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  • Nightmare: Upgrading Tomcat 5.5 to 6.0

    - by pavanlimo
    I'm trying to upgrade a perfectly running embedded Tomcat 5.5 to Tomcat 6.0. I understand that all I need to do is replace Tomcat 5.5 jars with 6.0. That's what I did. So I replaced the following jars: catalina-5.0.28.jar catalina-5.5.9.jar catalina-optional-5.5.9.jar commons-el.jar commons-modeler-1.1.0.jar jasper-compiler-jdt.jar jasper-compiler.jar jasper-runtime.jar jmx-5.0.28.jar jsp-api-2.0.jar naming-factory.jar naming-resources.jar servlet-api-2.4.jar servlets-default.jar tomcat-coyote.jar tomcat-http.jar tomcat-util.jar with: annotations-api.jar catalina.jar jasper.jar tomcat-dbcp.jar catalina-ant.jar el-api.jar jsp-api.jar tomcat-i18n-es.jar catalina-ha.jar jasper-el.jar servlet-api.jar tomcat-i18n-fr.jar catalina-tribes.jar jasper-jdt.jar tomcat-coyote.jar tomcat-i18n-ja.jar tomcat-juli.jar As soon as I start the server, I get the following message in the logs at INFO level: INFO: Starting Servlet Engine: Apache Tomcat/6.0.29 Dec 31, 2010 6:04:18 AM org.apache.catalina.loader.WebappClassLoader validateJarFile INFO: validateJarFile(/usr/local/blah/blue/./WEB-INF/lib/servlet-api.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class Based on the this explanation, I need to remove a jar file which has a conflicting Servlet.class. I swear to God, there is no other conflicting jar file, I grepped system wide for Servlet.class, it matched only servlet-api.jar. I also downloaded javaee.jar and replaced it by servlet-api.jar, to same avail. Having tried lot of these stuff, I did not have much to look upto, so set the tomcat logging level to ALL. In the log I could see that it is trying to check for Servlet.class in each and every jar it is loading until it finds servlet-api.jar and throws "jar not loaded" message as soon as it finds servlet-api.jar. See below: FINE: Checking for javax/servlet/Servlet.class Jan 2, 2011 7:39:33 AM org.apache.catalina.loader.WebappLoader setRepositories FINE: Deploy JAR /WEB-INF/lib/servlet-api.jar to /usr/local/blah/blue/./WEB-INF/lib/servlet-api.jar Jan 2, 2011 7:39:33 AM org.apache.catalina.loader.WebappClassLoader addJar FINE: addJar(/WEB-INF/lib/servlet-api.jar) Jan 2, 2011 7:39:33 AM org.apache.catalina.loader.WebappClassLoader validateJarFile FINE: Checking for javax/servlet/Servlet.class Jan 2, 2011 7:39:33 AM org.apache.catalina.loader.WebappClassLoader validateJarFile INFO: validateJarFile(/usr/local/blah/blue/./WEB-INF/lib/servlet-api.jar) - jar not loaded. See Servlet Spec 2.3, section 9.7.2. Offending class: javax/servlet/Servlet.class Jan 2, 2011 7:39:33 AM org.apache.catalina.loader.WebappLoader setRepositories Please note however, that Tomcat starts successfully! And as soon as I hit the URL on the browser, I get blank page(this may be in my case only, I guess 'cuz of my web.xml, sorta different from most. Other people on the internet have got Error 404 instead.) with following log statements(at finest level) Jan 2, 2011 9:40:01 AM org.apache.catalina.connector.CoyoteAdapter parseSessionCookiesId FINE: Requested cookie session id is 0FBA716E3F9B0147C3AF7ABAE3B1C27B Jan 2, 2011 9:40:01 AM org.apache.catalina.authenticator.AuthenticatorBase invoke FINE: Security checking request GET /login.jsp Jan 2, 2011 9:40:01 AM org.apache.catalina.realm.RealmBase findSecurityConstraints FINE: Checking constraint 'SecurityConstraint[protected]' against GET /login.jsp --> false Jan 2, 2011 9:40:01 AM org.apache.catalina.realm.RealmBase findSecurityConstraints FINE: Checking constraint 'SecurityConstraint[protected]' against GET /login.jsp --> false Jan 2, 2011 9:40:01 AM org.apache.catalina.realm.RealmBase findSecurityConstraints FINE: Checking constraint 'SecurityConstraint[protected]' against GET /login.jsp --> false Jan 2, 2011 9:40:01 AM org.apache.catalina.realm.RealmBase findSecurityConstraints FINE: Checking constraint 'SecurityConstraint[protected]' against GET /login.jsp --> false Jan 2, 2011 9:40:01 AM org.apache.catalina.realm.RealmBase findSecurityConstraints FINE: No applicable constraint located Jan 2, 2011 9:40:01 AM org.apache.catalina.authenticator.AuthenticatorBase invoke FINE: Not subject to any constraint Jan 2, 2011 9:40:01 AM org.apache.catalina.core.StandardWrapper allocate FINEST: Returning non-STM instance I'm not sure if the above log message is important, but I'm for all-out disclosure here. One interesting thing though, I manually created a dummy jsp file containing only "helloooo" just outside WEB-INF folder(no security constraints for this file). This file was accessible and could be displayed. But, all my jsp's and classes are inside WEB-INF(ofcourse). Sick and tired of this issue, please help me solve it. I've already spent 20-24 hours on this unsuccessfully. Any pointers directions hints leads?

