---
title: kpccl_shm_comm_create
description: "创建kpccl comm。"
url: https://www.hikunpeng.com/document/detail/zh/hpchistory/hpckit/develop2400/KunoengHPCKit_developer_054.html
sourcePath: /source/zh/hpchistory/hpckit/develop2400/KunoengHPCKit_developer_054.html
indexId: 08b2dba2b8ff9ec633614287486711313eb4fc6ad298ac086f7573e098335e4573
---
# kpccl_shm_comm_create

创建kpccl comm。

#### 接口定义

int kpccl_shm_comm_create(int size, int rank, int pid, kpccl_shm_oob_allgather_cb_t oob_allgather

kpccl_shm_oob_cb_h oob_cbs

, void *group, kpccl_shm_comm_h *comm);


#### 参数


**表1 参数定义**

| 参数名 | 类型 | 描述 | 输入/输出 |
| --- | --- | --- | --- |
| size | int | 需要创建的kpccl通信域大小 | 输入 |
| rank | int | 当前进程的进程号 | 输入 |
| pid | int | 当前进程的pid | 输入 |
| oob\_cbs | kpccl\_shm\_oob\_cb\_h | 带外函数指针 | 输入 |
| group | void \* | 带外函数指针依赖的参数 | 输入 |
| comm | kpccl\_shm\_comm\_h | 需要创建的kpccl通信域 | 输出 |


#### 返回值

- 成功：返回KPCCL_OK
- 失败：返回KPCCL_ERROR


#### 示例

```
#include <stdio.h>
#include <mpi.h>
#include "kpccl.h"
int oob_allgather_callback(const void *sendbuf, void *recvbuf, int size, void *group，kpccl_shm_datatype_t datatype)
{
switch (datatype) {
case KPCCL_SHM_DATATYPE_CHAR:
return MPI_Allgather(sendbuf, size, MPI_CHAR, recvbuf, size, MPI_CHAR, (MPI_Comm)group);
case KPCCL_SHM_DATATYPE_INT:
return MPI_Allgather(sendbuf, size, MPI_INT, recvbuf, size, MPI_INT, (MPI_Comm)group);
case KPCCL_SHM_DATATYPE_LONG:
return MPI_Allgather(sendbuf, size, MPI_LONG, recvbuf, size, MPI_LONG, (MPI_Comm)group);
case KPCCL_SHM_DATATYPE_FLOAT:
return MPI_Allgather(sendbuf, size, MPI_FLOAT, recvbuf, size, MPI_FLOAT, (MPI_Comm)group);
case KPCCL_SHM_DATATYPE_DOUBLE:
return MPI_Allgather(sendbuf, size, MPI_DOUBLE, recvbuf, size, MPI_DOUBLE, (MPI_Comm)group);
default:
kpccl_error("not support datatype");
return KPCCL_ERROR;
}
}
int
oob_barrier_callback(
void
*
group)
{
return MPI_Barrier((MPI_Comm)group);
}
int main()
{
int myid, numprocs;
MPI_Comm comm = MPI_COMM_WORLD;
MPI_Comm_size(comm, &numprocs);
MPI_Comm_rank(comm, &myid);
kpccl_shm_oob_cb_t oob_cbs;
kpccl_shm_oob_cb_h oob_cbs_h = &oob_cbs;
oob_cbs_h->oob_allgather = oob_allgather_callback;
oob_cbs_h->oob_barrier = oob_barrier_callback;
kpccl_shm_comm_h kpccl_comm;
kpccl_shm_comm_create
(numprocs, myid, myid, oob_cbs_h , (void *)comm, &kpccl_comm);
kpccl_shm_comm_destroy(kpccl_comm);
}
```

上述示例演示了创建、清理一个kpccl comm的流程。kpccl_shm_comm_create函数创建了一个kpccl comm。