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  • Gtk, Does deleting builder pointer deletes all the Widgets created using it.

    - by PP
    I am creating builder pointer as follows. GtkBuilder *builder_ptr; builder_ptr = gtk_builder_new(); if( ! gtk_builder_add_from_file(builder_ptr, "Test.glade", &error ) ) printf("\n Error Builder, Exit!\n"); and i am deleting this builder pointer as follows: g_object_unref(G_OBJECT(m_builder)); this builder pointer contains 2-3 GtkWindows and other widgets. So my question is that do i need to delete all the windows in this builder manually when i delete this builder or all the windows will get destroyed when i delete builder pointer. Thanks, PP.

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  • Is Catching a Null Pointer Exception a Code Smell?

    - by Drew
    Recently a co-worker of mine wrote in some code to catch a null pointer exception around an entire method, and return a single result. I pointed out how there could've been any number of reasons for the null pointer, so we changed it to a defensive check for the one result. However, catching NullPointerException just seemed wrong to me. In my mind, Null pointer exceptions are the result of bad code and not to be an expected exception in the system. Are there any cases where it makes sense to catch a null pointer exception?

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  • Is it reasonable to null guard every single dereferenced pointer?

    - by evadeflow
    At a new job, I've been getting flagged in code reviews for code like this: PowerManager::PowerManager(IMsgSender* msgSender) : msgSender_(msgSender) { } void PowerManager::SignalShutdown() { msgSender_->sendMsg("shutdown()"); } I'm told that last method should read: void PowerManager::SignalShutdown() { if (msgSender_) { msgSender_->sendMsg("shutdown()"); } } i.e., I must put a NULL guard around the msgSender_ variable, even though it is a private data member. It's difficult for me to restrain myself from using expletives to describe how I feel about this piece of 'wisdom'. When I ask for an explanation, I get a litany of horror stories about how some junior programmer, some-year, got confused about how a class was supposed to work and accidentally deleted a member he shouldn't have (and set it to NULL afterwards, apparently), and things blew up in the field right after a product release, and we've "learned the hard way, trust us" that it's better to just NULL check everything. To me, this feels like cargo cult programming, plain and simple. A few well-meaning colleagues are earnestly trying to help me 'get it' and see how this will help me write more robust code, but... I can't help feeling like they're the ones who don't get it. Is it reasonable for a coding standard to require that every single pointer dereferenced in a function be checked for NULL first—even private data members? (Note: To give some context, we make a consumer electronics device, not an air traffic control system or some other 'failure-equals-people-die' product.) EDIT: In the above example, the msgSender_ collaborator isn't optional. If it's ever NULL, it indicates a bug. The only reason it is passed into the constructor is so PowerManager can be tested with a mock IMsgSender subclass.

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  • Can't seem to install imagick

