我的程序正在读取文件并使用线程来计算最高质数,当我将打印语句放入 getNum() 函数时,我的数字正在打印出来。但是,无论我输入多少线程,它似乎都只是滞后。每个文件中有 100 万个整数。有人看到我的代码明显有问题吗?基本上,代码是在分配新线程之前给每个线程 1000 个整数进行检查。我仍然是一个 C 菜鸟,并且正在学习穿线的技巧。我的代码现在一团糟,因为我一直在不断地切换东西。
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <pthread.h>
#include <math.h>
#include <semaphore.h>
//Global variable declaration
char *file1 = "primes1.txt";
char *file2 = "primes2.txt";
char *file3 = "primes3.txt";
char *file4 = "primes4.txt";
char *file5 = "primes5.txt";
char *file6 = "primes6.txt";
char *file7 = "primes7.txt";
char *file8 = "primes8.txt";
char *file9 = "primes9.txt";
char *file10 = "primes10.txt";
char **fn; //file name variable
int numberOfThreads;
int *highestPrime = NULL;
int fileArrayNum = 0;
int loop = 0;
int currentFile = 0;
sem_t semAccess;
sem_t semAssign;
int prime(int n)//check for prime number, return 1 for prime 0 for nonprime
{
int i;
for(i = 2; i <= sqrt(n); i++)
if(n % i == 0)
return(0);
return(1);
}
int getNum(FILE* file)
{
int number;
char* tempS = malloc(20 *sizeof(char));
fgets(tempS, 20, file);
tempS[strlen(tempS)-1] = '\0';
number = atoi(tempS);
free(tempS);//free memory for later call
return(number);
}
void* findPrimality(void *threadnum) //main thread function to find primes
{
int tNum = (int)threadnum;
int checkNum;
char *inUseFile = NULL;
int x=1;
FILE* file;
while(currentFile < 10){
if(inUseFile == NULL){//inUseFIle being used to check if a file is still being read
sem_wait(&semAccess);//critical section
inUseFile = fn[currentFile];
sem_post(&semAssign);
file = fopen(inUseFile, "r");
while(!feof(file)){
if(x % 1000 == 0 && tNum !=1){ //go for 1000 integers and then wait
sem_wait(&semAssign);
}
checkNum = getNum(file);
/*
*
*
*
* I think the issue is here
*
*
*
*/
if(checkNum > highestPrime[tNum]){
if(prime(checkNum)){
highestPrime[tNum] = checkNum;
}
}
x++;
}
fclose(file);
inUseFile = NULL;
}
currentFile++;
}
}
int main(int argc, char* argv[])
{
if(argc != 2){ //checks for number of arguements being passed
printf("To many ARGS\n");
return(-1);
}
else{//Sets thread cound to user input checking for correct number of threads
numberOfThreads = atoi(argv[1]);
if(numberOfThreads < 1 || numberOfThreads > 10){
printf("To many threads entered\n");
return(-1);
}
time_t preTime, postTime; //creating time variables
int i;
fn = malloc(10 * sizeof(char*)); //create file array and initialize
fn[0] = file1;
fn[1] = file2;
fn[2] = file3;
fn[3] = file4;
fn[4] = file5;
fn[5] = file6;
fn[6] = file7;
fn[7] = file8;
fn[8] = file9;
fn[9] = file10;
sem_init(&semAccess, 0, 1); //initialize semaphores
sem_init(&semAssign, 0, numberOfThreads);
highestPrime = malloc(numberOfThreads * sizeof(int)); //create an array to store each threads highest number
for(loop = 0; loop < numberOfThreads; loop++){//set initial values to 0
highestPrime[loop] = 0;
}
pthread_t calculationThread[numberOfThreads]; //thread to do the work
preTime = time(NULL); //start the clock
for(i = 0; i < numberOfThreads; i++){
pthread_create(&calculationThread[i], NULL, findPrimality, (void *)i);
}
for(i = 0; i < numberOfThreads; i++){
pthread_join(calculationThread[i], NULL);
}
for(i = 0; i < numberOfThreads; i++){
printf("this is a prime number: %d \n", highestPrime[i]);
}
postTime= time(NULL);
printf("Wall time: %ld seconds\n", (long)(postTime - preTime));
}
}
是的,我试图找到最高的数字。所以在过去的几个小时里我已经取得了一些进展,正如 spudd 所说的那样重新构建程序,由于我使用结构,目前我遇到了分段错误,我试图在结构中保存最大的单个素数,同时给它们正确的指数。这是修改后的代码。所以简而言之,第一个线程正在做的是创建所有线程并为它们提供访问一个非常大的整数数组的访问点,它们将通过该数组并找到素数,我想在 while 循环周围实现信号量,以便在它们执行时每 2000 行或最后它们更新一个全局素数。
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <pthread.h>
#include <math.h>
#include <semaphore.h>
//Global variable declaration
