/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
 *                         University Research and Technology
 *                         Corporation.  All rights reserved.
 * Copyright (c) 2004-2009 The University of Tennessee and The University
 *                         of Tennessee Research Foundation.  All rights
 *                         reserved.
 * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart, 
 *                         University of Stuttgart.  All rights reserved.
 * Copyright (c) 2004-2005 The Regents of the University of California.
 *                         All rights reserved.
 * Copyright (c) 2006-2007 Mellanox Technologies. All rights reserved.
 * Copyright (c) 2010      Cisco Systems, Inc. All rights reserved.
 * $COPYRIGHT$
 * 
 * Additional copyrights may follow
 * 
 * $HEADER$
 */

#include "ompi_config.h"

#include "ompi/class/ompi_free_list.h"
#include "opal/align.h"
#include "opal/util/output.h"
#include "ompi/mca/mpool/mpool.h"

static void ompi_free_list_construct(ompi_free_list_t* fl);
static void ompi_free_list_destruct(ompi_free_list_t* fl);

OBJ_CLASS_INSTANCE(ompi_free_list_t, opal_atomic_lifo_t,
        ompi_free_list_construct, ompi_free_list_destruct);

typedef struct ompi_free_list_item_t ompi_free_list_memory_t;

OBJ_CLASS_INSTANCE(ompi_free_list_item_t, 
                   opal_list_item_t,
                   NULL, NULL); 

static void ompi_free_list_construct(ompi_free_list_t* fl)
{
    OBJ_CONSTRUCT(&fl->fl_lock, opal_mutex_t);
    OBJ_CONSTRUCT(&fl->fl_condition, opal_condition_t);
    fl->fl_max_to_alloc = 0;
    fl->fl_num_allocated = 0;
    fl->fl_num_per_alloc = 0;
    fl->fl_num_waiting = 0;
    fl->fl_frag_size = sizeof(ompi_free_list_item_t);
    fl->fl_frag_alignment = 0;
    fl->fl_payload_buffer_size=0;
    fl->fl_payload_buffer_alignment=0;
    fl->fl_frag_class = OBJ_CLASS(ompi_free_list_item_t);
    fl->fl_mpool = 0;
    fl->ctx = NULL;
    OBJ_CONSTRUCT(&(fl->fl_allocations), opal_list_t);
}

static void ompi_free_list_destruct(ompi_free_list_t* fl)
{
    opal_list_item_t *item;
    ompi_free_list_memory_t *fl_mem;

#if 0 && OPAL_ENABLE_DEBUG
    if(opal_list_get_size(&fl->super) != fl->fl_num_allocated) {
        opal_output(0, "ompi_free_list: %d allocated %d returned: %s:%d\n",
            fl->fl_num_allocated, opal_list_get_size(&fl->super),
            fl->super.super.cls_init_file_name, fl->super.super.cls_init_lineno);
    }
#endif

    if( NULL != fl->fl_mpool ) {
        while(NULL != (item = opal_list_remove_first(&(fl->fl_allocations)))) {
            fl_mem = (ompi_free_list_memory_t*)item;

            fl->fl_mpool->mpool_free(fl->fl_mpool, fl_mem->ptr,
                                     fl_mem->registration);

            /* destruct the item (we constructed it), then free the memory chunk */
            OBJ_DESTRUCT(item);
            free(item);
        }
    } else {
        while(NULL != (item = opal_list_remove_first(&(fl->fl_allocations)))) {
            /* destruct the item (we constructed it), then free the memory chunk */
            OBJ_DESTRUCT(item);
            free(item);
        }
    }

    OBJ_DESTRUCT(&fl->fl_allocations);
    OBJ_DESTRUCT(&fl->fl_condition);
    OBJ_DESTRUCT(&fl->fl_lock);
}

int ompi_free_list_init_ex(
    ompi_free_list_t *flist,
    size_t elem_size,
    size_t alignment,
    opal_class_t* elem_class,
    int num_elements_to_alloc,
    int max_elements_to_alloc,
    int num_elements_per_alloc,
    mca_mpool_base_module_t* mpool,
    ompi_free_list_item_init_fn_t item_init,
    void* ctx)
{
    /* alignment must be more than zero and power of two */
    if(alignment <= 1 || (alignment & (alignment - 1)))
        return OMPI_ERROR;

    if(elem_size > flist->fl_frag_size)
        flist->fl_frag_size = elem_size;
    flist->fl_frag_alignment = alignment;
    if(elem_class)
        flist->fl_frag_class = elem_class;
    flist->fl_payload_buffer_size=flist->fl_frag_size-
        flist->fl_frag_class->cls_sizeof;
    flist->fl_payload_buffer_alignment=alignment;
    flist->fl_max_to_alloc = max_elements_to_alloc;
    flist->fl_num_allocated = 0;
    flist->fl_num_per_alloc = num_elements_per_alloc;
    flist->fl_mpool = mpool;
    flist->item_init = item_init;
    flist->ctx = ctx;
    if(num_elements_to_alloc)
        return ompi_free_list_grow(flist, num_elements_to_alloc);
    return OMPI_SUCCESS;
}

