X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/2419060d3a83a35eccbe74985fd35e7b42253a62..394a9cd893e93ee04bf4a8f6ff4ad5a8697a0e82:/src/smpi/smpi_base.c

diff --git a/src/smpi/smpi_base.c b/src/smpi/smpi_base.c
index 6c7952eab5..05a391a4b2 100644
--- a/src/smpi/smpi_base.c
+++ b/src/smpi/smpi_base.c
@@ -7,415 +7,530 @@ XBT_LOG_EXTERNAL_CATEGORY(smpi_base);
 XBT_LOG_EXTERNAL_CATEGORY(smpi_bench);
 XBT_LOG_EXTERNAL_CATEGORY(smpi_kernel);
 XBT_LOG_EXTERNAL_CATEGORY(smpi_mpi);
+XBT_LOG_EXTERNAL_CATEGORY(smpi_mpi_dt);
+XBT_LOG_EXTERNAL_CATEGORY(smpi_coll);
 XBT_LOG_EXTERNAL_CATEGORY(smpi_receiver);
 XBT_LOG_EXTERNAL_CATEGORY(smpi_sender);
 XBT_LOG_EXTERNAL_CATEGORY(smpi_util);
 
-smpi_mpi_global_t smpi_mpi_global = NULL;
-
-/**
- * Operations of MPI_OP : implemented=land,sum,min,max
- **/
-void smpi_mpi_land_func(void *a, void *b, int *length,
-                        MPI_Datatype * datatype);
-
-void smpi_mpi_land_func(void *a, void *b, int *length,
-                        MPI_Datatype * datatype)
-{
-  int i;
-  if (*datatype == smpi_mpi_global->mpi_int) {
-    int *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] && y[i];
-    }
-  }
-}
+void smpi_process_init(int* argc, char*** argv) {
+  int index;
+  smpi_process_data_t data;
+  smx_process_t proc;
 
-/**
- * sum two vectors element-wise
- *
- * @param a the first vectors
- * @param b the second vectors
- * @return the second vector is modified and contains the element-wise sums
- **/
-void smpi_mpi_sum_func(void *a, void *b, int *length,
-                       MPI_Datatype * datatype);
-
-void smpi_mpi_sum_func(void *a, void *b, int *length, MPI_Datatype * datatype)
-{
-  int i;
-  if ((*datatype == smpi_mpi_global->mpi_byte) || (*datatype == smpi_mpi_global->mpi_char)) {
-    char *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] + y[i];
-    }
-  } else if (*datatype == smpi_mpi_global->mpi_int) {
-    int *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] + y[i];
-    }
-  } else if (*datatype == smpi_mpi_global->mpi_float) {
-    float *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] + y[i];
-    }
-  } else if (*datatype == smpi_mpi_global->mpi_double) {
-    double *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] + y[i];
-    }
-  }
-}
-/**
- *i multiply two vectors element-wise
- *
- * @param a the first vectors
- * @param b the second vectors
- * @return the second vector is modified and contains the element-wise products
- **/
-void smpi_mpi_prod_func(void *a, void *b, int *length,
-                       MPI_Datatype * datatype);
-
-void smpi_mpi_prod_func(void *a, void *b, int *length, MPI_Datatype * datatype)
-{
-  int i;
-  if ((*datatype == smpi_mpi_global->mpi_byte) || (*datatype == smpi_mpi_global->mpi_char)) {
-    char *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] * y[i];
-    }
-  } else if (*datatype == smpi_mpi_global->mpi_int) {
-    int *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] * y[i];
-    }
-  } else if (*datatype == smpi_mpi_global->mpi_float) {
-    float *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] * y[i];
-    }
-  } else if (*datatype == smpi_mpi_global->mpi_double) {
-    double *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] * y[i];
-    }
+  proc = SIMIX_process_self();
+  index = atoi((*argv)[1]);
+  data = smpi_process_remote_data(index);
+  SIMIX_process_set_data(proc, data);
+  if (*argc > 2) {
+    free((*argv)[1]);
+    memmove(&(*argv)[1], &(*argv)[2], sizeof(char *) * (*argc - 2));
+    (*argv)[(*argc) - 1] = NULL;
   }
+  (*argc)--;
+  DEBUG2("<%d> New process in the game: %p", index, proc);
 }
-/**
- * compute the min of two vectors element-wise
- **/
-void smpi_mpi_min_func(void *a, void *b, int *length,
-                       MPI_Datatype * datatype);
-
-void smpi_mpi_min_func(void *a, void *b, int *length, MPI_Datatype * datatype)
-{
-  int i;
-  if ((*datatype == smpi_mpi_global->mpi_byte) || (*datatype == smpi_mpi_global->mpi_char)) {
-    char *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] < y[i] ? x[i] : y[i];
-    }
-  } else {
-    if (*datatype == smpi_mpi_global->mpi_int) {
-      int *x = a, *y = b;
-      for (i = 0; i < *length; i++) {
-        y[i] = x[i] < y[i] ? x[i] : y[i];
-      }
-    } else {
-      if (*datatype == smpi_mpi_global->mpi_float) {
-        float *x = a, *y = b;
-        for (i = 0; i < *length; i++) {
-          y[i] = x[i] < y[i] ? x[i] : y[i];
-        }
-      } else {
-        if (*datatype == smpi_mpi_global->mpi_double) {
-          double *x = a, *y = b;
-          for (i = 0; i < *length; i++) {
-            y[i] = x[i] < y[i] ? x[i] : y[i];
-          }
 
