在for循环中接收信息会产生奇怪的错误

如何解决在for循环中接收信息会产生奇怪的错误

我正在尝试使用MPI库中的for循环将由对象组成的数组的一部分从主节点广播到工作线程。我在Recv步骤上遇到了问题。总体而言，我愿意提出任何建议，因为我认为有更简单的方法可以解决我的问题。在我的代码中，编译每个单独的MPI_Send / MPI_Recv可以完美地工作，但不能一次全部编译。

  if(rank==0){
    for(unsigned int r=1; r < com; r++){ //r is the node identifier
      for(int org = 0; org < NEAT::pop_size; org++){
        ...
        std::vector<NEAT::Trait*> gen_traits = ...; 
        struct traits sent_traits[num_traits];

        for(int id = 0; id < num_traits; id++){
          sent_traits[id].trait_id = gen_traits[id]->trait_id;
          ...and other stuff
        }

        MPI_Isend(&num_traits,1,MPI_INT,r,org,parallel_2,&reqs_2[org]);
        MPI_Isend(&sent_traits,mpi_trait,parallel_3,&reqs_3[org]);

使用相应的MPI_Recv（参见下文）进行编译。奇怪的部分如下：一旦我将节点向量的Recv包括在内，程序就会崩溃。

      struct nodes sent_nodes[num_nodes];
      for(int id = 0; id < num_nodes; id++){
        sent_nodes[id].node_id = gen_nodes[id]->node_id;
        if(gen_nodes[id]->nodetrait==0){
          sent_nodes[id].trait_id = 0;
        ...
      }
      
      MPI_Isend(&num_nodes,org+1,parallel_4,&reqs_4[org]); 
      MPI_Isend(&sent_nodes,mpi_node,parallel_5,&reqs_5[org]); 
    }
  }
}

MPI_Barrier;
if(rank!=0){
    for(int org = 0; org < num_orgs ; org++){
      /*this first part is ok*/ 
      traits rcvd_traits[num_rcvd_traits];
      MPI_Recv(&num_rcvd_traits,&status);
      MPI_Recv(&rcvd_traits,&status);

      std::vector<NEAT::Trait*> gen_traits;
      for(int id = 0; id < num_rcvd_traits; id++){
        traits p_trait = rcvd_traits[id];
        NEAT::Trait* build_trait = new NEAT::Trait(p_trait.trait_id,....
      }
      /*INCLUDING THIS ADDITIONAL PART LEADS TO A CRASH*/ 
      int num_rcvd_nodes;
      nodes rcvd_nodes[num_rcvd_nodes];
      MPI_Recv(&num_rcvd_nodes,&status);
      MPI_Recv(&rcvd_nodes,&status);

      std::vector<NEAT::NNode*> gen_nodes;
      for(int id = 0; id < num_rcvd_nodes; id++){
        nodes p_node = rcvd_nodes[id];
        NEAT::NNode* build_node = new NEAT::NNode(p_node.trait_id,p_node.type,p_node.gen_node_label,p_node.ftype,gen_traits);
        gen_nodes.push_back(build_node);
      } 
    }
    std::cout << "finished " << std::endl;
}   

MPI_Finalize();

我得到了错误：

===================================================================================
=   BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
=   PID 124551 RUNNING AT joachim-X399-AORUS-PRO
=   EXIT CODE: 139
=   CLEANING UP REMAINING PROCESSES
=   YOU CAN IGNORE THE BELOW CLEANUP MESSAGES
===================================================================================
YOUR APPLICATION TERMINATED WITH THE EXIT STRING: Segmentation fault (signal 11)
This typically refers to a problem with your application.

我从这个玩具示例中得到启发：

int rank,com,num_orgs;
MPI_Init(NULL,NULL);
MPI_Status status;
MPI_Comm parallel_0 = MPI_COMM_WORLD;
MPI_Comm_rank(parallel_0,&rank);
MPI_Comm_size(parallel_0,&com);
MPI_Request reqs[4000];

if(rank==0){

  for(int r=1; r < com; r++){

    for(int q=0; q < 100; q++){

      MPI_Send(&r,q,parallel_0);//,&reqs[r*(q+1)]);

    }
  }
}

if(rank!=0){
  for(int q=0; q < 100; q++){
    int rcvd;
    MPI_Recv(&rcvd,MPI_COMM_WORLD,&status);
  }
}

MPI_Finalize();