    - by PolishHurricane
    I'm trying to install the PHP PEAR PECL extension "imagick" (image magick), but failing horribly. It seems that I keed installing packages to progress, but this one has me stumped. It seems to fail all the way at the bottom. Please Note: I'm using ArchLinux, apt-get doesn't save me. [root@Crux tmp]# pecl install imagick downloading imagick-3.0.1.tgz ... Starting to download imagick-3.0.1.tgz (93,920 bytes) .....................done: 93,920 bytes 13 source files, building running: phpize Configuring for: PHP Api Version: 20100412 Zend Module Api No: 20100525 Zend Extension Api No: 220100525 Please provide the prefix of Imagemagick installation [autodetect] : building in /tmp/pear/temp/pear-build-rootLbSUWT/imagick-3.0.1 running: /tmp/pear/temp/imagick/configure --with-imagick checking for grep that handles long lines and -e... /usr/bin/grep checking for egrep... /usr/bin/grep -E checking for a sed that does not truncate output... /bin/sed checking for cc... cc checking whether the C compiler works... yes checking for C compiler default output file name... a.out checking for suffix of executables... checking whether we are cross compiling... no checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether cc accepts -g... yes checking for cc option to accept ISO C89... none needed checking how to run the C preprocessor... cc -E checking for icc... no checking for suncc... no checking whether cc understands -c and -o together... yes checking for system library directory... lib checking if compiler supports -R... no checking if compiler supports -Wl,-rpath,... yes checking build system type... i686-pc-linux-gnu checking host system type... i686-pc-linux-gnu checking target system type... i686-pc-linux-gnu checking for PHP prefix... /usr checking for PHP includes... -I/usr/include/php -I/usr/include/php/main -I/usr/include/php/TSRM -I/usr/include/php/Zend -I/usr/include/php/ext -I/usr/include/php/ext/date/lib checking for PHP extension directory... /usr/lib/php/modules checking for PHP installed headers prefix... /usr/include/php checking if debug is enabled... no checking if zts is enabled... no checking for re2c... re2c checking for re2c version... 0.13.5 (ok) checking for gawk... gawk checking whether to enable the imagick extension... yes, shared checking whether to enable the imagick GraphicsMagick backend... no checking ImageMagick MagickWand API configuration program... found in /usr/bin/MagickWand-config checking if ImageMagick version is at least 6.2.4... found version 6.7.8 Q16 checking for MagickWand.h header file... found in /usr/include/ImageMagick/wand/MagickWand.h checking PHP version is at least 5.1.3... yes. found 5.4.6 checking for ld used by cc... /usr/bin/ld checking if the linker (/usr/bin/ld) is GNU ld... yes checking for /usr/bin/ld option to reload object files... -r checking for BSD-compatible nm... /usr/bin/nm -B checking whether ln -s works... yes checking how to recognize dependent libraries... pass_all checking for ANSI C header files... yes checking for sys/types.h... yes checking for sys/stat.h... yes checking for stdlib.h... yes checking for string.h... yes checking for memory.h... yes checking for strings.h... yes checking for inttypes.h... yes checking for stdint.h... yes checking for unistd.h... yes checking dlfcn.h usability... yes checking dlfcn.h presence... yes checking for dlfcn.h... yes checking the maximum length of command line arguments... 1572864 checking command to parse /usr/bin/nm -B output from cc object... ok checking for objdir... .libs checking for ar... ar checking for ranlib... ranlib checking for strip... strip checking if cc supports -fno-rtti -fno-exceptions... no checking for cc option to produce PIC... -fPIC checking if cc PIC flag -fPIC works... yes checking if cc static flag -static works... yes checking if cc supports -c -o file.o... yes checking whether the cc linker (/usr/bin/ld) supports shared libraries... yes checking whether -lc should be explicitly linked in... no checking dynamic linker characteristics... GNU/Linux ld.so checking how to hardcode library paths into programs... immediate checking whether stripping libraries is possible... yes checking if libtool supports shared libraries... yes checking whether to build shared libraries... yes checking whether to build static libraries... no creating libtool appending configuration tag "CXX" to libtool configure: creating ./config.status config.status: creating config.h running: make /bin/sh /tmp/pear/temp/pear-build-rootLbSUWT/imagick-3.0.1/libtool --mode=compile cc -I. -I/tmp/pear/temp/imagick -DPHP_ATOM_INC -I/tmp/pear/temp/pear-build-rootLbSUWT/imagick-3.0.1/include -I/tmp/pear/temp/pear-build-rootLbSUWT/imagick-3.0.1/main -I/tmp/pear/temp/imagick -I/usr/include/php -I/usr/include/php/main -I/usr/include/php/TSRM -I/usr/include/php/Zend -I/usr/include/php/ext -I/usr/include/php/ext/date/lib -I/usr/include/ImageMagick -DHAVE_CONFIG_H -g -O2 -c /tmp/pear/temp/imagick/imagick_class.c -o imagick_class.lo mkdir .libs cc -I. -I/tmp/pear/temp/imagick -DPHP_ATOM_INC -I/tmp/pear/temp/pear-build-rootLbSUWT/imagick-3.0.1/include -I/tmp/pear/temp/pear-build-rootLbSUWT/imagick-3.0.1/main -I/tmp/pear/temp/imagick -I/usr/include/php -I/usr/include/php/main -I/usr/include/php/TSRM -I/usr/include/php/Zend -I/usr/include/php/ext -I/usr/include/php/ext/date/lib -I/usr/include/ImageMagick -DHAVE_CONFIG_H -g -O2 -c /tmp/pear/temp/imagick/imagick_class.c -fPIC -DPIC -o .libs/imagick_class.o /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getimagematteâ: /tmp/pear/temp/imagick/imagick_class.c:268:2: warning: âMagickGetImageMatteâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:82) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getsizeoffsetâ: /tmp/pear/temp/imagick/imagick_class.c:406:2: warning: passing argument 2 of âMagickGetSizeOffsetâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:87:3: note: expected âssize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_paintfloodfillimageâ: /tmp/pear/temp/imagick/imagick_class.c:1016:3: warning: âMagickPaintFloodfillImageâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:99) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c:1019:3: warning: âMagickPaintFloodfillImageâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:99) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getimagepropertiesâ: /tmp/pear/temp/imagick/imagick_class.c:1083:2: warning: passing argument 3 of âMagickGetImagePropertiesâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:35:5: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getimageprofilesâ: /tmp/pear/temp/imagick/imagick_class.c:1131:2: warning: passing argument 3 of âMagickGetImageProfilesâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:33:5: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_recolorimageâ: /tmp/pear/temp/imagick/imagick_class.c:1402:2: warning: âMagickRecolorImageâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:109) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_setfontâ: /tmp/pear/temp/imagick/imagick_class.c:1442:3: error: âstruct _php_core_globalsâ has no member named âsafe_modeâ /tmp/pear/temp/imagick/imagick_class.c:1442:3: error: âCHECKUID_CHECK_FILE_AND_DIRâ undeclared (first use in this function) /tmp/pear/temp/imagick/imagick_class.c:1442:3: note: each undeclared identifier is reported only once for each function it appears in /tmp/pear/temp/imagick/imagick_class.c:1442:3: error: âCHECKUID_NO_ERRORSâ undeclared (first use in this function) /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_queryformatsâ: /tmp/pear/temp/imagick/imagick_class.c:2580:2: warning: passing argument 2 of âMagickQueryFormatsâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:41:5: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_queryfontsâ: /tmp/pear/temp/imagick/imagick_class.c:2607:2: warning: passing argument 2 of âMagickQueryFontsâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:40:5: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_colorfloodfillimageâ: /tmp/pear/temp/imagick/imagick_class.c:3396:2: warning: âMagickColorFloodfillImageâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:75) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_mapimageâ: /tmp/pear/temp/imagick/imagick_class.c:3730:2: warning: âMagickMapImageâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:86) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_mattefloodfillimageâ: /tmp/pear/temp/imagick/imagick_class.c:3763:2: warning: âMagickMatteFloodfillImageâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:88) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_medianfilterimageâ: /tmp/pear/temp/imagick/imagick_class.c:3790:2: warning: âMagickMedianFilterImageâ is deprecated (declared at /usr/include/ImageMagick/wand/magick-image.h:217) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_paintopaqueimageâ: /tmp/pear/temp/imagick/imagick_class.c:3853:2: warning: âMagickPaintOpaqueImageChannelâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:104) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_painttransparentimageâ: /tmp/pear/temp/imagick/imagick_class.c:3916:2: warning: âMagickPaintTransparentImageâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:107) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_reducenoiseimageâ: /tmp/pear/temp/imagick/imagick_class.c:4059:2: warning: âMagickReduceNoiseImageâ is deprecated (declared at /usr/include/ImageMagick/wand/magick-image.h:266) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getimageattributeâ: /tmp/pear/temp/imagick/imagick_class.c:5068:2: warning: âMagickGetImageAttributeâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:59) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getimagechannelextremaâ: /tmp/pear/temp/imagick/imagick_class.c:5253:2: warning: âMagickGetImageChannelExtremaâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:78) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c:5253:2: warning: passing argument 3 of âMagickGetImageChannelExtremaâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:68:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/deprecate.h:78:3: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c:5253:2: warning: passing argument 4 of âMagickGetImageChannelExtremaâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:68:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/deprecate.h:78:3: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getimageextremaâ: /tmp/pear/temp/imagick/imagick_class.c:5506:2: warning: âMagickGetImageExtremaâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:80) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c:5506:2: warning: passing argument 2 of âMagickGetImageExtremaâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:68:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/deprecate.h:80:3: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c:5506:2: warning: passing argument 3 of âMagickGetImageExtremaâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:68:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/deprecate.h:80:3: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getimagehistogramâ: /tmp/pear/temp/imagick/imagick_class.c:5629:2: warning: passing argument 2 of âMagickGetImageHistogramâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:74:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-image.h:415:5: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getimagepageâ: /tmp/pear/temp/imagick/imagick_class.c:5740:2: warning: passing argument 2 of âMagickGetImagePageâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:74:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-image.h:192:3: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c:5740:2: warning: passing argument 3 of âMagickGetImagePageâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:74:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-image.h:192:3: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c:5740:2: warning: passing argument 4 of âMagickGetImagePageâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:74:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-image.h:192:3: note: expected âssize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c:5740:2: warning: passing argument 5 of âMagickGetImagePageâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:74:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-image.h:192:3: note: expected âssize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getimageindexâ: /tmp/pear/temp/imagick/imagick_class.c:6344:2: warning: âMagickGetImageIndexâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:65) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_setimageindexâ: /tmp/pear/temp/imagick/imagick_class.c:6369:2: warning: âMagickSetImageIndexâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:113) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getimagesizeâ: /tmp/pear/temp/imagick/imagick_class.c:6447:2: warning: âMagickGetImageSizeâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:140) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_setimageattributeâ: /tmp/pear/temp/imagick/imagick_class.c:6796:2: warning: âMagickSetImageAttributeâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:111) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_flattenimagesâ: /tmp/pear/temp/imagick/imagick_class.c:7043:2: warning: âMagickFlattenImagesâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:132) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_averageimagesâ: /tmp/pear/temp/imagick/imagick_class.c:8079:2: warning: âMagickAverageImagesâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:131) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_mosaicimagesâ: /tmp/pear/temp/imagick/imagick_class.c:8516:2: warning: âMagickMosaicImagesâ is deprecated (declared at /usr/include/ImageMagick/wand/deprecate.h:135) [-Wdeprecated-declarations] /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getpageâ: /tmp/pear/temp/imagick/imagick_class.c:9126:2: warning: passing argument 2 of âMagickGetPageâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:84:3: note: expected âsize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c:9126:2: warning: passing argument 3 of âMagickGetPageâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:84:3: note: expected âsize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c:9126:2: warning: passing argument 4 of âMagickGetPageâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:84:3: note: expected âssize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c:9126:2: warning: passing argument 5 of âMagickGetPageâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:84:3: note: expected âssize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getquantumdepthâ: /tmp/pear/temp/imagick/imagick_class.c:9154:2: warning: passing argument 1 of âMagickGetQuantumDepthâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:52:4: note: expected âsize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getquantumrangeâ: /tmp/pear/temp/imagick/imagick_class.c:9176:2: warning: passing argument 1 of âMagickGetQuantumRangeâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:53:4: note: expected âsize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getsamplingfactorsâ: /tmp/pear/temp/imagick/imagick_class.c:9247:2: warning: passing argument 2 of âMagickGetSamplingFactorsâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:59:4: note: expected âsize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getsizeâ: /tmp/pear/temp/imagick/imagick_class.c:9273:2: warning: passing argument 2 of âMagickGetSizeâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:86:3: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c:9273:2: warning: passing argument 3 of âMagickGetSizeâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:86:3: note: expected âsize_t *â but argument is of type âlong unsigned int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_getversionâ: /tmp/pear/temp/imagick/imagick_class.c:9299:2: warning: passing argument 1 of âMagickGetVersionâ from incompatible pointer type [enabled by default] In file included from /usr/include/ImageMagick/wand/MagickWand.h:73:0, from /tmp/pear/temp/imagick/php_imagick.h:49, from /tmp/pear/temp/imagick/imagick_class.c:21: /usr/include/ImageMagick/wand/magick-property.h:55:4: note: expected âsize_t *â but argument is of type âlong int *â /tmp/pear/temp/imagick/imagick_class.c: In function âzim_imagick_setimageprogressmonitorâ: /tmp/pear/temp/imagick/imagick_class.c:9534:2: error: âstruct _php_core_globalsâ has no member named âsafe_modeâ /tmp/pear/temp/imagick/imagick_class.c:9534:2: error: âCHECKUID_CHECK_FILE_AND_DIRâ undeclared (first use in this function) /tmp/pear/temp/imagick/imagick_class.c:9534:2: error: âCHECKUID_NO_ERRORSâ undeclared (first use in this function) make: *** [imagick_class.lo] Error 1 ERROR: `make' failed