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  • Compiling ruby1.9.1 hangs and fills swap!

    - by nfm
    I'm compiling Ruby 1.9.1-p376 under Ubuntu 8.04 server LTS (64-bit), by doing the following: $ ./configure $ make $ sudo make install ./configure works without complaints. make hangs indefinitely until all my RAM and swap is gone. It get stuck after the following output: compiling ripper make[1]: Entering directory `/tmp/ruby1.9.1/ruby-1.9.1-p376/ext/ripper' gcc -I. -I../../.ext/include/x86_64-linux -I../.././include -I../.././ext/ripper -I../.. -I../../. -DRUBY_EXTCONF_H=\"extconf.h\" -fPIC -O2 -g -Wall -Wno-parentheses -o ripper.o -c ripper.c If I run the gcc command by hand, with the -v argument to get verbose output, it hangs after the following: Using built-in specs. Target: x86_64-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.2 --program-suffix=-4.2 --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 4.2.4 (Ubuntu 4.2.4-1ubuntu4) /usr/lib/gcc/x86_64-linux-gnu/4.2.4/cc1 -quiet -v -I. -I../../.ext/include/x86_64-linux -I../.././include -I../.././ext/ripper -I../.. -I../../. -DRUBY_EXTCONF_H="extconf.h" ripper.c -quiet -dumpbase ripper.c -mtune=generic -auxbase-strip ripper.o -g -O2 -Wall -Wno-parentheses -version -fPIC -fstack-protector -fstack-protector -o /tmp/ccRzHvYH.s ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu" ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/4.2.4/../../../../x86_64-linux-gnu/include" ignoring nonexistent directory "/usr/include/x86_64-linux-gnu" ignoring duplicate directory "../.././ext/ripper" ignoring duplicate directory "../../." #include "..." search starts here: #include <...> search starts here: . ../../.ext/include/x86_64-linux ../.././include ../.. /usr/local/include /usr/lib/gcc/x86_64-linux-gnu/4.2.4/include /usr/include End of search list. GNU C version 4.2.4 (Ubuntu 4.2.4-1ubuntu4) (x86_64-linux-gnu) compiled by GNU C version 4.2.4 (Ubuntu 4.2.4-1ubuntu4). GGC heuristics: --param ggc-min-expand=47 --param ggc-min-heapsize=32795 Compiler executable checksum: 6e11fa7ca85fc28646173a91f2be2ea3 I just compiled ruby on another computer for reference, and it took about 10 seconds to print the following output (after the above Compiler executable checksum line): COLLECT_GCC_OPTIONS='-v' '-I.' '-I../../.ext/include/i686-linux' '-I../.././include' '-I../.././ext/ripper' '-I../..' '-I../../.' '-DRUBY_EXTCONF_H="extconf.h"' '-D_FILE_OFFSET_BITS=64' '-fPIC' '-O2' '-g' '-Wall' '-Wno-parentheses' '-o' 'ripper.o' '-c' '-mtune=generic' '-march=i486' as -V -Qy -o ripper.o /tmp/cca4fa7R.s GNU assembler version 2.20 (i486-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.20 COMPILER_PATH=/usr/lib/gcc/i486-linux-gnu/4.4.1/:/usr/lib/gcc/i486-linux-gnu/4.4.1/:/usr/lib/gcc/i486-linux-gnu/:/usr/lib/gcc/i486-linux-gnu/4.4.1/:/usr/lib/gcc/i486-linux-gnu/:/usr/lib/gcc/i486-linux-gnu/4.4.1/:/usr/lib/gcc/i486-linux-gnu/ LIBRARY_PATH=/usr/lib/gcc/i486-linux-gnu/4.4.1/:/usr/lib/gcc/i486-linux-gnu/4.4.1/:/usr/lib/gcc/i486-linux-gnu/4.4.1/../../../../lib/:/lib/../lib/:/usr/lib/../lib/:/usr/lib/gcc/i486-linux-gnu/4.4.1/../../../:/lib/:/usr/lib/ COLLECT_GCC_OPTIONS='-v' '-I.' '-I../../.ext/include/i686-linux' '-I../.././include' '-I../.././ext/ripper' '-I../..' '-I../../.' '-DRUBY_EXTCONF_H="extconf.h"' '-D_FILE_OFFSET_BITS=64' '-fPIC' '-O2' '-g' '-Wall' '-Wno-parentheses' '-o' 'ripper.o' '-c' '-mtune=generic' '-march=i486' I have absolutely no clue what could be going wrong here - any ideas where I should start?

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  • Calling function using 'new' is less expensive than without it?

