On Sat, Oct 13, 2012 at 11:16 AM, Canek Peláez Valdés <can...@gmail.com> wrote: > On Sat, Oct 13, 2012 at 12:10 PM, Mark Knecht <markkne...@gmail.com> wrote: >> On Sat, Oct 13, 2012 at 9:15 AM, Canek Peláez Valdés <can...@gmail.com> >> wrote: >> <SNIP> >>> >>> We can only know seeing the code. Timur, this is the little test I >>> made which creates 5 threads and runs them for 1 minute. In my case, >>> `ps x` shows only 1 PID, care to give it a try? >>> >>> ---------------------- >>> #include <pthread.h> <<====== >>> #include <unistd.h> >>> #include <stdlib.h> >>> #include <stdio.h> >> >> Thanks for the test case. Like you I see only one thread. However the >> test case wouldn't compile for me without the -pthread option so it >> makes me wonder what happens to a program like I had pointed to >> yesterday that uses the old style threading that did create lots of >> process ids? Possibly an nptl system would still generate lots of ids >> for that program and that's what he's seeing? >> >> Just curious. I don't program but I'm always sort of interested. > > You got your answer. NTPL stands for Native POSIX Thread *Library*. As > it name says, it is a library (with support in the kernel and in > glibc). If you don't use the library (-lpthread), you cannot make use > of its advantages. > > What "old style threading" did you use for your test case? > > Regards. > -- > Canek Peláez Valdés > Posgrado en Ciencia e Ingeniería de la Computación > Universidad Nacional Autónoma de México >
As for 'old style' I only meant code that did threads but didn't use the POSIX libraries. (I guess...) Actually I hadn't run the test case at the time but was referring to the one I pointed the OP at yesterday: http://www.makelinux.net/alp/032 However it's essentially the same as yours (not as elegant, but functionally similar). However the results shown on that page show different pids for the threads. When I run that same code here I get the same pids: mark@c2stable ~ $ ./pthread2 main thread pid is 5387 child thread pid is 5387 ^C mark@c2stable ~ $ Now, this does make me curious about some things running on my system. Two for instance, Google Chrome and akonadi_agent, have LOTS of pids. I was assuming those were different threads and were demonstrating what the OP was asking about, but now I'm not so sure. How does a single program on an nptl system generate all these different pids? Thanks, Mark
