01-02-2009
I very much doubt if malloc() is the problem. If you show us your code, somebody here can probably figure out what is going on.
10 More Discussions You Might Find Interesting
1. Programming
Hi,
I'm trying to learn how to manage memory when I have to deal with lots of data.
Basically I'm indexing a huge file (5GB, but it can be bigger), by creating tables that
holds offset <-> startOfSomeData information. Currently I'm mapping the whole file at
once (yep!) but of course the... (1 Reply)
Discussion started by: emitrax
1 Replies
2. Programming
Actually for a process to run it needs text, stack , heap and data segments. All these find a place in the physical memory.
Out of these 4 only heap does exist after the termination of the process that created it. I want to know the exact reason why this happens. Also why the other process need to... (20 Replies)
Discussion started by: karthiktceit
20 Replies
3. Programming
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. Programming
Hi to all,
Recently i am testing an equipment that runs in i586 fedora linux. I have to test mmap function. For that i determined to fill the memory and run the required application to check whether it throws any mmap error regarding low resources.
This is the line that does the allocation. ... (3 Replies)
Discussion started by: frozensmilz
3 Replies
5. Programming
In a 'C' program,when I am trying to allocate memory with the help of malloc () function, it is allocating the memory up to a certain limit for e.g. in my case, it is 670 MB (approx). malloc() returns NULL if I allocate more than this amount of memory.When I tried
to allocate memory in chunks of... (1 Reply)
Discussion started by: vipinsachan
1 Replies
6. Programming
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
7. Programming
*** 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
8. Programming
I am using libxml2 library for XMl parsing and libxml++ is C++ wrapper over that. So I am using API of libxml++. I am creating my class and composing instance xmlpp::Node *pNode in that. my class also have funciton prepareXPathQuery() which creates query string and have other fucntion... (2 Replies)
Discussion started by: sharadwagh
2 Replies
9. Programming
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
10. Programming
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
LEARN ABOUT LINUX
malloc_usable_size
MALLOC_USABLE_SIZE(3) Linux Programmer's Manual MALLOC_USABLE_SIZE(3)
NAME
malloc_usable_size - obtain size of block of memory allocated from heap
SYNOPSIS
#include <malloc.h>
size_t malloc_usable_size (void *ptr);
DESCRIPTION
The malloc_usable_size() function returns the number of usable bytes in the block pointed to by ptr, a pointer to a block of memory allo-
cated by malloc(3) or a related function.
RETURN VALUE
malloc_usable_size() returns the number of usable bytes in the block of allocated memory pointed to by ptr. If ptr is NULL, 0 is returned.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
+---------------------+---------------+---------+
|Interface | Attribute | Value |
+---------------------+---------------+---------+
|malloc_usable_size() | Thread safety | MT-Safe |
+---------------------+---------------+---------+
CONFORMING TO
This function is a GNU extension.
NOTES
The value returned by malloc_usable_size() may be greater than the requested size of the allocation because of alignment and minimum size
constraints. Although the excess bytes can be overwritten by the application without ill effects, this is not good programming practice:
the number of excess bytes in an allocation depends on the underlying implementation.
The main use of this function is for debugging and introspection.
SEE ALSO
malloc(3)
GNU
2015-03-02 MALLOC_USABLE_SIZE(3)