiler is using?
by Paul Archibald 31 Aug '06

31 Aug '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com I am trying to use a header file that contains some stuff like this: #ifdef __MWERKS__ ... #endif #ifdef __GNUC__ ... #endif Paul _______________________________________________ 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… The purpose of this is to enable certain #defines in my code. (Is there any other reason to do this??) What I would like to know is how do you determine what the choices are for these types of #defines? The compiler obviously knows about __GNUC__, and maybe __MWERKS__, but is there a way for me to query the compiler about which ones of these it has defined? (And, what is the proper terminology for these symbols? I would happily google for this info if I knew what to call it.) This email sent to site_archiver(a)lists.apple.com

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Re: .subsections_via_symbols broken in Xcode 2.4?
by Shantonu Sen 31 Aug '06

31 Aug '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com -gfull is for debugging symbols, and does not affect this behavior. Shantonu On Aug 31, 2006, at 9:28 AM, Jonas Maebe wrote: Hello, *** #include <stdio.h> void test() { printf("hello\n"); } void test2() { printf("goodbye\n"); } int main() { test(); return 0; } *** Jonas _______________________________________________ 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… Sounds like you are talking about dead code stripping, which is not and has never been the default. Pass -dead_strip to the compiler driver or linker. It seems smart linking is no longer working in Xcode 2.4? The test2 routine at least isn't stripped from the following test program: The generated assembler file does contain the .subsections_via_symbols statement. But after assembling and linking, the generated binary still contains the full test2() routine (verified with "otool -tV"). Adding -gfull to gcc's command line options doesn't change anything. PS: it seems the Xcode 2.4 sources haven't been posted yet? _______________________________________________ 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/ssen% 40opendarwin.org This email sent to ssen(a)opendarwin.org This email sent to site_archiver(a)lists.apple.com

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.subsections_via_symbols broken in Xcode 2.4?
by Jonas Maebe 31 Aug '06

31 Aug '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Hello, *** #include <stdio.h> void test() { printf("hello\n"); } void test2() { printf("goodbye\n"); } int main() { test(); return 0; } *** Jonas PS: it seems the Xcode 2.4 sources haven't been posted yet? _______________________________________________ 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… It seems smart linking is no longer working in Xcode 2.4? The test2 routine at least isn't stripped from the following test program: The generated assembler file does contain the .subsections_via_symbols statement. But after assembling and linking, the generated binary still contains the full test2() routine (verified with "otool -tV"). Adding -gfull to gcc's command line options doesn't change anything. This email sent to site_archiver(a)lists.apple.com

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Re: reading/writing files from mounted device directly
by Michael Smith 30 Aug '06

