Programming :: __attribute__ ((constructor)) Function Does Not Execute
Mar 16, 2011
My setup is Ubuntu 10.04, eclipse 3.5.2 I have created the source for a shared object and a test program to test it. The program executes dlopen() and I get back a valid library handle. I can use that handle and dlsym() to get the address of my C exported functions just as I expect. I recently added a change to have the so instantiate an object at load time by using a __attribute__ ((constructor)) function named so_init(). I also added a main() function (one wasn't required before). Adding a bunch of printf()s and using the debugger in eclipse I watch the code run and the so_init() and main() functions are never called. As far as I can tell, eclipse has -shared, -fPIC and -Wl setup and specified correctly. Am I missing a compile/link flag? Is there some magic I need in the so_main.cpp to get this working. I have this written as dual source code. The same code works quite nicely in Windows which calls dllMain() as expected.
I want to write a function that shall execute periodic. means if i set time 1 sec that function should execute in each 1 sec. let us call that function func1. But i dnt want to wait inside the func1 for that 1 sec. Meanwhile i want to run another function say func2 in background . some thing like less priority function. Whnever the time come to execute the periodic function func1 it has to go to func1 and then again in the waiting time , the second function func2 will resume. I wanted to know how to do it.. Can somebody tell me is it possible using signal in linux.
then i compile it, gcc -c add.c now we get a object file add.o, I want to execute the function add(int a,int b)(the functinon in the object file add.o) how can i use libbfd to execute it?
Can you tell me why gcc on LINUX is giving me this error (works find on our SCO machine)/us4/prw/include/vv_sys.h:797: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'typedef'
In my project,Login window is created as a Dialog box.So when i tried to call the constructor of Login from Main it was generating an error regarding the arguments passed.I have not used any arguments when i called. when i looked at the code, the function was declared as public Login(java.awt.Frame parent,boolean modal)so when i call it from main(),what am i supposed to do ?
how to call a c function or to execute a c pgm o/p from php file and this output should be displayed in the html page ? I have tried with system() and exec()but its not working.
I am doing some Linux kernel programming for my research project. I need to record the timestamp (by using cpuid and rdtsc) when an interrupt handler (top half) is first invoked. Due to the time critical nature of the problem itself, I have to do the timestamping inside the interrupt handler itself (the first operation when the handler is called). However, I understand that tasks that are not so time critical should be deferred to a tasklet function (bottom half) for processing because other interrupts are disabled in a (top-half) interrupt handler. I am currently out of idea on how I can pass the timestamp information that I have obtained in the interrupt handler to the corresponding tasklet function.
I looked on the net for such function or example and didin't find anything, thus after having made one i guess it would be legitimate to drop it to see what others thinks of it.
#!/bin/bash addelementtoarray() { local arrayname=$1
i have a server program which accept multiple client connection and am using polling. like every 2 secs it will look to client whether any data is received after it binded. i have used setitimer but there is runtime error i got.. the server accept all client connection but doesn't execute any msg which client sent.
fit a surface i.e. W(x,y) using svdfit() provided by "Numerical Recipes in C". svdfit() is written for curve fitting and not for surface fitting.But one can use svdfit(), as claimed by authors of NR book, to do surface fitting. On page 680 of NR book, authors have given a hint on how to use svdfit() for fitting a surface. But I have not understood it.This link may be helpful (Chapter 15 th is relevant here.):[URL]This is my problem:
Code: I have a set of 100 numbers. I want to fit a 2-Dimensional function W(x,y) to these numbers.
I don't know if this is the best place to ask this question. This question arose when I had a g++ compilation error: error: expected constructor, destructor, or type conversion before '.' token The above message can be correctly displayed in urxvt or xterm. But in mrxvt the '.' part can't be displayed correctly. Then I noticed that the quote signs are actually different from the usual ones and there seems no way to type ' ' from the keyboard. What are the differences and how to make mrxvt to display ' ' correctly. I found mrxvt very good and easy to configure.
I have a question about calling an asm function from C....It doesn't work unless I create an asm variable to hold the value of the function in....Why?Here's the code that doesn't work...
asmfile.s - version one Code: .section .data mydata: .ascii "this is the message! .equ mylen, . - mydata
I want to use backtrace() function to debug a crash issue. I tried this sample code to see how backtrace works. backtrace() function always returns 0 with the below code. Is there any kernel configuration that needs to be set for proper working of backtrace?
#include <execinfo.h> #include <stdio.h> #include <stdlib.h> /* Obtain a backtrace and print it to stdout. */ void print_trace (void)
Can you offer me the code about fmod() in C. I want to know how this function work, i am very interested in it because i have no idea to implement it, i want to know... how to write the function... not 'how to use the function' can anyone post the source codes of this function here?
i have an open source application that was developed in C++ (it uses objects and namespaces all over the place). I also have another application that was developed in C. Now i am trying to insert the code made in C into C++ application, but when i do that , i get this error on compilation of the source code:
Code: error: 'mpi_init_vars' was not declared in this scope the function mpi_init_vars() is not part of object oriented programming and it doesn't belong to any scope, it was compiled into an object file and i am linking it with all objects of C++ application.
How can invoke the C function from C++ object oriented code?
Code: #!/bin/sh #System commands and other configurable. IPT=/sbin/iptables IP6T=/sbin/ip6tables IPST=/usr/sbin/ipset MODP=/sbin/modprobe GET=/usr/bin/wget INT_NET=192.168.1.0/24 .....
I can find lots of tutorials in how to use if, then, else. However, how do I define a variable inside the function? SEE>> Code: for c in $ISO Also, am I using the 'test' command correctly( -/+ week as valid test)?
I am doing a web site program and what I need is to call a C program in the PHP cloud.Do u think it would be possible? The web site would get the user input from PHP UI and pass to the C program , the C program would process the function with the user input and output the a PHP page.
Code: return ((unsigned int)(unsigned long)base & TBASE_DEFERRABLE_FLAG); What is the above function returning.I am not clear with definition of what is being returned in the above code.
i want to compile function c in java and compile library is success.. when i call the library in java and error is :
Exception in thread "main" java.lang.UnsatisfiedLinkError: no libfunc.so in java.library.path at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1689) at java.lang.Runtime.loadLibrary0(Runtime.java:823) at java.lang.System.loadLibrary(System.java:1028)
Is there, by chance, a fancy name to describe code that must be in a program but will never be executed? In one of my (Haskell) programs, I have some error-handling code that must be in the program to keep the compiler happy (due to the type checking). However I know that, due to the logical structure of the program, it is impossible for the code to be evaluated. I am curious if there is a technical name given to code that must exist but cannot be executed.
