I need to parallelize "while" loop by the means of PPL. I have the following code in Visual C++ in MS VS 2013.
int WordCount::CountWordsInTextFiles(basic_string<char> p_FolderPath, vector<basic_string<char>>& p_TextFilesNames)
{
// Word counter in all files.
atomic<unsigned> wordsInFilesTotally = 0;
// Critical section.
critical_section cs;
// Set specified folder as current folder.
::SetCurrentDirectory(p_FolderPath.c_str());
// Concurrent iteration through p_TextFilesNames vector.
parallel_for(size_t(0), p_TextFilesNames.size(), [&](size_t i)
{
// Create a stream to read from file.
ifstream fileStream(p_TextFilesNames[i]);
// Check if the file is opened
if (fileStream.is_open())
{
// Word counter in a particular file.
unsigned wordsInFile = 0;
// Read from file.
while (fileStream.good())
{
string word;
fileStream >> word;
// Count total number of words in all files.
wordsInFilesTotally++;
// Count total number of words in a particular file.
wordsInFile++;
}
// Verify the values.
cs.lock();
cout << endl << "In file " << p_TextFilesNames[i] << " there are " << wordsInFile << " words" << endl;
cs.unlock();
}
});
// Destroy critical section.
cs.~critical_section();
// Return total number of words in all files in the folder.
return wordsInFilesTotally;
}
This code does parallel iteration through std::vector in outer loop. Parallelism is provided by concurrency::parallel_for() algorithm. But this code also has nested "while" loop that executes reading from file. I need to parallelize this nested "while" loop. How can this nested "while" loop can be parallelized by the means of PPL. Please help.