simplify barrier

xprof/sync_daemon_mpi.c

@@ -78,62 +78,34 @@ int MPIX_Init_Session(MPI_Session *lib_shandle, MPI_Comm *lib_comm) {
 }
 
 int signal_loop(int parent_pid, MPI_Comm MPI_COMM_WORLD_THAPI, MPI_Comm MPI_COMM_NODE) {
-  // Required MPI info
-  int global_rank;
-  MPI_Comm_rank(MPI_COMM_WORLD_THAPI, &global_rank);
-  int global_size;
-  MPI_Comm_size(MPI_COMM_WORLD_THAPI, &global_size);
-  int local_rank;
-  MPI_Comm_rank(MPI_COMM_NODE, &local_rank);
-  int local_size;
-  MPI_Comm_size(MPI_COMM_NODE, &local_size);
-
   // Initialize signal set and add signals
   sigset_t signal_set;
   sigemptyset(&signal_set);
   sigaddset(&signal_set, RT_SIGNAL_GLOBAL_BARRIER);
   sigaddset(&signal_set, RT_SIGNAL_LOCAL_BARRIER);
   sigaddset(&signal_set, RT_SIGNAL_FINISH);
-
   sigprocmask(SIG_BLOCK, &signal_set, NULL);
-
-  // Send ready to parent
   kill(parent_pid, RT_SIGNAL_READY);
-  // Main loop
-  // Non blocked signal will be handled as usual
+
+  // Processing loop:
+  //   Should be only exited when receiving RT_SIGNAL_FINISH
   while (true) {
     int signum;
     sigwait(&signal_set, &signum);
     if (signum == RT_SIGNAL_FINISH) {
+      // Ready signal will be sent after cleaning
       return 0;
     } else if (signum == RT_SIGNAL_LOCAL_BARRIER) {
       MPI_Barrier(MPI_COMM_NODE);
-      goto next_iteration;
     } else if (signum == RT_SIGNAL_GLOBAL_BARRIER) {
-      // Local master who are not the global master, send a message
-      if (global_rank != 0 && local_rank == 0) {
-        MPI_Send(&local_size, 1, MPI_INT, 0, MPI_TAG_GLOBAL_BARRIER, MPI_COMM_WORLD_THAPI);
-      // Global master receive messages from local masters
-      } else if (global_rank == 0) {
-	// Global master may or may not be a local master
-	int sum_local_size_recv = 0;
-        if (local_rank == 0)
-	   sum_local_size_recv = local_size;
-        while (sum_local_size_recv != global_size) {
-          int local_size_recv;
-          MPI_Recv(&local_size_recv, 1, MPI_INT, MPI_ANY_SOURCE, MPI_TAG_GLOBAL_BARRIER,
-                   MPI_COMM_WORLD_THAPI, MPI_STATUS_IGNORE);
-          sum_local_size_recv += local_size_recv;
-        }
-      }
-      goto next_iteration;
+      MPI_Barrier(MPI_COMM_WORLD_THAPI);
     } else {
       fprintf(stderr, "Wrong signal rreseved %d. Exiting", signum);
       return 1;
     }
-    next_iteration:
-      kill(parent_pid, RT_SIGNAL_READY);
+    kill(parent_pid, RT_SIGNAL_READY);
   }
+
   // Unreachable
   fprintf(stderr, "Wrong signal_loop exit");
   return 1;