Clocking proccesses' time

[babis85]

Hello guys, i have this part of code and i want to compute the time of
processes A, B and C :

/* process A */
pid_t pid1, pid2, pid;
struct rusage ru1, ru2;

pid1 = fork();
if (pid != 0) {/* parent process */
pid2 = fork();
if (pid2 != 0) {/* parent process */
pid = waitpid(-1, &status, 0);
getrusage(RUSAGE_CHILDREN, &ru1);
waitpid(-1, &status, 0);
getrusage(_CHILDREN, &ru2);

if (pid == pid1) {
printf("B took time...\n", ru1.ru_utime.tv_sec);
printf("C took time...\n", ru2.ru_utime.tv_sec);

} else {
printf("C took time...\n", ru1.ru_utime.tv_sec);
printf("B took time...\n", ru2.ru_utime.tv_sec);
}
getrusage(RUSAGE_SELF, &ru);
printf("A took overall time...\n", ru.ru_utime.tv_sec);

} else {
/* process C */
execp(...);
}

} else {
/* process B */
execp(...);
}
The question is : Do i compute the time of each process successfully?
I get shorter time for proccess A than for its children... Isn't it
peculiar?Why?
I think that the time for proccess B is right, but i wonder if the next
call of getrusage adds c's time over b's. Do anyone know sth about
that?
Thanks a lot...

[Michael Mair]

ba*****@gmail.com wrote:

Hello guys, i have this part of code and i want to compute the time of
processes A, B and C :

/* process A */
pid_t pid1, pid2, pid;
struct rusage ru1, ru2;

pid1 = fork(); <snip!>
The question is : Do i compute the time of each process successfully?
I get shorter time for proccess A than for its children... Isn't it
peculiar?Why?
I think that the time for proccess B is right, but i wonder if the next
call of getrusage adds c's time over b's. Do anyone know sth about
that?

fork(), thread, child processes etc. are not topical to comp.lang.c,
thus you cannot rely on getting the best/good advice on that here.
comp.unix.programmer or similar may be a better place to ask.

Cheers
Michael
--
E-Mail: Mine is an /at/ gmx /dot/ de address.

[Jack Klein]

On 27 Nov 2005 10:08:50 -0800, ba*****@gmail.com wrote in comp.lang.c:

Hello guys, i have this part of code and i want to compute the time of
processes A, B and C :
The problem here is that your question is not about the C language,
but about non-standard, system-specific extensions.

/* process A */
pid_t pid1, pid2, pid;
struct rusage ru1, ru2;

pid1 = fork();
if (pid != 0) {/* parent process */
pid2 = fork();
if (pid2 != 0) {/* parent process */
pid = waitpid(-1, &status, 0);
getrusage(RUSAGE_CHILDREN, &ru1);
waitpid(-1, &status, 0);
getrusage(_CHILDREN, &ru2);

if (pid == pid1) {
printf("B took time...\n", ru1.ru_utime.tv_sec);
printf("C took time...\n", ru2.ru_utime.tv_sec);

} else {
printf("C took time...\n", ru1.ru_utime.tv_sec);
printf("B took time...\n", ru2.ru_utime.tv_sec);
}
getrusage(RUSAGE_SELF, &ru);
printf("A took overall time...\n", ru.ru_utime.tv_sec);

} else {
/* process C */
execp(...);
}

} else {
/* process B */
execp(...);
}
The question is : Do i compute the time of each process successfully?
I get shorter time for proccess A than for its children... Isn't it
peculiar?Why?
I think that the time for proccess B is right, but i wonder if the next
call of getrusage adds c's time over b's. Do anyone know sth about
that?
Thanks a lot...

None of fork(), waitpid(), getrusage(), or execp() are standard C
library functions, although I imagine they are all POSIX.

You need to ask in a platform specific group. Since you posted via
Google, the headers do not reveal your platform, so I can only suggest
either news:comp.os.linux.development.apps or
news:comp.unix.programmer.

--
Jack Klein
Home: http://JK-Technology.Com
FAQs for
comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html
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alt.comp.lang.learn.c-c++
http://www.contrib.andrew.cmu.edu/~a...FAQ-acllc.html

[babis85]

Ok, then , sorry for that and thanks for the advice.