    - by Matthew Taylor
    Given this very familiar model of prototypal construction: function Rectangle(w,h) { this.width = w; this.height = h; } Rectangle.prototype.area = function() { return this.width * this.height; }; Can anyone explain why calling "new Rectangle(2,3)" is consistently 10x FASTER than calling "Rectangle(2,3)" without the 'new' keyword? I would have assumed that because new adds more complexity to the execution of a function by getting prototypes involved, it would be slower. Example: var myTime; function startTrack() { myTime = new Date(); } function stopTrack(str) { var diff = new Date().getTime() - myTime.getTime(); println(str + ' time in ms: ' + diff); } function trackFunction(desc, func, times) { var i; if (!times) times = 1; startTrack(); for (i=0; i<times; i++) { func(); } stopTrack('(' + times + ' times) ' + desc); } var TIMES = 1000000; trackFunction('new rect classic', function() { new Rectangle(2,3); }, TIMES); trackFunction('rect classic (without new)', function() { Rectangle(2,3); }, TIMES); Yields (in Chrome): (1000000 times) new rect classic time in ms: 33 (1000000 times) rect classic (without new) time in ms: 368 (1000000 times) new rect classic time in ms: 35 (1000000 times) rect classic (without new) time in ms: 374 (1000000 times) new rect classic time in ms: 31 (1000000 times) rect classic (without new) time in ms: 368

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  • Installing VS2010 components with SP1 beta

    - by Jesus Rodriguez
    Hello, I hope this is the place for this kind of question. I have VS2010 ult with the Service Pack 1 beta installed. I want to play with F# and I need to install it. The problem is that because I have the SP1 installed, the VS DVD can't install the F# compiler. I click on add new feature, I click on F#, the installer says: "A selected drive is not longer valid. Please review your installation path settings before continuing with setup." Of course the path is correct and I can't change it anyway... I think that problem is because I have the SP1. I had the same problem in the past with VS2008 + SP1. What can I do? Uninstalling VS2010 is not an option, it take ages. Thank you.

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  • Java Swing Threading with Updatable JProgressBar

    - by Anthony Sparks
    First off I've been working with Java's Concurency package quite a bit lately but I have found an issue that I am stuck on. I want to have and Application and the Application can have a SplashScreen with a status bar and the loading of other data. So I decided to use SwingUtilities.invokeAndWait( call the splash component here ). The SplashScreen then appears with a JProgressBar and runs a group of threads. But I can't seem to get a good handle on things. I've looked over SwingWorker and tried using it for this purpose but the thread just returns. Here is a bit of sudo-code. and the points I'm trying to achieve. Have an Application that has a SplashScreen that pauses while loading info Be able to run multiple threads under the SplashScreen Have the progress bar of the SplashScreen Update-able yet not exit until all threads are done. Launching splash screen try { SwingUtilities.invokeAndWait( SplashScreen ); } catch (InterruptedException e) { } catch (InvocationTargetException e) { } Splash screen construction SplashScreen extends JFrame implements Runnable{ public void run() { //run threads //while updating status bar } } I have tried many things including SwingWorkers, Threads using CountDownLatch's, and others. The CountDownLatch's actually worked in the manner I wanted to do the processing but I was unable to update the GUI. When using the SwingWorkers either the invokeAndWait was basically nullified (which is their purpose) or it wouldn't update the GUI still even when using a PropertyChangedListener. If someone else has a couple ideas it would be great to hear them. Thanks in advance.

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  • MySQL table data transformation -- how can I dis-aggregate MySQL time data?

    - by lighthouse65
    We are coding for a MySQL data warehousing application that stores descriptive data (User ID, Work ID, Machine ID, Start and End Time columns in the first table below) associated with time and production quantity data (Output and Time columns in the first table below) upon which aggregate (SUM, COUNT, AVG) functions are applied. We now wish to dis-aggregate time data for another type of analysis. Our current data table design: +---------+---------+------------+---------------------+---------------------+--------+------+ | User ID | Work ID | Machine ID | Event Start Time | Event End Time | Output | Time | +---------+---------+------------+---------------------+---------------------+--------+------+ | 080025 | ABC123 | M01 | 2008-01-24 16:19:15 | 2008-01-24 16:34:45 | 2120 | 930 | +---------+---------+------------+---------------------+---------------------+--------+------+ Reprocessing dis-aggregation that we would like to do would be to transform table content based on a granularity of minutes, rather than the current production event ("Event Start Time" and "Event End Time") granularity. The resulting reprocessing of existing table rows would look like: +---------+---------+------------+---------------------+--------+ | User ID | Work ID | Machine ID | Production Minute | Output | +---------+---------+------------+---------------------+--------+ | 080025 | ABC123 | M01 | 2010-01-24 16:19 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:20 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:21 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:22 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:23 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:24 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:25 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:26 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:27 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:28 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:29 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:30 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:31 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:22 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:33 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:34 | 133 | +---------+---------+------------+---------------------+--------+ So the reprocessing would take an existing row of data created at the granularity of production event and modify the granularity to minutes, eliminating redundant (Event End Time, Time) columns while doing so. It assumes a constant rate of production and divides output by the difference in minutes plus one to populate the new table's Output column. I know this can be done in code...but can it be done entirely in a MySQL insert statement (or otherwise entirely in MySQL)? I am thinking of a INSERT ... INTO construction but keep getting stuck. An additional complexity is that there are hundreds of machines to include in the operation so there will be multiple rows (one for each machine) for each minute of the day. Any ideas would be much appreciated. Thanks.

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  • Mocking an object that uses jni using EasyMock

    - by Visage
    So my class under test has code that looks braodly like this public void doSomething(int param) { Report report = new Report() ...do some calculations report.someMethod(someData) } my intention was to extract the construction of report into a protected method and override it to use a mock object that I could then test to ensure that someMethod had been called with the right data. So far so good. But Report isnt under my control, and to mkae things worse it uses JNI to load a library at runtime. If I do Report report = EasyMock.createMock(Report.class) then EasyMock attempts to use reflection to find out the class members, but this causes an attempt to load the JNI library, which fails (the JNI libraries are only available on UNIX). Im considering two things: a) Introduce a ReportWrapper interface with two implementations, one of which will delegate calls to an real Report (so basically a Proxy), and a second which will basically use a mock object. or b) instead of calling someMethod, call a protected method which will in turn call someMethod that I can override in a testing subclass. Either way it seems nasty. Any better ways?

