model-checker : smpi mutual exclusion example

[simgrid.git] / examples / smpi / mc / mutual_exclusion.c

diff --git a/examples/smpi/mc/mutual_exclusion.c b/examples/smpi/mc/mutual_exclusion.c
new file mode 100644 (file)
index 0000000..a917060
--- /dev/null
+++ b/examples/smpi/mc/mutual_exclusion.c
@@ -0,0 +1,72 @@
+#include <stdio.h>
+#include <mpi.h>
+#include <simgrid/modelchecker.h>
+
+#define GRANT_TAG 0
+#define REQUEST_TAG 1
+#define RELEASE_TAG 2
+
+int main(int argc, char **argv){
+
+  int err, size, rank;
+  int recv_buff;
+  MPI_Status status;
+  int CS_used = 0;
+  xbt_dynar_t requests = xbt_dynar_new(sizeof(int), NULL);
+  
+  /* Initialize MPI */
+  err = MPI_Init(&argc, &argv);
+  if(err !=  MPI_SUCCESS){
+    printf("MPI initialization failed !\n");
+    exit(1);
+  }
+
+  MC_ignore(&(status.count), sizeof(status.count));
+
+  /* Get number of processes */
+  err = MPI_Comm_size(MPI_COMM_WORLD, &size);
+  /* Get id of this process */
+  err = MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+
+  if(rank == 0){ /* Coordinator */
+    while(1){
+      MPI_Recv(&recv_buff, 1, MPI_INT, MPI_ANY_SOURCE, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
+      if(status.MPI_TAG == REQUEST_TAG){
+        if(CS_used){
+          printf("CS already used. Queue the request.\n");
+          xbt_dynar_push(requests, &recv_buff);
+        }else{
+          printf("CS idle. Grant immediatly.\n");
+          MPI_Send(&rank, 1, MPI_INT, recv_buff, GRANT_TAG, MPI_COMM_WORLD);
+          CS_used = 1;
+        }
+      }else{
+        if(!xbt_dynar_is_empty(requests)){
+          printf("CS release. Grant to queued requests (queue size: %lu)",
+              xbt_dynar_length(requests));
+          xbt_dynar_shift(requests, &recv_buff);
+          MPI_Send(&rank, 1, MPI_INT, recv_buff, GRANT_TAG, MPI_COMM_WORLD);
+          CS_used = 1;
+        }else{
+          printf("CS release. Resource now idle.\n");
+          CS_used = 0;
+        }
+      }
+    }
+  }else{ /* Client */
+    while(1){
+      printf("%d asks the request.\n", rank);
+      MPI_Send(&rank, 1, MPI_INT, 0, REQUEST_TAG, MPI_COMM_WORLD);
+    
+      MPI_Recv(&recv_buff, 1, MPI_INT, 0, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
+    
+      printf("%d got the answer. Release it.\n", rank);
+      MPI_Send(&rank, 1, MPI_INT, 0, RELEASE_TAG, MPI_COMM_WORLD);
+    
+    }
+  }
+
+  MPI_Finalize();
+
+  return 0;
+}