Creates a method by which a thread invokes a class member function.

When a class member function creates a thread to invoke another function of a class member, there are two ways to fix it.

The first kind is more troublesome,
For example, there is a class
void* Gstartvod (void* pvoid);
Class record{
Friend void* Gstartvod (void* pvoid);

void Create_pthread_fun (void* pvoid);
void* thread (void* pvoid);
static record *_record;

PTHREAD_ID _threadid;

}
void*
Gsavevideodata (void* pvoid)
{
Record::_record->thread (PVOID);
}
void Record::create_pthread_fun (void* pvoid)
{
Pthread_create (&_threadid, NULL, GSaveVideoData2, pvoid);

}

Set a static pointer variable for the class itself in the class. Defines a global function. For example, to implement a call to a class member.

The second method is simpler, declaring the called Class member function as a static variable.
Class record{
Friend void* Gstartvod (void* pvoid);

void Create_pthread_fun (void* pvoid);

Static void* thread (void* pvoid);

PTHREAD_ID _threadid;

}
void Record::create_pthread_fun (void* pvoid)
{
Pthread_create (&_threadid, NULL, Thread, pvoid);

}