#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include "log.h"


//variables for indexing of messages by logging functions
int logindex=0;
int *logi = &logindex;
//thread mutex lock for access to the log
pthread_mutex_t tlock = PTHREAD_MUTEX_INITIALIZER; 


void* doit(void*);
char* p = 0;
pthread_t tid1, tid2;


// function main  ------------------------------------------------- 
int main()
{
  create_log("log.txt");

  Msg("going to create the first thread");
  pthread_create(&tid1,NULL,doit,NULL);
  
  Msg("going to create the second thread");
  pthread_create(&tid2,NULL,doit,NULL);
  
  Msg("going to wait for the first thread to exit");
  pthread_join(tid1,NULL);
  Msg("the first thread exited");

  Msg("going to wait for the second thread to exit");
  pthread_join(tid2,NULL);
  Msg("the second thread exited");

  exit(0);

}//end main



// function doit -------------------------------------------------- 
void* doit(void* x)
{
  pthread_t me;

  me = pthread_self();
  Msg("I am thread %u (p=%u)",me,p);
  
  p = malloc(10);
  Msg("I am thread %u and I allocated segment %u",me,p);
  if (me==tid1)  // allow thread B to do the
    sleep(2);    // allocation and deallocation

  if (p) {
    free(p);
    Msg("I am thread %u and I deallocated segment %u",
        pthread_self(),p);
    p = NULL;
  }

  pthread_exit(NULL);
  return NULL;

}//end doit