xref: /petsc/src/vec/is/sf/tutorials/ex2.c (revision 0baf8eba40dbc839082666f9f7396a225d6f663c)
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   PetscFunctionBeginUser;
23   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
24   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
25   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
26 
27   PetscCheck(size == 2, PETSC_COMM_WORLD, PETSC_ERR_USER, "Only coded for two MPI processes");
28 
29   PetscCall(PetscSFCreate(PETSC_COMM_WORLD, &sf));
30   PetscCall(PetscSFSetFromOptions(sf));
31 
32   nleaves = 2;
33   nroots  = 1;
34   PetscCall(PetscMalloc1(nleaves, &ilocal));
35 
36   for (i = 0; i < nleaves; i++) ilocal[i] = i;
37 
38   PetscCall(PetscMalloc1(nleaves, &iremote));
39   if (rank == 0) {
40     iremote[0].rank  = 0;
41     iremote[0].index = 0;
42     iremote[1].rank  = 1;
43     iremote[1].index = 0;
44   } else {
45     iremote[0].rank  = 1;
46     iremote[0].index = 0;
47     iremote[1].rank  = 0;
48     iremote[1].index = 0;
49   }
50   PetscCall(PetscSFSetGraph(sf, nroots, nleaves, ilocal, PETSC_OWN_POINTER, iremote, PETSC_OWN_POINTER));
51   PetscCall(PetscSFSetUp(sf));
52   PetscCall(PetscSFView(sf, PETSC_VIEWER_STDOUT_WORLD));
53   PetscCall(VecCreate(PETSC_COMM_WORLD, &A));
54   PetscCall(VecSetSizes(A, 2, PETSC_DETERMINE));
55   PetscCall(VecSetFromOptions(A));
56   PetscCall(VecSetUp(A));
57 
58   PetscCall(VecDuplicate(A, &B));
59   PetscCall(VecDuplicate(A, &Aout));
60   PetscCall(VecDuplicate(A, &Bout));
61   PetscCall(VecGetArray(A, &bufA));
62   PetscCall(VecGetArray(B, &bufB));
63   for (i = 0; i < 2; i++) {
64     bufA[i] = (PetscScalar)rank;
65     bufB[i] = (PetscScalar)rank + 10.0;
66   }
67   PetscCall(VecRestoreArray(A, &bufA));
68   PetscCall(VecRestoreArray(B, &bufB));
69 
70   PetscCall(VecGetArrayRead(A, (const PetscScalar **)&bufA));
71   PetscCall(VecGetArrayRead(B, (const PetscScalar **)&bufB));
72   PetscCall(VecGetArray(Aout, &bufAout));
73   PetscCall(VecGetArray(Bout, &bufBout));
74   PetscCall(PetscSFBcastBegin(sf, MPIU_SCALAR, (const void *)bufA, (void *)bufAout, MPI_REPLACE));
75   PetscCall(PetscSFBcastBegin(sf, MPIU_SCALAR, (const void *)bufB, (void *)bufBout, MPI_REPLACE));
76   PetscCall(PetscSFBcastEnd(sf, MPIU_SCALAR, (const void *)bufA, (void *)bufAout, MPI_REPLACE));
77   PetscCall(PetscSFBcastEnd(sf, MPIU_SCALAR, (const void *)bufB, (void *)bufBout, MPI_REPLACE));
78   PetscCall(VecRestoreArrayRead(A, (const PetscScalar **)&bufA));
79   PetscCall(VecRestoreArrayRead(B, (const PetscScalar **)&bufB));
80   PetscCall(VecRestoreArray(Aout, &bufAout));
81   PetscCall(VecRestoreArray(Bout, &bufBout));
82 
83   PetscCall(VecView(Aout, PETSC_VIEWER_STDOUT_WORLD));
84   PetscCall(VecView(Bout, PETSC_VIEWER_STDOUT_WORLD));
85   PetscCall(VecDestroy(&A));
86   PetscCall(VecDestroy(&B));
87   PetscCall(VecDestroy(&Aout));
88   PetscCall(VecDestroy(&Bout));
89   PetscCall(PetscSFDestroy(&sf));
90 
91   PetscCall(PetscFinalize());
92   return 0;
93 }
94 
95 /*TEST
96 
97    test:
98       suffix: basic
99       nsize: 2
100       filter: grep -v "type" | grep -v "sort"
101       args: -sf_type basic
102 
103    test:
104       suffix: window
105       nsize: 2
106       filter: grep -v "type" | grep -v "sort"
107       output_file: output/ex2_basic.out
108       args: -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create dynamic allocate}}
109       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)
110 
111    # The nightly test suite with MPICH uses ch3:sock, which is broken when winsize == 0 in some of the processes
112    test:
113       suffix: window_shared
114       nsize: 2
115       filter: grep -v "type" | grep -v "sort"
116       output_file: output/ex2_basic.out
117       args: -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor shared
118       requires: defined(PETSC_HAVE_MPI_PROCESS_SHARED_MEMORY) !defined(PETSC_HAVE_MPICH) defined(PETSC_HAVE_MPI_ONE_SIDED)
119 
120 TEST*/
121