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libs/ck-libs/ampi/romio/adio/common/async_list.c

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/* -*- Mode: C; c-basic-offset:4 ; -*- */
/* 
 *   $Id$    
 *
 *   Copyright (C) 1997 University of Chicago. 
 *   See COPYRIGHT notice in top-level directory.
 */

#include "adio.h"
#include "adio_extern.h"

ADIOI_Async_node *ADIOI_Malloc_async_node(void)
{
/* returns a pointer to a new node that can be added to ADIOI_Async_list.
   To reduce the number of system calls, mallocs NUM nodes at a time
   and maintains list of available nodes. Supplies a node from this
   list if available, else mallocs a new set of NUM and provides one
   from that set. Is NUM=100 a good number? */

#define NUM 100

    ADIOI_Async_node *curr, *ptr;
    int i;

    if (!ADIOI_Async_avail_head) {
        ADIOI_Async_avail_head = (ADIOI_Async_node *)
                      ADIOI_Malloc(NUM*sizeof(ADIOI_Async_node));  
        curr = ADIOI_Async_avail_head;
        for (i=1; i<NUM; i++) {
            curr->next = ADIOI_Async_avail_head+i;
            curr = curr->next;
        }
        curr->next = NULL;
        ADIOI_Async_avail_tail = curr;

        /* keep track of malloced area that needs to be freed later */
        if (!ADIOI_Malloc_async_tail) {
            ADIOI_Malloc_async_tail = (ADIOI_Malloc_async *)
                ADIOI_Malloc(sizeof(ADIOI_Malloc_async)); 
            ADIOI_Malloc_async_head = ADIOI_Malloc_async_tail;
            ADIOI_Malloc_async_head->ptr = ADIOI_Async_avail_head;
            ADIOI_Malloc_async_head->next = NULL;
        }
        else {
            ADIOI_Malloc_async_tail->next = (ADIOI_Malloc_async *)
                ADIOI_Malloc(sizeof(ADIOI_Malloc_async));
            ADIOI_Malloc_async_tail = ADIOI_Malloc_async_tail->next;
            ADIOI_Malloc_async_tail->ptr = ADIOI_Async_avail_head;
            ADIOI_Malloc_async_tail->next = NULL;
        }
    }

    ptr = ADIOI_Async_avail_head;
    ADIOI_Async_avail_head = ADIOI_Async_avail_head->next;
    if (!ADIOI_Async_avail_head) ADIOI_Async_avail_tail = NULL;

    return ptr;
}


void ADIOI_Free_async_node(ADIOI_Async_node *node)
{
/* moves this node to available pool. does not actually free it. */

    if (!ADIOI_Async_avail_tail)
        ADIOI_Async_avail_head = ADIOI_Async_avail_tail = node;
    else {
        ADIOI_Async_avail_tail->next = node;
        ADIOI_Async_avail_tail = node;
    }
    node->next = NULL;
}


void ADIOI_Add_req_to_list(ADIO_Request *request)
{
/* add request to list of outstanding requests */

    ADIOI_Async_node *curr;

    if (!ADIOI_Async_list_head) {
        ADIOI_Async_list_head = ADIOI_Malloc_async_node();
        ADIOI_Async_list_head->request = request;
        ADIOI_Async_list_head->prev = ADIOI_Async_list_head->next = NULL;
        ADIOI_Async_list_tail = ADIOI_Async_list_head;
        (*request)->ptr_in_async_list = ADIOI_Async_list_head;
    }
    else {
        curr = ADIOI_Async_list_tail;
        curr->next = ADIOI_Malloc_async_node();
        ADIOI_Async_list_tail = curr->next;
        ADIOI_Async_list_tail->request = request;
        ADIOI_Async_list_tail->prev = curr;
        ADIOI_Async_list_tail->next = NULL;
        (*request)->ptr_in_async_list = ADIOI_Async_list_tail;
    }
}
        

void ADIOI_Complete_async(int *error_code)
{
/* complete all outstanding async I/O operations so that new ones can be
   initiated. Remove them all from async_list. */

    ADIO_Status status;
    ADIO_Request *request;
    ADIOI_Async_node *tmp;

    if (!ADIOI_Async_list_head) *error_code = MPI_SUCCESS;
    while (ADIOI_Async_list_head) {
        request = ADIOI_Async_list_head->request;
        (*request)->queued = -1; /* ugly internal hack that prevents
                  ADIOI_xxxComplete from freeing the request object. 
                  This is required, because the user will call MPI_Wait
                  later, which would require status to be filled. */
        switch ((*request)->optype) {
        case ADIOI_READ:
/*          (*((*request)->fd->fns->ADIOI_xxx_ReadComplete))(request,
                                                    &status,error_code);*/
            ADIO_ReadComplete(request, &status, error_code);
            break;
        case ADIOI_WRITE:
/*          (*((*request)->fd->fns->ADIOI_xxx_WriteComplete))(request,
                                                     &status, error_code);*/
            ADIO_WriteComplete(request, &status, error_code);
            break;
        default:
            FPRINTF(stderr, "Error in ADIOI_Complete_Async\n");
            break;
        }
        (*request)->queued = 0;  /* dequeued, but request object not
                                    freed */

        tmp = ADIOI_Async_list_head;
        ADIOI_Async_list_head = ADIOI_Async_list_head->next;
        ADIOI_Free_async_node(tmp);
    }
    ADIOI_Async_list_tail = NULL;
}


void ADIOI_Del_req_from_list(ADIO_Request *request)
{
/* Delete a request that has already been completed from the async
   list and move it to the list of available nodes. Typically called
   from within an ADIO_Test/ADIO_Wait. */ 

    ADIOI_Async_node *curr, *prev, *next;

    curr = (*request)->ptr_in_async_list;
    prev = curr->prev;

    if (prev) prev->next = curr->next;
    else ADIOI_Async_list_head = curr->next;

    next = curr->next;
    if (next) next->prev = prev;
    else ADIOI_Async_list_tail = prev;

    ADIOI_Free_async_node(curr);
}

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