text: /* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
  /*
   *
   *  (C) 2001 by Argonne National Laboratory.
   *      See COPYRIGHT in top-level directory.
   */
  
  #include "mpiimpl.h"
  
  /* -- Begin Profiling Symbol Block for routine MPI_Sendrecv */
  #if defined(HAVE_PRAGMA_WEAK)
  #pragma weak MPI_Sendrecv = PMPI_Sendrecv
  #elif defined(HAVE_PRAGMA_HP_SEC_DEF)
  #pragma _HP_SECONDARY_DEF PMPI_Sendrecv  MPI_Sendrecv
  #elif defined(HAVE_PRAGMA_CRI_DUP)
  #pragma _CRI duplicate MPI_Sendrecv as PMPI_Sendrecv
  #elif defined(HAVE_WEAK_ATTRIBUTE)
  int MPI_Sendrecv(const void *sendbuf, int sendcount, MPI_Datatype sendtype, int dest,
                   int sendtag, void *recvbuf, int recvcount, MPI_Datatype recvtype,
                   int source, int recvtag, MPI_Comm comm, MPI_Status *status)
                   __attribute__((weak,alias("PMPI_Sendrecv")));
  #endif
  /* -- End Profiling Symbol Block */
  
  /* Define MPICH_MPI_FROM_PMPI if weak symbols are not supported to build
     the MPI routines */
  #ifndef MPICH_MPI_FROM_PMPI
  #undef MPI_Sendrecv
  #define MPI_Sendrecv PMPI_Sendrecv
  
  #endif
  
  #undef FUNCNAME
  #define FUNCNAME MPI_Sendrecv
  
  /*@
      MPI_Sendrecv - Sends and receives a message
  
  Input Parameters:
  + sendbuf - initial address of send buffer (choice) 
  . sendcount - number of elements in send buffer (integer) 
  . sendtype - type of elements in send buffer (handle) 
  . dest - rank of destination (integer) 
  . sendtag - send tag (integer) 
  . recvcount - number of elements in receive buffer (integer) 
  . recvtype - type of elements in receive buffer (handle) 
  . source - rank of source (integer) 
  . recvtag - receive tag (integer) 
  - comm - communicator (handle) 
  
  Output Parameters:
  + recvbuf - initial address of receive buffer (choice) 
  - status - status object (Status).  This refers to the receive operation.
  
  .N ThreadSafe
    
  .N Fortran
  
  .N FortranStatus
  
  .N Errors
  .N MPI_SUCCESS
  .N MPI_ERR_COMM
  .N MPI_ERR_COUNT
  .N MPI_ERR_TYPE
  .N MPI_ERR_TAG
  .N MPI_ERR_RANK
  
  @*/
  int MPI_Sendrecv(const void *sendbuf, int sendcount, MPI_Datatype sendtype,
  		 int dest, int sendtag,
  		 void *recvbuf, int recvcount, MPI_Datatype recvtype,
  		 int source, int recvtag,
  		 MPI_Comm comm, MPI_Status *status)
  {
      static const char FCNAME[] = "MPI_Sendrecv";
      int mpi_errno = MPI_SUCCESS;
      MPID_Comm *comm_ptr = NULL;
      MPID_Request * sreq;
      MPID_Request * rreq;
      MPID_MPI_STATE_DECL(MPID_STATE_MPI_SENDRECV);
      
      MPIR_ERRTEST_INITIALIZED_ORDIE();
      
      MPIU_THREAD_CS_ENTER(ALLFUNC,);
      MPID_MPI_PT2PT_FUNC_ENTER_BOTH(MPID_STATE_MPI_SENDRECV);
      
      /* Validate handle parameters needing to be converted */
  #   ifdef HAVE_ERROR_CHECKING
      {
          MPID_BEGIN_ERROR_CHECKS;
          {
  	    MPIR_ERRTEST_COMM(comm, mpi_errno);
  	}
          MPID_END_ERROR_CHECKS;
      }
  #   endif /* HAVE_ERROR_CHECKING */
      
      /* Convert handles to MPI objects. */
      MPID_Comm_get_ptr( comm, comm_ptr );
      
  #   ifdef HAVE_ERROR_CHECKING
      {
          MPID_BEGIN_ERROR_CHECKS;
          {
  	    /* Validate communicator */
              MPID_Comm_valid_ptr( comm_ptr, mpi_errno, FALSE );
              if (mpi_errno) goto fn_fail;
  	    
  	    /* Validate count */
  	    MPIR_ERRTEST_COUNT(sendcount,mpi_errno);
  	    MPIR_ERRTEST_COUNT(recvcount,mpi_errno);
  
  	    /* Validate status (status_ignore is not the same as null) */
  	    MPIR_ERRTEST_ARGNULL( status, "status", mpi_errno );
  
  	    /* Validate tags */
  	    MPIR_ERRTEST_SEND_TAG(sendtag,mpi_errno );
  	    MPIR_ERRTEST_RECV_TAG(recvtag,mpi_errno );
  
  	    /* Validate source and destination */
  	    if (comm_ptr) {
  		MPIR_ERRTEST_SEND_RANK(comm_ptr, dest, mpi_errno );
  		MPIR_ERRTEST_RECV_RANK(comm_ptr, source, mpi_errno );
  	    }
  
  	    /* Validate datatype handles */
  	    MPIR_ERRTEST_DATATYPE(sendtype, "datatype", mpi_errno);
  	    MPIR_ERRTEST_DATATYPE(recvtype, "datatype", mpi_errno);
  	    