char *file1 = "primes1.txt";
char *file2 = "primes2.txt";
char *file3 = "primes3.txt";
char *file4 = "primes4.txt";
char *file5 = "primes5.txt";
char *file6 = "primes6.txt";
char *file7 = "primes7.txt";
char *file8 = "primes8.txt";
char *file9 = "primes9.txt";
char *file10 = "primes10.txt";
int numberOfThreads;
int entries[10000000];
int entryIndex = 0;
int fileCount = 0;
char** fileName;
int largestPrimeNumber = 0;
//Register functions
int prime(int n);
int getNum(FILE* file);
void* findPrimality(void *threadNum);
void* assign(void *num);
typedef struct package{
int largestPrime;
int startingIndex;
int numberCount;
}pack;
//Beging main code block
int main(int argc, char* argv[])
{
if(argc != 2){ //checks for number of arguements being passed
printf("To many threads!!\n");
return(-1);
}
else{ //Sets thread cound to user input checking for correct number of threads
numberOfThreads = atoi(argv[1]);
if(numberOfThreads < 1 || numberOfThreads > 10){
printf("To many threads entered\n");
return(-1);
}
int threadPointer[numberOfThreads]; //Pointer array to point to entries
time_t preTime, postTime; //creating time variables
int i;
fileName = malloc(10 * sizeof(char*)); //create file array and initialize
fileName[0] = file1;
fileName[1] = file2;
fileName[2] = file3;
fileName[3] = file4;
fileName[4] = file5;
fileName[5] = file6;
fileName[6] = file7;
fileName[7] = file8;
fileName[8] = file9;
fileName[9] = file10;
FILE* filereader;
int currentNum;
for(i = 0; i < 10; i++){
filereader = fopen(fileName[i], "r");
while(!feof(filereader)){
char* tempString = malloc(20 *sizeof(char));
fgets(tempString, 20, filereader);
tempString[strlen(tempString)-1] = '\0';
entries[entryIndex] = atoi(tempString);
entryIndex++;
free(tempString);
}
}
//sem_init(&semAccess, 0, 1); //initialize semaphores
//sem_init(&semAssign, 0, numberOfThreads);
time_t tPre, tPost;
pthread_t coordinate;
tPre = time(NULL);
pthread_create(&coordinate, NULL, assign, (void**)numberOfThreads);
pthread_join(coordinate, NULL);
tPost = time(NULL);
}
}
void* findPrime(void* pack_array)
{
pack* currentPack= pack_array;
int lp = currentPack->largestPrime;
int si = currentPack->startingIndex;
int nc = currentPack->numberCount;
int i;
int j = 0;
for(i = si; i < nc; i++){
while(j < 2000 || i == (nc-1)){
if(prime(entries[i])){
if(entries[i] > lp)
lp = entries[i];
}
j++;
}
}
return (void*)currentPack;
}
void* assign(void* num)
{
int y = (int)num;
int i;
int count = 10000000/y;
int finalCount = count + (10000000%y);
int sIndex = 0;
pack pack_array[(int)num];
pthread_t workers[numberOfThreads]; //thread to do the workers
for(i = 0; i < y; i++){
if(i == (y-1)){
pack_array[i].largestPrime = 0;
pack_array[i].startingIndex = sIndex;
pack_array[i].numberCount = finalCount;
}
pack_array[i].largestPrime = 0;
pack_array[i].startingIndex = sIndex;
pack_array[i].numberCount = count;
pthread_create(&workers[i], NULL, findPrime, (void *)&pack_array[i]);
sIndex += count;
}
for(i = 0; i< y; i++)
pthread_join(workers[i], NULL);
}
//Functions
int prime(int n)//check for prime number, return 1 for prime 0 for nonprime
{
int i;
for(i = 2; i <= sqrt(n); i++)
if(n % i == 0)
return(0);
return(1);
}
这是我的最新更新,我的线程运行有问题,唯一的线程是线程 0 正在完成
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <pthread.h>
#include <math.h>
#include <semaphore.h>
//Global variable declaration
char *file1 = "primes1.txt";
char *file2 = "primes2.txt";
char *file3 = "primes3.txt";
char *file4 = "primes4.txt";
char *file5 = "primes5.txt";
char *file6 = "primes6.txt";
char *file7 = "primes7.txt";
char *file8 = "primes8.txt";
char *file9 = "primes9.txt";
char *file10 = "primes10.txt";
sem_t semHold;
int numberOfThreads;
long unsigned int entries[10000000];
