On Thu, Aug 4, 2011 at 11:20 PM, Steven W. Orr <ste...@syslang.net> wrote:
> On 8/4/2011 9:51 AM, lina wrote:
>>
>> Actually I got a bash script which contains several process (jobs)
>>
>> The waiting time is so long, I mean, run one by one,
>>
>> I can submit one by one separately I can see the cores were used 100%
>> one by one,
>> but it's better use some bash script so I can easily modify in large
>> amounts.
>>
>> How can I enable thread in bash script,
>>
>> like the one they did in 'make' file. I tried to understand but it's so
>> hard,
>>
>> Thanks for any further suggestions,
>
> There is no thread interface in bash. You can only create processes. But,
> there are some tricks you can do to better leverage your resources. Here's
> an example:
>
> waitpids=()
> for machine in $list_of_machine
> do
> {
> lets do a bunch of stuff here on $machine
> } &
> waitpids+=( $! $machine )
> done
>
> # Now just wait for all the machines to finish what they were doing:
> sleeptime=0
> def_sleeptime=2
> while (( ${#waitpids[@]} > 0 ))
> do
> sleep $sleeptime
> for (( kk=0; kk < ${#waitpids[@]}; kk+=2 ))
> do
> sleeptime=$def_sleeptime
> pid=${waitpids[kk]}
> machine=${waitpids[kk+1]}
> # Check each pid to see if it still exists
> # If it doesn't, then harvest the exit status
> # and remove it from the list of waitpids.
> # Don't wait for a pid that's still alive or you just hang.
> # kill returns 0 if it successfully delivered the signal.
> # Signal 0 is a trick to see if a pid is there.
> if ! kill -0 $pid 2> /dev/null
> then
> wait $pid
> stat=$?
> echo -n "=== $machine has finished "
> if (( stat != 0 ))
> then
> if (( stat > 128 ))
> then
> echo -n "BUT TERMINATED BECAUSE OF SIGNAL $(( stat - 128
> ))"
> else
> echo -n "BUT IT DIED WITH EXIT STATUS:$stat"
> fi
> fi
> echo
> sleeptime=0
> unset waitpids[kk] waitpids[kk+1]
> # Reset waitpids or else the old indexes will return a null
> value.
> # The reassignment will actually shrink it.
> waitpids=("${waitpids[@]}")
> break
> fi
> done
> #If any of the pids still exist, we continue to loop
> done
Thanks.
There is another question, how do I change the nice level in bash script.
I don't have root previlege, and I notice my nice level is 19 when run
a .sh, but for normal operation, it's default 0.
really thanks,
>
>
>
>
> --
> Time flies like the wind. Fruit flies like a banana. Stranger things have
> .0.
> happened but none stranger than this. Does your driver's license say Organ
> ..0
> Donor?Black holes are where God divided by zero. Listen to me! We are all-
> 000
> individuals! What if this weren't a hypothetical question?
> steveo at syslang.net
>
>
--
Best Regards,
lina
