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 BSD
vfork
VFORK(2) System Calls Manual VFORK(2)NAME
vfork - spawn new process in a virtual memory efficient way
SYNOPSIS
pid = vfork()
int pid;
DESCRIPTION
Vfork can be used to create new processes without fully copying the address space of the old process, which is horrendously inefficient in
a paged environment. It is useful when the purpose of fork(2) would have been to create a new system context for an execve. Vfork differs
from fork in that the child borrows the parent's memory and thread of control until a call to execve(2) or an exit (either by a call to
exit(2) or abnormally.) The parent process is suspended while the child is using its resources.
Vfork returns 0 in the child's context and (later) the pid of the child in the parent's context.
Vfork can normally be used just like fork. It does not work, however, to return while running in the childs context from the procedure
that called vfork since the eventual return from vfork would then return to a no longer existent stack frame. Be careful, also, to call
_exit rather than exit if you can't execve, since exit will flush and close standard I/O channels, and thereby mess up the parent processes
standard I/O data structures. (Even with fork it is wrong to call exit since buffered data would then be flushed twice.)
SEE ALSO fork(2), execve(2), sigvec(2), wait(2),
DIAGNOSTICS
Same as for fork.
BUGS
This system call will be eliminated when proper system sharing mechanisms are implemented. Users should not depend on the memory sharing
semantics of vfork as it will, in that case, be made synonymous to fork.
To avoid a possible deadlock situation, processes that are children in the middle of a vfork are never sent SIGTTOU or SIGTTIN signals;
rather, output or ioctls are allowed and input attempts result in an end-of-file indication.
4th Berkeley Distribution June 30, 1985 VFORK(2)