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  • Can a conforming C implementation #define NULL to be something wacky

    - by janks
    I'm asking because of the discussion that's been provoked in this thread: http://stackoverflow.com/questions/2597142/when-was-the-null-macro-not-0/2597232 Trying to have a serious back-and-forth discussion using comments under other people's replies is not easy or fun. So I'd like to hear what our C experts think without being restricted to 500 characters at a time. The C standard has precious few words to say about NULL and null pointer constants. There's only two relevant sections that I can find. First: 3.2.2.3 Pointers An integral constant expression with the value 0, or such an expression cast to type void * , is called a null pointer constant. If a null pointer constant is assigned to or compared for equality to a pointer, the constant is converted to a pointer of that type. Such a pointer, called a null pointer, is guaranteed to compare unequal to a pointer to any object or function. and second: 4.1.5 Common definitions <stddef.h> The macros are NULL which expands to an implementation-defined null pointer constant; The question is, can NULL expand to an implementation-defined null pointer constant that is different from the ones enumerated in 3.2.2.3? In particular, could it be defined as: #define NULL __builtin_magic_null_pointer Or even: #define NULL ((void*)-1) My reading of 3.2.2.3 is that it specifies that an integral constant expression of 0, and an integral constant expression of 0 cast to type void* must be among the forms of null pointer constant that the implementation recognizes, but that it isn't meant to be an exhaustive list. I believe that the implementation is free to recognize other source constructs as null pointer constants, so long as no other rules are broken. So for example, it is provable that #define NULL (-1) is not a legal definition, because in if (NULL) do_stuff(); do_stuff() must not be called, whereas with if (-1) do_stuff(); do_stuff() must be called; since they are equivalent, this cannot be a legal definition of NULL. But the standard says that integer-to-pointer conversions (and vice-versa) are implementation-defined, therefore it could define the conversion of -1 to a pointer as a conversion that produces a null pointer. In which case if ((void*)-1) would evaluate to false, and all would be well. So what do other people think? I'd ask for everybody to especially keep in mind the "as-if" rule described in 2.1.2.3 Program execution. It's huge and somewhat roundabout, so I won't paste it here, but it essentially says that an implementation merely has to produce the same observable side-effects as are required of the abstract machine described by the standard. It says that any optimizations, transformations, or whatever else the compiler wants to do to your program are perfectly legal so long as the observable side-effects of the program aren't changed by them. So if you are looking to prove that a particular definition of NULL cannot be legal, you'll need to come up with a program that can prove it. Either one like mine that blatantly breaks other clauses in the standard, or one that can legally detect whatever magic the compiler has to do to make the strange NULL definition work. Steve Jessop found an example of way for a program to detect that NULL isn't defined to be one of the two forms of null pointer constants in 3.2.2.3, which is to stringize the constant: #define stringize_helper(x) #x #define stringize(x) stringize_helper(x) Using this macro, one could puts(stringize(NULL)); and "detect" that NULL does not expand to one of the forms in 3.2.2.3. Is that enough to render other definitions illegal? I just don't know. Thanks!

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  • socket operation on nonsocket or bad file descriptor

