Using Memory Tracing

You can request Cactus to store the memory consumption at a certain instance in the program flow, and return the difference in memory allocation some time later.

int CCTK_MemTicketRequest(void)

Request a ticket: save the current total memory to a database. Return an integer (ticket). Use the ticket to calculate the difference in memory allocation between the two instances in CCTK_MemTicketCash.

long int CCTK_MemTicketCash(int your_ticket)

Cash in your ticket: return the memory difference between now and the time the ticket was requested. Tickets can be cashed in several times. See example below. This only tracks the real data memory, which is the same as in undebug mode. It does not keep track of the internal allocations done to provide the database, the motivation is that this is not allocated either if you compile undebugged.

int CCTK_MemTicketDelete(int your_ticket)

Delete the memory ticket. The ticket ID will not be reused, since it's incremented with every ticket request, but the memory of the memory datastructure is deallocated.

unsigned long int CCTK_TotalMemory(void)

Returns the total allocated memory (not including the tracing data structures).

void CCTK_MemStat

Prints an info string, stating the current, past, and total memory (in bytes) allocation between two successive calls to this routine, as well as the difference.

Sample C code demonstrating the ticket handling. Two tickets are requested during malloc operations. The CCTK_MALLOC statement is used directly. They are cashed in, and the memory difference is printed. Ticket 1 is cashed twice. The tickets are deleted at the end.

int ticket1;
int ticket2;

/* store current memstate, ticket: t1*/
t1 = CCTK_MemTicketRequest();

/* allocate data */
hi = (int*) CCTK_MALLOC(10*sizeof(int));

/* store current memstate, ticket: t2*/
t2 = CCTK_MemTicketRequest();

/* cash ticket t1, print mem difference */
printf("NOW1a: %+d \n",CCTK_MemTicketCash(t1));

/* allocte some more data */
wo = (CCTK_REAL*)CCTK_MALLOC(10*sizeof(CCTK_REAL));

/* cash ticket t1 and t2, print mem difference */
printf("NOW1b: %+d \n",CCTK_MemTicketCash(t1));
printf("NOW2 : %+d \n",CCTK_MemTicketCash(t2));

/* delete the tickets from the database */
CCTK_MemTicketDelete(t1);
CCTK_MemTicketDelete(t2);