text: /*
   * Copyright 2020-2022 Hewlett Packard Enterprise Development LP
   * Copyright 2004-2019 Cray Inc.
   * Other additional copyright holders may be indicated within.
   *
   * The entirety of this work is licensed under the Apache License,
   * Version 2.0 (the "License"); you may not use this file except
   * in compliance with the License.
   *
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <assert.h>
  
  #include "chplrt.h"
  
  #include "chpl-comm.h"
  #include "error.h"
  #include "chpl-comm-callbacks.h"
  #include "chpl-comm-callbacks-internal.h"
  
  //
  // Communication callback support
  //
  #define MAX_CBS_PER_EVENT 10
  
  
  //
  // Storage for call back information
  //
  static struct cb_info {
    chpl_comm_cb_fn_t fns[MAX_CBS_PER_EVENT];
  } cb_info[chpl_comm_cb_num_event_kinds];
  
  int chpl_comm_callback_counts[chpl_comm_cb_num_event_kinds] = {0};
  
  
  //
  // Communication callback support.
  //
  int chpl_comm_install_callback(chpl_comm_cb_event_kind_t event_kind,
                                 chpl_comm_cb_fn_t cb_fn) {
    int i;
  
    if (event_kind >= chpl_comm_cb_num_event_kinds) {
      errno = ERANGE;
      return -1;
    }
  
    i = chpl_comm_callback_counts[event_kind];
  
    if (i >= MAX_CBS_PER_EVENT) {
      errno = ENOMEM;
      return -1;
    }
  
    chpl_comm_callback_counts[event_kind]++;
    cb_info[event_kind].fns[i]= cb_fn;
  
    return 0;
  }
  
  
  int chpl_comm_uninstall_callback(chpl_comm_cb_event_kind_t event_kind,
                                   chpl_comm_cb_fn_t cb_fn) {
    int i;
    int found_i;
  
    if (event_kind >= chpl_comm_cb_num_event_kinds) {
      errno = ERANGE;
      return -1;
    }
  
    for (i = 0, found_i = -1; i < chpl_comm_callback_counts[event_kind]; i++) {
      if (cb_info[event_kind].fns[i] == cb_fn) {
        found_i = i;
        break;
      }
    }
  
    if (found_i < 0) {
      errno = ENOENT;
      return -1;
    }
  
    for (i = found_i + 1; i < chpl_comm_callback_counts[event_kind]; i++) {
      cb_info[event_kind].fns[i - 1] = cb_info[event_kind].fns[i];
    }
  
    chpl_comm_callback_counts[event_kind]--;
  
    return 0;
  }
  
  void chpl_comm_do_callbacks(const chpl_comm_cb_info_t *info)
  {
    int i;
    struct cb_info *cb;
  
    // Don't do anything if the event kind is bad
    if (info->event_kind >= chpl_comm_cb_num_event_kinds)
      return;
  
    // Call the callbacks
    cb = &cb_info[info->event_kind];
    for (i = 0; i < chpl_comm_callback_counts[info->event_kind]; i++) {
      (cb->fns[i])(info);
    }
  }
  