    - by Magn3s1um
    I'm writing a pthread server which takes requests from clients and sends them back a bunch of .ppm files. Everything seems to go well, but sometimes when I have just 1 client connected, when trying to read from the file descriptor (for the file), it says Bad file Descriptor. This doesn't make sense, since my int fd isn't -1, and the file most certainly exists. Other times, I get this "Socket operation on nonsocket" error. This is weird because other times, it doesn't give me this error and everything works fine. When trying to connect multiple clients, for some reason, it will only send correctly to one, and then the other client gets the bad file descriptor or "nonsocket" error, even though both threads are processing the same messages and do the same routines. Anyone have an idea why? Here's the code that is giving me that error: while(mqueue.head != mqueue.tail && count < dis_m){ printf("Sending to client %s: %s\n", pointer->id, pointer->message); int fd; fd = open(pointer->message, O_RDONLY); char buf[58368]; int bytesRead; printf("This is fd %d\n", fd); bytesRead=read(fd,buf,58368); send(pointer->socket,buf,bytesRead,0); perror("Error:\n"); fflush(stdout); close(fd); mqueue.mcount--; mqueue.head = mqueue.head->next; free(pointer->message); free(pointer); pointer = mqueue.head; count++; } printf("Sending %s\n", pointer->message); int fd; fd = open(pointer->message, O_RDONLY); printf("This is fd %d\n", fd); printf("I am hhere2\n"); char buf[58368]; int bytesRead; bytesRead=read(fd,buf,58368); send(pointer->socket,buf,bytesRead,0); perror("Error:\n"); close(fd); mqueue.mcount--; if(mqueue.head != mqueue.tail){ mqueue.head = mqueue.head->next; } else{ mqueue.head->next = malloc(sizeof(struct message)); mqueue.head = mqueue.head->next; mqueue.head->next = malloc(sizeof(struct message)); mqueue.tail = mqueue.head->next; mqueue.head->message = NULL; } free(pointer->message); free(pointer); pthread_mutex_unlock(&numm); pthread_mutex_unlock(&circ); pthread_mutex_unlock(&slots); The messages for both threads are the same, being of the form ./path/imageXX.ppm where XX is the number that should go to the client. The file size of each image is 58368 bytes. Sometimes, this code hangs on the read, and stops execution. I don't know this would be either, because the file descriptor comes back as valid. Thanks in advanced. Edit: Here's some sample output: Sending to client a: ./support/images/sw90.ppm This is fd 4 Error: : Socket operation on non-socket Sending to client a: ./support/images/sw91.ppm This is fd 4 Error: : Socket operation on non-socket Sending ./support/images/sw92.ppm This is fd 4 I am hhere2 Error: : Socket operation on non-socket My dispatcher has defeated evil Sample with 2 clients (client b was serviced first) Sending to client b: ./support/images/sw87.ppm This is fd 6 Error: : Success Sending to client b: ./support/images/sw88.ppm This is fd 6 Error: : Success Sending to client b: ./support/images/sw89.ppm This is fd 6 Error: : Success This is fd 6 Error: : Bad file descriptor Sending to client a: ./support/images/sw85.ppm This is fd 6 Error: As you can see, who ever is serviced first in this instance can open the files, but not the 2nd person. Edit2: Full code. Sorry, its pretty long and terribly formatted. #include <netinet/in.h> #include <netinet/in.h> #include <netdb.h> #include <arpa/inet.h> #include <sys/types.h> #include <sys/socket.h> #include <errno.h> #include <stdio.h> #include <unistd.h> #include <pthread.h> #include <stdlib.h> #include <string.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include "ring.h" /* Version 1 Here is what is implemented so far: The threads are created from the arguments specified (number of threads that is) The server will lock and update variables based on how many clients are in the system and such. The socket that is opened when a new client connects, must be passed to the threads. To do this, we need some sort of global array. I did this by specifying an int client and main_pool_busy, and two pointers poolsockets and nonpoolsockets. My thinking on this was that when a new client enters the system, the server thread increments the variable client. When a thread is finished with this client (after it sends it the data), the thread will decrement client and close the socket. HTTP servers act this way sometimes (they terminate the socket as soon as one transmission is sent). *Note down at bottom After the server portion increments the client counter, we must open up a new socket (denoted by new_sd) and get this value to the appropriate thread. To do this, I created global array poolsockets, which will hold all the socket descriptors for our pooled threads. The server portion gets the new socket descriptor, and places the value in the first spot of the array that has a 0. We only place a value in this array IF: 1. The variable main_pool_busy < worknum (If we have more clients in the system than in our pool, it doesn't mean we should always create a new thread. At the end of this, the server signals on the condition variable clientin that a new client has arrived. In our pooled thread, we then must walk this array and check the array until we hit our first non-zero value. This is the socket we will give to that thread. The thread then changes the array to have a zero here. What if our all threads in our pool our busy? If this is the case, then we will know it because our threads in this pool will increment main_pool_busy by one when they are working on a request and decrement it when they are done. If main_pool_busy >= worknum, then we must dynamically create a new thread. Then, we must realloc the size of our nonpoolsockets array by 1 int. We then add the new socket descriptor to our pool. Here's what we need to figure out: NOTE* Each worker should generate 100 messages which specify the worker thread ID, client socket descriptor and a copy of the client message. Additionally, each message should include a message number, starting from 0 and incrementing for each subsequent message sent to the same client. I don't know how to keep track of how many messages were to the same client. Maybe we shouldn't close the socket descriptor, but rather keep an array of structs for each socket that includes how many messages they have been sent. Then, the server adds the struct, the threads remove it, then the threads add it back once they've serviced one request (unless the count is 100). ------------------------------------------------------------- CHANGES Version 1 ---------- NONE: this is the first version. */ #define MAXSLOTS 30 #define dis_m 15 //problems with dis_m ==1 //Function prototypes void inc_clients(); void init_mutex_stuff(pthread_t*, pthread_t*); void *threadpool(void *); void server(int); void add_to_socket_pool(int); void inc_busy(); void dec_busy(); void *dispatcher(); void create_message(long, int, int, char *, char *); void init_ring(); void add_to_ring(char *, char *, int, int, int); int socket_from_string(char *); void add_to_head(char *); void add_to_tail(char *); struct message * reorder(struct message *, struct message *, int); int get_threadid(char *); void delete_socket_messages(int); struct message * merge(struct message *, struct message *, int); int get_request(char *, char *, char*); ///////////////////// //Global mutexes and condition variables pthread_mutex_t startservice; pthread_mutex_t numclients; pthread_mutex_t pool_sockets; pthread_mutex_t nonpool_sockets; pthread_mutex_t m_pool_busy; pthread_mutex_t slots; pthread_mutex_t numm; pthread_mutex_t circ; pthread_cond_t clientin; pthread_cond_t m; /////////////////////////////////////// //Global variables int clients; int main_pool_busy; int * poolsockets, nonpoolsockets; int worknum; struct ring mqueue; /////////////////////////////////////// int main(int argc, char ** argv){ //error handling if not enough arguments to program if(argc != 3){ printf("Not enough arguments to server: ./server portnum NumThreadsinPool\n"); _exit(-1); } //Convert arguments from strings to integer values int port = atoi(argv[1]); worknum = atoi(argv[2]); //Start server portion server(port); } /////////////////////////////////////////////////////////////////////////////////////////////// //The listen server thread///////////////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////////////////////////////////////////// void server(int port){ int sd, new_sd; struct sockaddr_in name, cli_name; int sock_opt_val = 1; int cli_len; pthread_t threads[worknum]; //create our pthread id array pthread_t dis[1]; //create our dispatcher array (necessary to create thread) init_mutex_stuff(threads, dis); //initialize mutexes and stuff //Server setup /////////////////////////////////////////////////////// if ((sd = socket (AF_INET, SOCK_STREAM, 0)) < 0) { perror("(servConn): socket() error"); _exit (-1); } if (setsockopt (sd, SOL_SOCKET, SO_REUSEADDR, (char *) &sock_opt_val, sizeof(sock_opt_val)) < 0) { perror ("(servConn): Failed to set SO_REUSEADDR on INET socket"); _exit (-1); } name.sin_family = AF_INET; name.sin_port = htons (port); name.sin_addr.s_addr = htonl(INADDR_ANY); if (bind (sd, (struct sockaddr *)&name, sizeof(name)) < 0) { perror ("(servConn): bind() error"); _exit (-1); } listen (sd, 5); //End of server Setup ////////////////////////////////////////////////// for (;;) { cli_len = sizeof (cli_name); new_sd = accept (sd, (struct sockaddr *) &cli_name, &cli_len); printf ("Assigning new socket descriptor: %d\n", new_sd); inc_clients(); //New client has come in, increment clients add_to_socket_pool(new_sd); //Add client to the pool of sockets if (new_sd < 0) { perror ("(servConn): accept() error"); _exit (-1); } } pthread_exit(NULL); //Quit } //Adds the new socket to the array designated for pthreads in the pool void add_to_socket_pool(int socket){ pthread_mutex_lock(&m_pool_busy); //Lock so that we can check main_pool_busy int i; //If not all our main pool is busy, then allocate to one of them if(main_pool_busy < worknum){ pthread_mutex_unlock(&m_pool_busy); //unlock busy, we no longer need to hold it pthread_mutex_lock(&pool_sockets); //Lock the socket pool array so that we can edit it without worry for(i = 0; i < worknum; i++){ //Find a poolsocket that is -1; then we should put the real socket there. This value will be changed back to -1 when the thread grabs the sockfd if(poolsockets[i] == -1){ poolsockets[i] = socket; pthread_mutex_unlock(&pool_sockets); //unlock our pool array, we don't need it anymore inc_busy(); //Incrememnt busy (locks the mutex itself) pthread_cond_signal(&clientin); //Signal first thread waiting on a client that a client needs to be serviced break; } } } else{ //Dynamic thread creation goes here pthread_mutex_unlock(&m_pool_busy); } } //Increments the client number. If client number goes over worknum, we must dynamically create new pthreads void inc_clients(){ pthread_mutex_lock(&numclients); clients++; pthread_mutex_unlock(&numclients); } //Increments busy void inc_busy(){ pthread_mutex_lock(&m_pool_busy); main_pool_busy++; pthread_mutex_unlock(&m_pool_busy); } //Initialize all of our mutexes at the beginning and create our pthreads void