30 Aug '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On Aug 30, 2006, at 12:03 PM, darwin-dev-request(a)lists.apple.com wrote: I am developing a product for the Macintosh platform that requires I read and write files from a mounted device. David, Information on the mounted device is being updated in real time but I am unable to detect the changes due to the operating system (Darwin?) caching the contents of the device into a buffer which remains static until I unmount the drive with a "diskutil unmount" command. Continually mounting and unmounting the device to see changes in a file is not desirable. Such writers and readers would, however, be very poorly-performing general-purpose FAT implementations. Merely "not caching" the disk blocks would in no wise be sufficient to achieve this. ... yet this is exactly what you expect the filesystem to do. As noted above, this is not a practical solution. Assuming, for the moment, that you are stuck with a device that thinks that it's reasonable for you to read its active FAT filesystem, you need to do something like this: 3) Determine an order of reading for these metadata items interleaved in any fashion amongst the write operations for the procedures in step 1 that *guarantees* that your operations will either succeed or detectably fail. This needs to include data read/write operations (i.e. file data must be guaranteed to be on-disk before any metadata referencing it is committed to disk). At any point during the above procedure, optionally take a blunt object and beat on the designer of the USB device. Repeat as required. Local filesystems are *not* multi-client databases. Period. = Mike _______________________________________________ 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… It's good that you've attempted to get help in this phase of your development, as perhaps there is still some hope of fixing the situation. First, though, I need to understand what you're saying above. If the product is in development, why is it "required" that you do this? If there is some part of the product that is set in stone, one would assume that is because it's already committed for some other environment. What other environment is that, and how do they solve the problem? Have they actually solved it, or do they just wave their hands at it? If your product is, however, truly still "in development", it would be wise of you to reconsider this 'sharing' of a filesystem. There are almost unquestionably better ways to do what you're trying to do. Certain clues suggest to me that this is probably a FAT filesystem. Like most other single-owner filesystems, FAT implementations reasonably expect that nothing on the disk is going to change unless they change it, and so they consider themselves free to cache the contents of various metadata structures (and file data) as necessary. Darwin does not cache block devices, period. Filesystems cache metadata, and the VM subsystem caches file data. Due to the above consideration and a basic requirement for performance, this behaviour is not conditional. There is no fundamental utility in not caching metadata for read operations (one can argue write-through caching aids in disaster recovery, and many filesystems support this as an option). FAT, along with most other single-owner filesystem formats, is poorly suited to use as a sharing format. If you were in total control of the writer, and could be assured that there was only ever *one* writer, then it would be possible to enforce strict ordering rules over which metadata items were written in which order, and make it possible for a likewise customised reader to avoid becoming confused. Using the IOKit to obtain a handle to the device and then using POSIX funtions to open/read/write does allow access to the raw disk, but I can only access bytes. Reading the entire device and programmatically reproducing the file structure to locate the file I am interested in reading is prohibitive. Is there a no-cache option on mounting what is effectively a USB storage device? Or how do I bypass the cached buffer? 1) Document the strict order of operations as performed by the device when creating, appending to, shrinking, moving and deleting files. If the device performs any sort of deferred write buffering or re-orders or clusters its operations, you may want to give up now. 2) Document the metadata items that are required to be read (bootblock, FAT1/FAT2, root directory, subdirectory, etc.) for all of the file operations that you need to perform. 4) Implement the necessary portions of the read-only filesystem in your application. Note that for FAT, there are plenty of simple, read-only implementations that you can lift; consider for example the dosfs.[ch] from the FreeBSD bootloader that can be found here: http://www.freebsd.org/cgi/cvsweb.cgi/src/lib/libstand/ 5) Test. Extensively. The issue you are attempting to resolve with all this talk of "strict ordering" is that FAT (and most other filesystems) have relational dependencies between various metadata items. For example, the starting cluster number in a directory entry is not useful for any file longer than a cluster unless the FAT chain in one or both FATs is valid. If the writing filesystem writes the directory entry before it updates the FAT, for example (this is common) then you cannot read the file (and may become confused trying to follow an invalid chain, depending on the writing filesystem's policy regarding cleaning out chains for deleted files). Because these issues are sensitive to the relative timing of operations between the reader and writer, they are hard to reproduce and hard to debug. However, in any un-synchronised system they will eventually manifest and make your customers unhappy. This email sent to site_archiver(a)lists.apple.com

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Re: Strange sound issues
by Dan Shoop 30 Aug '06

30 Aug '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Most of these apps have no individual sound preferences. Another kind lister privately post the following link: http://macosx.com/forums/showthread.php?t=275622 Thanks to all for their posts. -- -dhan ------------------------------------------------------------------------ Dan Shoop AIM: iWiring Systems & Networks Architect http://www.ustsvs.com/ shoop(a)iwiring.net http://www.iwiring.net/ 1-714-363-1174 "The wise man doesn't give the right answers, he poses the right questions." -- Claude Levi-Strauss ------------------------------------------------------------------------ iWiring provides systems and networks support for Mac OS X, unix, and Open Source application technologies at affordable rates. _______________________________________________ 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… At 3:57 PM -0400 8/29/06, Dan Shoop wrote: Recently I began having a very strange sound problem. Applications, for no known reason, have switched their audio output from the system default (internal speakers) to my Bluetooth headset. This started with Eudora, then befell QuickTime Player, Safari, and iChat. How is the system determining, by application, which audio I/O device to use for it's sound? I've not noticed anything suspicious in any of these app's plists, in fact most of them haven't been modified. Any pointers are welcomed. It was indeed the culprit. It was very strange though how this started "eating" applications almost one by one. And it wasn't that all newly launched apps were "eaten", sometimes I'd launch them a few times and there'd be no incident but once "eaten" remained fuxored. This email sent to site_archiver(a)lists.apple.com

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Re: Strange sound issues
by Dirk Stegemann 30 Aug '06

