Example QMPI Tool implementing the API from https://github.com/pmodels/mpich/pull/4715

Makefile

CC=mpicc
CFLAGS= -std=c99 -fPIC -rdynamic -shared -O2 -g
OBJ= mpich_example.so

all: $(OBJ)

mpich_example.so: mpich_example.c
	$(CC) $(CFLAGS) -o $@ $<

clean:
	rm -f *.so

mpich_example.c

#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mpi.h>

#ifndef _EXTERN_C_
#ifdef __cplusplus
#define _EXTERN_C_ extern "C"
#else /* __cplusplus */
#define _EXTERN_C_
#endif /* __cplusplus */
#endif /* _EXTERN_C_ */

_EXTERN_C_ int Example_Init(QMPI_Context context, int tool_id, int *argc, char ***argv);
_EXTERN_C_ int Example_Recv(QMPI_Context context, int tool_id, void *buf, int count,
                            MPI_Datatype datatype, int source, int tag, MPI_Comm comm,
                            MPI_Status *status);
_EXTERN_C_ int Example_Send(QMPI_Context context, int tool_id, const void *buf, int count,
                            MPI_Datatype datatype, int dest, int tag, MPI_Comm comm);
_EXTERN_C_ int Example_Irecv(QMPI_Context context, int tool_id, void *buf, int count,
                             MPI_Datatype datatype, int source, int tag, MPI_Comm comm,
                             MPI_Request *request);
_EXTERN_C_ int Example_Isend(QMPI_Context context, int tool_id, const void *buf, int count,
                             MPI_Datatype datatype, int dest, int tag, MPI_Comm comm,
                             MPI_Request *request);

struct tool_struct {
    int my_tool_id;
};
QMPI_Recv_t *next_recv_fn; int next_recv_id;
QMPI_Send_t *next_send_fn; int next_send_id;
QMPI_Irecv_t *next_irecv_fn; int next_irecv_id;
QMPI_Isend_t *next_isend_fn; int next_isend_id;

void example_init_function_pointer(int tool_id);

__attribute__((constructor)) void register_my_tool()
{
    fprintf(stderr, "Registering init function\n");

    QMPI_Register_tool_name("example", &example_init_function_pointer);
}

void example_init_function_pointer(int tool_id)
{
    fprintf(stderr, "Init callback function\n");

    struct tool_struct * my_tool_struct = calloc(0, sizeof(struct tool_struct));
    my_tool_struct->my_tool_id = tool_id;

    QMPI_Register_tool_storage(tool_id, my_tool_struct);
    QMPI_Register_function(tool_id, MPI_INIT_T, (void (*)(void)) &Example_Init);
    QMPI_Register_function(tool_id, MPI_SEND_T, (void (*)(void)) &Example_Send);
    QMPI_Register_function(tool_id, MPI_RECV_T, (void (*)(void)) &Example_Recv);
    QMPI_Register_function(tool_id, MPI_ISEND_T, (void (*)(void)) &Example_Isend);
    QMPI_Register_function(tool_id, MPI_IRECV_T, (void (*)(void)) &Example_Irecv);
}

_EXTERN_C_ int Example_Init(QMPI_Context context, int tool_id, int *argc, char ***argv)
{
    QMPI_Init_t *next_init_fn;
    int next_tool_id, ret;

    QMPI_Get_function(tool_id, MPI_INIT_T, (void (**)(void)) &next_init_fn, &context, &next_tool_id);
    QMPI_Get_function(tool_id, MPI_RECV_T, (void (**)(void)) &next_recv_fn, &context, &next_recv_id);
    QMPI_Get_function(tool_id, MPI_SEND_T, (void (**)(void)) &next_send_fn, &context, &next_send_id);
    QMPI_Get_function(tool_id, MPI_IRECV_T, (void (**)(void)) &next_irecv_fn, &context, &next_irecv_id);
    QMPI_Get_function(tool_id, MPI_ISEND_T, (void (**)(void)) &next_isend_fn, &context, &next_isend_id);

    ret = (*next_init_fn)(context, next_tool_id, argc, argv);

    return ret;
}

_EXTERN_C_ int Example_Recv(QMPI_Context context, int tool_id, void *buf, int count,
                            MPI_Datatype datatype, int source, int tag, MPI_Comm comm,
                            MPI_Status *status)
{
    int ret;
    struct tool_struct *storage;

    QMPI_Get_tool_storage(context, tool_id, (void *) &storage);

    //fprintf(stderr, "In Example Receive QMPI wrapper. Storage tool ID: %d\n", storage->my_tool_id);

    ret = (*next_recv_fn)(context, next_recv_id, buf, count, datatype, source, tag, comm, status);

    return ret;
}

_EXTERN_C_ int Example_Send(QMPI_Context context, int tool_id, const void *buf, int count,
                            MPI_Datatype datatype, int dest, int tag, MPI_Comm comm)
{
    int ret;
    struct tool_struct *storage;

    QMPI_Get_tool_storage(context, tool_id, (void *) &storage);

    //fprintf(stderr, "In Example Send QMPI wrapper. Storage tool ID: %d\n", storage->my_tool_id);

    ret = (*next_send_fn)(context, next_send_id, buf, count, datatype, dest, tag, comm);

    return ret;
}

_EXTERN_C_ int Example_Irecv(QMPI_Context context, int tool_id, void *buf, int count,
                             MPI_Datatype datatype, int source, int tag, MPI_Comm comm,
                             MPI_Request *request)
{
    int ret;
    struct tool_struct *storage;

    QMPI_Get_tool_storage(context, tool_id, (void *) &storage);

    //fprintf(stderr, "In Example Ireceive QMPI wrapper. Storage tool ID: %d\n", storage->my_tool_id);

    ret = (*next_irecv_fn)(context, next_irecv_id, buf, count, datatype, source, tag, comm, request);

    return ret;
}

_EXTERN_C_ int Example_Isend(QMPI_Context context, int tool_id, const void *buf, int count,
                            MPI_Datatype datatype, int dest, int tag, MPI_Comm comm,
                            MPI_Request *request)
{
    int ret;
    struct tool_struct *storage;

    QMPI_Get_tool_storage(context, tool_id, (void *) &storage);

    //fprintf(stderr, "In Example Isend QMPI wrapper. Storage tool ID: %d\n", storage->my_tool_id);

    ret = (*next_isend_fn)(context, next_isend_id, buf, count, datatype, dest, tag, comm, request);

    return ret;
}