xref: /petsc/src/vec/is/sf/tutorials/ex2.c (revision f97672e55eacc8688507b9471cd7ec2664d7f203)
1 static const char help[] = "Test overlapped communication on a single star forest (PetscSF)\n\n";
2 
3 #include <petscvec.h>
4 #include <petscsf.h>
5 #include <petscviewer.h>
6 
7 int main(int argc, char **argv)
8 {
9   PetscSF     sf;
10   Vec         A,Aout;
11   Vec         B,Bout;
12   PetscScalar *bufA;
13   PetscScalar *bufAout;
14   PetscScalar *bufB;
15   PetscScalar *bufBout;
16   PetscMPIInt rank, size;
17   PetscInt    nroots, nleaves;
18   PetscInt    i;
19   PetscInt    *ilocal;
20   PetscSFNode *iremote;
21 
22   PetscCall(PetscInitialize(&argc,&argv,NULL,help));
23   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
24   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
25 
26   PetscCheck(size == 2,PETSC_COMM_WORLD, PETSC_ERR_USER, "Only coded for two MPI processes");
27 
28   PetscCall(PetscSFCreate(PETSC_COMM_WORLD,&sf));
29   PetscCall(PetscSFSetFromOptions(sf));
30 
31   nleaves = 2;
32   nroots = 1;
33   PetscCall(PetscMalloc1(nleaves,&ilocal));
34 
35   for (i = 0; i<nleaves; i++) {
36     ilocal[i] = i;
37   }
38 
39   PetscCall(PetscMalloc1(nleaves,&iremote));
40   if (rank == 0) {
41     iremote[0].rank = 0;
42     iremote[0].index = 0;
43     iremote[1].rank = 1;
44     iremote[1].index = 0;
45   } else {
46     iremote[0].rank = 1;
47     iremote[0].index = 0;
48     iremote[1].rank = 0;
49     iremote[1].index = 0;
50   }
51   PetscCall(PetscSFSetGraph(sf,nroots,nleaves,ilocal,PETSC_OWN_POINTER,iremote,PETSC_OWN_POINTER));
52   PetscCall(PetscSFSetUp(sf));
53   PetscCall(PetscSFView(sf,PETSC_VIEWER_STDOUT_WORLD));
54   PetscCall(VecCreate(PETSC_COMM_WORLD,&A));
55   PetscCall(VecSetSizes(A,2,PETSC_DETERMINE));
56   PetscCall(VecSetFromOptions(A));
57   PetscCall(VecSetUp(A));
58 
59   PetscCall(VecDuplicate(A,&B));
60   PetscCall(VecDuplicate(A,&Aout));
61   PetscCall(VecDuplicate(A,&Bout));
62   PetscCall(VecGetArray(A,&bufA));
63   PetscCall(VecGetArray(B,&bufB));
64   for (i=0; i<2; i++) {
65     bufA[i] = (PetscScalar)rank;
66     bufB[i] = (PetscScalar)(rank) + 10.0;
67   }
68   PetscCall(VecRestoreArray(A,&bufA));
69   PetscCall(VecRestoreArray(B,&bufB));
70 
71   PetscCall(VecGetArrayRead(A,(const PetscScalar**)&bufA));
72   PetscCall(VecGetArrayRead(B,(const PetscScalar**)&bufB));
73   PetscCall(VecGetArray(Aout,&bufAout));
74   PetscCall(VecGetArray(Bout,&bufBout));
75   PetscCall(PetscSFBcastBegin(sf,MPIU_SCALAR,(const void*)bufA,(void *)bufAout,MPI_REPLACE));
76   PetscCall(PetscSFBcastBegin(sf,MPIU_SCALAR,(const void*)bufB,(void *)bufBout,MPI_REPLACE));
77   PetscCall(PetscSFBcastEnd(sf,MPIU_SCALAR,(const void*)bufA,(void *)bufAout,MPI_REPLACE));
78   PetscCall(PetscSFBcastEnd(sf,MPIU_SCALAR,(const void*)bufB,(void *)bufBout,MPI_REPLACE));
79   PetscCall(VecRestoreArrayRead(A,(const PetscScalar**)&bufA));
80   PetscCall(VecRestoreArrayRead(B,(const PetscScalar**)&bufB));
81   PetscCall(VecRestoreArray(Aout,&bufAout));
82   PetscCall(VecRestoreArray(Bout,&bufBout));
83 
84   PetscCall(VecView(Aout,PETSC_VIEWER_STDOUT_WORLD));
85   PetscCall(VecView(Bout,PETSC_VIEWER_STDOUT_WORLD));
86   PetscCall(VecDestroy(&A));
87   PetscCall(VecDestroy(&B));
88   PetscCall(VecDestroy(&Aout));
89   PetscCall(VecDestroy(&Bout));
90   PetscCall(PetscSFDestroy(&sf));
91 
92   PetscCall(PetscFinalize());
93   return 0;
94 }
95 
96 /*TEST
97 
98    test:
99       suffix: basic
100       nsize: 2
101       filter: grep -v "type" | grep -v "sort"
102       args: -sf_type basic
103 
104    test:
105       suffix: window
106       nsize: 2
107       filter: grep -v "type" | grep -v "sort"
108       output_file: output/ex2_basic.out
109       args: -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create dynamic allocate}}
110       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)
111 
112    # The nightly test suite with MPICH uses ch3:sock, which is broken when winsize == 0 in some of the processes
113    test:
114       suffix: window_shared
115       nsize: 2
116       filter: grep -v "type" | grep -v "sort"
117       output_file: output/ex2_basic.out
118       args: -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor shared
119       requires: defined(PETSC_HAVE_MPI_PROCESS_SHARED_MEMORY) !defined(PETSC_HAVE_MPICH_NUMVERSION) defined(PETSC_HAVE_MPI_ONE_SIDED)
120 
121 TEST*/
122