kpccl_shm_fence

接口定义

int kpccl_shm_fence(kpccl_shm_win_h win)

环境变量

使用环境变量 KPCCL_SHM_FENCE_ALGORITHM控制fence的底层实现。

可选值：

• rd（默认）
• linear

参数

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_win_h win;
    void *baseptr, *otherptr;
kpccl_shm_win_alloc(65536, kpccl_comm, &baseptr, &win);
 
    ((int*)baseptr)[0] = 0;
    MPI_Barrier(comm);
 
    for (int i = 0; i < 5; i++) {
        ((int*)baseptr)[0]++;
        kpccl_shm_fence(win);
        int cnt = 0;
        if (myid == 0) {
            while (cnt < 1000000) {
                cnt++;
            }
        }
        if (myid == 1) {
            while (cnt < 10000) {
                cnt++;
            }
        }
        if (myid == 2) {
            while (cnt < 100) {
                cnt++;
            }
        }
    }
 
    MPI_Barrier(comm);
    kpccl_shm_win_free(win);
    kpccl_shm_comm_destroy(kpccl_comm);
}

上述示例演示了使用kpccl fence的流程。kpccl_shm_fence函数用于win中所有进程间的同步。