30 Aug '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Hi, This behaviour can only be fixed through a system reboot. Hope this does help in any way. Best regards, Dirk Stegemann _______________________________________________ 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… Am 29.08.2006 um 22:57 schrieb Dan Shoop: Recently I began having a very strange sound problem. Applications, for no known reason, have switched their audio output from the system default (internal speakers) to my Bluetooth headset. This started with Eudora, then befell QuickTime Player, Safari, and iChat. I'm seeing a very simal behaviour on my machine, usually this befalls iChat only. After some days, iChat starts using an external sound output device which was -- but is not any longer -- connected. For audio chats, I often connect a Logitech USB Headset, for iTunes music listening I sometimes connect my Mac via phone jack to either my stereo or head phones. Re-connecting the device in question makes the sounds iChat produces audible again. I have to mention that the kable which connects the Mac to the stereo is somewhat broken, it happens to produce an awful sound until I use a bit of force to put (and fix) the cable into the right angle -- if this happens while iTunes is playing music, iTunes might get unresponsive and silent, and it can take a couple of seconds until it recovers from this condition after the "cable situation" is fixed. Unfortunately, this behaviour of iChat doesn't seem to happen immediately after using / unplugging one of those external sound output devices, so I wasn't able to file a reproducible bug report yet. The last time iChat stopped behaving normally was about three days ago, I didnt restar my Mac since then, but currently iChat does not produce *any* sound to *any* sound output device... so this behaviour is even worse. I'm using the VLC movie player application quite regularly and know it also handles sound output a bit differently (it does not always seem to be affected by the system default settings). Maybe it messes things up a bit? I'll try to take this into account for further observations. My system: PowerBook G4 17" (1,67GHz), Mac OS X 10.4.7, all updates applied. IIRC, I saw this behaviour on a regular basis for all the "Tiger" updates. I also have "Little Snitch" installed, so I have some third-party code running inside my kernel... This email sent to site_archiver(a)lists.apple.com

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Re: Strange sound issues
by Bryan Dulock 29 Aug '06

29 Aug '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com On Aug 29, 2006, at 2:57 PM, Dan Shoop wrote: Most of these apps have no individual sound preferences. ............................................ DULOCK CONSULTING Bryan Dulock | ACTC 10.4 281-584-0476 Houston, Texas _______________________________________________ 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… Recently I began having a very strange sound problem. Applications, for no known reason, have switched their audio output from the system default (internal speakers) to my Bluetooth headset. This started with Eudora, then befell QuickTime Player, Safari, and iChat. How is the system determining, by application, which audio I/O device to use for it's sound? I've not noticed anything suspicious in any of these app's plists, in fact most of them haven't been modified. Any pointers are welcomed. Check out the Audio MIDI Setup utility in the Utilities folder. It might give some clues about what's going on with the System audio. This email sent to site_archiver(a)lists.apple.com

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Re: MacOS-X Aqua Port of Perl-Tk?
by Jordan K. Hubbard 29 Aug '06

29 Aug '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com - Jordan On Aug 29, 2006, at 2:28 PM, Stewart.Dickson(a)noaa.gov wrote: OK, How about this one? #! /usr/bin/perl use Tk; Can't locate Tk.pm in @INC (@INC contains: /sw/lib/perl5/5.8.6/darwin-thread-multi-2level /sw/lib/perl5/5.8.6 /sw/lib/perl5 /sw/lib/perl5/darwin /System/Library/Perl/5.8.6/darwin-thread-multi-2level /System/Library/Perl/5.8.6 /Library/Perl/5.8.6/darwin-thread-multi-2level /Library/Perl/5.8.6 /Library/Perl /Network/Library/Perl/5.8.6/darwin-thread-multi-2level /Network/Library/Perl/5.8.6 /Network/Library/Perl /System/Library/Perl/Extras/5.8.6/darwin-thread-multi-2level /System/Library/Perl/Extras/5.8.6 /Library/Perl/5.8.1 .) Thanks again, -Stewart Dickson, Principal Scientific Subject Matter Expert in Visualization, NOAA National Climatic Data Center _______________________________________________ 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/jkh%40apple.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… We don't currently support PERL bindings for Tk, I'm afraid. You can either grab it off the net and add it yourself (probably in CPAN) or use Python or Ruby, for which we do provide TK bindings. This email sent to jkh(a)apple.com This email sent to site_archiver(a)lists.apple.com

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MacOS-X Aqua Port of Perl-Tk?
by Stewart.Dickson＠noaa.gov 29 Aug '06

29 Aug '06

site_archiver(a)lists.apple.com Delivered-To: darwin-dev(a)lists.apple.com Priority: normal OK, How about this one? #! /usr/bin/perl use Tk; Can't locate Tk.pm in @INC (@INC contains: /sw/lib/perl5/5.8.6/darwin-thread-multi-2level /sw/lib/perl5/5.8.6 /sw/lib/perl5 /sw/lib/perl5/darwin /System/Library/Perl/5.8.6/darwin-thread-multi-2level /System/Library/Perl/5.8.6 /Library/Perl/5.8.6/darwin-thread-multi-2level /Library/Perl/5.8.6 /Library/Perl /Network/Library/Perl/5.8.6/darwin-thread-multi-2level /Network/Library/Perl/5.8.6 /Network/Library/Perl /System/Library/Perl/Extras/5.8.6/darwin-thread-multi-2level /System/Library/Perl/Extras/5.8.6 /Library/Perl/5.8.1 .) Thanks again, -Stewart Dickson, Principal Scientific Subject Matter Expert in Visualization, NOAA National Climatic Data Center _______________________________________________ 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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