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  • What Scheme Does Ghuloum Use?

    - by Don Wakefield
    I'm trying to work my way through Compilers: Backend to Frontend (and Back to Front Again) by Abdulaziz Ghuloum. It seems abbreviated from what one would expect in a full course/seminar, so I'm trying to fill in the pieces myself. For instance, I have tried to use his testing framework in the R5RS flavor of DrScheme, but it doesn't seem to like the macro stuff: src/ghuloum/tests/tests-driver.scm:6:4: read: illegal use of open square bracket I've read his intro paper on the course, An Incremental Approach to Compiler Construction, which gives a great overview of the techniques used, and mentions a couple of Schemes with features one might want to implement for 'extra credit', but he doesn't mention the Scheme he uses in the course. Update I'm still digging into the original question (investigating options such as Petit Scheme suggested by Eli below), but found an interesting link relating to Gholoum's work, so I am including it here. [Ikarus Scheme](http://en.wikipedia.org/wiki/Ikarus_(Scheme_implementation)) is the actual implementation of Ghuloum's ideas, and appears to have been part of his Ph.D. work. It's supposed to be one of the first implementations of R6RS. I'm trying to install Ikarus now, but the configure script doesn't want to recognize my system's install of libgmp.so, so my problems are still unresolved. Example The following example seems to work in PLT 2.4.2 running in DrEd using the Pretty Big (require lang/plt-pretty-big) (load "/Users/donaldwakefield/ghuloum/tests/tests-driver.scm") (load "/Users/donaldwakefield/ghuloum/tests/tests-1.1-req.scm") (define (emit-program x) (unless (integer? x) (error "---")) (emit " .text") (emit " .globl scheme_entry") (emit " .type scheme_entry, @function") (emit "scheme_entry:") (emit " movl $~s, %eax" x) (emit " ret") ) Attempting to replace the require directive with #lang scheme results in the error message foo.scm:7:3: expand: unbound identifier in module in: emit which appears to be due to a failure to load tests-driver.scm. Attempting to use #lang r6rs disables the REPL, which I'd really like to use, so I'm going to try to continue with Pretty Big. My thanks to Eli Barzilay for his patient help.

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  • Making Python scripts more user friendly?

    - by Michael Morisy
    I have a bunch of python scripts I've put together that cut down on busy work, but I'd like to be able to share them in an easier-to-use format for others to be used internally. The scripts aren't accessing anything local, just open API's across a couple web apps. Ideally: a) Users wouldn't have to have a python compiler installed b) They can be using Windows when running it. c) It's simple enough they can just click something, and it will work. I've tried some of the Windows Python executable compilers, but none have really worked well and I was considering just uploading it to a webserver and putting up some basic password access protection around it Any suggestions for sharing scripts?

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  • When to use "property" builtin: auxiliary functions and generators

    - by Seth Johnson
    I recently discovered Python's property built-in, which disguises class method getters and setters as a class's property. I'm now being tempted to use it in ways that I'm pretty sure are inappropriate. Using the property keyword is clearly the right thing to do if class A has a property _x whose allowable values you want to restrict; i.e., it would replace the getX() and setX() construction one might write in C++. But where else is it appropriate to make a function a property? For example, if you have class Vertex(object): def __init__(self): self.x = 0.0 self.y = 1.0 class Polygon(object): def __init__(self, list_of_vertices): self.vertices = list_of_vertices def get_vertex_positions(self): return zip( *( (v.x,v.y) for v in self.vertices ) ) is it appropriate to add vertex_positions = property( get_vertex_positions ) ? Is it ever ok to make a generator look like a property? Imagine if a change in our code meant that we no longer stored Polygon.vertices the same way. Would it then be ok to add this to Polygon? @property def vertices(self): for v in self._new_v_thing: yield v.calculate_equivalent_vertex()

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  • testing if constructor in constructor chain

    - by Delan Azabani
    I'm attempting to implement a GTK+ inspired widget toolkit for the web in JavaScript. One of the constructor chains goes gtk.widget => gtk.container => gtk.bin => gtk.window Every gtk.widget has a showAll method, which, if and only if the widget is a gtk.container or derivative (such as gtk.bin or gtk.window), will recursively show the children of that widget. Obviously, if it isn't a gtk.container or derivative, we shouldn't do anything because the widget in question can't contain anything. For reference, here is my inheritance function; it's probably not the best, but it's a start: function inherit(target, parent) { target.prototype = new parent; target.prototype.constructor = target; } I know that I can check for the direct constructor like this: if (this.constructor === gtk.container) ... However, this only tests for direct construction and not, say, if the object is a gtk.bin or gtk.window. How can I test whether gtk.container is somewhere up in the constructor chain?