init_mutex_stuff(pthread_t * threads, pthread_t * dis){ pthread_mutex_init(&startservice, NULL); pthread_mutex_init(&numclients, NULL); pthread_mutex_init(&pool_sockets, NULL); pthread_mutex_init(&nonpool_sockets, NULL); pthread_mutex_init(&m_pool_busy, NULL); pthread_mutex_init(&circ, NULL); pthread_cond_init (&clientin, NULL); main_pool_busy = 0; poolsockets = malloc(sizeof(int)*worknum); int threadreturn; //error checking variables long i = 0; //Loop and create pthreads for(i; i < worknum; i++){ threadreturn = pthread_create(&threads[i], NULL, threadpool, (void *) i); poolsockets[i] = -1; if(threadreturn){ perror("Thread pool created unsuccessfully"); _exit(-1); } } pthread_create(&dis[0], NULL, dispatcher, NULL); } ////////////////////////////////////////////////////////////////////////////////////////// /////////Main pool routines ///////////////////////////////////////////////////////////////////////////////////////// void dec_busy(){ pthread_mutex_lock(&m_pool_busy); main_pool_busy--; pthread_mutex_unlock(&m_pool_busy); } void dec_clients(){ pthread_mutex_lock(&numclients); clients--; pthread_mutex_unlock(&numclients); } //This is what our threadpool pthreads will be running. void *threadpool(void * threadid){ long id = (long) threadid; //Id of this thread int i; int socket; int counter = 0; //Try and gain access to the next client that comes in and wait until server signals that a client as arrived while(1){ pthread_mutex_lock(&startservice); //lock start service (required for cond wait) pthread_cond_wait(&clientin, &startservice); //wait for signal from server that client exists pthread_mutex_unlock(&startservice); //unlock mutex. pthread_mutex_lock(&pool_sockets); //Lock the pool socket so we can get the socket fd unhindered/interrupted for(i = 0; i < worknum; i++){ if(poolsockets[i] != -1){ socket = poolsockets[i]; poolsockets[i] = -1; pthread_mutex_unlock(&pool_sockets); } } printf("Thread #%d is past getting the socket\n", id); int incoming = 1; while(counter < 100 && incoming != 0){ char buffer[512]; bzero(buffer,512); int startcounter = 0; incoming = read(socket, buffer, 512); if(buffer[0] != 0){ //client ID:priority:request:arguments char id[100]; long prior; char request[100]; char arg1[100]; char message[100]; char arg2[100]; char * point; point = strtok(buffer, ":"); strcpy(id, point); point = strtok(NULL, ":"); prior = atoi(point); point = strtok(NULL, ":"); strcpy(request, point); point = strtok(NULL, ":"); strcpy(arg1, point); point = strtok(NULL, ":"); if(point != NULL){ strcpy(arg2, point); } int fd; if(strcmp(request, "start_movie") == 0){ int count = 1; while(count <= 100){ char temp[10]; snprintf(temp, 50, "%d\0", count); strcpy(message, "./support/images/"); strcat(message, arg1); strcat(message, temp); strcat(message, ".ppm"); printf("This is message %s to %s\n", message, id); count++; add_to_ring(message, id, prior, counter, socket); //Adds our created message to the ring counter++; } printf("I'm out of the loop\n"); } else if(strcmp(request, "seek_movie") == 0){ int count = atoi(arg2); while(count <= 100){ char temp[10]; snprintf(temp, 10, "%d\0", count); strcpy(message, "./support/images/"); strcat(message, arg1); strcat(message, temp); strcat(message, ".ppm"); printf("This is message %s\n", message); count++; } } //create_message(id, socket, counter, buffer, message); //Creates our message from the input from the client. Stores it in buffer } else{ delete_socket_messages(socket); break; } } counter = 0; close(socket);//Zero out counter again } dec_clients(); //client serviced, decrement clients dec_busy(); //thread finished, decrement busy } //Creates a message void create_message(long threadid, int socket, int counter, char * buffer, char * message){ snprintf(message, strlen(buffer)+15, "%d:%d:%d:%s", threadid, socket, counter, buffer); } //Gets the socket from the message string (maybe I should just pass in the socket to another method) int socket_from_string(char * message){ char * substr1 = strstr(message, ":"); char * substr2 = substr1; substr2++; int occurance = strcspn(substr2, ":"); char sock[10]; strncpy(sock, substr2, occurance); return atoi(sock); } //Adds message to our ring buffer's head void add_to_head(char * message){ printf("Adding to head of ring\n"); mqueue.head->message = malloc(strlen(message)+1); //Allocate space for message strcpy(mqueue.head->message, message); //copy bytes into allocated space } //Adds our message to our ring buffer's tail void add_to_tail(char * message){ printf("Adding to tail of ring\n"); mqueue.tail->message = malloc(strlen(message)+1); //allocate space for message strcpy(mqueue.tail->message, message); //copy bytes into allocated space mqueue.tail->next = malloc(sizeof(struct message)); //allocate space for the next message struct } //Adds a message to our ring void add_to_ring(char * message, char * id, int prior, int mnum, int socket){ //printf("This is message %s:" , message); pthread_mutex_lock(&circ); //Lock the ring buffer pthread_mutex_lock(&numm); //Lock the message count (will need this to make sure we can't fill the buffer over the max slots) if(mqueue.head->message == NULL){ add_to_head(message); //Adds it to head mqueue.head->socket = socket; //Set message socket mqueue.head->priority = prior; //Set its priority (thread id) mqueue.head->mnum = mnum; //Set its message number (used for sorting) mqueue.head->id = malloc(sizeof(id)); strcpy(mqueue.head->id, id); } else if(mqueue.tail->message == NULL){ //This is the problem for dis_m 1 I'm pretty sure add_to_tail(message); mqueue.tail->socket = socket; mqueue.tail->priority = prior; mqueue.tail->mnum = mnum; mqueue.tail->id = malloc(sizeof(id)); strcpy(mqueue.tail->id, id); } else{ mqueue.tail->next = malloc(sizeof(struct message)); mqueue.tail = mqueue.tail->next; add_to_tail(message); mqueue.tail->socket = socket; mqueue.tail->priority = prior; mqueue.tail->mnum = mnum; mqueue.tail->id = malloc(sizeof(id)); strcpy(mqueue.tail->id, id); } mqueue.mcount++; pthread_mutex_unlock(&circ); if(mqueue.mcount >= dis_m){ pthread_mutex_unlock(&numm); pthread_cond_signal(&m); } else{ pthread_mutex_unlock(&numm); } printf("out of add to ring\n"); fflush(stdout); } ////////////////////////////////// //Dispatcher routines ///////////////////////////////// void *dispatcher(){ init_ring(); while(1){ pthread_mutex_lock(&slots); pthread_cond_wait(&m, &slots); pthread_mutex_lock(&numm); pthread_mutex_lock(&circ); printf("Dispatcher to the rescue!\n"); mqueue.head = reorder(mqueue.head, mqueue.tail, mqueue.mcount); //printf("This is the head %s\n", mqueue.head->message); //printf("This is the tail %s\n", mqueue.head->message); fflush(stdout); struct message * pointer = mqueue.head; int count = 0; while(mqueue.head != mqueue.tail && count < dis_m){ printf("Sending to client %s: %s\n", pointer->id, pointer->message); int fd; fd = open(pointer->message, O_RDONLY); char buf[58368]; int bytesRead; printf("This is fd %d\n", fd); bytesRead=read(fd,buf,58368); send(pointer->socket,buf,bytesRead,0); perror("Error:\n"); fflush(stdout); close(fd); mqueue.mcount--; mqueue.head = mqueue.head->next; free(pointer->message); free(pointer); pointer = mqueue.head; count++; } printf("Sending %s\n", pointer->message); int fd; fd = open(pointer->message, O_RDONLY); printf("This is fd %d\n", fd); printf("I am hhere2\n"); char buf[58368]; int bytesRead; bytesRead=read(fd,buf,58368); send(pointer->socket,buf,bytesRead,0); perror("Error:\n"); close(fd); mqueue.mcount--; if(mqueue.head != mqueue.tail){ mqueue.head = mqueue.head->next; } else{ mqueue.head->next = malloc(sizeof(struct message)); mqueue.head = mqueue.head->next; mqueue.head->next = malloc(sizeof(struct message)); mqueue.tail = mqueue.head->next; mqueue.head->message = NULL; } free(pointer->message); free(pointer); pthread_mutex_unlock(&numm); pthread_mutex_unlock(&circ); pthread_mutex_unlock(&slots); printf("My dispatcher has defeated evil\n"); } } void init_ring(){ mqueue.head = malloc(sizeof(struct message)); mqueue.head->next = malloc(sizeof(struct message)); mqueue.tail = mqueue.head->next; mqueue.mcount = 0; } struct message * reorder(struct message * begin, struct message * end, int num){ //printf("I am reordering for size %d\n", num); fflush(stdout); int i; if(num == 1){ //printf("Begin: %s\n", begin->message); begin->next = NULL; return begin; } else{ struct message * left = begin; struct message * right; int middle = num/2; for(i = 1; i < middle; i++){ left = left->next; } right = left -> next; left -> next = NULL; //printf("Begin: %s\nLeft: %s\nright: %s\nend:%s\n", begin->message, left->message, right->message, end->message); left = reorder(begin, left, middle); if(num%2 != 0){ right = reorder(right, end, middle+1); } else{ right = reorder(right, end, middle); } return merge(left, right, num); } } struct message * merge(struct message * left, struct message * right, int num){ //printf("I am merginging! left: %s %d, right: %s %dnum: %d\n", left->message,left->priority, right->message, right->priority, num); struct message * start, * point; int lenL= 0; int lenR = 0; int flagL = 0; int flagR = 0; int count = 0; int middle1 = num/2; int middle2; if(num%2 != 0){ middle2 = middle1+1; } else{ middle2 = middle1; } while(lenL < middle1 && lenR < middle2){ count++; //printf("In here for count %d\n", count); if(lenL == 0 && lenR == 0){ if(left->priority < right->priority){ start = left; //Set the start point point = left; //set our enum; left = left->next; //move the left pointer point->next = NULL; //Set the next node to NULL lenL++; } else if(left->priority > right->priority){ start = right; point = right; right = right->next; point->next = NULL; lenR++; } else{ if(left->mnum < right->mnum){ ////printf("This is where we are\n"); start = left; //Set the start point point = left; //set our enum; left = left->next; //move the left pointer point->next = NULL; //Set the next node to NULL lenL++; } else{ start = right; point = right; right = right->next; point->next = NULL; lenR++; } } } else{ if(left->priority < right->priority){ point->next = left; left = left->next; //move the left pointer point = point->next; point->next = NULL; //Set the next node to NULL lenL++; } else if(left->priority > right->priority){ point->next = right; right = right->next; point = point->next; point->next = NULL; lenR++; } else{ if(left->mnum < right->mnum){ point->next = left; //set our enum; left = left->next; point = point->next;//move the left pointer point->next = NULL; //Set the next node to NULL lenL++; } else{ point->next = right; right = right->next; point = point->next; point->next = NULL; lenR++; } } } if(lenL == middle1){ flagL = 1; break; } if(lenR == middle2){ flagR = 1; break; } } if(flagL == 1){ point->next = right; point = point->next; for(lenR; lenR< middle2-1; lenR++){ point = point->next; } point->next = NULL; mqueue.tail = point; } else{ point->next = left; point = point->next; for(lenL; lenL< middle1-1; lenL++){ point = point->next; } point->next = NULL; mqueue.tail = point; } //printf("This is the start %s\n", start->message); //printf("This is mqueue.tail %s\n", mqueue.tail->message); return start; } void delete_socket_messages(int a){ }

