[boost] Re: linked_ptr update (long)

From: Greg Colvin (gcolvin_at_[hidden])
Date: 2000-02-05 16:52:39

I retried my tests with a higher (but still safe) level of optimization,
and the results switched to favor linked_ptr.

   testing 1000000 int*
   fill vector: 843
   sort vector: 438
   fill list: 1687
   sort list: 7063

   testing 1000000 shared_ptr<int>
   fill vector: 1875
   sort vector: 1828
   fill list: 2578
   sort list: 8547

   testing 1000000 linked_ptr<int>
   fill vector: 1312
   sort vector: 1719
   fill list: 1891
   sort list: 9296
   
Also, I tried turning on synchronization with BOOST_MULTI_THREAD:

   testing 1000000 linked_ptr<int>
   fill vector: 2765
   sort vector: 4375
   fill list: 2890
   sort list: 9797

This seems pretty expensive.  Eliminating the unnecessary try/catch in
sync_lock::lock() helps some:

   testing 1000000 linked_ptr<int>
   fill vector: 2313
   sort vector: 3500
   fill list: 2609
   sort list: 9719

   

----- Original Message ----- 
From: Greg Colvin <gcolvin_at_[hidden]>
To: <boost_at_[hidden]>
Sent: Saturday, February 05, 2000 11:54 AM
Subject: [boost] Re: linked_ptr update (long)

> Thanks for pushing on this.  Here are my timings for the program shown below.
> 
> What I am seeing in this test is that the time to allocate the long vanishes
> in the overhead of allocating and filling the vector or list, and that the
> size of the smart pointer makes a difference when you start copying them
> around a lot, as in sorting the vector.
> 
> testing 1000000 int*
> fill vector: 1046
> sort vector: 1000
> fill list: 2406
> sort list: 20125
> 
> testing 1000000 shared_ptr<int>
> fill vector: 2000
> sort vector: 6093
> fill list: 3062
> sort list: 25047
> 
> testing 1000000 linked_ptr<int>
> fill vector: 2422
> sort vector: 8047
> fill list: 3375
> sort list: 26062
> 
> 
> 
> int main(int argc, char** argv) {
>    const int N = atoi(argv[1]);
> 
>    #if defined(RAW)
>       typedef int* ptr_int;
>       printf("testing %d int* \n", N);
>    #elif defined(LINKED)
>       typedef linked_ptr<int> ptr_int;
>       printf("testing %d linked_ptr<int>\n", N);
>    #else
>       typedef shared_ptr<int> ptr_int;
>       printf("testing %d shared_ptr<int>\n", N);
>    #endif
> 
>    {  clock_t start = clock();
>       vector<ptr_int> container(N);;
>       for (int i = 0; i < N; i++ )
>          container[i] = ptr_int(new int(rand()));
>       printf("fill vector: %ld\n",
>              ((long)clock() - start)*1000/CLOCKS_PER_SEC);
>       start = clock();
>       sort(container.begin(), container.end());
>       printf("sort vector: %ld\n",
>               ((long)clock() - start)*1000/CLOCKS_PER_SEC);
>    }
>    {  clock_t start = clock();
>       list<ptr_int> container;
>       for (int i = 0; i < N; i++ )
>          container.push_back(ptr_int(new int(rand())));
>       printf("fill list: %ld\n",
>              ((long)clock() - start)*1000/CLOCKS_PER_SEC);
>       start = clock();
>       container.sort();
>       printf("sort list: %ld\n",
>              ((long)clock() - start)*1000/CLOCKS_PER_SEC);
>    }
> 
>    return 0;
> }
> 
> 
> 
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