threads_ex.cpp

Threads example.

#include "nixsys.h"
#include "thread.h"
#include "semaphore.h"

using namespace std ;
using namespace n2nc ;

n2nc::sync::Semaphore g_sem(0);

void* fun1(void *arg1){
  cerr << "fun1 callled with args: " << (char*)arg1 ;
  cerr << " Thread name: " << n2nc::sync::Thread::getCurrent().toString() << endl ;
  sleep(3);
  /* NOTE the possible race condition */
  g_sem.post();
  
  return (void*)"fun1" ;
}

int fun1_exit(void* arg1){
  cerr << "fun1 exited with args: " << (char*)arg1 ;
  cerr << " Thread name: " << n2nc::sync::Thread::getCurrent().toString() << endl ;
}

class myclass1 : public n2nc::sync::Thread {
    virtual void* entry_point(){
      cerr << "myclass1 callled with args: " << (char*)this->m_args ;
      cerr << " Thread name: " << n2nc::sync::Thread::getCurrent().toString() << endl ;
      sleep(6);
      return (void*)"myclass1" ;
    }
    virtual int exit_point(){
      /* NOTE HERE we avoid race condition because the thread
      has already terminated its routine and saved returns values. */
      g_sem.post();
    }

};

int main(int argc, char *argv[]){
  void *myretval1,*myretval2 ;
  n2nc::sync::Thread::init();
  n2nc::sync::Thread *t1 = new n2nc::sync::InlineThread(&fun1);
  n2nc::sync::Thread *t2 = new myclass1() ;
  n2nc::sync::Thread *t3 = new n2nc::sync::InlineThread(&fun1,&fun1_exit);
  t1->setName("fun1 thread name");
  t2->setName("myclass1 thread name");
  t3->setName("fun1 thread name, with exit point callback");
  t1->run((void*)"args to function fun1");
  t2->run((void*)"args to class myclass1");
  t3->run((void*)"args to function fun1 with callback");
  /* wait the 2 threads termination through a global semaphore */
  g_sem.wait();
  g_sem.wait();
  g_sem.wait();
/*  t1->wait(&myretval1);
  t2->wait(&myretval2);*/
  cerr << (char*)t1->getRetVal() << endl ;
  cerr << (char*)t2->getRetVal() << endl ;
  cerr << (char*)t3->getRetVal() << endl ;
  return EXIT_SUCCESS;
}