-        }
-      }
-    }
-  }
+void smpi_process_destroy(void) {
+  int index = smpi_process_index();
+
+  DEBUG1("<%d> Process left the game", index);
 }
 
-/**
- * compute the max of two vectors element-wise
- **/
-void smpi_mpi_max_func(void *a, void *b, int *length,
-                       MPI_Datatype * datatype);
-
-void smpi_mpi_max_func(void *a, void *b, int *length, MPI_Datatype * datatype)
-{
-  int i;
-  if ((*datatype == smpi_mpi_global->mpi_byte) || (*datatype == smpi_mpi_global->mpi_char)) {
-    char *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] > y[i] ? x[i] : y[i];
-    }
-  } else if (*datatype == smpi_mpi_global->mpi_int) {
-    int *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] > y[i] ? x[i] : y[i];
-    }
-  } else if (*datatype == smpi_mpi_global->mpi_float) {
-    float *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] > y[i] ? x[i] : y[i];
-    }
-  } else if (*datatype == smpi_mpi_global->mpi_double) {
-    double *x = a, *y = b;
-    for (i = 0; i < *length; i++) {
-      y[i] = x[i] > y[i] ? x[i] : y[i];
-    }
+/* MPI Low level calls */
+MPI_Request smpi_mpi_isend(void* buf, int count, MPI_Datatype datatype, int dst, int tag, MPI_Comm comm) {
+  MPI_Request request;
+
+  request = xbt_new(s_smpi_mpi_request_t, 1);
+  request->comm = comm;
+  request->src = smpi_comm_rank(comm);
+  request->dst = dst;
+  request->tag = tag;
+  request->size = smpi_datatype_size(datatype) * count;
+  request->complete = 0;
+  request->data = request;
+  smpi_process_post_send(comm, request);
+  request->pair = SIMIX_network_isend(request->rdv, request->size, -1.0, buf, request->size, NULL);
+  return request;
+}
 
-  }
+MPI_Request smpi_mpi_irecv(void* buf, int count, MPI_Datatype datatype, int src, int tag, MPI_Comm comm) {
+  MPI_Request request;
+
+  request = xbt_new(s_smpi_mpi_request_t, 1);
+  request->comm = comm;
+  request->src = src;
+  request->dst = smpi_comm_rank(comm);
+  request->tag = tag;
+  request->size = smpi_datatype_size(datatype) * count;
+  request->complete = 0;
+  request->data = MPI_REQUEST_NULL;
+  smpi_process_post_recv(request);
+  request->pair = SIMIX_network_irecv(request->rdv, buf, &request->size);
+  return request;
 }
 
+void smpi_mpi_recv(void* buf, int count, MPI_Datatype datatype, int src, int tag, MPI_Comm comm, MPI_Status* status) {
+  MPI_Request request;
 
+  request = smpi_mpi_irecv(buf, count, datatype, src, tag, comm);
+  smpi_mpi_wait(&request, status);
+}
 
+void smpi_mpi_send(void* buf, int count, MPI_Datatype datatype, int src, int tag, MPI_Comm comm) {
+  MPI_Request request;
 
-/**
- * tell the MPI rank of the calling process (from its SIMIX process id)
- **/
-int smpi_mpi_comm_rank(smpi_mpi_communicator_t comm)
-{
-  return comm->index_to_rank_map[smpi_process_index()];
+  request = smpi_mpi_isend(buf, count, datatype, src, tag, comm);
+  smpi_mpi_wait(&request, MPI_STATUS_IGNORE);
 }
 
