Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: readdir and dynamic array memory corruption
Top Forums Programming readdir and dynamic array memory corruption Post 302491556 by Corona688 on Thursday 27th of January 2011 05:57:49 PM
Old 01-27-2011
Quote:
Originally Posted by DreamWarrior
Also...your incrementing the size with <<= 1 may be a little more...extreme than you'd like. I hope you know exactly why you're doing that. The array size you'll be allocating will grow quite quickly.
Never more than twice as much memory as is currently used. It'll be sane enough unless there's frankly insane numbers of directory entries. Reducing the number of times you call malloc() for tiny things cuts down on memory fragmentation, and once the readdir() loop finishes he's free to shrink it, too.

Quote:
Even better still, use a linked list and there will be no wastage.
Ever try calling qsort() on a linked list? Smilie I swear, the amount of time some programs take to sort things is simply obscene, and could've been avoided if they'd kept it in a numerically-addressable form.
Last edited by Corona688; 01-27-2011 at 07:03 PM..
 

10 More Discussions You Might Find Interesting

1. Programming

Creating an array to hold posix thread ids: Only dynamic array works

I am facing a strange error while creating posix threads: Given below are two snippets of code, the first one works whereas the second one gives a garbage value in the output. Snippet 1 This works: -------------- int *threadids; threadids = (int *) malloc (num_threads * sizeof(int)); ... (4 Replies)
Discussion started by: kmehta
4 Replies

2. UNIX for Dummies Questions & Answers

'memory corruption' error when using Awk

Hello, everyone. I got the following error when I am using awk to analysis some text file: *** glibc detected *** awk: malloc(): memory corruption: 0x080c67f8 *** ======= Backtrace: ========= /lib/tls/i686/cmov/libc.so.6 /lib/tls/i686/cmov/libc.so.6... (5 Replies)
Discussion started by: kooyee
5 Replies

3. Programming

Why does this occur? *** glibc detected *** malloc(): memory corruption: 0x10013ff8 ***

there seems not to be error in this segment. In some computers, it can work well. But in others, it will give a failure. why it ocurrs and how to deal with it? in a function: if( *ver == NULL ) { *ver = (vertex *) malloc(sizeof(vertex)); //this line ... (17 Replies)
Discussion started by: cdbug
17 Replies

4. SCO

SCO openserver Dynamic linker corruption

Hi every body I have a problem like that "Dynamic linker error" message. I can't load many of programs in sco unix openserver 5.0.6. I guess this problem appear after my last effort to install "SCO Development System" package. How can I fix this problem? would you please help me ? (1 Reply)
Discussion started by: javad1_maroofi
1 Replies

5. Programming

./match_pattern.out: malloc(): memory corruption: 0x0000000013a11600 ***

Hi All, I have a simple code which does some computation by matching string patterns. In brief: 1. The code reads .dat and .txt files. 2. .dat files are huge text files and .txt files contain some important words. 3. I am just doing strstr to find the patterns. 4. The function returns the... (3 Replies)
Discussion started by: shoaibjameel123
3 Replies

6. Programming

*** glibc detected *** ./a.out: malloc(): memory corruption (fast):

*** glibc detected *** ./a.out: malloc(): memory corruption (fast): Posted A minute ago M trying to make multiway tree and dont know what happend when this part of code get executed: 01void ins(NODE *ptr) 02{ 03 //working 04 if(ptr!=NULL) 05 { 06 SNODE *var=NULL; 07 var=(SNODE... (3 Replies)
Discussion started by: exgenome
3 Replies

7. Programming

*** glibc detected *** : malloc(): memory corruption (fast)

Hi Friends, while executing the below code, am getting *** glibc detected *** ./ok: malloc(): memory corruption (fast) error, please suggest how to solve this issue. #include <stdio.h> #include <string.h> #include <sqlca.h> #include <alloca.h> /* Define constants for VARCHAR... (2 Replies)
Discussion started by: mpjobsrch
2 Replies

8. Programming

*** glibc detected *** ./a.out malloc() memory corruption

I am facing a problem of memory corruption. The loop runs for the first time but does not go through the second time. What could be the problem? for(int z=0;z<2;z++) { fp=fopen("poly.dat","r"); /*do something which reads this file into a 2D array*/ fclose(fp); ... (10 Replies)
Discussion started by: dare
10 Replies

9. Solaris

Solaris 10 Shared Memory Corruption with X11

I am having a problem with shared memory corruption. I have two 86 servers running Solaris 10 (150400-06). One of the servers is accessed by a Sun Ray thin client Version 11.1.3.0.2.6. I login into server one from the thin client. I then ssh -X to server two. When a process that contains a... (2 Replies)
Discussion started by: salerno
2 Replies

10. Programming

Memory corruption in dynamic array of strings

I put together a C function to add strings to a dynamic array of strings (mostly for educational purpose to explain pointers to my kid). It works, but sometimes one or two strings in the array becomes corrupted. Running example on 64 bit Ubuntu, gcc ver. 4.8.4 Hope my code is self-explanatory: ... (2 Replies)
Discussion started by: migurus
2 Replies

LEARN ABOUT OSX

ppmtopgm

ppmtopgm(1)						      General Commands Manual						       ppmtopgm(1)

NAME

       ppmtopgm - convert a portable pixmap into a portable graymap

SYNOPSIS

       ppmtopgm [ppmfile]

DESCRIPTION

       Reads  a  portable  pixmap  as  input.  Produces a portable graymap as output.  The output is a "black and white" rendering of the original
       image, as in a black and white photograph.  The quantization formula used is .299 r + .587 g + .114 b.

       Note that although there is a pgmtoppm program, it is not necessary for simple conversions from pgm to ppm , because any  ppm  program  can
       read  pgm  (and	pbm  ) files automatically.  pgmtoppm is for colorizing a pgm file.  Also, see ppmtorgb3 for a different way of converting
       color to gray.  And ppmdist generates a grayscale image from a color image, but in a way that makes it easy to differentiate  the  original
       colors, not necessarily a way that looks like a black and white photograph.

QUOTE

       Cold-hearted orb that rules the night
       Removes the colors from our sight
       Red is gray, and yellow white
       But we decide which is right
       And which is a quantization error.

SEE ALSO

       pgmtoppm(1),ppmtorgb3(1),rgb3toppm(1),ppmdist(1),ppm(5),pgm(5)

AUTHOR

       Copyright (C) 1989 by Jef Poskanzer.

								   10 April 2000						       ppmtopgm(1)
All times are GMT -4. The time now is 08:17 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy