Linux thread operation functions

# Include <pthread. h>

Create thread
[Prototype]: int pthread_create (pthread_t * thread, pthread_attr_t * ATTR, void * (* start_routine) (void *), void * Arg ))
[Parameters]
Thread: Specifies the thread ID.
ATTR: thread attribute settings
Start_routine: the starting address of the thread function.
Arg: parameters passed to start_routine
[Return]
0: Success-1: Error

[Prototype] void pthread_exit (void * retval)
[Parameters]
Retval: the return value of the pthread_exit () call thread. It can be retrieved and obtained by other functions such as pthread_join.

[Prototype] int pthread_join (pthread_t th, void ** thread_return ))
[Parameters]
TH: ID of the waiting thread
Thread_return: User-Defined pointer, used to store the return value of the waiting thread (not null)
[Return]
0: Success-1: Error