Pthread Statistics Text Count

Source: Internet
Author: User

The program uses Pthread to count the occurrences of each word in a text. Each thread handles a single line of string.

Use a map<string, size_t> word_count as a global variable.

Kernel function, use Pthread_mutex_lock to control changes to the global variable Word_count. Use StringStream to process strings.


First sentence.

Second sentence,

Third sentence.

Fourth sentence.

Five sentence

Six sentence

Seven sentence


First occurs 1 time

Five occurs 1 time

Fourth occurs 1 time

Second occurs 1 time

Sentence occurs 7 times

Seven occurs 1 time

Six occurs 1 time

Third occurs 1 time



g++-std=c++0x-o A.out-lpthread MAP.O


g++-std=c++0x-c Map.cpp


Cat Paragraph.txt |./a.out


#include  <pthread.h> #include  <map> #include  <string> #include  <iostream > #include  <sstream> #include  <algorithm> #include  <vector>using  namespace std; #define  line_per_thread1pthread_mutex_t count_mutex = pthread_mutex_ initializer;map<string, size_t> word_count;struct para {int tidx;string  str;};/ /kernel functionvoid * wordcount  (VOID&NBSP;*PT) {struct para *local =  (struct para *)  pt;string local_str = local->str;pthread_mutex_lock (& Count_mutex); Stringstream ss (LOCAL_STR); String token;while (Ss >> token) ++word_count[ Token];p thread_mutex_unlock (&count_mutex);} Int main () {String word;vector<string> vstr;int num_lines = 0;while (cin  && getline (Cin, word)  && !cin.eof ()) {Num_linEs++;word.erase (Remove (Word.begin (),  word.end (), ', '),  word.end ()), Word.erase (Remove (Word.begin (),  word.end (), '. '),  word.end ()); Vstr.push_back (word);} int num_threads =  (num_lines + line_per_thread - 1)  / LINE_PER_ Thread;pthread_t threads[num_threads];for (int i = 0; i < num_threads;  i++) {Struct para *str_para = new para (); str_para->tidx = i;str_ Para->str = vstr[i];p thread_create (&threads[i], NULL, wordCount,  (void *)  str_para);} for (int i = 0; i < num_threads; i++) pthread_join (Threads[i], NULL);  map<string, size_t>::iterator it;for  (It = word_count.begin ();  it  != word_count.end ();  ++it) {cout << it->first <<  "  occurs  " << it->second <<  ((it->second > 1)  ?  " times"  :  " time")  <<  endl;}}

This article from "Hu A Knife" blog, declined reprint!

Pthread Statistics Text Count

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