-void smpi_process_init(int *argc, char ***argv)
-{
-  smpi_process_data_t pdata;
+void smpi_mpi_sendrecv(void* sendbuf, int sendcount, MPI_Datatype sendtype, int dst, int sendtag, void* recvbuf, int recvcount, MPI_Datatype recvtype, int src, int recvtag, MPI_Comm comm, MPI_Status* status) {
+  MPI_Request requests[2];
+  MPI_Status stats[2];
 
-  // initialize some local variables
+  requests[0] = smpi_mpi_isend(sendbuf, sendcount, sendtype, dst, sendtag, comm);
+  requests[1] = smpi_mpi_irecv(recvbuf, recvcount, recvtype, src, recvtag, comm);
+  smpi_mpi_waitall(2, requests, stats);
+  if(status != MPI_STATUS_IGNORE) {
+    // Copy receive status
+    memcpy(status, &stats[1], sizeof(MPI_Status));
+  }
+}
 
-  pdata = xbt_new(s_smpi_process_data_t, 1);
-  SIMIX_process_set_data(SIMIX_process_self(), pdata);
+static void finish_wait(MPI_Request* request, MPI_Status* status) {
+  MPI_Request data = (*request)->data;
 
-  /* get rank from command line, and remove it from argv */
-  pdata->index = atoi((*argv)[1]);
-  DEBUG1("I'm rank %d", pdata->index);
-  if (*argc > 2) {
-    memmove((*argv)[1], (*argv)[2], sizeof(char *) * (*argc - 2));
-    (*argv)[(*argc) - 1] = NULL;
+  xbt_assert0(data != MPI_REQUEST_NULL, "Erroneous situation");
+  if(status != MPI_STATUS_IGNORE) {
+    status->MPI_SOURCE = (*request)->src;
+    status->MPI_TAG = (*request)->tag;
+    status->MPI_ERROR = MPI_SUCCESS;
   }
-  (*argc)--;
-
-  pdata->mutex = SIMIX_mutex_init();
-  pdata->cond = SIMIX_cond_init();
-  pdata->finalize = 0;
-
-  pdata->pending_recv_request_queue = xbt_fifo_new();
-  pdata->pending_send_request_queue = xbt_fifo_new();
-  pdata->received_message_queue = xbt_fifo_new();
-
-  pdata->main = SIMIX_process_self();
-  pdata->sender = SIMIX_process_create("smpi_sender",
-                                       smpi_sender, pdata,
-                                       SIMIX_host_get_name(SIMIX_host_self()),
-                                       0, NULL,
-                                       /*props */ NULL);
-  pdata->receiver = SIMIX_process_create("smpi_receiver",
-                                         smpi_receiver, pdata,
-                                         SIMIX_host_get_name(SIMIX_host_self
-                                                             ()), 0, NULL,
-                                         /*props */ NULL);
-
-  smpi_global->main_processes[pdata->index] = SIMIX_process_self();
-  return;
+  DEBUG3("finishing wait for %p [data = %p, complete = %d]", *request, data, data->complete);
+  // data == *request if sender is first to finish its wait
+  // data != *request if receiver is first to finish its wait
+  if(data->complete == 0) {
+    // first arrives here
+    data->complete = 1;
+    if(data != *request) {
+      // receveiver cleans its part
+      xbt_free(*request);
+    }
+  } else {
+    // second arrives here
+    if(data != *request) {
+      // receiver cleans everything
+      xbt_free(data);
+    }
+    SIMIX_rdv_destroy((*request)->rdv);
+    xbt_free(*request);
+  }
+  *request = MPI_REQUEST_NULL;
 }
 
-void smpi_process_finalize()
-{
-  smpi_process_data_t pdata = SIMIX_process_get_data(SIMIX_process_self());
+int smpi_mpi_test(MPI_Request* request, MPI_Status* status) {
+  MPI_Request data = (*request)->data;
+  int flag = data && data->complete == 1;
 
-  pdata->finalize = 2;          /* Tell sender and receiver to quit */
-  SIMIX_process_resume(pdata->sender);
-  SIMIX_process_resume(pdata->receiver);
-  while (pdata->finalize > 0) { /* wait until it's done */
-    SIMIX_cond_wait(pdata->cond, pdata->mutex);
+  if(flag) {
+    SIMIX_communication_destroy((*request)->pair);
+    finish_wait(request, status);
   }
-
-  SIMIX_mutex_destroy(pdata->mutex);
-  SIMIX_cond_destroy(pdata->cond);
-  xbt_fifo_free(pdata->pending_recv_request_queue);
-  xbt_fifo_free(pdata->pending_send_request_queue);
-  xbt_fifo_free(pdata->received_message_queue);
-  xbt_free(pdata);
+  return flag;
 }
 