  	    /* Validate datatype objects */
  	    if (HANDLE_GET_KIND(sendtype) != HANDLE_KIND_BUILTIN)
  	    {
  		MPID_Datatype *datatype_ptr = NULL;
  
  		MPID_Datatype_get_ptr(sendtype, datatype_ptr);
  		MPID_Datatype_valid_ptr(datatype_ptr, mpi_errno);
  		if (mpi_errno) goto fn_fail;
  		MPID_Datatype_committed_ptr(datatype_ptr, mpi_errno);
  		if (mpi_errno) goto fn_fail;
  	    }
  	    if (HANDLE_GET_KIND(recvtype) != HANDLE_KIND_BUILTIN)
  	    {
  		MPID_Datatype *datatype_ptr = NULL;
  
  		MPID_Datatype_get_ptr(recvtype, datatype_ptr);
  		MPID_Datatype_valid_ptr(datatype_ptr, mpi_errno);
  		if (mpi_errno) goto fn_fail;
  		MPID_Datatype_committed_ptr(datatype_ptr, mpi_errno);
  		if (mpi_errno) goto fn_fail;
  	    }
  	    
  	    /* Validate buffers */
  	    MPIR_ERRTEST_USERBUFFER(sendbuf,sendcount,sendtype,mpi_errno);
  	    MPIR_ERRTEST_USERBUFFER(recvbuf,recvcount,recvtype,mpi_errno);
          }
          MPID_END_ERROR_CHECKS;
      }
  #   endif /* HAVE_ERROR_CHECKING */
  
      /* ... body of routine ...  */
      
      mpi_errno = MPID_Irecv(recvbuf, recvcount, recvtype, source, recvtag, comm_ptr, MPID_CONTEXT_INTRA_PT2PT, &rreq);
      if (mpi_errno != MPI_SUCCESS) goto fn_fail;
  
      /* FIXME - Performance for small messages might be better if MPID_Send() were used here instead of MPID_Isend() */
      mpi_errno = MPID_Isend(sendbuf, sendcount, sendtype, dest, sendtag, comm_ptr, MPID_CONTEXT_INTRA_PT2PT, &sreq);
      if (mpi_errno != MPI_SUCCESS)
      {
  	/* --BEGIN ERROR HANDLING-- */
  	/* FIXME: should we cancel the pending (possibly completed) receive request or wait for it to complete? */
  	MPID_Request_release(rreq);
  	goto fn_fail;
  	/* --END ERROR HANDLING-- */
      }
  
      if (!MPID_Request_is_complete(sreq) || !MPID_Request_is_complete(rreq))
      {
  	MPID_Progress_state progress_state;
  	
  	MPID_Progress_start(&progress_state);
          while (!MPID_Request_is_complete(sreq) || !MPID_Request_is_complete(rreq))
  	{
  	    mpi_errno = MPID_Progress_wait(&progress_state);
  	    if (mpi_errno != MPI_SUCCESS)
  	    {
  		/* --BEGIN ERROR HANDLING-- */
  		MPID_Progress_end(&progress_state);
  		goto fn_fail;
  		/* --END ERROR HANDLING-- */
  	    }
  
              if (unlikely(MPIR_CVAR_ENABLE_FT &&
                          !MPID_Request_is_complete(rreq) &&
                          MPID_Request_is_anysource(rreq) &&
                          !MPID_Comm_AS_enabled(rreq->comm))) {
                  /* --BEGIN ERROR HANDLING-- */
                  MPID_Cancel_recv(rreq);
                  MPIR_STATUS_SET_CANCEL_BIT(rreq->status, FALSE);
                  MPIU_ERR_SET(rreq->status.MPI_ERROR, MPIX_ERR_PROC_FAILED, "**proc_failed");
                  mpi_errno = rreq->status.MPI_ERROR;
                  if (!MPID_Request_is_complete(sreq)) {
                      MPID_Cancel_send(sreq);
                      MPIR_STATUS_SET_CANCEL_BIT(sreq->status, FALSE);
                  }
                  goto fn_fail;
                  /* --END ERROR HANDLING-- */
              }
  	}
  	MPID_Progress_end(&progress_state);
      }
  
      mpi_errno = rreq->status.MPI_ERROR;
      MPIR_Request_extract_status(rreq, status);
      MPID_Request_release(rreq);
      
      if (mpi_errno == MPI_SUCCESS)
      {
  	mpi_errno = sreq->status.MPI_ERROR;
      }
      MPID_Request_release(sreq);
  
      if (mpi_errno != MPI_SUCCESS) goto fn_fail;
      
      /* ... end of body of routine ... */
      
    fn_exit:
      MPID_MPI_PT2PT_FUNC_EXIT_BOTH(MPID_STATE_MPI_SENDRECV);
      MPIU_THREAD_CS_EXIT(ALLFUNC,);
      return mpi_errno;
  
    fn_fail:
      /* --BEGIN ERROR HANDLING-- */
  #   ifdef HAVE_ERROR_CHECKING
      {
  	mpi_errno = MPIR_Err_create_code(
  	    mpi_errno, MPIR_ERR_RECOVERABLE, FCNAME, __LINE__, MPI_ERR_OTHER, "**mpi_sendrecv",
  	    "**mpi_sendrecv %p %d %D %i %t %p %d %D %i %t %C %p", sendbuf, sendcount, sendtype, dest, sendtag,
  	    recvbuf, recvcount, recvtype, source, recvtag, comm, status);
      }
  #   endif
      mpi_errno = MPIR_Err_return_comm( comm_ptr, FCNAME, mpi_errno );
      goto fn_exit;
      /* --END ERROR HANDLING-- */
  }
  