Visit The New, Modern Unix Linux Community

parent and child process question?

Thread Tools Search this Thread
Top Forums Programming parent and child process question?
# 1  
Question parent and child process question?

Hi everybody,

I'm trying to understand how a parent and child processes interact.

This function( below) basically measures the fork time from the perspective of the parent only.

what i would like to know is how to measure the time from the perspective of parent and child (ie: inserting the GETTIME(endt) inside the child).
Any help would be appreciated.

HTML Code:
void run_tests(int nt)
  struct timeval begt;
  struct timeval endt;

  double secs;
  int i;
  pid_t pid;
  int waitid;
  int status;

  double max_secs = 0.000000;
  double min_secs = 0.000000;
  double average  = 0.000000;
  double sum      = 0.000000;

  for(i=0; i<nt; i++)
    GETTIME(begt);  // gettimeofday()

    if((pid = fork()) < 0)
     perror("fork() failed!\n");
    if( pid == 0)
    waitid = wait(&status);
    GETTIME(endt);  // gettimeofday()

    secs = TOTALSECS(begt,endt);
    max_secs = max(secs,max_secs);
    min_secs = min(secs,min_secs);

    sum += secs;

   printf("%2d: secs = %.6f\n", i,secs);
  }    /* end of FOR loop */

  average = sum / (i + 1);

  printf("min:     %.6f\n", min_secs);
  printf("max:     %.6f\n", max_secs);
  printf("sum:     %.6f\n", sum);
  printf("average: %.6f\n", average);
  printf("waitid: %d \n", waitid);
  printf(" \n");


Previous Thread | Next Thread
Thread Tools Search this Thread
Search this Thread:
Advanced Search

Test Your Knowledge in Computers #305
Difficulty: Easy
A regular expression is an integer array that can be used to describe several sequences of characters.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

System should not kill the child process when parent id is 1

HI i would like to know how i can simulate a shell scripts for my requirement. example Server name child Process id Parent Process id Vpesh 16013 15637 Server name child Process id Parent Process id Vpesh 16014 15637 Server name child... (1 Reply)
Discussion started by: vpesh
1 Replies

2. Shell Programming and Scripting

How make parent to wait from child process?

Hi all, I am starting mgen5 for sometime depends on input from a file, in a child process. now I want to make parent to wait in this child process till mgen5 finishes, or timeout happens. could anyone please tell me how to make parent to wait in child process in shell script? thanks... (2 Replies)
Discussion started by: girijajoshi
2 Replies

3. Shell Programming and Scripting

forking a child process and kill its parent to show that child process has init() as its parent

Hi everyone i am very new to linux , working on bash shell. I am trying to solve the given problem 1. Create a process and then create children using fork 2. Check the Status of the application for successful running. 3. Kill all the process(threads) except parent and first child... (2 Replies)
Discussion started by: vizz_k
2 Replies

4. Emergency UNIX and Linux Support

signal between parent process and child process

Hello, everyone. Here's a program: pid_t pid = fork(); if (0 == pid) // child process { execvp ...; } I send a signal (such as SIGINT) to the parent process, the child process receive the signal as well as the parent process. However I don't want to child process to receive the... (7 Replies)
Discussion started by: jackliang
7 Replies

5. Programming

Parent process starts before the child using signal, in C

Hi, i want that the parent process start before the child, this code doesn't work, if the child start before the parent it wait for signal, then the father send the signal SIGALRM and the child catch it and call printf; else the father call printf and send the signal to the child that call its... (1 Reply)
Discussion started by: blob84
1 Replies

6. UNIX for Dummies Questions & Answers

Command to find parent and child process?

Hi, I have a script that calls other scripts/commands which may or may not spawn other process. From my understanding, when I do a ps -ef, the highest numbered process ID is supposed to be the parent ID of all the other related child processes, is this correct? In most or all... (3 Replies)
Discussion started by: newbie_01
3 Replies

7. Shell Programming and Scripting

[KSH/Bash] Starting a parent process from a child process?

Hey all, I need to launch a script from within 2 other scripts that can run independently of the two parent scripts... Im having a hard time doing this, if anyone knows how please let me know. More detail. ScriptA (bash), ScriptB (ksh), ScriptC (bash) ScriptA, launches ScriptB ScirptB,... (7 Replies)
Discussion started by: trey85stang
7 Replies

8. UNIX for Dummies Questions & Answers

Sending signal from child to parent process!

Hi All, I facing a problem in handling signals between parent process communication. I am trying to send a signal(SIGINT) from child to parent. I am using kill function to do so and I am trying to read the signal using sigaction(). But the program is ending abruptly and I am not able to figure out... (4 Replies)
Discussion started by: vkn_1985
4 Replies

9. Shell Programming and Scripting

How to make the parent process to wait for the child process

Hi All, I have two ksh script. 1st script calls the 2nd script and the second script calls an 'C' program. I want 1st script to wait until the 'C' program completes. I cant able to get the process id for the 'C' program (child process) to make the 1st script to wait for the second... (7 Replies)
Discussion started by: sennidurai
7 Replies

10. UNIX for Advanced & Expert Users

How to find all the child processes of a parent process

Hi I am trying to see if there are some options in ps command or if there is a shell script which basically shows you all the processes spawned by a parent process , then all the processes of its child processes and so on down the hierarchy may be like a tree structure. It might be a generic... (6 Replies)
Discussion started by: clifford
6 Replies

Featured Tech Videos