/* -*- 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_Recv */

#if defined(HAVE_PRAGMA_WEAK)

#pragma weak MPI_Recv = PMPI_Recv

#elif defined(HAVE_PRAGMA_HP_SEC_DEF)

#pragma _HP_SECONDARY_DEF PMPI_Recv  MPI_Recv

#elif defined(HAVE_PRAGMA_CRI_DUP)

#pragma _CRI duplicate MPI_Recv as PMPI_Recv

#elif defined(HAVE_WEAK_ATTRIBUTE)

int MPI_Recv(void *buf, int count, MPI_Datatype datatype, int source, int tag,

             MPI_Comm comm, MPI_Status *status) __attribute__((weak,alias("PMPI_Recv")));

#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_Recv

#define MPI_Recv PMPI_Recv

#endif

#undef FUNCNAME

#define FUNCNAME MPI_Recv

/*@

    MPI_Recv - Blocking receive for a message

Output Parameters:

+ buf - initial address of receive buffer (choice) 

- status - status object (Status) 

Input Parameters:

+ count - maximum number of elements in receive buffer (integer) 

. datatype - datatype of each receive buffer element (handle) 

. source - rank of source (integer) 

. tag - message tag (integer) 

- comm - communicator (handle) 

Notes:

The 'count' argument indicates the maximum length of a message; the actual 

length of the message can be determined with 'MPI_Get_count'.  

.N ThreadSafe

.N Fortran

.N FortranStatus

.N Errors

.N MPI_SUCCESS

.N MPI_ERR_COMM

.N MPI_ERR_TYPE

.N MPI_ERR_COUNT

.N MPI_ERR_TAG

.N MPI_ERR_RANK

@*/

int MPI_Recv(void *buf, int count, MPI_Datatype datatype, int source, int tag,

	     MPI_Comm comm, MPI_Status *status)

{

    static const char FCNAME[] = "MPI_Recv";

    int mpi_errno = MPI_SUCCESS;

    MPID_Comm *comm_ptr = NULL;

    MPID_Request * request_ptr = NULL;

    MPID_MPI_STATE_DECL(MPID_STATE_MPI_RECV);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

    MPID_THREAD_CS_ENTER(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);

    MPID_MPI_PT2PT_FUNC_ENTER_BACK(MPID_STATE_MPI_RECV);

    /* Validate handle parameters needing to be converted */

#   ifdef HAVE_ERROR_CHECKING

    {

        MPID_BEGIN_ERROR_CHECKS;

        {

	    MPIR_ERRTEST_COMM(comm, mpi_errno);

	    /* NOTE: MPI_STATUS_IGNORE != NULL */

	    MPIR_ERRTEST_ARGNULL(status, "status", mpi_errno);

	}

        MPID_END_ERROR_CHECKS;

    }

#   endif /* HAVE_ERROR_CHECKING */

    /* Convert MPI object handles to object pointers */

    MPID_Comm_get_ptr( comm, comm_ptr );

    /* Validate parameters if error checking is enabled */

#   ifdef HAVE_ERROR_CHECKING

    {

        MPID_BEGIN_ERROR_CHECKS;

        {

            MPID_Comm_valid_ptr( comm_ptr, mpi_errno, FALSE );

            if (mpi_errno) goto fn_fail;

	    MPIR_ERRTEST_COUNT(count, mpi_errno);

	    MPIR_ERRTEST_RECV_RANK(comm_ptr, source, mpi_errno);

	    MPIR_ERRTEST_RECV_TAG(tag, mpi_errno);

	    /* Validate datatype handle */

	    MPIR_ERRTEST_DATATYPE(datatype, "datatype", mpi_errno);

	    /* Validate datatype object */

	    if (HANDLE_GET_KIND(datatype) != HANDLE_KIND_BUILTIN)

	    {

		MPID_Datatype *datatype_ptr = NULL;

		MPID_Datatype_get_ptr(datatype, 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 buffer */

	    MPIR_ERRTEST_USERBUFFER(buf,count,datatype,mpi_errno);

        }

        MPID_END_ERROR_CHECKS;

    }

#   endif /* HAVE_ERROR_CHECKING */

    /* ... body of routine ...  */

    /* MT: Note that MPID_Recv may release the SINGLE_CS if it

       decides to block internally.  MPID_Recv in that case will

       re-aquire the SINGLE_CS before returnning */

    mpi_errno = MPID_Recv(buf, count, datatype, source, tag, comm_ptr, 

			  MPID_CONTEXT_INTRA_PT2PT, status, &request_ptr);

    if (mpi_errno != MPI_SUCCESS) goto fn_fail;

    if (request_ptr == NULL)

    {

	goto fn_exit;

    }

    /* If a request was returned, then we need to block until the request is 

       complete */

    if (!MPID_Request_is_complete(request_ptr))

    {

	MPID_Progress_state progress_state;

	MPID_Progress_start(&progress_state);

        while (!MPID_Request_is_complete(request_ptr))

	{

	    /* MT: Progress_wait may release the SINGLE_CS while it

	       waits */

	    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(request_ptr) &&

                        MPID_Request_is_anysource(request_ptr) &&

                        !MPID_Comm_AS_enabled(request_ptr->comm))) {

                /* --BEGIN ERROR HANDLING-- */

                MPID_Cancel_recv(request_ptr);

                MPIR_STATUS_SET_CANCEL_BIT(request_ptr->status, FALSE);

                MPIR_ERR_SET(request_ptr->status.MPI_ERROR, MPIX_ERR_PROC_FAILED, "**proc_failed");

                mpi_errno = request_ptr->status.MPI_ERROR;

                goto fn_fail;

                /* --END ERROR HANDLING-- */

            }

	}

	MPID_Progress_end(&progress_state);

    }

    mpi_errno = request_ptr->status.MPI_ERROR;

    MPIR_Request_extract_status(request_ptr, status);

    MPID_Request_release(request_ptr);

    if (mpi_errno != MPI_SUCCESS) goto fn_fail;

    /* ... end of body of routine ... */

  fn_exit:

    MPID_MPI_PT2PT_FUNC_EXIT_BACK(MPID_STATE_MPI_RECV);

    MPID_THREAD_CS_EXIT(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);

    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_recv",

	    "**mpi_recv %p %d %D %i %t %C %p", buf, count, datatype, source, tag, comm, status);

    }

#   endif

    mpi_errno = MPIR_Err_return_comm( comm_ptr, FCNAME, mpi_errno );

    goto fn_exit;

    /* --END ERROR HANDLING-- */

}