如果用户在命令行中只输入1个数字,则此程序可以正常工作。它会将主要因素分解出来并将它们输出到控制台就好了。
J_10542741@cs3060:~/assn3$ ./assn3 12
12: 2, 2, 3,
我的问题是当我在其他两个案例中测试它时:
A)多个参数:
J_10542741@cs3060:~/assn3$ ./assn3 10 8 6
10: 2, 5,
8: 2, 5,
6: 2, 5,
B)使用一系列数字(即{1..5}):
J_10542741@cs3060:~/assn3$ ./assn3 {1..5}
1:
2:
3:
4:
5:
我已经浏览了这个网站,了解pthread_join()的返回值以及通过Google搜索的任何内容。我觉得这部分代码存在问题:
// FOR loop to join each thread w/ Main Thread 1x1
for(i = 0; i < argc-1; i++){
retCode = pthread_join(t_id[i], &factors);
results = factors;
if (retCode != 0){
// Print Error Message and return -1
fprintf(stderr, "Failure to join threads.");
return -1;
}
else{
printf("%s: ", argv[i+1]);
while(*results != 0){
printf("%d, ", *results);
results++;
}
}
free(factors);
printf("\n");
}
以下是其中的代码:
#include<stdio.h>
#include<stdlib.h>
#include<pthread.h>
#include<string.h>
// Return a pointer to the pFactors array
void *primeFactors(void* number){
int *pFactors = malloc(sizeof(int)); // Dynamic Array for prime factors
int capacity = 0;
int size = 1;
int num = atoi((char*)number);
int prime = 2;
// If num < 4, then that number is already prime
if(num < 4)
pFactors[capacity] = num;
else{
while(num > 1){
while(num % prime == 0){
if(capacity == size){
size++;
pFactors = realloc(pFactors, size*sizeof(int));
}
num /= prime;
pFactors[capacity] = prime;
capacity++;
}
prime++;
}
}
if(capacity == size){
size++;
pFactors = realloc(pFactors, size*sizeof(int));
}
pFactors[capacity] = 0;
pthread_exit((void*)pFactors);
}
// MAIN FUNCTION
int main(int argc, char* argv[]){
int i, retCode; // retCode holds the value of successful/fail operation for pthread_create/join
int j = 1;
int* results;
void* factors;
//Thread Identifier value is equal to the number of actual int(s) in argv
pthread_t t_id[argc-1];
// Check argc for too few arguments
if(argc < 2){
fprintf(stderr, "Usage: ./assn3 <integer value>...");
return -1;
}
// Loop through argv and check argv[j] value to ensure it's >= 0
while(j <= argc-1){
if(atoi(argv[j]) < 0){
fprintf(stderr, "%d must be >= 0", atoi(argv[j]));
return -1;
}
j++;
}
// Create the thread
for(i = 0; i < argc-1; i++){
retCode = pthread_create(&t_id[i], NULL, primeFactors, *(argv+1));
if (retCode != 0){
// Print Error Message and return -1
printf("Failure to start thread. Error: %d\n", retCode);
return -1;
}
}
// FOR loop to join each thread w/ Main Thread 1x1
for(i = 0; i < argc-1; i++){
retCode = pthread_join(t_id[i], &factors);
results = factors;
if (retCode != 0){
// Print Error Message and return -1
fprintf(stderr, "Failure to join threads.");
return -1;
}
else{
printf("%s: ", argv[i+1]);
while(*results != 0){
printf("%d, ", *results);
results++;
}
}
free(factors);
printf("\n");
}
return 0;
}
重申一下,如果我只输入1个参数,这个程序就可以了。但是,当存在多个参数时,程序会正确输出第一个参数的素数因子,但以下参数将使用第一个参数的素因子打印。其次,当你输入一个bash脚本范围(即{1..5})时,它只打印出参数而不是它们各自的素因子。如果有需要澄清的事情,请随时提出。此外,如果某个地方似乎有重复/类似的问题,我无法找到,请告诉我。感谢。
答案 0 :(得分:2)
pthread_create(&t_id[i], NULL, primeFactors, *(argv+1))
您将相同的参数*(argv+1)
传递给每个线程。请尝试使用*(argv+1+i)
。