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  • Does unboxing just return a pointer to the value within the boxed object on the heap?

    - by Charles
    I this MSDN Magazine article, the author states (emphasis mine): Note that boxing always creates a new object and copies the unboxed value's bits to the object. On the other hand, unboxing simply returns a pointer to the data within a boxed object: no memory copy occurs. However, it is commonly the case that your code will cause the data pointed to by the unboxed reference to be copied anyway. I'm confused by the sentence I've bolded and the sentence that follows it. From everything else I've read, including this MSDN page, I've never before heard that unboxing just returns a pointer to the value on the heap. I was under the impression that unboxing would result in you having a variable containing a copy of the value on the stack, just as you began with. After all, if my variable contains "a pointer to the value on the heap", then I haven't got a value type, I've got a pointer. Can someone explain what this means? Was the author on crack? (There is at least one other glaring error in the article). And if this is true, what are the cases where "your code will cause the data pointed to by the unboxed reference to be copied anyway"? I just noticed that the article is nearly 10 years old, so maybe this is something that changed very early on in the life of .Net.

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  • The mouse pointer in my Ubuntu VM has turned into a little hand with a document, and clicks are igno

    - by Daryl Spitzer
    The mouse pointer in my Ubuntu 8.04.3 LTS VM (running in VMware Fusion) has changed into a little hand holding a document. It doesn't show up in screen-shots. All mouse clicks (left or right) are ignored. But I can still type in the one Terminal window I have open. (And commands work fine.) I wonder if I'm in some kind of drag-and-drop mode. How do I get out of this? Update: Rebooting (from the command-line) worked. Ubuntu came up with the regular mouse-pointer.

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  • How to take input for a character pointer without using fget?

    - by ashish yadav
    consider the code #include<stdio.h> int main() { char* a; scanf("%s",a);//&a and &a[0] give same results-crashes printf("%s",); return 0; } why does this code results in crashing?whereas this code using character array works fine? #include<stdio.h> int main() { char a[100]; scanf("%s",&a[0]);//works fine printf("%s",a); return 0; } the difference being character array and pointer?but i knew that pointer just points to the first element that is &a[0] should work fine but upper code crashes for all three that is a,&a and &a[0]? the main thing i would to gather is how can i take input of a character pointer if i insist on using scanf only? i apologize if i am not clear. thanks in advance:)

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  • Why we used double pointer in objective-C or C language?

