Intro to Posix Threads (pThreads)

Objectives

1. Look at a simple application of the pthread library.

Notes

• The pthread library is very large and complex.
• This is just a basic overview
• Source: Kerrisk chapter 29

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

  • Creates a new thread
  • With thread id, thread, a return value.
  • With attributes, attributes, but this can be null
  • Calling start_routine
  • Passing arg as the argument.
    • But arg must be on the heap, or in the global storage.
• int pthread_join(pthread_t thread, void **retval);
  • thread the thread id to wait for
  • retval a pointer to return data.
    • retval needs to be space to which the results can be copied.
    • Or null.
• [[noreturn]] void pthread_exit(void *retval);
  • return *retval is the same
• pthread_self() returns the thread id
• Look at pi.cpp.