To add a new thread to the current process, POSIX uses the pthread _
create
() function with the following syntax:
#include
int pthread_create (pthread_t * th, pthread_attr * attr,
void * (* thread_fun) (void *). void * arg);
Consider the parameters of this function:
❖
th is a pointer to a predefined structure of type pthread _ t which
will then be passed to other functions of work with flows;
then call the
AI to
handle the flow ( thread handle )
❖
Attr is a pointer to a structure with flow attributes (you need to pass
a null pointer
to use the default attributes; some attributes will be
reviewed later)
❖
thread _ fun is a pointer to a stream function that should be
described as
void * mythread_fun (void * value)
{
//
executing the stream code
}
❖
arg - the data passed to the stream function (there they will get a
parameter value )
An example of creating a POSIX stream:
# include < pthread . h >
//
flow function
void * thread_fun (void * num)
{
printf (" stream number % d \ n", (int) num);
}
// ……………………………
pthread_ t th;
// create the second thread
pthread_create (& th, NULL, thread_fun, (void *) ++ thread_num);
// there are two threads running in parallel
The new thread begins to run in parallel with the thread that created it. For
example, if a thread was created inside the main ()
function, then two
threads would continue to execute: an original program executing
the main () code and a new one.
