xref: /petsc/src/sys/tutorials/ex3.c (revision 6a98f8dc3f2c9149905a87dc2e9d0fedaf64e09a)
1 
2 static char help[] = "Augmenting PETSc profiling by add events.\n\
3 Run this program with one of the\n\
4 following options to generate logging information:  -log, -log_view,\n\
5 -log_all.  The PETSc routines automatically log event times and flops,\n\
6 so this monitoring is intended solely for users to employ in application\n\
7 codes.\n\n";
8 
9 /*T
10    Concepts: PetscLog^user-defined event profiling
11    Concepts: profiling^user-defined event
12    Concepts: PetscLog^activating/deactivating events for profiling
13    Concepts: profiling^activating/deactivating events
14    Processors: n
15 T*/
16 
17 
18 
19 /*
20   Include "petscsys.h" so that we can use PETSc profiling routines.
21 */
22 #include <petscsys.h>
23 #include <petscviewer.h>
24 
25 int main(int argc,char **argv)
26 {
27   PetscErrorCode ierr;
28   PetscMPIInt    rank;
29   int            i,imax=10000,icount;
30   PetscLogEvent  USER_EVENT,check_USER_EVENT;
31 
32   ierr = PetscInitialize(&argc,&argv,NULL,help);if (ierr) return ierr;
33 
34   /*
35      Create a new user-defined event.
36       - Note that PetscLogEventRegister() returns to the user a unique
37         integer event number, which should then be used for profiling
38         the event via PetscLogEventBegin() and PetscLogEventEnd().
39       - The user can also optionally log floating point operations
40         with the routine PetscLogFlops().
41   */
42   ierr = PetscLogEventRegister("User event",PETSC_VIEWER_CLASSID,&USER_EVENT);CHKERRQ(ierr);
43   ierr = PetscLogEventGetId("User event",&check_USER_EVENT);CHKERRQ(ierr);
44   if (USER_EVENT != check_USER_EVENT) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Event Ids do not match");
45 
46   ierr = PetscLogEventBegin(USER_EVENT,0,0,0,0);CHKERRQ(ierr);
47   icount = 0;
48   for (i=0; i<imax; i++) icount++;
49   ierr = PetscLogFlops(imax);CHKERRQ(ierr);
50   ierr = PetscSleep(0.5);CHKERRQ(ierr);
51   ierr = PetscLogEventEnd(USER_EVENT,0,0,0,0);CHKERRQ(ierr);
52 
53   /*
54      We disable the logging of an event.
55 
56   */
57   ierr = PetscLogEventDeactivate(USER_EVENT);CHKERRQ(ierr);
58   ierr = PetscLogEventBegin(USER_EVENT,0,0,0,0);CHKERRQ(ierr);
59   ierr = PetscSleep(0.5);CHKERRQ(ierr);
60   ierr = PetscLogEventEnd(USER_EVENT,0,0,0,0);CHKERRQ(ierr);
61 
62   /*
63      We next enable the logging of an event
64   */
65   ierr = PetscLogEventActivate(USER_EVENT);CHKERRQ(ierr);
66   ierr = PetscLogEventBegin(USER_EVENT,0,0,0,0);CHKERRQ(ierr);
67   ierr = PetscSleep(0.5);CHKERRQ(ierr);
68   ierr = PetscLogEventEnd(USER_EVENT,0,0,0,0);CHKERRQ(ierr);
69 
70   /*
71      We test event logging imbalance
72   */
73   ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
74   if (!rank) {ierr = PetscSleep(0.5);CHKERRQ(ierr);}
75   ierr = PetscLogEventSync(USER_EVENT,PETSC_COMM_WORLD);CHKERRQ(ierr);
76   ierr = PetscLogEventBegin(USER_EVENT,0,0,0,0);CHKERRQ(ierr);
77   ierr = MPI_Barrier(PETSC_COMM_WORLD);CHKERRQ(ierr);
78   ierr = PetscSleep(0.5);CHKERRQ(ierr);
79   ierr = PetscLogEventEnd(USER_EVENT,0,0,0,0);CHKERRQ(ierr);
80 
81   ierr = PetscFinalize();
82   return ierr;
83 }
84 
85 
86 
87 /*TEST
88 
89    build:
90      requires: define(PETSC_USE_LOG)
91 
92    test:
93 
94 TEST*/
95