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  • Installing PHP with iconv on Mac OSX 10.6 gives error: "Undefined symbols for architecture x86_64"

    - by Jason
    I am setting up PHP on my local web server with iconv, which should be there by default, but I am getting the following error: Undefined symbols for architecture x86_64: "_iconv", referenced from: __php_iconv_strlen in iconv.o _php_iconv_string in iconv.o __php_iconv_strpos in iconv.o __php_iconv_appendl in iconv.o _zif_iconv_substr in iconv.o _zif_iconv_mime_encode in iconv.o _php_iconv_stream_filter_append_bucket in iconv.o ... (maybe you meant: _zif_iconv_strlen, _zif_iconv_strpos , _zif_iconv_mime_decode , _php_iconv_string , _zif_iconv_set_encoding , _zif_iconv_get_encoding , _zif_iconv_mime_decode_headers , _iconv_functions , _zif_iconv_mime_encode , _zif_iconv_strrpos , _iconv_module_entry , _iconv_globals , _zif_iconv_substr , _php_if_iconv , _zif_ob_iconv_handler ) ld: symbol(s) not found for architecture x86_64 Now, presumably this means that my iconv is not 64 bit. I tried to download libiconv and manually reinstall it with 64 bit, as such: CFLAGS='-arch i386 -arch ppc -arch ppc64 -arch x86_64' CCFLAGS='-arch i386 -arch ppc -arch ppc64 -arch x86_64' CXXFLAGS='-arch i386 -arch ppc -arch ppc64 -arch x86_64' ./configure But I get the following error: configure: error: in `/Users/jason/Downloads/libiconv-1.13.1': configure: error: C compiler cannot create executables See `config.log' for more details. In my config.lob file, it says at the bottom: configure: exit 77 Any suggestions?

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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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  • segfault during __cxa_allocate_exception in SWIG wrapped library

    - by lefticus
    While developing a SWIG wrapped C++ library for Ruby, we came across an unexplained crash during exception handling inside the C++ code. I'm not sure of the specific circumstances to recreate the issue, but it happened first during a call to std::uncaught_exception, then after a some code changes, moved to __cxa_allocate_exception during exception construction. Neither GDB nor valgrind provided any insight into the cause of the crash. I've found several references to similar problems, including: http://wiki.fifengine.de/Segfault_in_cxa_allocate_exception http://forums.fifengine.de/index.php?topic=30.0 http://code.google.com/p/osgswig/issues/detail?id=17 https://bugs.launchpad.net/ubuntu/+source/libavg/+bug/241808 The overriding theme seems to be a combination of circumstances: A C application is linked to more than one C++ library More than one version of libstdc++ was used during compilation Generally the second version of C++ used comes from a binary-only implementation of libGL The problem does not occur when linking your library with a C++ application, only with a C application The "solution" is to explicitly link your library with libstdc++ and possibly also with libGL, forcing the order of linking. After trying many combinations with my code, the only solution that I found that works is the LD_PRELOAD="libGL.so libstdc++.so.6" ruby scriptname option. That is, none of the compile-time linking solutions made any difference. My understanding of the issue is that the C++ runtime is not being properly initialized. By forcing the order of linking you bootstrap the initialization process and it works. The problem occurs only with C applications calling C++ libraries because the C application is not itself linking to libstdc++ and is not initializing the C++ runtime. Because using SWIG (or boost::python) is a common way of calling a C++ library from a C application, that is why SWIG often comes up when researching the problem. Is anyone out there able to give more insight into this problem? Is there an actual solution or do only workarounds exist? Thanks.

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  • Explicitly instantiating a generic member function of a generic structure

    - by Dennis Zickefoose
    I have a structure with a template parameter, Stream. Within that structure, there is a function with its own template parameter, Type. If I try to force a specific instance of the function to be generated and called, it works fine, if I am in a context where the exact type of the structure is known. If not, I get a compile error. This feels like a situation where I'm missing a typename, but there are no nested types. I suspect I'm missing something fundamental, but I've been staring at this code for so long all I see are redheads, and frankly writing code that uses templates has never been my forte. The following is the simplest example I could come up with that illustrates the issue. #include <iostream> template<typename Stream> struct Printer { Stream& str; Printer(Stream& str_) : str(str_) { } template<typename Type> Stream& Exec(const Type& t) { return str << t << std::endl; } }; template<typename Stream, typename Type> void Test1(Stream& str, const Type& t) { Printer<Stream> out = Printer<Stream>(str); /****** vvv This is the line the compiler doesn't like vvv ******/ out.Exec<bool>(t); /****** ^^^ That is the line the compiler doesn't like ^^^ ******/ } template<typename Type> void Test2(const Type& t) { Printer<std::ostream> out = Printer<std::ostream>(std::cout); out.Exec<bool>(t); } template<typename Stream, typename Type> void Test3(Stream& str, const Type& t) { Printer<Stream> out = Printer<Stream>(str); out.Exec(t); } int main() { Test2(5); Test3(std::cout, 5); return 0; } As it is written, gcc-4.4 gives the following: test.cpp: In function 'void Test1(Stream&, const Type&)': test.cpp:22: error: expected primary-expression before 'bool' test.cpp:22: error: expected ';' before 'bool' Test2 and Test3 both compile cleanly, and if I comment out Test1 the program executes, and I get "1 5" as I expect. So it looks like there's nothing wrong with the idea of what I want to do, but I've botched something in the implementation. If anybody could shed some light on what I'm overlooking, it would be greatly appreciated.

