Hi Experts
I need some help in static memory allocation in C. I have a program in which I declared 2 variables, one char array and one integer. I was little surprised to see the addresses of the variables.
First:
I got the addresses displayed as : 3219437172 3219437170
The above result is straight forward wherein the array a got 2 bytes allocated.
Second:
When I changed the program as below:
I got the addresses displayed as : 3219437172 3219437144
The array a got allocated 28 bytes when the declaration is for 3 bytes.
Hello!
First of all, forgive me for bad English.
When I starts new thread (pthread_create), system allocates some memory for it (for example, for thread's stack). I wonder when does it deallocate this memory? The problem is that I have a program which sometimes creates new threads and sometimes... (3 Replies)
Hi all,
I have a HP-UX Server with 4 gigabytes of physical RAM. When I use the 'Glance' utility to see what my memory utilization is, my memory usage shows up maxed out at 99%. I shut off all the known processes that I'm running on that box and the memory utilization is still at 78% (with Swap... (3 Replies)
Hi,
I am trying to process line by line of a file. But I should not be allocating static allocation for reading the contents of the file. The memory should be dynamically allocated. The confusion here is how do I determine the size of each line, put it into a buffer with the memory allocated... (11 Replies)
I have a program that will fetch some particular lines and store it in a buffer for further operations.The code which is given below works but with some errors.I couldn't trace out the error.Can anybody help on this plz??
#include <stdio.h>
#include <stdlib.h>
#include<string.h>
#define... (1 Reply)
I have a scenario like the client has to search for the active server.There will be many servers.But not all server are active.And at a time not more than one server will be active.
The client will be in active state always i.e, it should always search for an active server until it gets one.I... (1 Reply)
Hi everyone,
I'm not new to C programming, but I'm having question regarding the memory allocation of a pointer variable which, for instance, will be declared in main(), but its memory will be allocated in subroutine.
To clearify my question, I provide a small working example:
#include... (1 Reply)
hello all..
i'm a beginner in shell scripting. I need to know what is really happening when we are creating a variable in shell scripting? how memory is allocated for that variable? (3 Replies)
hi
in the following code, how the memory is allocated for a1 which holds the values of a2 after cpy function call.
#include <stdio.h>
#include <string.h>
void cpy(char* d, const char* s){
while(*d++=*s++);
}
main(){
char* a1;
char* a2="done";
cpy(a1,a2);
... (3 Replies)
Hello,
I am new to C++ programming, so I'm still getting a feel for things. I recently wrote a simple C++ program (to be used as a ROOT Macro) to conduct a statistical analysis of a varied version of the Monty Hall problem (code below). Basically, the programs runs a few simple calculations to... (7 Replies)
Discussion started by: Tyler_92
7 Replies
LEARN ABOUT OPENSOLARIS
bsdmalloc
bsdmalloc(3MALLOC) Memory Allocation Library Functions bsdmalloc(3MALLOC)NAME
bsdmalloc - memory allocator
SYNOPSIS
cc [ flag ... ] file ... -lbsdmalloc [ library ... ]
char *malloc(sizeunsigned size;
int free( ptrchar *ptr;
char *realloc( ptr, sizechar *ptr;
unsigned size;
DESCRIPTION
These routines provide a general-purpose memory allocation package. They maintain a table of free blocks for efficient allocation and coa-
lescing of free storage. When there is no suitable space already free, the allocation routines call sbrk(2) to get more memory from the
system. Each of the allocation routines returns a pointer to space suitably aligned for storage of any type of object. Each returns a
null pointer if the request cannot be completed.
The malloc() function returns a pointer to a block of at least size bytes, which is appropriately aligned.
The free() function releases a previously allocated block. Its argument is a pointer to a block previously allocated by malloc() or real-
loc(). The free() function does not set errno.
The realloc() function changes the size of the block pointed to by ptr to size bytes and returns a pointer to the (possibly moved) block.
The contents will be unchanged up to the lesser of the new and old sizes. If the new size of the block requires movement of the block, the
space for the previous instantiation of the block is freed. If the new size is larger, the contents of the newly allocated portion of the
block are unspecified. If ptr is NULL, realloc() behaves like malloc() for the specified size. If size is 0 and ptr is not a null pointer,
the space pointed to is freed.
RETURN VALUES
The malloc() and realloc() functions return a null pointer if there is not enough available memory. They return a non-null pointer if size
is 0. These pointers should not be dereferenced. When realloc() returns NULL, the block pointed to by ptr is left intact. Always cast the
value returned by malloc() and realloc().
ERRORS
If malloc() or realloc() returns unsuccessfully, errno will be set to indicate the following:
ENOMEM size bytes of memory cannot be allocated because it exceeds the physical limits of the system.
EAGAIN There is not enough memory available at this point in time to allocate size bytes of memory; but the application could try again
later.
USAGE
Using realloc() with a block freed before the most recent call to malloc() or realloc() results in an error.
Comparative features of the various allocation libraries can be found in the umem_alloc(3MALLOC) manual page.
SEE ALSO brk(2), malloc(3C), malloc(3MALLOC), mapmalloc(3MALLOC), umem_alloc(3MALLOC)WARNINGS
Use of libbsdmalloc renders an application non-SCD compliant.
The libbsdmalloc routines are incompatible with the memory allocation routines in the standard C-library (libc): malloc(3C), alloca(3C),
calloc(3C), free(3C), memalign(3C), realloc(3C), and valloc(3C).
SunOS 5.11 21 Mar 2005 bsdmalloc(3MALLOC)