Hi, Xiaojie,
Please provide a reproducible example. I am afraid it is very hard to help
with just a small code snippet.
Best,
Qiang Kou
On Tue, Jun 6, 2017 at 6:22 PM, Xiaojie Qiu <x...@uw.edu> wrote:
> Hi Rcpp friends,
>
> I have a question regarding to parallel my rcpp code for KNN querying. I
> used ANN c++ package and the following is a test code related to the code
> for the querying. I can run through the code when I don' use the openMP.
> But I get error like the following when I use it :
>
> *** caught illegal operation ***
> address 0x1128e667d, cause 'illegal opcode'
>
> I have a few questions, 1. what are the potential errors I made in the
> following code? 2. do we need to require the annkSearch function
> be thread-safe in order to use openMP here? 3. If we cannot use openMP
> here because annkSearch is not thread-safe, can we use RcppParallel here?
>
> Thanks a lot,
>
> *ANNpoint pq;*
> * pq = annAllocPt(d);*
> * int i, j;*
> * nn_idx = new ANNidx[k]; // Allocate near neigh indices*
> * dists = new ANNdist[k]; // Allocate near neighbor dists*
> * omp_set_num_threads(3);*
> * for(j = 0; j < d; j++)*
> * {*
> * pq[j]=data[ d_ptr[j]++ ];*
> * }*
>
> * // ------------ test kdtree search loop: ------------ *
> * Rcout << "before search 1" << std::endl;*
> * #pragma omp parallel for shared(the_tree, k, error_bound) private(i,
> pq, nn_idx, dists)*
> * for(i = 0; i < 3; i ++)*
> * { *
> * if(i == 2){*
> * the_tree->annkSearch( // search*
> * pq, // query point*
> * k, // number of near neighbors*
> * nn_idx, // nearest neighbors (returned)*
> * dists, // distance (returned)*
> * error_bound); // error bound*
> * }*
> * }*
> * Rcout << "end search 1" << std::endl;*
>
>
>
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>
--
Qiang Kou
q...@umail.iu.edu
School of Informatics and Computing, Indiana University
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