10 More Discussions You Might Find Interesting
1. Programming
Hello.
I am new to this forum and I would like to ask for advice about low level POSIX programming.
I have to implement a POSIX compliant C shared library.
A file will have some variables and the shared library will have some functions which need those variables.
There is one special... (5 Replies)
Discussion started by: iamjag
5 Replies
2. AIX
1.How to know wich process is using the shared memory?
2.How to flush (release) the process from the shared memory? (1 Reply)
Discussion started by: pchangba
1 Replies
3. UNIX for Advanced & Expert Users
Hi,
Using ipcs we can see shared memory, etc.. details. How can I add/remove shared memory(command name)?
Thanks,
Naga:cool: (2 Replies)
Discussion started by: Nagapandi
2 Replies
4. Programming
I am writing a shared library in Linux (but compatible with other UNIXes) and I want to allow multiple instances to share a piece of memory -- 1 byte is enough. What's the "best" way to do this? I want to optimize for speed and portability.
Obviously, I'll have to worry about mutual exclusion. (0 Replies)
Discussion started by: otheus
0 Replies
5. Programming
I need to create a shared library to access an in memory DB. The DB is not huge, but big enough to make it cumbersome to carry around in every single process using the shared library. Luckily, it is pretty static information, so I don't need to worry much about synchronizing the data between... (12 Replies)
Discussion started by: DreamWarrior
12 Replies
6. Programming
hi,
this is the problem: i want to swap a linked list between 4 processes (unrelated), is there any way i can do that just by sending a pointer to a structure?
//example
typedef struct node
{
int x;
char c;
struct node *next;
} node;
or i should send the items ( x,c ) by... (9 Replies)
Discussion started by: elzalem
9 Replies
7. Programming
what i want to do is have an int that can been written into by 2 processes but my code doesn't seem to work.
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/shm.h>
#include<stdio.h>
#define KEY1 (1492)
int main()
{
int shmid;
volatile int * addr;... (6 Replies)
Discussion started by: ddx08
6 Replies
8. AIX
Hi All,
I'm facing the following issue with my shared libraries in AIX.
memory related calls such as memset, memcpy, malloc etc are failing miserably.
there is something wrong with stack/memory which i can't guess.
i've used the following flags to build my libraray:
ld -G... (0 Replies)
Discussion started by: abhinav05252
0 Replies
9. HP-UX
Hi, there
On HP-UX, there is a problem about shared memory. The code open the data file and use the "mmap" system call to map into the shared memory, when the contents are make changes, there is no effective on shared memory. The codes look like the following:
...... (0 Replies)
Discussion started by: Frank2004
0 Replies
10. UNIX for Advanced & Expert Users
I am running HP-UX B.11.11.
I'm increasing a parameter for a database engine so that it uses more memory to buffer the disk drive (to speed up performance). I have over 5GB of memory not being used.
But when I try to start the DB with the increased buffer parameter I get told.
"Not... (1 Reply)
Discussion started by: cjcamaro
1 Replies
core_addshmem_write(5) File Formats Manual core_addshmem_write(5)
NAME
core_addshmem_write - determines the inclusion of read/write shared memory in process core dump
VALUES
Failsafe
Default
Allowed values
or
DESCRIPTION
The tunable was added in response to a problem where a customer was limited in debugging a user-level process crash because shared memory
segments were not written as part of the core file.
Upon core dump, the sections of user memory labeled as shared read-write are written (along with the normal data sections) if this tunable
is set to and left out if it is set to
Who is Expected to Change This Tunable?
Anyone.
Restrictions on Changing
Changes to this tunable take effect immediately.
When Should the Value of This Tunable Be Raised?
When you wish to include read-write shared memory segments in user core files due to debugging needs by developers or maintainers on the
system.
What Are the Side Effects of Raising the Value?
User process core files would increase in most cases (most applications use at least some shared memory). This could be a problem on sys-
tems where disk space is at a premium.
When Should the Value of This Tunable Be Lowered?
When there is no need for debugging core files where shared memory corruption or data values are in question.
What Are the Side Effects of Lowering the Value?
Core files will tend to be smaller.
What Other Tunable Values Should Be Changed at the Same Time?
Certainly think about which does the same thing for read-only shared memory segments.
WARNINGS
All HP-UX kernel tunable parameters are release specific. This parameter may be removed or have its meaning changed in future releases of
HP-UX.
Installation of optional kernel software, from HP or other vendors, may cause changes to tunable parameter values. After installation,
some tunable parameters may no longer be at the default or recommended values. For information about the effects of installation on tun-
able values, consult the documentation for the kernel software being installed. For information about optional kernel software that was
factory installed on your system, see at
AUTHOR
was developed by HP.
Tunable Kernel Parameters core_addshmem_write(5)
