/* -*- 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_Comm_get_attr */
#if defined(HAVE_PRAGMA_WEAK)
#pragma weak MPI_Comm_get_attr = PMPI_Comm_get_attr
#elif defined(HAVE_PRAGMA_HP_SEC_DEF)
#pragma _HP_SECONDARY_DEF PMPI_Comm_get_attr  MPI_Comm_get_attr
#elif defined(HAVE_PRAGMA_CRI_DUP)
#pragma _CRI duplicate MPI_Comm_get_attr as PMPI_Comm_get_attr
#elif defined(HAVE_WEAK_ATTRIBUTE)
int MPI_Comm_get_attr(MPI_Comm comm, int comm_keyval, void *attribute_val, int *flag)
    __attribute__ ((weak, alias("PMPI_Comm_get_attr")));
#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_Comm_get_attr
#define MPI_Comm_get_attr PMPI_Comm_get_attr

#undef FUNCNAME
#define FUNCNAME MPII_Comm_get_attr
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)
/* Find the requested attribute.  If it exists, return either the attribute
   entry or the address of the entry, based on whether the request is for
   a pointer-valued attribute (C or C++) or an integer-valued attribute
   (Fortran, either 77 or 90).

   If the attribute has the same type as the request, it is returned as-is.
   Otherwise, the address of the attribute is returned.
*/
int MPII_Comm_get_attr(MPI_Comm comm, int comm_keyval, void *attribute_val,
                       int *flag, MPIR_Attr_type outAttrType)
{
    int mpi_errno = MPI_SUCCESS;
    MPIR_Comm *comm_ptr = NULL;
    static PreDefined_attrs attr_copy;  /* Used to provide a copy of the
                                         * predefined attributes */
    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPIR_COMM_GET_ATTR);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPIR_COMM_GET_ATTR);

    /* Validate parameters, especially handles needing to be converted */
#ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
            MPIR_ERRTEST_COMM(comm, mpi_errno);
            MPIR_ERRTEST_KEYVAL(comm_keyval, MPIR_COMM, "communicator", mpi_errno);
#ifdef NEEDS_POINTER_ALIGNMENT_ADJUST
            /* A common user error is to pass the address of a 4-byte
             * int when the address of a pointer (or an address-sized int)
             * should have been used.  We can test for this specific
             * case.  Note that this code assumes sizeof(intptr_t) is
             * a power of 2. */
            if ((intptr_t) attribute_val & (sizeof(intptr_t) - 1)) {
                MPIR_ERR_SETANDSTMT(mpi_errno, MPI_ERR_ARG, goto fn_fail, "**attrnotptr");
            }
#endif
        }
        MPID_END_ERROR_CHECKS;
    }
#endif

    /* Convert MPI object handles to object pointers */
    MPIR_Comm_get_ptr(comm, comm_ptr);

    /* Validate parameters and objects (post conversion) */
#ifdef HAVE_ERROR_CHECKING
    {
        MPID_BEGIN_ERROR_CHECKS;
        {
            /* Validate comm_ptr */
            MPIR_Comm_valid_ptr(comm_ptr, mpi_errno, TRUE);
            /* If comm_ptr is not valid, it will be reset to null */
            MPIR_ERRTEST_ARGNULL(attribute_val, "attr_val", mpi_errno);
            MPIR_ERRTEST_ARGNULL(flag, "flag", mpi_errno);
        }
        MPID_END_ERROR_CHECKS;
    }
#endif /* HAVE_ERROR_CHECKING */

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

    /* Check for builtin attribute */
    /* This code is ok for correct programs, but it would be better
     * to copy the values from the per-process block and pass the user
     * a pointer to a copy */
    /* Note that if we are called from Fortran, we must return the values,
     * not the addresses, of these attributes */
    if (HANDLE_GET_KIND(comm_keyval) == HANDLE_KIND_BUILTIN) {
        int attr_idx = comm_keyval & 0x0000000f;
        void **attr_val_p = (void **) attribute_val;
#ifdef HAVE_FORTRAN_BINDING
        /* This is an address-sized int instead of a Fortran (MPI_Fint)
         * integer because, even for the Fortran keyvals, the C interface is
         * used which stores the result in a pointer (hence we need a
         * pointer-sized int).  Thus we use intptr_t instead of MPI_Fint.
         * On some 64-bit plaforms, such as Solaris-SPARC, using an MPI_Fint
         * will cause the value to placed into the high, rather than low,
         * end of the output value. */
#endif
        *flag = 1;