+int smpi_mpi_testany(int count, MPI_Request requests[], int* index, MPI_Status* status) {
+  MPI_Request data;
+  int i, flag;
 
-/*int smpi_mpi_barrier(smpi_mpi_communicator_t comm)
-{
-
-  SIMIX_mutex_lock(comm->barrier_mutex);
-  ++comm->barrier_count;
-  if (comm->barrier_count > comm->size) {       // only happens on second barrier...
-    comm->barrier_count = 0;
-  } else if (comm->barrier_count == comm->size) {
-    SIMIX_cond_broadcast(comm->barrier_cond);
-  }
-  while (comm->barrier_count < comm->size) {
-    SIMIX_cond_wait(comm->barrier_cond, comm->barrier_mutex);
+  *index = MPI_UNDEFINED;
+  flag = 0;
+  for(i = 0; i < count; i++) {
+    if(requests[i] != MPI_REQUEST_NULL) {
+      data = requests[i]->data;
+      if(data != MPI_REQUEST_NULL && data->complete == 1) {
+        SIMIX_communication_destroy(requests[i]->pair);
+        finish_wait(&requests[i], status);
+        *index = i;
+        flag = 1;
+        break;
+      }
+    }
   }
-  SIMIX_mutex_unlock(comm->barrier_mutex);
-
-  return MPI_SUCCESS;
+  return flag;
 }
-*/
 
-int smpi_mpi_isend(smpi_mpi_request_t request)
-{
-  smpi_process_data_t pdata = SIMIX_process_get_data(SIMIX_process_self());
-  int retval = MPI_SUCCESS;
+void smpi_mpi_wait(MPI_Request* request, MPI_Status* status) {
+  MPI_Request data = (*request)->data;
 
-  if (NULL == request) {
-    retval = MPI_ERR_INTERN;
+  DEBUG6("wait for request %p (%p: %p) [src = %d, dst = %d, tag = %d]",
+         *request, (*request)->pair, data, (*request)->src, (*request)->dst, (*request)->tag);
+  // data is null if receiver waits before sender enters the rdv
+  if(data == MPI_REQUEST_NULL || data->complete == 0) {
+    SIMIX_network_wait((*request)->pair, -1.0);
   } else {
-    xbt_fifo_push(pdata->pending_send_request_queue, request);
-    SIMIX_process_resume(pdata->sender);
+    SIMIX_communication_destroy((*request)->pair);
   }
-
-  return retval;
+  finish_wait(request, status);
 }
 
-int smpi_mpi_irecv(smpi_mpi_request_t request)
-{
-  int retval = MPI_SUCCESS;
-  smpi_process_data_t pdata = SIMIX_process_get_data(SIMIX_process_self());
+int smpi_mpi_waitany(int count, MPI_Request requests[], MPI_Status* status) {
+  xbt_dynar_t comms;
+  MPI_Request data;
+  int i, size, index;
+  int* map;
+
+  index = MPI_UNDEFINED;
+  if(count > 0) {
+    // First check for already completed requests
+    for(i = 0; i < count; i++) {
+      if(requests[i] != MPI_REQUEST_NULL) {
+        data = requests[i]->data;
+        if(data != MPI_REQUEST_NULL && data->complete == 1) {
+          index = i;
+          SIMIX_communication_destroy(requests[index]->pair); // always succeeds (but cleans the simix layer)
+          break;
+        }
+      }
+    }
+    if(index == MPI_UNDEFINED) {
+      // Otherwise, wait for a request to complete
+      comms = xbt_dynar_new(sizeof(smx_comm_t), NULL);
+      map = xbt_new(int, count);
+      size = 0;
+      DEBUG0("Wait for one of");
+      for(i = 0; i < count; i++) {
+        if(requests[i] != MPI_REQUEST_NULL && requests[i]->complete == 0) {
+         DEBUG4("   request %p [src = %d, dst = %d, tag = %d]",
+                requests[i], requests[i]->src, requests[i]->dst, requests[i]->tag);
+          xbt_dynar_push(comms, &requests[i]->pair);
+          map[size] = i;
+          size++;
+        }
+      }
+      if(size > 0) {
+        index = SIMIX_network_waitany(comms);
+        index = map[index];
+      }
+      xbt_free(map);
+      xbt_dynar_free_container(&comms);
+    }
+    if(index != MPI_UNDEFINED) {
+      finish_wait(&requests[index], status);
+    }
+  }
+  return index;
+}
 
-  if (NULL == request) {
-    retval = MPI_ERR_INTERN;
-  } else {
-    xbt_fifo_push(pdata->pending_recv_request_queue, request);
+void smpi_mpi_waitall(int count, MPI_Request requests[],  MPI_Status status[]) {
+  int index;
+  MPI_Status stat;
 