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  • How to install pecl uploadprogress on Debian Lenny

    - by kidrobot
    I am getting this output/error for # pecl install uploadprogress downloading uploadprogress-1.0.1.tgz ... Starting to download uploadprogress-1.0.1.tgz (8,536 bytes) .....done: 8,536 bytes 4 source files, building running: phpize Configuring for: PHP Api Version: 20041225 Zend Module Api No: 20060613 Zend Extension Api No: 220060519 building in /var/tmp/pear-build-root/uploadprogress-1.0.1 running: /tmp/pear/temp/uploadprogress/configure checking for grep that handles long lines and -e... /bin/grep checking for egrep... /bin/grep -E checking for a sed that does not truncate output... /bin/sed checking for gcc... no checking for cc... no checking for cl.exe... no configure: error: no acceptable C compiler found in $PATH See `config.log' for more details. ERROR: `/tmp/pear/temp/uploadprogress/configure' failed php-pear is installed. I'm stumped.

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  • javascript plugin - singleton pattern?

    - by Adam Kiss
    intro Hello, I'm trying to develop some plugin or/*and* object in javascript, which will control some properties over some object. It will also use jQuery, to ease development. idea This is in pseudocode to give you an idea, since I can't really describe it in english with the right words, it's impossible to go and use google to find out what I want to use (and learn). I will have plugin (maybe object?) with some variables and methods: plugin hideshow(startupconfig){ var c, //collection add: function(what){ c += what; }, do: function(){ c.show().hide().stop(); //example code } } and I will use it this way (or sort-of): var p = new Plugin(); p .add($('p#simple')) .add($('p#simple2')) .do(); note I'm not really looking for jQuery plugin tutorials - it's more like usage of singleton pattern in document in javascript, jQuery is mentione only because it will be used to modify dom and simplify selectors, jQuery plugin maybe just for that one little function add. I'm looking for something, that will sit on top of my document and call functions from itselft based on timer, or user actions, or whatever. problems I don't really know where to start with construction of this object/plugin I'm not really sure how to maintain one variable, which is collection of jQuery objects (something like $('#simple, #simple2');) I would maybe like to extedn jQuery with $.fn.addToPlugin to use chaining of objects, but that should be simple (really just each( p.add($(this)); )) I hope I make any sense, ideas, links or advices appreciated.

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  • Reconstructing trees from a "fingerprint"

    - by awshepard
    I've done my SO and Google research, and haven't found anyone who has tackled this before, or at least, anyone who has written about it. My question is, given a "universal" tree of arbitrary height, with each node able to have an arbitrary number of branches, is there a way to uniquely (and efficiently) "fingerprint" arbitrary sub-trees starting from the "universal" tree's root, such that given the universal tree and a tree's fingerprint, I can reconstruct the original tree? For instance, I have a "universal" tree (forgive my poor illustrations), representing my universe of possibilities: Root / / / | \ \ ... \ O O O O O O O (Level 1) /|\/|\...................\ (Level 2) etc. I also have tree A, a rooted subtree of my universe Root / /|\ \ O O O O O / Etc. Is there a way to "fingerprint" the tree, so that given that fingerprint, and the universal tree, I could reconstruct A? I'm thinking something along the lines of a hash, a compression, or perhaps a functional/declarative construction? Big-O analysis (in time or space) is a plus. As a for-instance, a nested expression like: {{(Root)},{(1),(2),(3)},{(2,3),(1),(4,5)}...} representing the actual nodes present at each level in the tree is probably valid, but can it be done more efficiently?

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  • Thread-safe initialization of function-local static const objects

    - by sbi
    This question made me question a practice I had been following for years. For thread-safe initialization of function-local static const objects I protect the actual construction of the object, but not the initialization of the function-local reference referring to it. Something like this: namspace { const some_type& create_const_thingy() { lock my_lock(some_mutex); static const some_type the_const_thingy; return the_const_thingy; } } void use_const_thingy() { static const some_type& the_const_thingy = create_const_thingy(); // use the_const_thingy } The idea is that locking takes time, and if the reference is overwritten by several threads, it won't matter. I'd be interested if this is safe enough in practice? safe according to The Rules? (I know, the current standard doesn't even know what "concurrency" is, but what about trampling over an already initialized reference? And do other standards, like POSIX, have something to say that's relevant to this?) For the inquiring minds: Many such function-local static const objects I used are maps which are initialized from const arrays upon first use and used for lookup. For example, I have a few XML parsers where tag name strings are mapped to enum values, so I could later switch over the tags enum values.

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  • Confused about definition of a 'median' when constructing a kd-Tree

    - by user352636
    Hi there. Im trying to build a kd-tree for searching through a set of points, but am getting confused about the use of 'median' in the wikipedia article. For ease of use, the wikipedia article states the pseudo-code of kd-tree construction as: function kdtree (list of points pointList, int depth) { if pointList is empty return nil; else { // Select axis based on depth so that axis cycles through all valid values var int axis := depth mod k; // Sort point list and choose median as pivot element select median by axis from pointList; // Create node and construct subtrees var tree_node node; node.location := median; node.leftChild := kdtree(points in pointList before median, depth+1); node.rightChild := kdtree(points in pointList after median, depth+1); return node; } } I'm getting confused about the "select median..." line, simply because I'm not quite sure what is the 'right' way to apply a median here. As far as I know, the median of an odd-sized (sorted) list of numbers is the middle element (aka, for a list of 5 things, element number 3, or index 2 in a standard zero-based array), and the median of an even-sized array is the sum of the two 'middle' elements divided by two (aka, for a list of 6 things, the median is the sum of elements 3 and 4 - or 2 and 3, if zero-indexed - divided by 2.). However, surely that definition does not work here as we are working with a distinct set of points? How then does one choose the correct median for an even-sized list of numbers, especially for a length 2 list? I appreciate any and all help, thanks! -Stephen

