Sponsored Content
Full Discussion: Multi threading using fork
Top Forums Programming Multi threading using fork Post 44029 by Perderabo on Thursday 27th of November 2003 05:18:13 PM
Old 11-27-2003
Well, you're not off to very good start here. Smilie

The text of your post says your program "will run a set of process using fork." But even the comments in your code disagrees with that. When you run system() in a loop as you are doing, you will run one program after another. After the tenth program finishes, the ChildProcess function will return. Then your program finally performs it's first and only fork() which is a demo. And then it exits.

To get the ball rolling, you need to call fork() 10 times in a loop. And each child process will need run one of your jobs. One of the exec() calls would be much better than system().

I think that you should get this much working first.

But basicly you will need to install a signal handler that catches SIGCHLD to detect the death of a child.
 

10 More Discussions You Might Find Interesting

1. Programming

Multi threading using posix thread library

hi all, can anyone tell me some good site for the mutithreading tutorials, its application, and some code examples. -sushil (2 Replies)
Discussion started by: shushilmore
2 Replies

2. Programming

Multi-threading questions

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)
Discussion started by: DreamWarrior
1 Replies

3. Programming

Regarding Multi-Threading

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)
Discussion started by: matrixmadhan
5 Replies

4. Programming

Multi threading?

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)
Discussion started by: enuenu
4 Replies

5. Programming

Multi-threading-- calling same function through different threads

Sir, Can I call same function in the start routines of different Threads. I have created two different threads....and wanna call same function from both threads....is it possible??? Also can I fork inside a thread??? (1 Reply)
Discussion started by: arunchaudhary19
1 Replies

6. Programming

Multi-threading

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)
Discussion started by: jramesh1
1 Replies

7. Programming

Multi-threading

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)
Discussion started by: saman_glorious
4 Replies

8. UNIX for Dummies Questions & Answers

Confusion over Multi Threading

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)
Discussion started by: jimthompson
3 Replies

9. UNIX for Beginners Questions & Answers

Does UNIX support multi-Threading ?

Not just background process running ... but im looking if unix has any multi-threading concept like in Java, C# ... if not present, can you pls share the nearest feature in unix that is close to multi-threaded concept (3 Replies)
Discussion started by: i4ismail
3 Replies

10. UNIX for Beginners Questions & Answers

Multi threading in UNIX

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
stopping(7)						 Miscellaneous Information Manual					       stopping(7)

NAME
stopping - event signalling that a job is stopping SYNOPSIS
stopping JOB=JOB INSTANCE=INSTANCE RESULT=RESULT [PROCESS=PROCESS] [EXIT_STATUS=STATUS] [EXIT_SIGNAL=SIGNAL] [ENV]... DESCRIPTION
The stopping event is generated by the Upstart init(8) daemon when an instance of a job begins stopping. The JOB environment variable con- tains the job name, and the INSTANCE environment variable contains the instance name which will be empty for single-instance jobs. If the job is stopping normally, the RESULT environment variable will be ok, otherwise if the job is stopping because it has failed it will be failed. When the job has failed, the process that failed will be given in the PROCESS environment variable. This may be pre-start, post-start, main, pre-stop or post-stop; it may also be the special value respawn to indicate that the job is stopping because it hit the respawn limit. Finally in the case of a failed job, one of either EXIT_STATUS or EXIT_SIGNAL may be given to indicate the cause of the stop. Either EXIT_STATUS will contain the exit status code of the process, or EXIT_SIGNAL will contain the name of the signal that the process received. The normal exit job configuration stanza can be used to prevent particular exit status values or signals resulting in a failed job, see init(5) for more information. If neither EXIT_STATUS or EXIT_SIGNAL is given for a failed process, it is because the process failed to spawn (for example, file not found). See the system logs for the error. init(8) will wait for all services started by this event to be running, all tasks started by this event to have finished and all jobs stopped by this event to be stopped before allowing the job to continue stopping. This allows jobs to depend on other jobs, safely stopping themselves before their dependency goes away. This event is typically combined with the started(7) event by services. Job configuration files may use the export stanza to export environment variables from their own environment into the stopping event. See init(5) for more details. EXAMPLE
A service that wishes to depend on another service might use: start on started apache stop on stopping apache A task that must be run before another task or service is stopped might use: start on stopping postgresql RESULT=ok SEE ALSO
starting(7) started(7) stopped(7) init(5) Upstart 2009-07-09 stopping(7)
All times are GMT -4. The time now is 03:35 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy