難度創建Pthreads（錯誤22）

Question

學習pthreads，但我無法創建它們。這裏是我的輸出和GDB信息：

 
In main(), creating thread 1 
ERROR: return code from pthread_create() is 22 for thread 1 
In main(), creating thread 2 
ERROR: return code from pthread_create() is 22 for thread 2 
In main(), creating thread 3 
ERROR: return code from pthread_create() is 22 for thread 3 
In main(), creating thread 4 
ERROR: return code from pthread_create() is 22 for thread 4 
In main(), creating thread 5 
ERROR: return code from pthread_create() is 22 for thread 5 

Program received signal SIGSEGV, Segmentation fault. 0xb7fb4d8a in 
pthread_join (threadid=76038327, thread_return=0x0) 
    at pthread_join.c:46 46 pthread_join.c: No such file or directory. 

這裏是我的代碼：

#include <stdlib.h> 
#include <stdio.h> 
#include <strings.h> 
#include <errno.h> 
#include <pthread.h> 
#include <unistd.h> 

#define SBUFSIZE 1025 

char errorstr[SBUFSIZE]; 
FILE* inputfp[5]; 

void* f(void* inpFile) { 
    fprintf(stderr, "%s\n", (char*)inpFile); 
    return NULL; 
} 

int main (int argc, char* argv[]) { 

    int i; 

    /* Thread Variables */ 
    pthread_attr_t attr; 
    pthread_t *th[argc-2]; //one thread for each input file 

    /* allocate memory for the threads */ 
    for (i = 0; i < (argc-2); i++) { 
     th[i] = (pthread_t *) malloc(sizeof(pthread_t)); 
     inputfp[i] = fopen(argv[i], "r"); 
     if (!inputfp[i]) { 
      sprintf(errorstr, "Error Opening Input File: %s", argv[i]); 
      perror(errorstr); 
     } 
    } 

    /* Create one thread for each input file */ 
    for (i = 1; i < (argc - 1); i++) { 
     fprintf (stderr, "In main(), creating thread %1d\n", i); 
     int rc = pthread_create (th[i], &attr, f, inputfp[i-1]); 
     if (rc) { 
      printf("ERROR: return code from pthread_create() is %d for thread %d\n", 
       rc, i); 
     } 
    } 

    /* wait for the threads to finish */ 
    for (i = 1; i < (argc - 1); i++) { 
     pthread_join(*th[i], 0); 
    } 

    return EXIT_SUCCESS; 
} 

我失去了一些東西，但我不知道是什麼。誰能幫忙？謝謝！

編輯：這裏是我如何更改從約阿希姆Pileborg每個建議的代碼。我仍然收到從pthread_create（）返回的錯誤22，但pthread_join上的SIGSEGV錯誤不再發生。

任何人都有關於如何讓pthread_create（）返回0（表示成功創建線程）的任何建議？再次感謝！

int main (int argc, char* argv[]) { 

    int i; 

    /* Thread Variables */ 
    pthread_attr_t attr; 
    pthread_t *th[argc-2]; //one thread for each input file 

    /* allocate memory for the threads */ 
    for (i = 0; i < (argc-2); i++) { 
     th[i] = (pthread_t *) malloc(sizeof(pthread_t)); 
     printf("%s\n", argv[i+1]); 
     inputfp[i] = fopen(argv[i+1], "r"); 
     if (!inputfp[i]) { 
      sprintf(errorstr, "Error Opening Input File: %s", argv[i]); 
      perror(errorstr); 
     } 
    } 

    /* Create one thread for each input file */ 
    for (i = 0; i < (argc - 2); i++) { 
     fprintf (stderr, "In main(), creating thread %1d\n", i); 
     int rc = pthread_create (th[i], &attr, f, inputfp[i]); 
     if (rc) { 
      printf("ERROR: return code from pthread_create() is %d for thread %d\n", 
       rc, i); 
     } 
    } 

    /* wait for the threads to finish */ 
    for (i = 0; i < (argc - 2); i++) { 
     pthread_join(*th[i], 0); 
    } 

    return EXIT_SUCCESS; 
} 

Answer 1

你有一個循環，你循環從零到argc - 3，並使用正確的索引（從0到「陣列減一的大小」。

然後你有兩個循環，你循環從一到從1到「數組大小」 argc - 2，並使用索引。

你應該使用相同的循環在所有三個地方的第一個。