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  • compiling php5.4 on macosx 10.6.8

    - by ling
    I'm trying to compile php 5.4.7 on mac osx 10.6.8. I could install it using the default procedure: ./configure \ --prefix=/usr/local \ --with-config-file-path=/usr/local/etc \ --with-apxs2=/usr/local/apache2/bin/apxs \ --with-mysql sudo make clean sudo make sudo make install But now if I try to install to compile php with the curl module it fails: ./configure \ --prefix=/usr/local \ --with-config-file-path=/usr/local/etc \ --with-curl=/usr \ --with-apxs2=/usr/local/apache2/bin/apxs \ --with-mysql sudo make clean sudo make = last lines of make output: Undefined symbols: "_CRYPTO_set_locking_callback", referenced from: _zm_shutdown_curl in interface.o _zm_startup_curl in interface.o "_CRYPTO_num_locks", referenced from: _zm_shutdown_curl in interface.o _zm_startup_curl in interface.o "_CRYPTO_get_id_callback", referenced from: _zm_startup_curl in interface.o "_CRYPTO_set_id_callback", referenced from: _zm_shutdown_curl in interface.o _zm_startup_curl in interface.o ld: symbol(s) not found collect2: ld returned 1 exit status make: * [libs/libphp5.bundle] Error 1 I read somewhere ( http://user.xmission.com/~georgeps/documentation/tutorials/compilation_and_makefiles.html ) that in this case, I should tell the compiler where to find the missing library, so that it can links the missing files. The problem is that I don't what library I should look for, is it libssl2 ?

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  • Is Form validation and Business validation too much?

    - by Robert Cabri
    I've got this question about form validation and business validation. I see a lot of frameworks that use some sort of form validation library. You submit some values and the library validates the values from the form. If not ok it will show some errors on you screen. If all goes to plan the values will be set into domain objects. Here the values will be or, better said, should validated (again). Most likely the same validation in the validation library. I know 2 PHP frameworks having this kind of construction Zend/Kohana. When I look at programming and some principles like Don't Repeat Yourself (DRY) and single responsibility principle (SRP) this isn't a good way. As you can see it validates twice. Why not create domain objects that do the actual validation. Example: Form with username and email form is submitted. Values of the username field and the email field will be populated in 2 different Domain objects: Username and Email class Username {} class Email {} These objects validate their data and if not valid throw an exception. Do you agree? What do you think about this aproach? Is there a better way to implement validations? I'm confused about a lot of frameworks/developers handling this stuff. Are they all wrong or am I missing a point? Edit: I know there should also be client side kind of validation. This is a different ballgame in my Opinion. If You have some comments on this and a way to deal with this kind of stuff, please provide.

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  • MySQL table data transformation -- how can I dis-aggreate MySQL time data?

    - by lighthouse65
    We are coding for a MySQL data warehousing application that stores descriptive data (User ID, Work ID, Machine ID, Start and End Time columns in the first table below) associated with time and production quantity data (Output and Time columns in the first table below) upon which aggregate (SUM, COUNT, AVG) functions are applied. We now wish to dis-aggregate time data for another type of analysis. Our current data table design: +---------+---------+------------+---------------------+---------------------+--------+------+ | User ID | Work ID | Machine ID | Event Start Time | Event End Time | Output | Time | +---------+---------+------------+---------------------+---------------------+--------+------+ | 080025 | ABC123 | M01 | 2008-01-24 16:19:15 | 2008-01-24 16:34:45 | 2120 | 930 | +---------+---------+------------+---------------------+---------------------+--------+------+ Reprocessing dis-aggregation that we would like to do would be to transform table content based on a granularity of minutes, rather than the current production event ("Event Start Time" and "Event End Time") granularity. The resulting reprocessing of existing table rows would look like: +---------+---------+------------+---------------------+--------+ | User ID | Work ID | Machine ID | Production Minute | Output | +---------+---------+------------+---------------------+--------+ | 080025 | ABC123 | M01 | 2010-01-24 16:19 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:20 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:21 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:22 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:23 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:24 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:25 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:26 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:27 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:28 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:29 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:30 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:31 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:22 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:33 | 133 | | 080025 | ABC123 | M01 | 2010-01-24 16:34 | 133 | +---------+---------+------------+---------------------+--------+ So the reprocessing would take an existing row of data created at the granularity of production event and modify the granularity to minutes, eliminating redundant (Event End Time, Time) columns while doing so. It assumes a constant rate of production and divides output by the difference in minutes plus one to populate the new table's Output column. I know this can be done in code...but can it be done entirely in a MySQL insert statement (or otherwise entirely in MySQL)? I am thinking of a INSERT ... INTO construction but keep getting stuck. An additional complexity is that there are hundreds of machines to include in the operation so there will be multiple rows (one for each machine) for each minute of the day. Any ideas would be much appreciated. Thanks.

