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 decide the winner, nothing too complex, and is designed to be run many times for a statistical analysis. What I have noticed is the program uses memory VERY inefficiently. Using Mac Activity Monitor, I notice that when I just loop through 10,000 times my free memory loses ~0.5 gigabytes. This is a program that I want to be able to run at least a million times if not more. Is there some basic error in my code that is causing this? Thanks in advance.
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)
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 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:
int x;
char a;
printf("%u %u\n', &x, a);
I got the addresses displayed... (2 Replies)
Hello Guys
I have a small confusion in the dynamic memory allocation concept.
If we declare a pointer say a char pointer, we need to allocate adequate memory space.
char* str = (char*)malloc(20*sizeof(char));
str = "This is a string";
But this will also work.
char* str = "This... (2 Replies)
When we dynamically allocate the memory say 100 integers say
int *x = new int(1000);
then does entire chunk of memory gets allocated at once after the completion of the statement?
I mean will the the concept of page fault come into picture over here? (3 Replies)
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)
I am using ubuntu. I have written a program to calculate prime factors. it works perfectly fine till entered number is less than 9989 (or so ) but when one enters a number higher than that, for example 15000, it does not work. Can anyone guide me whats the problem ? although new codes are welcome,... (2 Replies)
Discussion started by: Abhishek_kumar
2 Replies
LEARN ABOUT REDHAT
fattach
fattach(3C) Standard C Library Functions fattach(3C)NAME
fattach - attach a STREAMS- or doors-based file descriptor to an object in the file system name space
SYNOPSIS
#include <stropts.h>
int fattach(int fildes, const char *path);
DESCRIPTION
The fattach() function attaches a STREAMS- or doors-based file descriptor to an object in the file system name space, effectively associat-
ing a name with fildes. The fildes argument must be a valid open file descriptor representing a STREAMS or doors file. The path argument is
a path name of an existing object and the user must have appropriate privileges or be the owner of the file and have write permissions. All
subsequent operations on path will operate on the STREAMS or doors file until the STREAMS or doors file is detached from the node. The
fildes argument can be attached to more than one path, that is, a stream or door can have several names associated with it.
The attributes of the named stream or door (see stat(2)), are initialized as follows: the permissions, user ID, group ID, and times are set
to those of path, the number of links is set to 1, and the size and device identifier are set to those of the streams or doors device asso-
ciated with fildes. If any attributes of the named stream or door are subsequently changed (for example, chmod(2)), the attributes of the
underlying object are not affected.
RETURN VALUES
Upon successful completion, fattach() returns 0. Otherwise it returns -1 and sets errno to indicate an error.
ERRORS
The fattach() function will fail if:
EACCES The user is the owner of path but does not have write permissions on path or fildes is locked.
EBADF The fildes argument is not a valid open file descriptor.
EBUSY The path argument is currently a mount point or has a STREAMS or doors file descriptor attached to it.
EINVAL The path argument is a file in a remotely mounted directory.
EINVAL The fildes argument does not represent a STREAMS or doors file.
ELOOP Too many symbolic links were encountered in translating path.
ENAMETOOLONG The size of path exceeds {PATH_MAX}, or the component of a path name is longer than {NAME_MAX} while
{_POSIX_NO_TRUNC} is in effect.
ENOENT The path argument does not exist.
ENOTDIR A component of a path prefix is not a directory.
EPERM The effective user ID is not the owner of path or a user with the appropriate privileges.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO fdetach(1M), chmod(2), mount(2), stat(2), door_create(3DOOR), fdetach(3C), isastream(3C), attributes(5), standards(5), streamio(7I)
STREAMS Programming Guide
SunOS 5.10 24 Jul 2002 fattach(3C)