        /* FIXME : We could initialize some of these here; only tag_ub is
         * used in the error checking. */
        /*
         * The C versions of the attributes return the address of a
         * *COPY* of the value (to prevent the user from changing it)
         * and the Fortran versions provide the actual value (as an Fint)
         */
        attr_copy = MPIR_Process.attrs;
        switch (attr_idx) {
            case 1:    /* TAG_UB */
            case 2:
                *attr_val_p = &attr_copy.tag_ub;
                break;
            case 3:    /* HOST */
            case 4:
                *attr_val_p = &attr_copy.host;
                break;
            case 5:    /* IO */
            case 6:
                *attr_val_p = &attr_copy.io;
                break;
            case 7:    /* WTIME */
            case 8:
                *attr_val_p = &attr_copy.wtime_is_global;
                break;
            case 9:    /* UNIVERSE_SIZE */
            case 10:
                /* This is a special case.  If universe is not set, then we
                 * attempt to get it from the device.  If the device is doesn't
                 * supply a value, then we set the flag accordingly.  Note that
                 * we must initialize the cached value, in MPIR_Process.attr,
                 * not the value in the copy, since that is vulnerable to being
                 * overwritten by the user, and because we always re-initialize
                 * the copy from the cache (yes, there was a time when the code
                 * did the wrong thing here). */
                if (attr_copy.universe >= 0) {
                    *attr_val_p = &attr_copy.universe;
                } else if (attr_copy.universe == MPIR_UNIVERSE_SIZE_NOT_AVAILABLE) {
                    *flag = 0;
                } else {
                    /* We call MPID_Get_universe_size only once (see 10.5.1).
                     * Thus, we must put the value into the "master" copy */
                    mpi_errno = MPID_Get_universe_size(&MPIR_Process.attrs.universe);
                    /* --BEGIN ERROR HANDLING-- */
                    if (mpi_errno != MPI_SUCCESS) {
                        MPIR_Process.attrs.universe = MPIR_UNIVERSE_SIZE_NOT_AVAILABLE;
                        goto fn_fail;
                    }
                    /* --END ERROR HANDLING-- */
                    attr_copy.universe = MPIR_Process.attrs.universe;
                    if (attr_copy.universe >= 0) {
                        *attr_val_p = &attr_copy.universe;
                    } else {
                        *flag = 0;
                    }
                }
                break;
            case 11:   /* LASTUSEDCODE */
            case 12:
                *attr_val_p = &attr_copy.lastusedcode;
                break;
            case 13:   /* APPNUM */
            case 14:
                /* This is another special case.  If appnum is negative,
                 * we take that as indicating no value of APPNUM, and set
                 * the flag accordingly */
                if (attr_copy.appnum < 0) {
                    *flag = 0;
                } else {
                    *attr_val_p = &attr_copy.appnum;
                }
                break;
        }
        /* All of the predefined attributes are stored internally as C ints;
         * since we've set the output value as the pointer to these, we need
         * to dereference it here. We must also be very careful of the 3
         * different output cases, since the two Fortran cases correspond
         * to MPI_Fint and MPIR_FAint (an internal MPICH typedef for C
         * version of INTEGER (KIND=MPI_ADDRESS_KIND)) */
        if (*flag) {
            /* Use the internal pointer-sized-int for systems (e.g., BG/P)
             * that define MPI_Aint as a different size than intptr_t.
             * The casts must be as they are:
             * On the right, the value is a pointer to an int, so to
             * get the correct value, we need to extract the int.
             * On the left, the output type is given by the argument
             * outAttrType - and the cast must match the intended results */
            /* FIXME: This code is broken.  The MPIR_ATTR_INT is for Fortran
             * MPI_Fint types, not int, and MPIR_ATTR_AINT is for Fortran
             * INTEGER(KIND=MPI_ADDRESS_KIND), which is probably an MPI_Aint,
             * and intptr_t is for exactly the case where MPI_Aint is not
             * the same as intptr_t.
             * This code needs to be fixed in every place that it occurs
             * (i.e., see the win and type get_attr routines). */
            if (outAttrType == MPIR_ATTR_AINT)
                *(intptr_t *) attr_val_p = *(int *) *(void **) attr_val_p;
            else if (outAttrType == MPIR_ATTR_INT) {
                /* *(int*)attr_val_p = *(int *)*(void **)attr_val_p; */
                /* This is correct, because the cooresponding code
                 * in the Fortran interface expects to find a pointer-length
                 * integer value.  Thus, this works for both big and little
                 * endian systems. Any changes made here must have
                 * corresponding changes in src/binding/f77/attr_getf.c ,
                 * which is generated by src/binding/f77/buildiface . */
                *(intptr_t *) attr_val_p = *(int *) *(void **) attr_val_p;
            }
        }
    } else {
        MPIR_Attribute *p = comm_ptr->attributes;