-    if (SIMIX_process_is_suspended(pdata->receiver)) {
-      SIMIX_process_resume(pdata->receiver);
+  while(count > 0) {
+    index = smpi_mpi_waitany(count, requests, &stat);
+    if(index == MPI_UNDEFINED) {
+      break;
     }
+    if(status != MPI_STATUS_IGNORE) {
+      memcpy(&status[index], &stat, sizeof(stat));
+    }
+    // Move the last request to the found position
+    requests[index] = requests[count - 1];
+    requests[count - 1] = MPI_REQUEST_NULL;
+    count--;
   }
+}
 
-  return retval;
+int smpi_mpi_waitsome(int incount, MPI_Request requests[], int* indices, MPI_Status status[]) {
+  MPI_Request data;
+  int i, count;
+
+  count = 0;
+  for(i = 0; i < incount; i++) {
+    if(requests[i] != MPI_REQUEST_NULL) {
+      data = requests[i]->data;
+      if(data != MPI_REQUEST_NULL && data->complete == 1) {
+        SIMIX_communication_destroy(requests[i]->pair);
+        finish_wait(&requests[i], status != MPI_STATUS_IGNORE ? &status[i] : MPI_STATUS_IGNORE);
+        indices[count] = i;
+        count++;
+      }
+    }
+  }
+  return count;
 }
 
-void  print_req( smpi_mpi_request_t r ); 
-void  print_req( smpi_mpi_request_t r ) {
-        printf("***req %p-> src=%d dst=%d tag=%d completed=0x%x consumed=0x%x\n",r,r->src,r->dst,r->tag,r->completed,r->consumed);
+void smpi_mpi_bcast(void* buf, int count, MPI_Datatype datatype, int root, MPI_Comm comm) {
+  // arity=2: a binary tree, arity=4 seem to be a good setting (see P2P-MPI))
+  nary_tree_bcast(buf, count, datatype, root, comm, 4);
 }
 
+void smpi_mpi_barrier(MPI_Comm comm) {
+  // arity=2: a binary tree, arity=4 seem to be a good setting (see P2P-MPI))
+  nary_tree_barrier(comm, 4);
+}
 
-/**
- * wait and friends ...
- **/
-int smpi_mpi_wait(smpi_mpi_request_t request, smpi_mpi_status_t * status)
-{
-  int retval = MPI_SUCCESS;
+void smpi_mpi_gather(void* sendbuf, int sendcount, MPI_Datatype sendtype, void* recvbuf, int recvcount, MPI_Datatype recvtype, int root, MPI_Comm comm) {
+  int system_tag = 666;
+  int rank, size, src, index, sendsize, recvsize;
+  MPI_Request* requests;
 
-  if (NULL == request) {
-    retval = MPI_ERR_INTERN;
+  rank = smpi_comm_rank(comm);
+  size = smpi_comm_size(comm);
+  if(rank != root) {
+    // Send buffer to root
+    smpi_mpi_send(sendbuf, sendcount, sendtype, root, system_tag, comm);
   } else {
-    SIMIX_mutex_lock(request->mutex);
-
-#ifdef DEBUG_STEPH
-    print_req( request );  //@@
-#endif
-    while (!request->completed) {
-      SIMIX_cond_wait(request->cond, request->mutex);
+    sendsize = smpi_datatype_size(sendtype);
+    recvsize = smpi_datatype_size(recvtype);
+    // Local copy from root
+    memcpy(&((char*)recvbuf)[root * recvcount * recvsize], sendbuf, sendcount * sendsize * sizeof(char));
+    // Receive buffers from senders
+    requests = xbt_new(MPI_Request, size - 1);
+    index = 0;
+    for(src = 0; src < size; src++) {
+      if(src != root) {
+        requests[index] = smpi_mpi_irecv(&((char*)recvbuf)[src * recvcount * recvsize], recvcount, recvtype, src, system_tag, comm);
+        index++;
+      }
     }
-    if (NULL != status) {
-      status->MPI_SOURCE = request->src;
-      status->MPI_TAG = request->tag;
-      status->MPI_ERROR = MPI_SUCCESS;
+    // Wait for completion of irecv's.
+    smpi_mpi_waitall(size - 1, requests, MPI_STATUS_IGNORE);
+    xbt_free(requests);
+  }
+}
+
+void smpi_mpi_gatherv(void* sendbuf, int sendcount, MPI_Datatype sendtype, void* recvbuf, int* recvcounts, int* displs, MPI_Datatype recvtype, int root, MPI_Comm comm) {
+  int system_tag = 666;
+  int rank, size, src, index, sendsize;
+  MPI_Request* requests;
+
+  rank = smpi_comm_rank(comm);
+  size = smpi_comm_size(comm);
+  if(rank != root) {
+    // Send buffer to root
+    smpi_mpi_send(sendbuf, sendcount, sendtype, root, system_tag, comm);
+  } else {
+    sendsize = smpi_datatype_size(sendtype);
+    // Local copy from root
+    memcpy(&((char*)recvbuf)[displs[root]], sendbuf, sendcount * sendsize * sizeof(char));
+    // Receive buffers from senders
+    requests = xbt_new(MPI_Request, size - 1);
+    index = 0;
+    for(src = 0; src < size; src++) {
+      if(src != root) {
+        requests[index] = smpi_mpi_irecv(&((char*)recvbuf)[displs[src]], recvcounts[src], recvtype, src, system_tag, comm);
+        index++;
+      }
     }
-    SIMIX_mutex_unlock(request->mutex);
+    // Wait for completion of irecv's.
+    smpi_mpi_waitall(size - 1, requests, MPI_STATUS_IGNORE);
+    xbt_free(requests);
   }
+}
 
