06-21-2008
synchronize processes
hi.
i am writing a c program under bash shell.
i would like to use semaphore functions like sem_wait(), sem_post()
and i included <semaphore.h> and it compailes fine
but when i try to run it gives me an error "undefined reference to sem_wait() , sem_post() , sem_init()"
what have i missed ?
9 More Discussions You Might Find Interesting
1. Programming
Hi,
I am trying to implement the synchronize feature of java using C. I am using a semaphore for the same. I have a wrapper called "synch" to which I pass the function pointer(any_fn). This pointer points to the function (my_fn) which needs to be synchronized.
However to create the semaphore I... (8 Replies)
Discussion started by: linuxpenguin
8 Replies
2. Shell Programming and Scripting
Hi,
I have three Linux machine have three different times.
Can I synchronize them using one process?
I have root access.
Thanks! (1 Reply)
Discussion started by: whatisthis
1 Replies
3. Shell Programming and Scripting
I have 4 directory
Dir1
file1 file2 file3 file4
Dir2
file3 file5 file6 file8
Dir3
file1 file2 file6 file9 file10
Dir4
file3 file6 file12 file15
and all the 4 dirs are having couple of files.
Few of the files are common to other directory/ies and few... (1 Reply)
Discussion started by: reldb
1 Replies
4. Programming
I am writing a program in C for my networking class, so I am relatively new to this.
To begin, I have 7 processes that need do send messages to every other one, and every one of them needs to receive the messages sent by others.
I am using fork() to create 6 more processes.
The message... (1 Reply)
Discussion started by: inabramova
1 Replies
5. Programming
i am trying to synchronize between father process and son process
created by fork() command, to print simultaneously.
my program is written in c under bash shell.
the compile goes ok but when i try to run nothing happens and the program doesnot end.
my code is:
#include <stdio.h>... (1 Reply)
Discussion started by: emil2006
1 Replies
6. Shell Programming and Scripting
Hi,
I have two servers1&2, one is not in the network. Cant communicate from it to other servers. The second one can communicate to above mentioned server. I am trying a script which synchronizes files between server 1 an 2?
server1: cant communicate to any other servers
server2: can... (4 Replies)
Discussion started by: Tuxidow
4 Replies
7. Shell Programming and Scripting
Hi everyone!
I need to write a script that will synchronize two servers using FTP. So basically the script will get only the files that exist on the remote server that do not exist on the local server. Is there an option to do this when using mget? If not, is there a way to copy over only the... (2 Replies)
Discussion started by: Fatbob
2 Replies
8. AIX
Hi
Earlier we used to move the resource groups between nodes manually. Recently I have added the HACMP startup and stop scripts.
Then I moved the resource group to see if everything works fine as per the startup and stop scripts, but it didn't work out as expected.
Do i need to do bring... (4 Replies)
Discussion started by: samsungsamsung
4 Replies
9. UNIX for Advanced & Expert Users
Hello, I have the latest stable release of a UNIX-like O.S. in the ISO format, and want to synchronize it with the latest Release Candidate (RC) of it, in order to reducing bandwidth usage. The ISO images for that O.S. is provided via different protocols including rsync, FTP and HTTP
Is this... (4 Replies)
Discussion started by: temp-usr
4 Replies
LEARN ABOUT FREEBSD
sem_post
SEM_POST(3) BSD Library Functions Manual SEM_POST(3)
NAME
sem_post -- increment (unlock) a semaphore
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <semaphore.h>
int
sem_post(sem_t *sem);
DESCRIPTION
The sem_post() function increments (unlocks) the semaphore pointed to by sem. If there are threads blocked on the semaphore when sem_post()
is called, then the highest priority thread that has been blocked the longest on the semaphore will be allowed to return from sem_wait().
The sem_post() function is signal-reentrant and may be called within signal handlers.
RETURN VALUES
The sem_post() function returns the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indi-
cate the error.
ERRORS
The sem_post() function will fail if:
[EINVAL] The sem argument points to an invalid semaphore.
[EOVERFLOW] The semaphore value would exceed SEM_VALUE_MAX.
SEE ALSO
sem_getvalue(3), sem_trywait(3), sem_wait(3)
STANDARDS
The sem_post() function conforms to ISO/IEC 9945-1:1996 (``POSIX.1'').
BSD
January 28, 2015 BSD