I've been doing some reading lately about threading (Posix threads) and I'm really curious about a couple things that I've read. I'm not sure if many people here have threading experience, but I thought it would be nice to be able to discuss some questions about it.
(For the record, I did... (1 Reply)
Hi,
I have written a code which will run a set of process using
fork.
I want to know from You how can i start another job when one of my job in my loop is completed
My code is
#include<stdio.h>
#include<ctype.h>
main() {
int pid,cid;
ChildProcess();
... (1 Reply)
Hi All,
Here's my question
I have a 385 MB file containing 5,000,000 records.
I need to read from the file and load into a table.
Initially i thought of doing it in a single thread (execution of a single program) but when calculated accounted 16 hours of time on a standard benchmark.
Hence... (5 Replies)
I am not sure if multi threading is the correct term, but here is what I am trying to do. I have a while loop that displays the number 1, pauses, displays the number 2, pauses , displays the number 3 ad infinitum. It just keeps counting.
While the screen displays the sequence of numbers counting... (4 Replies)
Hi, If we create 10 threads to invoke runQuery method at same time, Will queryProcessor will be overriden sometime or 10 different copies will be created?
We are not using any sunchronzation mechnism in runQuery(). so there is not gurantee on QueryProcessor class variables right OR each 10... (1 Reply)
In this piece i implemented the gossip method. The first thread is invoked from inside the (msg is first sent from node -1 to 0 from main()) and the other threads are invoked from inside of the thread function itself. I used two mutexes and a condition variable to control the synchronization. ... (4 Replies)
Hi, I am trying to get my head round Multi Threading and I have a few queries to try and clear up my confusion
Q1. Is multi threading a hardware / chip level concept, an OS level or an application level concept ? I am trying to work out where SMT architecture fits in.
Q2. What's the multi... (3 Replies)
Hello everybody ,
I launched cron to execute a task every hour but the job takes more than hour that's why I'm getting more than 1000 cron processes running at the same time !!!
My question is how to tell cron not to execute unless the job terminated in order to have only one process running .... (14 Replies)
Hi All
I have been asked to write scripts within our monitoring tool for a vast requirement set.
One of the requirements is below:
• Lowest, Highest & Average response times of the Documentum process threads serving client requests
Essentially they want a view where we can see the... (4 Replies)
Hi,
Can we apply multi threading in Unix. I am using bash shell.
We have a generic script to load the data to table based on file input. For each file there is an individual table to load.
For each file found in directory I want to load the data in parallel to target table using
... (3 Replies)
Discussion started by: vedanta
3 Replies
LEARN ABOUT XFREE86
pbmreduce
pbmreduce(1) General Commands Manual pbmreduce(1)NAME
pbmreduce - read a portable bitmap and reduce it N times
SYNOPSIS
pbmreduce [-floyd|-fs|-threshold ] [-value val] N [pbmfile]
DESCRIPTION
Reads a portable bitmap as input. Reduces it by a factor of N, and produces a portable bitmap as output.
pbmreduce duplicates a lot of the functionality of pgmtopbm; you could do something like pnmscale | pgmtopbm, but pbmreduce is a lot
faster.
pbmreduce can be used to "re-halftone" an image. Let's say you have a scanner that only produces black&white, not grayscale, and it does a
terrible job of halftoning (most b&w scanners fit this description). One way to fix the halftoning is to scan at the highest possible res-
olution, say 300 dpi, and then reduce by a factor of three or so using pbmreduce. You can even correct the brightness of an image, by
using the -value flag.
OPTIONS
By default, the halftoning after the reduction is done via boustrophedonic Floyd-Steinberg error diffusion; however, the -threshold flag
can be used to specify simple thresholding. This gives better results when reducing line drawings.
The -value flag alters the thresholding value for all quantizations. It should be a real number between 0 and 1. Above 0.5 means darker
images; below 0.5 means lighter.
All flags can be abbreviated to their shortest unique prefix.
SEE ALSO pnmenlarge(1), pnmscale(1), pgmtopbm(1), pbm(5)AUTHOR
Copyright (C) 1988 by Jef Poskanzer.
02 August 1989 pbmreduce(1)