I just want to create n number of childs and after each child would start executing some instruction, but when i execute the program i don't receive anything, I wonder how you get the result.
my linux system is
Hey all. I recently ported a multithreaded program from WinNT to LINUX using pthreads. Everything works fine, except that it turns out the drivers for the hardware I'm working with aren't thread safe. So, now I have to find a way to make this multi-process instead of multi-threaded.
I just... (1 Reply)
I need a quick script that will serve as a sort of "real time monitor" for watching some log files. I am using Bourne shell in HP-UX 10.20. I have basically created a script that never ends, unless of course I manually terminate it. Here's the script (it's called qhistory):
clear
echo "REAL... (3 Replies)
hello,
Every time i use fork() in the for loop, my college network(which i work in) either gets slow or hangs up.Can any 1 explain why it is so?
Of course there is no use of doing it though. But still i want to clear my doubt.
Thanks (2 Replies)
I have a parent that is passing data to child A and then child A has to process it and pass to child B. I am able to pass the data to child A but am not able to pass it to child B. Child B seems to only be receiving the last data instead of the whole data.
I saw one example in a book but it uses... (1 Reply)
hai,
i am doing my masters degree in computers.please any one tell me about
fork(),semaphores,mutex,messaging queues,messaging using pipes ,and msgget(),msgrecv() funtions
in ipc programming .
i have exam on that i have a book but in that they not given clearly.
hope u will
... (2 Replies)
Hi! I'm trying to write this program: in my intentions it should get a message and send it to a second process (pid_upost), then to a third process (pid1, pid2, pid3, depending on the choice made when a new message is inserted). This program should write the message in a file (message1, message2 or... (1 Reply)
I was asked to look into a problem with a Sun Netra 440 in another department. On the server in question, the relevant 'uname -a' information is, "SunOS host1 5.9 Generic_118558-16 sun4u sparc SUNW,Netra-440". That information aside, while the other admin is logged into the ALOM, these errors are... (0 Replies)
I am trying to ping through a list of devices in parallel.
When the code below is executed, I enter a infinite loop.
I want to used the number of lines in the file as my boundry.
I am a perl rookie and just cant see whats wrong.
would appreciate help ...
use Net::Ping;
#
$filename... (0 Replies)
Hello people.
I'm trying to do something like a search engine.
Server runs in the background by using ./server & which has data from a textfile stored in an array.
Client then runs by using ./client
It will then prompt "Search for:"
For example, if I searched for Products called Instant... (0 Replies)
Hi Experts,
Need your help for checking te interprocess communications settings on HP-UX box.
Using ipcs command I am able to view Message queue,semapohores etc, but from that output I m not able to understand how to determine if there is any issue with ipc settings and how to resolve that? (1 Reply)
Discussion started by: sai_2507
1 Replies
LEARN ABOUT PLAN9
rendezvous
RENDEZVOUS(2) System Calls Manual RENDEZVOUS(2)NAME
rendezvous - user level process synchronization
SYNOPSIS
#include <u.h>
#include <libc.h>
ulong rendezvous(ulong tag, ulong value)
DESCRIPTION
The rendezvous system call allows two processes to synchronize and exchange a value. In conjunction with the shared memory system calls
(see segattach(2) and fork(2)), it enables parallel programs to control their scheduling.
Two processes wishing to synchronize call rendezvous with a common tag, typically an address in memory they share. One process will arrive
at the rendezvous first; it suspends execution until a second arrives. When a second process meets the rendezvous the value arguments are
exchanged between the processes and returned as the result of the respective rendezvous system calls. Both processes are awakened when the
rendezvous succeeds.
The tag space is common to processes in the same file name space, so rendezvous only works between processes in the same file name space.
If a rendezvous is interrupted the return value is ~0, so that value should not be used in normal communication.
SOURCE
/sys/src/libc/9syscall
SEE ALSO segattach(2), fork(2)DIAGNOSTICS
Sets errstr.
BUGS
The correlation of rendezvous tags and file name space is a historical accident. If two unrelated processes happen to be in the same name
space and do a rendezvous, trouble will result. The solution is to call rfork(RFNAMEG) (see fork(2)) in programs that use rendezvous
unless they need to share the name space with their parent. This is especially important in Alef programs.
RENDEZVOUS(2)