+ int i;
+ char *allreduce_identifier;
+ char mailbox[80];
+ double comm_size = parse_double(action[2]);
+ double comp_size = parse_double(action[3]);
+ msg_task_t task = NULL, comp_task = NULL;
+ const char *process_name;
+ double clock = MSG_get_clock();
+
+ process_globals_t counters =
+ (process_globals_t) MSG_process_get_data(MSG_process_self());
+
+ xbt_assert(communicator_size, "Size of Communicator is not defined, "
+ "can't use collective operations");
+
+ process_name = MSG_process_get_name(MSG_process_self());
+
+ allreduce_identifier = bprintf("allReduce_%d", counters->allReduce_counter++);
+
+ if (!strcmp(process_name, "p0")) {
+ XBT_DEBUG("%s: %s is the Root", allreduce_identifier, process_name);
+
+ msg_comm_t *comms = xbt_new0(msg_comm_t, communicator_size - 1);
+ msg_task_t *tasks = xbt_new0(msg_task_t, communicator_size - 1);
+ for (i = 1; i < communicator_size; i++) {
+ sprintf(mailbox, "%s_p%d_p0", allreduce_identifier, i);
+ comms[i - 1] = MSG_task_irecv(&(tasks[i - 1]), mailbox);
+ }
+ MSG_comm_waitall(comms, communicator_size - 1, -1);
+ for (i = 1; i < communicator_size; i++) {
+ MSG_comm_destroy(comms[i - 1]);
+ MSG_task_destroy(tasks[i - 1]);
+ }
+ free(tasks);
+
+ comp_task = MSG_task_create("allReduce_comp", comp_size, 0, NULL);
+ XBT_DEBUG("%s: computing 'reduce_comp'", allreduce_identifier);
+ MSG_task_execute(comp_task);
+ MSG_task_destroy(comp_task);
+ XBT_DEBUG("%s: computed", allreduce_identifier);
+
+ for (i = 1; i < communicator_size; i++) {
+ sprintf(mailbox, "%s_p0_p%d", allreduce_identifier, i);
+ comms[i - 1] =
+ MSG_task_isend(MSG_task_create(mailbox, 0, comm_size, NULL), mailbox);
+ }
+ MSG_comm_waitall(comms, communicator_size - 1, -1);
+ for (i = 1; i < communicator_size; i++)
+ MSG_comm_destroy(comms[i - 1]);
+ free(comms);
+
+ XBT_DEBUG("%s: all messages sent by %s have been received",
+ allreduce_identifier, process_name);
+
+ } else {
+ XBT_DEBUG("%s: %s sends", allreduce_identifier, process_name);
+ sprintf(mailbox, "%s_%s_p0", allreduce_identifier, process_name);
+ XBT_DEBUG("put on %s", mailbox);
+ MSG_task_send(MSG_task_create(allreduce_identifier, 0, comm_size, NULL),
+ mailbox);
+
+ sprintf(mailbox, "%s_p0_%s", allreduce_identifier, process_name);
+ MSG_task_receive(&task, mailbox);
+ MSG_task_destroy(task);
+ XBT_DEBUG("%s: %s has received", allreduce_identifier, process_name);
+ }
+
+ if (XBT_LOG_ISENABLED(actions, xbt_log_priority_verbose)) {
+ char *a = xbt_str_join_array(action, " ");
+ XBT_VERB("%s %f", a, MSG_get_clock() - clock);
+ free(a);
+ }
+ free(allreduce_identifier);
+}
+
+static void action_comm_size(const char *const *action)
+{
+ char *name = NULL;
+ const char *size = action[2];
+ double clock = MSG_get_clock();
+
+ if (XBT_LOG_ISENABLED(actions, xbt_log_priority_verbose))
+ name = xbt_str_join_array(action, " ");