    - by Rajendra Bhole
    Hi, I confused when i want to take single pointer and when should i take double pointer? In following structure what exactly did? struct objc_class { Class isa; Class super_class; const char *name; long version; long info; long instance_size; struct objc_ivar_list *ivars; struct objc_method_list **methodLists; struct objc_cache *cache; struct objc_protocol_list *protocols; }; Why we use the "**methodLists" double pointer?

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  • How do I marshal a pointer to an array of pointers to structures?

    - by Daniel Stutzbach
    I have a C function with the following signature: int my_function(int n, struct player **players) players is a pointer to an array of pointers to struct player objects. n is the number of pointers in the array. The function does not modify the array nor the contents of the structures, and it does not retain any pointers after returning. I tried the following: [DllImport("mylibary.dll")] static extern int my_function(int n, [In, MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 0)] player_in []players); However, that marshals the data as a pointer to an array of structures, not a pointer to an array of pointers to structures.

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  • NSArray : release its objects, but keep a pointer to it.

    - by Leo
    Hello, I declare an NSArray in my code then building the array from another array. I process my NSArray and when I'm finished, I would like to release the objects, but I'm reusing this pointer to NSAarray again later to do the same process (creating the array from another array, process then releasing).. So I need to keep the pointer. What should I do ? Here is roughly what I want to do, the buildArray is creating and returning an autoreleased NSArray : NSArray *myArray; for (int i = 0, i < 10, i++){ [myArray arrayWithArray:[self buildArray]]; // Here I process myArray [myArray = nil] // is my guess } I need to keep a pointer to my NSArray, in order to reuse later in the loop, but what is happening to the objects created with [self buildArray]? What is the best to do in order not to keep unused object and arrays ? Or maybe the best solution is simply to removeAllObject of the array..? Thank you!

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  • Is there a way to have a bit bucket pointer? (C/C++)

    - by Crazy Chenz
    Is there a way to have a bit bucket pointer? A lot of IO (specifically input related) system calls return data to a buffer of a specific size. Is there a trick or way to make a sorta bit bucket pointer, so I can accept any amount of data that will be thrown away. Doing something like "char tmp[INT_MAX]" is crazy. The behavior I am looking for is something like /dev/null, only in a pointer world. Not to hopeful on this.... just curious. Thanks, Chenz UPDATE: Perhaps mmap-ing /dev/null. Forgot about that when I asked the question.

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  • What is better: to delete pointer or set it with a new value?

    - by user63898
    Hi simple question in c++ , say i have a loop and i have function that returns pointer to item so i have to define inner loop pointer so my question is what to do with the pointer inside the loop , delete it ? or to set it with new value is good for example: for(int i =0;i<count();i++) { ptrTmp* ptr = getItemPtr(); // do somthing with the ptr ... // what to do here ? to delete the poinetr or not? delete ptr; // ?? }

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  • Touchpad not working on an Acer One 725

    - by big-marc
    I installed ubuntu on a usb drive on a acer one 725, and cannot seem to be able to make the touchpad work....here is what i have xinpbig-marc@Big-Marc:~$ xinput --list ? Virtual core pointer id=2 [master pointer (3)] ? ? Virtual core XTEST pointer id=4 [slave pointer (2)] ? ? Logitech USB Optical Mouse id=10 [slave pointer (2)] ? ? ETPS/2 Elantech Touchpad id=13 [slave pointer (2)] any can help me out....

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  • Cursor (touchpad) moves and clicks erratically

    - by James Wood
    Sometimes (usually after two-finger scrolling) the touchpad on my Asus X54C becomes unresponsive and the cursor begins to click and move small distances. Clicking seems to happen more often than moving. Unlike with other similar problems, I've never seen the cursor move to (0, 0). Suspending (closing the lid) and unsuspending doesn't help, and neither does moving to a tty and back or rebooting. I've also tried disabling the touchpad via Fn+F9. That tends to take a long time, but doesn't have any effect. I'm on 13.10 at the moment, but I remember it happening on 13.04 as well. Here's the pointer section of xinput: ? Virtual core pointer id=2 [master pointer (3)] ? ? Virtual core XTEST pointer id=4 [slave pointer (2)] ? ? ETPS/2 Elantech Touchpad id=12 [slave pointer (2)]

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  • pecl-ssh2-0.11 Freebsd Compile error after upgrading to php 5.3.2

    - by penfold45
    Hi I've been looking for answers for this all day and can find nothing to solve my issue. I also came across a question about this port on serverfault that I just answered and will hopefully help someone else. however my problem is this. While running "make" in /usr/ports/security/pecl-ssh2 I get this error === Building for pecl-ssh2-0.11 /bin/sh /usr/ports/security/pecl-ssh2/work/ssh2-0.11/libtool --mode=compile cc -I. -I/usr/ports/security/pecl-ssh2/work/ssh2-0.11 -DPHP_ATOM_INC -I/usr/ports/security/pecl-ssh2/work/ssh2-0.11/include -I/usr/ports/security/pecl-ssh2/work/ssh2-0.11/main -I/usr/ports/security/pecl-ssh2/work/ssh2-0.11 -I/usr/local/include/php -I/usr/local/include/php/main -I/usr/local/include/php/TSRM -I/usr/local/include/php/Zend -I/usr/local/include/php/ext -I/usr/local/include/php/ext/date/lib -I/usr/local/include -I/usr/local/include -DHAVE_CONFIG_H -O2 -pipe -fno-strict-aliasing -c /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c -o ssh2.lo cc -I. -I/usr/ports/security/pecl-ssh2/work/ssh2-0.11 -DPHP_ATOM_INC -I/usr/ports/security/pecl-ssh2/work/ssh2-0.11/include -I/usr/ports/security/pecl-ssh2/work/ssh2-0.11/main -I/usr/ports/security/pecl-ssh2/work/ssh2-0.11 -I/usr/local/include/php -I/usr/local/include/php/main -I/usr/local/include/php/TSRM -I/usr/local/include/php/Zend -I/usr/local/include/php/ext -I/usr/local/include/php/ext/date/lib -I/usr/local/include -I/usr/local/include -DHAVE_CONFIG_H -O2 -pipe -fno-strict-aliasing -c /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c -fPIC -DPIC -o .libs/ssh2.o /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c: In function 'zif_ssh2_methods_negotiated': /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:502: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:503: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:507: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:508: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:509: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:510: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:515: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:516: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:517: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:518: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c: In function 'zif_ssh2_poll': /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:891: error: 'zval' has no member named 'is_ref' /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:891: error: 'zval' has no member named 'refcount' /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:901: error: 'zval' has no member named 'is_ref' /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:902: error: 'zval' has no member named 'refcount' /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c: In function 'zif_ssh2_publickey_add': /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:1011: error: 'zval' has no member named 'is_ref' /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:1012: error: 'zval' has no member named 'refcount' /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:1044: warning: passing argument 1 of '_efree' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c: In function 'zif_ssh2_publickey_list': /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:1103: warning: passing argument 4 of 'add_assoc_stringl_ex' discards qualifiers from pointer target type /usr/ports/security/pecl-ssh2/work/ssh2-0.11/ssh2.c:1104: warning: passing argument 4 of 'add_assoc_stringl_ex' discards qualifiers from pointer target type *** Error code 1 Stop in /usr/ports/security/pecl-ssh2/work/ssh2-0.11. *** Error code 1 Stop in /usr/ports/security/pecl-ssh2. I am trying to recompile this port after upgrading from php 5.2.12 to php 5.3.2 which was released on freebsd over the weekend. I have run out of ideas and steam with this so if anyone has any ideas on what this might be I would be truly grateful.