-  return retval;
+void smpi_mpi_allgather(void* sendbuf, int sendcount, MPI_Datatype sendtype, void* recvbuf, int recvcount, MPI_Datatype recvtype, MPI_Comm comm) {
+  int system_tag = 666;
+  int rank, size, other, index, sendsize, recvsize;
+  MPI_Request* requests;
+
+  rank = smpi_comm_rank(comm);
+  size = smpi_comm_size(comm);
+  sendsize = smpi_datatype_size(sendtype);
+  recvsize = smpi_datatype_size(recvtype);
+  // Local copy from self
+  memcpy(&((char*)recvbuf)[rank * recvcount * recvsize], sendbuf, sendcount * sendsize * sizeof(char));
+  // Send/Recv buffers to/from others;
+  requests = xbt_new(MPI_Request, 2 * (size - 1));
+  index = 0;
+  for(other = 0; other < size; other++) {
+    if(other != rank) {
+      requests[index] = smpi_mpi_isend(sendbuf, sendcount, sendtype, other, system_tag, comm);
+      index++;
+      requests[index] = smpi_mpi_irecv(&((char*)recvbuf)[other * recvcount * recvsize], recvcount, recvtype, other, system_tag, comm);
+      index++;
+    }
+  }
+  // Wait for completion of all comms.
+  smpi_mpi_waitall(2 * (size - 1), requests, MPI_STATUS_IGNORE);
+  xbt_free(requests);
 }
 
-/**
- * waitall
- **/
-int smpi_mpi_waitall(int count, smpi_mpi_request_t requests[],
-                smpi_mpi_status_t status[])
-{
-        int cpt;
-        int index;
-        int retval;
-        smpi_mpi_status_t stat;
-
-        for (cpt = 0; cpt < count; cpt++) {
-                retval = smpi_mpi_waitany(count, requests, &index, &stat);
-                if (retval != MPI_SUCCESS)
-                        return retval;
-                if (MPI_STATUS_IGNORE != status)
-                        memcpy(&(status[index]), &stat, sizeof(stat));
-        }
-        return MPI_SUCCESS;
+void smpi_mpi_allgatherv(void* sendbuf, int sendcount, MPI_Datatype sendtype, void* recvbuf, int* recvcounts, int* displs, MPI_Datatype recvtype, MPI_Comm comm) {
+  int system_tag = 666;
+  int rank, size, other, index, sendsize, recvsize;
+  MPI_Request* requests;
+
+  rank = smpi_comm_rank(comm);
+  size = smpi_comm_size(comm);
+  sendsize = smpi_datatype_size(sendtype);
+  recvsize = smpi_datatype_size(recvtype);
+  // Local copy from self
+  memcpy(&((char*)recvbuf)[displs[rank]], sendbuf, sendcount * sendsize * sizeof(char));
+  // Send buffers to others;
+  requests = xbt_new(MPI_Request, 2 * (size - 1));
+  index = 0;
+  for(other = 0; other < size; other++) {
+    if(other != rank) {
+      requests[index] = smpi_mpi_isend(sendbuf, sendcount, sendtype, other, system_tag, comm);
+      index++;
+      requests[index] = smpi_mpi_irecv(&((char*)recvbuf)[displs[other]], recvcounts[other], recvtype, other, system_tag, comm);
+      index++;
+    }
+  }
+  // Wait for completion of all comms.
+  smpi_mpi_waitall(2 * (size - 1), requests, MPI_STATUS_IGNORE);
+  xbt_free(requests);
 }
 
