/*
 * Copyright (c) 2004-2007 The Trustees of the University of Tennessee.
 *                         All rights reserved.
 * $COPYRIGHT$
 *
 * Additional copyrights may follow
 *
 * $HEADER$
 */

#include "ompi_config.h"

#include "opal/event/event.h"
#include "opal/mca/mca.h"
#include "opal/mca/base/mca_base_param.h"
#include "pml_v_protocol.h"
#include "pml_v_protocol_base.h"
#include "pml_v.h"
#include "static-components.h"

static opal_list_t mca_pml_v_protocol_base_components_available;

/**
 * Load any vprotocol MCA component, stored in available_vprotocol_components
 * call open function of all those components.
 */
int mca_pml_v_protocol_base_load_all(void)
{
  OBJ_CONSTRUCT(&mca_pml_v_protocol_base_components_available, opal_list_t);
  return mca_base_components_open("vprotocol", 0, mca_pml_v_protocol_base_static_components, 
                              &mca_pml_v_protocol_base_components_available, true);
}

typedef struct opened_component_t {
  opal_list_item_t super;
  mca_pml_v_protocol_base_component_t *om_component;
} opened_component_t;

/**
 * Function for selecting one component from all those that are
 * available.
 *
 * Call the init function on all available components and get their
 * priorities.  Select the component with the highest priority.  All
 * other components will be closed and unloaded.  The selected component
 * will have all of its function pointers saved and returned to the
 * caller.
 */
int mca_pml_v_protocol_base_select(bool enable_progress_threads, bool enable_mpi_threads)
{
  int priority = 0, best_priority = -1;
  opal_list_item_t *item = NULL;
  mca_base_component_list_item_t *cli = NULL;
  mca_pml_v_protocol_base_component_t *component = NULL, *best_component = NULL;
  mca_pml_v_protocol_base_module_t *module = NULL, *best_module = NULL;
  opal_list_t opened;
  opened_component_t *om = NULL;

  /* Traverse the list of available components; call their init
     functions. */
  OBJ_CONSTRUCT(&opened, opal_list_t);
  for(item = opal_list_get_first(&mca_pml_v_protocol_base_components_available);
       opal_list_get_end(&mca_pml_v_protocol_base_components_available) != item;
       item = opal_list_get_next(item)) {
    cli = (mca_base_component_list_item_t *) item;
    component = (mca_pml_v_protocol_base_component_t *) cli->cli_component;

    V_OUTPUT_VERBOSE(15, "vprotocol select: initializing %s component %s", component->pmlm_version.mca_type_name, component->pmlm_version.mca_component_name);
    if (NULL == component->pmlm_init) {
      V_OUTPUT_VERBOSE(1, "vprotocol select: no init function; ignoring component %s", component->pmlm_version.mca_component_name);
    } 
    else 
    {
      module = component->pmlm_init(&priority, enable_progress_threads, enable_mpi_threads);
      if (NULL == module) {
        V_OUTPUT_VERBOSE(1, "vprotocol select: init returned failure for component %s", component->pmlm_version.mca_component_name);
      } 
      else 
      {
        V_OUTPUT_VERBOSE(15, "vprotocol select: component %s init returned priority %d", component->pmlm_version.mca_component_name, priority);
        if (priority > best_priority) 
        {
          best_priority = priority;
          best_component = component;
          best_module = module;
        }

        om = malloc(sizeof(opened_component_t));
        if (NULL == om) return OMPI_ERR_OUT_OF_RESOURCE;
        OBJ_CONSTRUCT(om, opal_list_item_t);
        om->om_component = component;
        opal_list_append(&opened, (opal_list_item_t*) om);
      }
    }
  }

  /* Finished querying all components.  Check for the bozo case. */
  if (NULL == best_component) {
    V_OUTPUT_VERBOSE(1, "vprotocol select: no protocol has returned a positive priority, user don't want fault tolerance");
  } 
  else 
  {
    /* Save the winner */
    mca_pml_v.protocol_component = *best_component;
    mca_pml_v.protocol = *best_module;
  }

  /* Finalize all non-selected components */
  for (item = opal_list_remove_first(&opened);
       NULL != item;
       item = opal_list_remove_first(&opened)) {
    om = (opened_component_t *) item;
    if (om->om_component != best_component) {
      /* Finalize */
      V_OUTPUT_VERBOSE(15, "vprotocol select: component %s not selected / finalized", om->om_component->pmlm_version.mca_component_name);
      if (NULL != om->om_component->pmlm_finalize) {
        /* Blatently ignore the return code (what would we do to
           recover, anyway?  This component is going away, so errors
           don't matter anymore) */
        om->om_component->pmlm_finalize();
      }
    }
    OBJ_DESTRUCT(om);
    free(om);
  }

  /* This base function closes, unloads, and removes from the
     available list all unselected components.  The available list will
     contain only the selected component (if one). */
  mca_base_components_close(mca_pml_v.output, 
                            &mca_pml_v_protocol_base_components_available, 
                            (mca_base_component_t *) best_component);


  /* All done */
  if(best_component != NULL) 
  {
    V_OUTPUT_VERBOSE(10, "vprotocol select: component %s selected", mca_pml_v.protocol_component.pmlm_version.mca_component_name);
    return OMPI_SUCCESS;
  }
  else 
    return OMPI_ERR_NOT_FOUND;
}