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  • numpy calling sse2 via ctypes

    - by Daniel
    Hello, In brief, I am trying to call into a shared library from python, more specifically, from numpy. The shared library is implemented in C using sse2 instructions. Enabling optimisation, i.e. building the library with -O2 or –O1, I am facing strange segfaults when calling into the shared library via ctypes. Disabling optimisation (-O0), everything works out as expected, as is the case when linking the library to a c-program directly (optimised or not). Attached you find a snipped which exhibits the delineated behaviour on my system. With optimisation enabled, gdb reports a segfault in __builtin_ia32_loadupd (__P) at emmintrin.h:113. The value of __P is reported as optimised out. test.c: #include <emmintrin.h> #include <complex.h> void test(const int m, const double* x, double complex* y) { int i; __m128d _f, _x, _b; double complex f __attribute__( (aligned(16)) ); double complex b __attribute__( (aligned(16)) ); __m128d* _p; b = 1; _b = _mm_loadu_pd( (double *) &b ); _p = (__m128d*) y; for(i=0; i<m; ++i) { f = cexp(-I*x[i]); _f = _mm_loadu_pd( (double *) &f ); _x = _mm_loadu_pd( (double *) &x[i] ); _f = _mm_shuffle_pd(_f, _f, 1); *_p = _mm_add_pd(*_p, _f); *_p = _mm_add_pd(*_p, _x); *_p = _mm_mul_pd(*_p,_b); _p++; } return; } Compiler flags: gcc -o libtest.so -shared -std=c99 -msse2 -fPIC -O2 -g -lm test.c test.py: import numpy as np import os def zerovec_aligned(nr, dtype=np.float64, boundary=16): '''Create an aligned array of zeros. ''' size = nr * np.dtype(dtype).itemsize tmp = np.zeros(size + boundary, dtype=np.uint8) address = tmp.__array_interface__['data'][0] offset = boundary - address % boundary return tmp[offset:offset + size].view(dtype=dtype) lib = np.ctypeslib.load_library('libtest', '.' ) lib.test.restype = None lib.test.argtypes = [np.ctypeslib.ctypes.c_int, np.ctypeslib.ndpointer(np.float64, flags=('C', 'A') ), np.ctypeslib.ndpointer(np.complex128, flags=('C', 'A', 'W') )] n = 13 y = zerovec_aligned(n, dtype=np.complex128) x = np.ones(n, dtype=np.float64) # x = zerovec_aligned(n, dtype=np.float64) # x[:] = 1. lib.test(n,x,y) My system: Ubuntu Linux i686 2.6.31-22-generic Compiler: gcc (Ubuntu 4.4.1-4ubuntu9) Python: Python 2.6.4 (r264:75706, Dec 7 2009, 18:45:15) [GCC 4.4.1] Numpy: 1.4.0 I have taken provisions (cf. python code) that y is aligned and the alignment of x should not matter (I think; explicitly aligning x does not solve the problem though). Note also that i use _mm_loadu_pd instead of _mm_load_pd when loading b and f. For the C-only version _mm_load_pd works (as expected). However, when calling the function via ctypes using _mm_load_pd always segfaults (independent of optimisation). I have tried several days to sort out this issue without success ... and I am on the verge beating my monitor to death. Any input welcome. Daniel

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  • evaluating cost/benefits of using extension methods in C# => 3.0

    - by BillW
    Hi, In what circumstances (usage scenarios) would you choose to write an extension rather than sub-classing an object ? < full disclosure : I am not an MS employee; I do not know Mitsu Furota personally; I do know the author of the open-source Componax library mentioned here, but I have no business dealings with him whatsoever; I am not creating, or planning to create any commercial product using extensions : in sum : this post is from pure intellectal curiousity related to my trying to (continually) become aware of "best practices" I find the idea of extension methods "cool," and obviously you can do "far-out" things with them as in the many examples you can in Mitsu Furota's (MS) blog postslink text. A personal friend wrote the open-source Componax librarylink text, and there's some remarkable facilities in there; but he is in complete command of his small company with total control over code guidelines, and every line of code "passes through his hands." While this is speculation on my part : I think/guess other issues might come into play in a medium-to-large software team situation re use of Extensions. Looking at MS's guidelines at link text, you find : In general, you will probably be calling extension methods far more often than implementing your own. ... In general, we recommend that you implement extension methods sparingly and only when you have to. Whenever possible, client code that must extend an existing type should do so by creating a new type derived from the existing type. For more information, see Inheritance (C# Programming Guide). ... When the compiler encounters a method invocation, it first looks for a match in the type's instance methods. If no match is found, it will search for any extension methods that are defined for the type, and bind to the first extension method that it finds. And at Ms's link text : Extension methods present no specific security vulnerabilities. They can never be used to impersonate existing methods on a type, because all name collisions are resolved in favor of the instance or static method defined by the type itself. Extension methods cannot access any private data in the extended class. Factors that seem obvious to me would include : I assume you would not write an extension unless you expected it be used very generally and very frequently. On the other hand : couldn't you say the same thing about sub-classing ? Knowing we can compile them into a seperate dll, and add the compiled dll, and reference it, and then use the extensions : is "cool," but does that "balance out" the cost inherent in the compiler first having to check to see if instance methods are defined as described above. Or the cost, in case of a "name clash," of using the Static invocation methods to make sure your extension is invoked rather than the instance definition ? How frequent use of Extensions would affect run-time performance or memory use : I have no idea. So, I'd appreciate your thoughts, or knowing about how/when you do, or don't do, use Extensions, compared to sub-classing. thanks, Bill

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