-/**
- * waitany
- **/
-int smpi_mpi_waitany(int count, smpi_mpi_request_t * requests, int *index,
-                     smpi_mpi_status_t * status)
-{
-  int cpt;
+void smpi_mpi_scatter(void* sendbuf, int sendcount, MPI_Datatype sendtype, void* recvbuf, int recvcount, MPI_Datatype recvtype, int root, MPI_Comm comm) {
+  int system_tag = 666;
+  int rank, size, dst, index, sendsize, recvsize;
+  MPI_Request* requests;
 
-  *index = MPI_UNDEFINED;
-  if (NULL == requests) {
-    return MPI_ERR_INTERN;
-  }
-  /* First check if one of them is already done */
-  for (cpt = 0; cpt < count; cpt++) {
-#ifdef DEBUG_STEPH
-          printf("...exam req[%d] of msg from [%d]\n",cpt,requests[cpt]->src);
-#endif
-    if (requests[cpt]->completed && !requests[cpt]->consumed) { /* got ya */
-#ifdef DEBUG_STEPH
-          printf("...found match req[%d] of msg from [%d]\n",cpt,requests[cpt]->src);
-#endif
-      *index = cpt;
-      goto found_request;
+  rank = smpi_comm_rank(comm);
+  size = smpi_comm_size(comm);
+  if(rank != root) {
+    // Recv buffer from root
+    smpi_mpi_recv(recvbuf, recvcount, recvtype, root, system_tag, comm, MPI_STATUS_IGNORE);
+  } else {
+    sendsize = smpi_datatype_size(sendtype);
+    recvsize = smpi_datatype_size(recvtype);
+    // Local copy from root
+    memcpy(recvbuf, &((char*)sendbuf)[root * sendcount * sendsize], recvcount * recvsize * sizeof(char));
+    // Send buffers to receivers
+    requests = xbt_new(MPI_Request, size - 1);
+    index = 0;
+    for(dst = 0; dst < size; dst++) {
+      if(dst != root) {
+        requests[index] = smpi_mpi_isend(&((char*)sendbuf)[dst * sendcount * sendsize], sendcount, sendtype, dst, system_tag, comm);
+        index++;
+      }
     }
+    // Wait for completion of isend's.
+    smpi_mpi_waitall(size - 1, requests, MPI_STATUS_IGNORE);
+    xbt_free(requests);
   }
-  /* If none found, block */
-  /* FIXME: should use a SIMIX_cond_waitany, when implemented. For now, block on the first one */
-  while (1) {
-    for (cpt = 0; cpt < count; cpt++) {
-
-#ifdef DEBUG_STEPH
-      print_req( requests[cpt] );
-#endif
-      if (!requests[cpt]->completed) {  /* this one is not done, wait on it */
-#ifdef DEBUG_STEPH
-              printf("... blocked waiting a msg %d->%d, tag=%d\n",requests[cpt]->src,requests[cpt]->dst,requests[cpt]->tag);
-#endif
-        while (!requests[cpt]->completed)
-          SIMIX_cond_wait(requests[cpt]->cond, requests[cpt]->mutex);
-
-        *index = cpt;
-        goto found_request;
+}
+
+void smpi_mpi_scatterv(void* sendbuf, int* sendcounts, int* displs, MPI_Datatype sendtype, void* recvbuf, int recvcount, MPI_Datatype recvtype, int root, MPI_Comm comm) {
+  int system_tag = 666;
+  int rank, size, dst, index, sendsize, recvsize;
+  MPI_Request* requests;
+
+  rank = smpi_comm_rank(comm);
+  size = smpi_comm_size(comm);
+  if(rank != root) {
+    // Recv buffer from root
+    smpi_mpi_recv(recvbuf, recvcount, recvtype, root, system_tag, comm, MPI_STATUS_IGNORE);
+  } else {
+    sendsize = smpi_datatype_size(sendtype);
+    recvsize = smpi_datatype_size(recvtype);
+    // Local copy from root
+    memcpy(recvbuf, &((char*)sendbuf)[displs[root]], recvcount * recvsize * sizeof(char));
+    // Send buffers to receivers
+    requests = xbt_new(MPI_Request, size - 1);
+    index = 0;
+    for(dst = 0; dst < size; dst++) {
+      if(dst != root) {
+        requests[index] = smpi_mpi_isend(&((char*)sendbuf)[displs[dst]], sendcounts[dst], sendtype, dst, system_tag, comm);
+        index++;
       }
     }
-    if (cpt == count)           /* they are all done. Damn user */
-      return MPI_ERR_REQUEST;
+    // Wait for completion of isend's.
+    smpi_mpi_waitall(size - 1, requests, MPI_STATUS_IGNORE);
+    xbt_free(requests);
   }
+}
 