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  • Pecl install ssh2, make failed

    - by user28259
    Hi! I'm trying really hard since two hours to install ssh2 with pecl... But all I get is: /bin/sh /root/ssh2-0.11.0/libtool --mode=compile cc -I. -I/root/ssh2-0.11.0 -DPHP_ATOM_INC -I/root/ssh2-0.11.0/include -I/root/ssh2-0.11.0/main -I/root/ssh2-0.11.0 -I/usr/include/php -I/usr/include/php/main -I/usr/include/php/TSRM -I/usr/include/php/Zend -I/usr/include/php/ext -I/usr/include/php/ext/date/lib -DHAVE_CONFIG_H -g -O2 -c /root/ssh2-0.11.0/ssh2.c -o ssh2.lo mkdir .libs cc -I. -I/root/ssh2-0.11.0 -DPHP_ATOM_INC -I/root/ssh2-0.11.0/include -I/root/ssh2-0.11.0/main -I/root/ssh2-0.11.0 -I/usr/include/php -I/usr/include/php/main -I/usr/include/php/TSRM -I/usr/include/php/Zend -I/usr/include/php/ext -I/usr/include/php/ext/date/lib -DHAVE_CONFIG_H -g -O2 -c /root/ssh2-0.11.0/ssh2.c -fPIC -DPIC -o .libs/ssh2.o /root/ssh2-0.11.0/ssh2.c:52: error: duplicate 'static' /root/ssh2-0.11.0/ssh2.c: In function 'zif_ssh2_methods_negotiated': /root/ssh2-0.11.0/ssh2.c:503: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:360: note: expected 'char *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c:504: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:360: note: expected 'char *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c:508: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:360: note: expected 'char *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c:509: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:360: note: expected 'char *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c:510: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:360: note: expected 'char *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c:511: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:360: note: expected 'char *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c:516: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:360: note: expected 'char *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c:517: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:360: note: expected 'char *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c:518: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:360: note: expected 'char *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c:519: warning: passing argument 4 of 'add_assoc_string_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:360: note: expected 'char *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c: In function 'zif_ssh2_publickey_add': /root/ssh2-0.11.0/ssh2.c:1045: warning: passing argument 1 of '_efree' discards qualifiers from pointer target type /usr/include/php/Zend/zend_alloc.h:46: note: expected 'void *' but argument is of type 'const char *' /root/ssh2-0.11.0/ssh2.c: In function 'zif_ssh2_publickey_list': /root/ssh2-0.11.0/ssh2.c:1104: warning: passing argument 4 of 'add_assoc_stringl_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:361: note: expected 'char *' but argument is of type 'const unsigned char *' /root/ssh2-0.11.0/ssh2.c:1105: warning: passing argument 4 of 'add_assoc_stringl_ex' discards qualifiers from pointer target type /usr/include/php/Zend/zend_API.h:361: note: expected 'char *' but argument is of type 'const unsigned char *' make: *** [ssh2.lo] Error 1 I looked on google a lot, I found some patches which didn't worked at all. So if you think you could help me, go ahead! Thanks!

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  • COM IUnknown and do I need a pointer to it first before calling CoGetClassObject?

    - by Tony
    In COM, when you want to create an instance of some COM Server object, do you first need to get a pointer to it's IUnknown interface and only then create a class object using CoGetClassObject? As far as I understand it, IUnknown is used to manage object lifetimes, so from my understanding, whatever object the client wants to create, one needs a pointer to it's IUnknown interface implementation first. Sound correct? If not, can anyone tell me how it works?

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  • How to include only BOOST smart pointer codes into a project?

    - by afriza
    What are best practices to include boost smart pointer library only without adding all boost libraries into the project? I only want boost smart pointer library in my project and I don't want to check in/commit 200 MB source codes (boost 1.42.0) into my project repository just for that. What more, my windows mobile project itself doesn't even reach 10% of that size!

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  • Cocoa & Cocoa Touch. How do I create an NSData object from a plain ole pointer?

    - by dugla
    I have malloc'd a whole mess of data in an NSOperation instance. I have a pointer: data = malloc(humungous_amounts_of_god_knows_what); uint8_t* data; How do I package this up as an NSData instance and return it to the main thread? I am assuming that after conversion to an NSData instance I can simply call: free(data); Yes? Also, back on the main thread how do I retrieve the pointer? Thanks, Doug

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  • operator "new" returning a non-local heap pointer for only one class ?

    - by KaluSingh Gabbar
    Language : C++ Platform : Windows Server 2003 I have an exe calling a DLL, in which when I allocate (new) the memory for class A (which is in DLL) it returns me a non-local heap pointer. I try to new other classes which are in DLL and "new" returns a valid heap pointer for them, its only Class A which is not being allocated properly. I am on windows and validating the heap by this function call : _CrtIsValidHeapPointer ( (const void *) pPtr ) I am seriously confused why this only happens with new-ing Class A and no other class ? (All Native Code)

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  • How to obtain a pointer out of a C++ vtable?

    - by Josh Haberman
    Say you have a C++ class like: class Foo { public: virtual ~Foo() {} virtual DoSomething() = 0; }; The C++ compiler translates a call into a vtable lookup: Foo* foo; // Translated by C++ to: // foo->vtable->DoSomething(foo); foo->DoSomething(); Suppose I was writing a JIT compiler and I wanted to obtain the address of the DoSomething() function for a particular instance of class Foo, so I can generate code that jumps to it directly instead of doing a table lookup and an indirect branch. My questions are: Is there any standard C++ way to do this (I'm almost sure the answer is no, but wanted to ask for the sake of completeness). Is there any remotely compiler-independent way of doing this, like a library someone has implemented that provides an API for accessing a vtable? I'm open to completely hacks, if they will work. For example, if I created my own derived class and could determine the address of its DoSomething method, I could assume that the vtable is the first (hidden) member of Foo and search through its vtable until I find my pointer value. However, I don't know a way of getting this address: if I write &DerivedFoo::DoSomething I get a pointer-to-member, which is something totally different. Maybe I could turn the pointer-to-member into the vtable offset. When I compile the following: class Foo { public: virtual ~Foo() {} virtual void DoSomething() = 0; }; void foo(Foo *f, void (Foo::*member)()) { (f->*member)(); } On GCC/x86-64, I get this assembly output: Disassembly of section .text: 0000000000000000 <_Z3fooP3FooMS_FvvE>: 0: 40 f6 c6 01 test sil,0x1 4: 48 89 74 24 e8 mov QWORD PTR [rsp-0x18],rsi 9: 48 89 54 24 f0 mov QWORD PTR [rsp-0x10],rdx e: 74 10 je 20 <_Z3fooP3FooMS_FvvE+0x20> 10: 48 01 d7 add rdi,rdx 13: 48 8b 07 mov rax,QWORD PTR [rdi] 16: 48 8b 74 30 ff mov rsi,QWORD PTR [rax+rsi*1-0x1] 1b: ff e6 jmp rsi 1d: 0f 1f 00 nop DWORD PTR [rax] 20: 48 01 d7 add rdi,rdx 23: ff e6 jmp rsi I don't fully understand what's going on here, but if I could reverse-engineer this or use an ABI spec I could generate a fragment like the above for each separate platform, as a way of obtaining a pointer out of a vtable.

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