unsigned int entryIndex = 0;
int fileCount = 0;
char** fileName;
long unsigned int largestPrimeNumber = 0;
//Register functions
int prime(unsigned int n);
int getNum(FILE* file);
void* findPrimality(void *threadNum);
void* assign(void *num);
typedef struct package{
long unsigned int largestPrime;
unsigned int startingIndex;
unsigned int numberCount;
}pack;
pack pack_array[10];
//Beging main code block
int main(int argc, char* argv[])
{
if(argc != 2){ //checks for number of arguements being passed
printf("To many threads!!\n");
return(-1);
}
else{ //Sets thread cound to user input checking for correct number of threads
numberOfThreads = atoi(argv[1]);
if(numberOfThreads < 1 || numberOfThreads > 10){
printf("To many threads entered\n");
return(-1);
}
int threadPointer[numberOfThreads]; //Pointer array to point to entries
int i;
fileName = malloc(10 * sizeof(char*)); //create file array and initialize
fileName[0] = file1;
fileName[1] = file2;
fileName[2] = file3;
fileName[3] = file4;
fileName[4] = file5;
fileName[5] = file6;
fileName[6] = file7;
fileName[7] = file8;
fileName[8] = file9;
fileName[9] = file10;
FILE* filereader;
long unsigned int currentNum;
sem_init(&semHold, 0, 1);
for(i = 0; i < 10; i++){
filereader = fopen(fileName[i], "r");
while(fscanf(filereader, "%lu" , ¤tNum)!= EOF){
entries[entryIndex] = currentNum;
// while(entryIndex < 5){
//char* tempString = malloc(20 *sizeof(long unsigned int));
//fgets(tempString, 20, filereader);
//tempString[strlen(tempString)-1] = '\0';
//currentNum = atoi(tempString);
//printf("Test %lu\n",currentNum);
//entries[entryIndex] = atoi(tempString);
//entryIndex++;
//free(tempString);
//}
entryIndex++;
}
}
printf("Test %lu\n",entries[9999999]);
//sem_init(&semAccess, 0, 1); //initialize semaphores
//sem_init(&semAssign, 0, numberOfThreads);
time_t tPre, tPost;
pthread_t coordinate;
tPre = time(NULL);
pthread_create(&coordinate, NULL, assign, (void**)numberOfThreads);
pthread_join(coordinate, NULL);
tPost = time(NULL);
printf("Largest prime = %lu , time: %ld\n", largestPrimeNumber,(long)(tPost-tPre));
}
}
void* findPrime(void* pack_array)
{
pack* currentPack = pack_array;
unsigned int lp = currentPack->largestPrime;
unsigned int si = currentPack->startingIndex;
unsigned int nc = currentPack->numberCount;
int i;
printf("Starting index Count: %d\n", si);
for(i = si; i < nc; i++){
if(i%100000==0)
printf("Here is i: %d\n", i);
if(entries[i]%2 != 0){
if(entries[i] > currentPack->largestPrime){
if(prime(entries[i])){
currentPack->largestPrime = entries[i];
printf("%lu\n", currentPack->largestPrime);
if(currentPack->largestPrime > largestPrimeNumber)
sem_wait(&semHold);
largestPrimeNumber = currentPack->largestPrime;
sem_post(&semHold);
}
}
}
}
}
void* assign(void* num)
{
int y = (int)num;
int i;
int count = 10000000/y;
int finalCount = count + (10000000%y);
int sIndex = 0;
printf("This is count: %d\n", count);
printf("This is final count: %d\n", finalCount);
pthread_t workers[y]; //thread to do the workers
for(i = 0; i < y; i++){
printf("for thread %d Starting index: %d\n", i, sIndex);
if(i == (y-1)){
pack_array[i].largestPrime = 0;
pack_array[i].startingIndex = sIndex;
pack_array[i].numberCount = finalCount;
}
pack_array[i].largestPrime = 0;
pack_array[i].startingIndex = sIndex;
pack_array[i].numberCount = count;
pthread_create(&workers[i], NULL, findPrime, (void *)&pack_array[i]);
printf("thread created\n");
sIndex += count;
}
for(i = 0; i < y; i++)
pthread_join(workers[i], NULL);
}
//Functions
int prime(unsigned int n)//check for prime number, return 1 for prime 0 for nonprime
{
int i;
for(i = 2; i <= sqrt(n); i++)
if(n % i == 0)
return(0);
return(1);
}