创建动态pthread_t时出错

Question

I am trying to dynamically create pthread and facing the issue in addressing of the variable. Can you please tell how the address should be accessed

int main (int argc, char *argv[])
{
   pthread_t *threads;
   int rc, numberOfThreads;
   long t;
   cout<<"Number of Threads = ";
   cin>>numberOfThreads;
   cout<<endl;
   threads =(pthread_t*) malloc(numberOfThreads*sizeof(pthread_t));
   for(t=0; t<numberOfThreads; t++){
      printf("In main: creating thread %ld\n", t);
     // **ERROR ON BELOW LINE**
      rc = pthread_create((pthread_t)&(threads+numberOfThreads), NULL, FunctionForThread, (void *)t);
      (void) pthread_join(threads[t], NULL);

      if (rc){
         printf("ERROR; return code from pthread_create() is %d\n", rc);
         exit(-1);
      }
   }

   /* Last thing that main() should do */
   pthread_exit(NULL);
}

ERROR : lvalue required as unary '&' operand

Answer 1

pthread_create() requires a pthread_t* type as the first parameter. You have an array of pthread_t so pass an address of one of them:

rc = pthread_create(&threads[i], NULL, FunctionForThread, (void *)t);

Also note that the cast (void *)t is not correct. You should pass a pointer to a valid object.