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STL map and Posix Threads

Hello,

I wanted to use Threads on Sun 4 node SMP. In my program I use STL map and I
noticed that I don't get any speedup from using threads and I suspect that it
has something to do STL map. Can anybody throw some light on this issue ?

csv
Jul 22 '05 #1
6 2485
cs********@yaho o.com (Chaman Singh) wrote in
news:de******** *************** ***@posting.goo gle.com:
Hello,

I wanted to use Threads on Sun 4 node SMP. In my program I use STL map
and I noticed that I don't get any speedup from using threads and I
suspect that it has something to do STL map. Can anybody throw some
light on this issue ?


Not really. Threading is off-topic in comp.lang.c++. You need to talk to
your compiler vendor (and/or the vendor of your STL implementation. . they
may not be the same people) as to how they handle threading within their
STL implementation.
Jul 22 '05 #2
cs********@yaho o.com (Chaman Singh) wrote in
news:de******** *************** ***@posting.goo gle.com:
Hello,

I wanted to use Threads on Sun 4 node SMP. In my program I use STL map
and I noticed that I don't get any speedup from using threads and I
suspect that it has something to do STL map. Can anybody throw some
light on this issue ?


Not really. Threading is off-topic in comp.lang.c++. You need to talk to
your compiler vendor (and/or the vendor of your STL implementation. . they
may not be the same people) as to how they handle threading within their
STL implementation.
Jul 22 '05 #3
On 8 Apr 2004 08:53:12 -0700, cs********@yaho o.com (Chaman Singh)
wrote:
Hello,

I wanted to use Threads on Sun 4 node SMP. In my program I use STL map and I
noticed that I don't get any speedup from using threads and I suspect that it
has something to do STL map. Can anybody throw some light on this issue ?


Have you profiled the code to find out where the bottlenecks are? It
might be something to do with map (it might be making many memory
allocations, with a global, mutexed memory allocator). It might be
something else.

Tom
--
C++ FAQ: http://www.parashift.com/c++-faq-lite/
C FAQ: http://www.eskimo.com/~scs/C-faq/top.html
Jul 22 '05 #4
On 8 Apr 2004 08:53:12 -0700, cs********@yaho o.com (Chaman Singh)
wrote:
Hello,

I wanted to use Threads on Sun 4 node SMP. In my program I use STL map and I
noticed that I don't get any speedup from using threads and I suspect that it
has something to do STL map. Can anybody throw some light on this issue ?


Have you profiled the code to find out where the bottlenecks are? It
might be something to do with map (it might be making many memory
allocations, with a global, mutexed memory allocator). It might be
something else.

Tom
--
C++ FAQ: http://www.parashift.com/c++-faq-lite/
C FAQ: http://www.eskimo.com/~scs/C-faq/top.html
Jul 22 '05 #5

"Chaman Singh" <cs********@yah oo.com> wrote in message
news:de******** *************** ***@posting.goo gle.com...
Hello,

I wanted to use Threads on Sun 4 node SMP. In my program I use STL map and I noticed that I don't get any speedup from using threads and I suspect that it has something to do STL map. Can anybody throw some light on this issue ?

csv


Get a good book on writing programs with POSIX threads.
Threads cannot be efficiently bolted on to a prog in general.
Without more info it is impossible to say whether the map is a problem.
The map is unlikely to be thread safe anyway.
Jul 22 '05 #6

"Chaman Singh" <cs********@yah oo.com> wrote in message
news:de******** *************** ***@posting.goo gle.com...
Hello,

I wanted to use Threads on Sun 4 node SMP. In my program I use STL map and I noticed that I don't get any speedup from using threads and I suspect that it has something to do STL map. Can anybody throw some light on this issue ?

csv


Get a good book on writing programs with POSIX threads.
Threads cannot be efficiently bolted on to a prog in general.
Without more info it is impossible to say whether the map is a problem.
The map is unlikely to be thread safe anyway.
Jul 22 '05 #7

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