Cannot figure out waitany

[VictorEijkhout]

The crucial lines in my code are:

  if (procno==nprocs-1) {
    mpl::irequest_pool recv_requests;
    vector<int> recv_buffer(nprocs-1);
    for (int p=0; p<nprocs-1; p++) {
      recv_requests.push( comm_world.irecv( recv_buffer[p], p ) );
    }
    printf("Outstanding request #=%d\n",recv_requests.size());
    for (int p=0; p<nprocs-1; p++) {
      auto [success,index] = recv_requests.waitany();

This gives on the waitany call:

Assertion failed in file ./src/include/mpir_request.h at line 313: ((req))->ref_count >= 0
0   libpmpi.12.dylib                    0x000000010a7b44de backtrace_libc + 62
1   libpmpi.12.dylib                    0x000000010a7b4495 MPL_backtrace_show + 21
2   libpmpi.12.dylib                    0x000000010a7502f4 MPIR_Assert_fail + 36
3   libmpi.12.dylib                     0x000000010a579445 MPI_Waitany + 2469
4   irecvsource                         0x000000010a4ea4f0 main + 672
5   libdyld.dylib                       0x00007fff7319c3d5 start + 1

Do you immediately see what I'm doing wrong or do I need to supply a fully functioning reprodcuer?

[rabauke]

Thanks for your report. Please report if 47680a5 fixes your issues.

[VictorEijkhout]

Thank you. That fixed it.

Btw, instead of returning a pair of bool/index you could use std::optional. I don't know how many users you have, but I don't mind if you make a breaking change in the API here.

[rabauke]

std::optional is not part of C++ 11. The library will be ported to C++17 in the future. std::optional might be an option then.