1 /*
2  * Copyright (C) by Argonne National Laboratory
3  *     See COPYRIGHT in top-level directory
4  */
5 
6 #include "mpi.h"
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include "mpitest.h"
10 #include "mpithreadtest.h"
11 
12 /*
13  * static char MTEST_Descrip[] = "Creating communications concurrently in different threads";
14  */
15 
16 MTEST_THREAD_RETURN_TYPE dup_thread(void *);
17 
dup_thread(void * p)18 MTEST_THREAD_RETURN_TYPE dup_thread(void *p)
19 {
20     int rank;
21     int buffer[1];
22     MPI_Comm *comm2_ptr = (MPI_Comm *) p;
23     MPI_Comm comm3;
24     MPI_Request req;
25 
26     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
27 
28     if (rank & 0x1) {
29         /* If odd, wait for message */
30         MPI_Recv(buffer, 0, MPI_INT, rank, 0, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
31     }
32     MPI_Comm_idup(*comm2_ptr, &comm3, &req);
33     MPI_Wait(&req, MPI_STATUS_IGNORE);
34 
35     MPI_Barrier(comm3);
36     MPI_Recv(buffer, 0, MPI_INT, rank, 1, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
37 
38     MPI_Comm_free(&comm3);
39     /* Tell the main thread that we're done */
40     MPI_Send(buffer, 0, MPI_INT, rank, 2, MPI_COMM_WORLD);
41 
42     return (MTEST_THREAD_RETURN_TYPE) 0;
43 }
44 
main(int argc,char * argv[])45 int main(int argc, char *argv[])
46 {
47     int rank, size;
48     int provided;
49     int buffer[1];
50     MPI_Comm comm1, comm2, comm4;
51 
52     MTest_Init_thread(&argc, &argv, MPI_THREAD_MULTIPLE, &provided);
53 
54     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
55     MPI_Comm_size(MPI_COMM_WORLD, &size);
56 
57     /* Check that we're multi-threaded */
58     if (provided != MPI_THREAD_MULTIPLE) {
59         if (rank == 0) {
60             printf
61                 ("MPI_Init_thread must return MPI_THREAD_MULTIPLE in order for this test to run.\n");
62             fflush(stdout);
63         }
64         return 1;
65     }
66 
67     /* The test is this:
68      * The main thread on ODD processors tells the other thread to start
69      * a comm dup(on comm2), then starts a comm dup(on comm1) after a delay.
70      * The main thread on even processors starts a comm dup(on comm1)
71      *
72      * The second thread on ODD processors waits until it gets a message
73      * (from the same process) before starting the comm dup on comm2.
74      */
75 
76     /* Create two communicators */
77     MPI_Comm_dup(MPI_COMM_WORLD, &comm1);
78     MPI_Comm_dup(MPI_COMM_WORLD, &comm2);
79 
80     /* Start a thread that will perform a dup comm2 */
81     MTest_Start_thread(dup_thread, (void *) &comm2);
82 
83     /* If we're odd, send to our new thread and then delay */
84     if (rank & 0x1) {
85         MPI_Ssend(buffer, 0, MPI_INT, rank, 0, MPI_COMM_WORLD);
86         MTestSleep(1);
87     }
88     MPI_Comm_dup(comm1, &comm4);
89 
90     /* Tell the threads to exit after we've created our new comm */
91     MPI_Barrier(comm4);
92     MPI_Ssend(buffer, 0, MPI_INT, rank, 1, MPI_COMM_WORLD);
93     MPI_Recv(buffer, 0, MPI_INT, rank, 2, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
94 
95     MPI_Comm_free(&comm4);
96     MPI_Comm_free(&comm1);
97     MPI_Comm_free(&comm2);
98 
99     MTest_Finalize(0);
100     return 0;
101 }
102