-found_request:
-#ifdef DEBUG_STEPH
-      print_req( requests[cpt] );
-#endif
-  requests[*index]->consumed = 1;
-#ifdef DEBUG_STEPH
-      print_req( requests[cpt] );
-          printf("...accessing *req[%d]->consumed\n",cpt);
-#endif
-  if (NULL != status) {
-    status->MPI_SOURCE = requests[*index]->src;
-    status->MPI_TAG = requests[*index]->tag;
-    status->MPI_ERROR = MPI_SUCCESS;
+void smpi_mpi_reduce(void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op, int root, MPI_Comm comm) {
+  int system_tag = 666;
+  int rank, size, src, index, datasize;
+  MPI_Request* requests;
+  void** tmpbufs;
+ 
+  rank = smpi_comm_rank(comm);
+  size = smpi_comm_size(comm);
+  if(rank != root) {
+    // Send buffer to root
+    smpi_mpi_send(sendbuf, count, datatype, root, system_tag, comm);
+  } else {
+    datasize = smpi_datatype_size(datatype);
+    // Local copy from root
+    memcpy(recvbuf, sendbuf, count * datasize * sizeof(char)); 
+    // Receive buffers from senders
+    //TODO: make a MPI_barrier here ?
+    requests = xbt_new(MPI_Request, size - 1);
+    tmpbufs = xbt_new(void*, size - 1);
+    index = 0;
+    for(src = 0; src < size; src++) {
+      if(src != root) {
+        tmpbufs[index] = xbt_malloc(count * datasize);
+        requests[index] = smpi_mpi_irecv(tmpbufs[index], count, datatype, src, system_tag, comm);
+        index++;
+      }
+    }
+    // Wait for completion of irecv's.
+    for(src = 0; src < size - 1; src++) {
+      index = smpi_mpi_waitany(size - 1, requests, MPI_STATUS_IGNORE);
+      if(index == MPI_UNDEFINED) {
+        break;
+      }
+      smpi_op_apply(op, tmpbufs[index], recvbuf, &count, &datatype);
+    }
+    for(index = 0; index < size - 1; index++) {
+      xbt_free(tmpbufs[index]);
+    }
+    xbt_free(tmpbufs);
+    xbt_free(requests);
   }
-  return MPI_SUCCESS;
+}
 
+void smpi_mpi_allreduce(void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op, MPI_Comm comm) {
+  smpi_mpi_reduce(sendbuf, recvbuf, count, datatype, op, 0, comm);
+  smpi_mpi_bcast(recvbuf, count, datatype, 0, comm);
+
+/*
+FIXME: buggy implementation
+
+  int system_tag = 666;
+  int rank, size, other, index, datasize;
+  MPI_Request* requests;
+  void** tmpbufs;
+ 
+  rank = smpi_comm_rank(comm);
+  size = smpi_comm_size(comm);
+  datasize = smpi_datatype_size(datatype);
+  // Local copy from self
+  memcpy(recvbuf, sendbuf, count * datasize * sizeof(char)); 
+  // Send/Recv buffers to/from others;
+  //TODO: make a MPI_barrier here ?
+  requests = xbt_new(MPI_Request, 2 * (size - 1));
+  tmpbufs = xbt_new(void*, size - 1);
+  index = 0;
+  for(other = 0; other < size; other++) {
+    if(other != rank) {
+      tmpbufs[index / 2] = xbt_malloc(count * datasize);
+      requests[index] = smpi_mpi_isend(sendbuf, count, datatype, other, system_tag, comm);
+      requests[index + 1] = smpi_mpi_irecv(tmpbufs[index / 2], count, datatype, other, system_tag, comm);
+      index += 2;
+    }
+  }
+  // Wait for completion of all comms.
+  for(other = 0; other < 2 * (size - 1); other++) {
+    index = smpi_mpi_waitany(size - 1, requests, MPI_STATUS_IGNORE);
+    if(index == MPI_UNDEFINED) {
+      break;
+    }
+    if((index & 1) == 1) {
+      // Request is odd: it's a irecv
+      smpi_op_apply(op, tmpbufs[index / 2], recvbuf, &count, &datatype);
+    }
+  }
+  for(index = 0; index < size - 1; index++) {
+    xbt_free(tmpbufs[index]);
+  }
+  xbt_free(tmpbufs);
+  xbt_free(requests);
+*/
 }