B.2.1 helloRestart.c

#include <stdio.h>
#include <pmm/chPmm.h>
#include <hr/hr.h>

#define HR_GROUP "HELLO_GROUP"

    int 
main()
{
	
	int res;
	int any = 1;
	int* counter_p;  /* It will be stored in persistent memory */
	long *p;
	PmmName name; 
	KnRgnDesc rgn;
	
            /* 
             * Initialize the name and medium fields 
             * to identify the persistent memory block in the system.
             */
	bzero(&name, sizeof(name));
	strcpy(name.medium,"RAM");
	strcpy(name.name,"PM1");
	
            /* 
             * Initialize the block fields
             */	
	bzero(&rgn, sizeof(rgn));
	rgn.options = K_ANYWHERE | K_RESERVED;
	rgn.size    = vmPageSize();
	res = rgnAllocate(K_MYACTOR, &rgn);
	if (res != K_OK) {
            printf("rgnAllocate() failed res=%d\n", res);
            HR_EXIT_HDL();
            exit(-1);
	}

	p = (long*) rgn.startAddr;

            /*
             * From now on p is a bad pointer, since 
             * VIRTUAL_ADDRESS_SPACE is true.
             */

            /* 
             * Allocate the persistent memory block that stores
             * counter_p.
             */
	res=pmmAllocate((VmAddr *)&counter_p,
                        &name,sizeof(int),
                        HR_GROUP,
                        sizeof(HR_GROUP));
	
	if (res != K_OK) {
            printf("Cannot allocate or map the persistent memory block called %s."
                   " Error = %d\n", name.name, res);
            HR_EXIT_HDL();
            exit(-1);
	}
	
            /* 
             * From the value of *counter_p the actor detects  
             * whether it has been hot restarted or not.
             */
	if ( *counter_p==0 ) {
                /*
                 * This is the first time the actor is run.
                 */
            printf("Hello world!\n");
		
                /* 
                 * Increment the counter
                 */
            (*counter_p)++;
		
                /*
                 * Normally the next instruction causes a core dump and
                 * a hot restart of the actor
                 */
            *p = 0xDeadBeef;

	} else {
                /* 
                 * The actor has been restarted
                 * NOTE: this message will appear on the console!
                 */
            printf("The actor has been restarted.\n");
		
                /*
                 * Free the persistent memory block before exiting
                 */
            res = pmmFree(&name);
            if (res != K_OK) {
                printf(" pmmFree failed, res=%d. Exit\n", res);
                HR_EXIT_HDL();
                exit(-1);
            }	
                /* 
                 * Terminate cleanly. 
                 */ 
            printf("Example finished. Exit.\n");
            HR_EXIT_HDL();
            exit(0);
	}
            /* Never reached */
}