openmp - while loop for text file reading and using a pipeline

Question

I discovered that openmp doesn\'t support while loops( or at least doesn\'t like them too much). And also doesn\'t like the \' != \' operator.

I have this bit of cod

Answer 1

It's too bad people are so quick to select the best answer. Here is my answer.
First, you should read the file into a buffer with something like fread. This is very quick. An example of how to do this can be found here http://www.cplusplus.com/reference/cstdio/fread/

Then you can operate on the buffer in parallel with OpenMP. I have implemented most of this for you. Below is the code. You did not provide the segment_read function so I created a dummy one. I used a few functions from C++ such as std::vector and std::sort but with a little more work you could do this in pure C as well.

Edit: I edited this code and was able to remove the sorting and critical section.

I compiled with g++ foo.cpp -o foo -fopenmp -O3

#include 
#include 
#include 

using namespace std;

int segment_read(char *buff, const int len, const int count) {
  return 1;  
}

void foo(char* buffer, size_t size) {
    int count_of_reads = 0;
    int count = 1;
    std::vector *posa;
    int nthreads;

    #pragma omp parallel 
    {
        nthreads = omp_get_num_threads();
        const int ithread = omp_get_thread_num();
        #pragma omp single 
        {
            posa = new vector[nthreads];
            posa[0].push_back(0);
        }

        //get the number of lines and end of line position
        #pragma omp for reduction(+: count)
        for(int i=0; i