/* this will replace ompi_free_list_init_ex */
int ompi_free_list_init_ex_new(
    ompi_free_list_t *flist,
    size_t frag_size,
    size_t frag_alignment,
    opal_class_t* frag_class,
    size_t payload_buffer_size,
    size_t payload_buffer_alignment,
    int num_elements_to_alloc,
    int max_elements_to_alloc,
    int num_elements_per_alloc,
    mca_mpool_base_module_t* mpool,
    ompi_free_list_item_init_fn_t item_init,
    void* ctx)
{
    /* alignment must be more than zero and power of two */
    if (frag_alignment <= 1 || (frag_alignment & (frag_alignment - 1)))
        return OMPI_ERROR;
    if (0 < payload_buffer_size) {
        if (payload_buffer_alignment <= 1 || (payload_buffer_alignment & (payload_buffer_alignment - 1)))
            return OMPI_ERROR;
    }

    if (frag_size > flist->fl_frag_size)
        flist->fl_frag_size = frag_size;
    if (frag_class)
        flist->fl_frag_class = frag_class;
    flist->fl_payload_buffer_size=payload_buffer_size;
    flist->fl_max_to_alloc = max_elements_to_alloc;
    flist->fl_num_allocated = 0;
    flist->fl_num_per_alloc = num_elements_per_alloc;
    flist->fl_mpool = mpool;
    flist->fl_frag_alignment = frag_alignment;
    flist->fl_payload_buffer_alignment = payload_buffer_alignment;
    flist->item_init = item_init;
    flist->ctx = ctx;
    if (num_elements_to_alloc)
        return ompi_free_list_grow(flist, num_elements_to_alloc);
    return OMPI_SUCCESS;
}
int ompi_free_list_grow(ompi_free_list_t* flist, size_t num_elements)
{
    unsigned char *ptr, *mpool_alloc_ptr = NULL;
    ompi_free_list_memory_t *alloc_ptr;
    size_t i, alloc_size, head_size, elem_size = 0;
    mca_mpool_base_registration_t *reg = NULL;

    if(flist->fl_max_to_alloc > 0)
        if(flist->fl_num_allocated + num_elements > flist->fl_max_to_alloc)
            num_elements = flist->fl_max_to_alloc - flist->fl_num_allocated;

    if(num_elements == 0)
        return OMPI_ERR_TEMP_OUT_OF_RESOURCE;

    head_size = (NULL == flist->fl_mpool) ? flist->fl_frag_size:
        flist->fl_frag_class->cls_sizeof;
    head_size = OPAL_ALIGN(head_size, flist->fl_frag_alignment, size_t);

    /* calculate head allocation size */
    alloc_size = num_elements * head_size + sizeof(ompi_free_list_memory_t) +
        flist->fl_frag_alignment;

    alloc_ptr = (ompi_free_list_memory_t*)malloc(alloc_size);

    if(NULL == alloc_ptr)
        return OMPI_ERR_TEMP_OUT_OF_RESOURCE;

    /* allocate the rest from the mpool */
    if(flist->fl_mpool != NULL) {
        elem_size = OPAL_ALIGN(flist->fl_payload_buffer_size, 
                flist->fl_payload_buffer_alignment, size_t);
        if(elem_size != 0) {
            mpool_alloc_ptr = (unsigned char *) flist->fl_mpool->mpool_alloc(flist->fl_mpool,
                   num_elements * elem_size, flist->fl_payload_buffer_alignment,
                   MCA_MPOOL_FLAGS_CACHE_BYPASS, &reg);
            if(NULL == mpool_alloc_ptr) {
                free(alloc_ptr);
                return OMPI_ERR_TEMP_OUT_OF_RESOURCE;
            }
        }
    }

    /* make the alloc_ptr a list item, save the chunk in the allocations list,
     * and have ptr point to memory right after the list item structure */
    OBJ_CONSTRUCT(alloc_ptr, ompi_free_list_item_t);
    opal_list_append(&(flist->fl_allocations), (opal_list_item_t*)alloc_ptr);

    alloc_ptr->registration = reg;
    alloc_ptr->ptr = mpool_alloc_ptr;

    ptr = (unsigned char*)alloc_ptr + sizeof(ompi_free_list_memory_t);
    ptr = OPAL_ALIGN_PTR(ptr, flist->fl_frag_alignment, unsigned char*);

    for(i=0; i<num_elements; i++) {
        ompi_free_list_item_t* item = (ompi_free_list_item_t*)ptr;
        item->registration = reg;
        item->ptr = mpool_alloc_ptr;

        OBJ_CONSTRUCT_INTERNAL(item, flist->fl_frag_class);
        
        /* run the initialize function if present */
        if(flist->item_init) { 
            flist->item_init(item, flist->ctx);
        }

        opal_atomic_lifo_push(&(flist->super), &(item->super));
        ptr += head_size;
        mpool_alloc_ptr += elem_size;
        
    }
    flist->fl_num_allocated += num_elements;
    return OMPI_SUCCESS;
}

/**
 * This function resize the free_list to contain at least the specified
 * number of elements. We do not create all of them in the same memory
 * segment. Instead we will several time the fl_num_per_alloc elements
 * until we reach the required number of the maximum allowed by the 
 * initialization.
 */
int
ompi_free_list_resize(ompi_free_list_t* flist, size_t size)
{
    ssize_t inc_num;
    int ret = OMPI_SUCCESS;

    if (flist->fl_num_allocated > size) {
        return OMPI_SUCCESS;
    }
    OPAL_THREAD_LOCK(&((flist)->fl_lock));
    inc_num = (ssize_t)size - (ssize_t)flist->fl_num_allocated;
    while( inc_num > 0 ) {
        ret = ompi_free_list_grow(flist, flist->fl_num_per_alloc);
        if( OMPI_SUCCESS != ret ) break;
        inc_num = (ssize_t)size - (ssize_t)flist->fl_num_allocated;
    }
    OPAL_THREAD_UNLOCK(&((flist)->fl_lock));

    return ret;
}