/*
 * Josh Hursey
 * 7/20/2005
 *
 * Berkeley Labs Checkpoint Restart API example.
 *
 * To compile this program:
 *   $ gcc -lcr -o a_blcr_example a_blcr_example.c
 *
 * To run this program:
 *   $ cr_run ./a_blcr_example
 *
 * To generate a checkpoint context file:
 *  While the program is running, in a separate terminal execute:
 *   $ cr_checkpoint PID
 *  Where PID is the pid of this process.
 *
 * To restart from a context file:
 *   $ cr_restart context.PID
 *
 */
#include <stdio.h>
#include <libcr.h>

/*
 * Thread Context Callback
 */
static int my_thread_callback(void *data_ptr) {
   int did_restart;
   
   did_restart = cr_checkpoint(0);

   if(did_restart > 0) {
      printf("Restarting (Thread)...\n");
   }
   else {
      printf("Continuing (Thread)...\n");
   }
   
   return 0;
}

/*
 * Signal Context Callback
 */
static int my_signal_callback(void *data_ptr) {
   int did_restart;
   
   did_restart = cr_checkpoint(0);

   if(did_restart) {
      printf("Restarting (Signal)...\n");
   }
   else {
      printf("Continuing (Signal)...\n");
   }
   
   return 0;

}

int main() {
   int i;
   int handle = 0;
   int cr_signal_callback_id;
   int cr_thread_callback_id;

   /*
    * Initialize BLCR
    */
   if (cr_init() < 0) {
      printf("cr_init() failed!\n");
      return 0;
   }
   
   /*
    * Register the callbacks
    */
   cr_signal_callback_id = cr_register_callback(my_signal_callback, &handle, CR_SIGNAL_CONTEXT);
   cr_thread_callback_id = cr_register_callback(my_thread_callback, &handle, CR_THREAD_CONTEXT);
   
   /*
    * Start program
    */
   printf("My pid = %d\n", getpid());

   for(i = 0 ; i < 10; ++i) {
      printf("Iteration %d\n", i);
      sleep(1);
   }
   
   return 0;
}