Class 14: Homework

1. Suppose you have a program consisting of two threads: the initial thread, and a new thread corresponding to some function foo. If foo calls the exit function, does the entire process terminate, or just that thread?

2. Here's the prototype to pthread_create:

   int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void  *(*start_routine)(void*), void * arg);
   	

   Given the following following variable def's and function prototypes, circle the call to pthread_create (given below) that is valid:

   void *foo(void *p);
   int a;
   int *p;
   pthread_t b;
   

    p = pthread_create(b,NULL,foo,a);
   
   *p = pthread_create(b,NULL,foo,a);
   
    p = pthread_create(&b,NULL,foo,a);
   
   *p = pthread_create(&b,NULL,foo,a);
   
    p = pthread_create(b,NULL,foo,&a);
   
   *p = pthread_create(b,NULL,foo,&a);
   
    p = pthread_create(&b,NULL,foo,&a);
   
   *p = pthread_create(&b,NULL,foo,&a);
   
   
   

3. Suppose A is a process that calls fork, and B is the child process that's created. Circle the resources that are shared between A and B, assuming we're talking about immediately after the fork:
   • process id
   • function call stack
   • global variable space
   • file descriptor table
   • open file connections (i.e. system open file table entries)
   • Program Counter (i.e. address of next instruction to execute)
   Suppose A is a thread that calls pthread_create, and B is the thread that's created. Circle the resources that are shared between A and B, assuming we're talking about immediately after the pthread_create call:
   • process id
   • function call stack
   • global variable space
   • file descriptor table
   • open file connections (i.e. system open file table entries)
   • Program Counter (i.e. address of next instruction to execute)