운영체제/ 스레드

#include <pthread.h> #include <stdio.h> int sum; /* this data is shared by the thread(s) */ void *runner(void *param); /* the thread */ int main(int argc, char *argv[]) { pthread_t tid; /* the thread identifier */ pthread_attr_t attr; /* set of attributes for the thread */ if (argc != 2) { fprintf(stderr, "usage: a.out<integer value>\n"); return -1; } if (atoi(argv[1]) < 0 { fprintf(stderr, "%d must be >= 0\n", atoi(argv[1])); } /* get the defaults attributes */ pthread_attr_init(&attr); /* create the thread */ pthread_create(&tid, &attr, runner, argv[1]); /* now wiat for the thread to exit */ pthread_join(tid, NULL); printf("sum = %d\n", sum); } /* The thread will begin control in this function */ void *runner(void *param) { int i, upper = atoi(param); sum = 0; for (int i = 1; i <= upper; i++) sum += i; ptread_exit(0); }

#define NUM_THREADS 10 /* an array of threads to be joined upon */ pthread t workers[NUM_THREADS]; for (int i = 0; i < NUM_THREADS; i++) pthread join(workers[i], NULL);

#include <windows.h> #include <stdio.h> DWORD Sum; /* data is shared by the thread(s) */ /* the thread run in this separate function */ DWORD WINAPI Sumation(LPVOID Param) { DWORD Upper = *(DWORD*)Param; for (DWORD i = 0; i <= Upper; i++) Sum += i; return 0; } int main(int argc, char *argv[]) { DWORD ThreadId; HANDLE ThreadHandle; int Param; // perform some basic error checking if (argc != 2) { fprintf(stderr, "An integer paramter is required\n"); return -1; } Param = atoi(argv[1]); if (Param < 0) { fprintf(stderr, "An integer >= 0 is required\n"); return -1; } // create the thread ThreadHandle = CreateThread( NULL, // // default security attributes 0, // default stack size Summation, // thread function &Param, // parameter to thread function 0, // default creation flags &ThreadId); // returns the thread identifier if (THreadHandle != NULL) { // now wait for the tread to finish WaitForSingleObject(ThreadHandle, INFINITE); // close the thread handle CloseHandle(ThreadHandle); printf("sum = %d\n", Sum); } }

WaitForMultipleObjects(N, THandles, TRUE, INFINITE);

public interface Runnable { public abstract void run(); }

class Sum { private int sum; public int getSum() { return sum; } public void setSum(int sum) { this.sum = sum; } } class Summation implements Runnable { private int upper; private Sum sumValue; public Summation(int upper, Sum sumValue) { this.upper = upper; this.sumValue = sumValue; } public void run() { int sum = 0; for (int i = 0; i <= upper; i++) sum += i; sumValue.setSum(sum); } } public class Driver { public static void main(String[] args) { if (args.length > 0) { if (Integer.parseInt(args[0]) < 0) System.err.println(args[0] + " must be >= 0"); else { // create the object to be shared Sum sumObject = new Sum(); int upper = Integer.parseInt(args[0]); Thread thrd = new Thread(new Summation(upper, sumObject)); thrd.start(); try { thrd.join(); System.out.Println("The sum of " + upper + " is " + sumObject.getSum()); } catch (InterruptedException ie) { } } } else System.err.println("m of " + upper + " is " + sumObject.get()); // 책의 코드가 뭔가 이상한데 이게 catch 문 안에 들어가야 하는거 아닌가? } }

DWORD WINAPI PoolCuntion(AVOID Param) { // this function runs as a separate thread }

QueueUserWorkItem(&PollFunction, NULL, 0);

#include <omp.h> #include <stdio.h> int main(int argc, char *argv[]) { /* sequential code */ #pragma omp parallel { printf("I am a parallel region"); } /* sequential code */ return 0; }

#pragma omp parallel for for (i = 0; i < N; i++) { c[i] = a[i] + b[i]; }

^{ printf("I am a block"); }

dispatch queue t queue = dispatch get global queue (DISPATCH QUEUE PRIORITY DEFAULT, 0); dispatch async(queue, ^{ printf("I am a block"); });

pthread t tid; /* create the thread */ pthread create(&tid, 0, worker, NULL); ... /* cancel the thread */ pthread cancel(tid);

while (1) { /* do some work for awhile */ /* ... */ /* check if there is a cancellation request */ pthread testcancel(); }