        /*   */
        *flag = 0;
        while (p) {
            if (p->keyval->handle == comm_keyval) {
                *flag = 1;
                if (outAttrType == MPIR_ATTR_PTR) {
                    if (p->attrType == MPIR_ATTR_INT) {
                        /* This is the tricky case: if the system is
                         * bigendian, and we have to return a pointer to
                         * an int, then we may need to point to the
                         * correct location in the word. */
#if defined(WORDS_LITTLEENDIAN) || (SIZEOF_VOID_P == SIZEOF_INT)
                        *(void **) attribute_val = &(p->value);
#else
                        int *p_loc = (int *) &(p->value);
#if SIZEOF_VOID_P == 2 * SIZEOF_INT
                        p_loc++;
#else
#error Expected sizeof(void*) to be either sizeof(int) or 2*sizeof(int)
#endif
                        *(void **) attribute_val = p_loc;
#endif
                    } else if (p->attrType == MPIR_ATTR_AINT) {
                        *(void **) attribute_val = &(p->value);
                    } else {
                        *(void **) attribute_val = (void *) (intptr_t) (p->value);
                    }
                } else {
                    *(void **) attribute_val = (void *) (intptr_t) (p->value);
                }

                break;
            }
            p = p->next;
        }
    }
    /* ... end of body of routine ... */

  fn_exit:
    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPIR_COMM_GET_ATTR);
    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,
                                 "**mpir_comm_get_attr", "**mpir_comm_get_attr %C %d %p %p", comm,
                                 comm_keyval, attribute_val, flag);
    }
#endif
    mpi_errno = MPIR_Err_return_comm(comm_ptr, FCNAME, mpi_errno);
    goto fn_exit;
    /* --END ERROR HANDLING-- */
}

/* This function is called by the fortran bindings. */
/* FIXME: There is no reason to have this routine since it unnecessarily
   duplicates the MPII_Comm_get_attr interface. */
int MPII_Comm_get_attr_fort(MPI_Comm comm, int comm_keyval, void *attribute_val,
                            int *flag, MPIR_Attr_type outAttrType)
{
    int mpi_errno;

    MPID_THREAD_CS_ENTER(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
    mpi_errno = MPII_Comm_get_attr(comm, comm_keyval, attribute_val, flag, outAttrType);
    MPID_THREAD_CS_EXIT(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);

    return mpi_errno;
}


#endif /* MPICH_MPI_FROM_PMPI */

#undef FUNCNAME
#define FUNCNAME MPI_Comm_get_attr
#undef FCNAME
#define FCNAME MPL_QUOTE(FUNCNAME)

/* FIXME: Attributes must be visable from all languages */
/*@
   MPI_Comm_get_attr - Retrieves attribute value by key

Input Parameters:
+ comm - communicator to which attribute is attached (handle)
- comm_keyval - key value (integer)

Output Parameters:
+ attribute_val - attribute value, unless 'flag' = false
- flag -  true if an attribute value was extracted;  false if no attribute is
  associated with the key

   Notes:
    Attributes must be extracted from the same language as they were inserted
    in with 'MPI_Comm_set_attr'.  The notes for C and Fortran below explain
    why.

Notes for C:
    Even though the 'attr_value' argument is declared as 'void *', it is
    really the address of a void pointer.  See the rationale in the
    standard for more details.

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_COMM
.N MPI_ERR_KEYVAL
@*/
int MPI_Comm_get_attr(MPI_Comm comm, int comm_keyval, void *attribute_val, int *flag)
{
    int mpi_errno = MPI_SUCCESS;
    MPIR_FUNC_TERSE_STATE_DECL(MPID_STATE_MPI_COMM_GET_ATTR);

    MPIR_ERRTEST_INITIALIZED_ORDIE();

    MPID_THREAD_CS_ENTER(GLOBAL, MPIR_THREAD_GLOBAL_ALLFUNC_MUTEX);
    MPIR_FUNC_TERSE_ENTER(MPID_STATE_MPI_COMM_GET_ATTR);

    /* Instead, ask for a desired type. */
    mpi_errno = MPII_Comm_get_attr(comm, comm_keyval, attribute_val, flag, MPIR_ATTR_PTR);
    if (mpi_errno)
        goto fn_fail;
    /* ... end of body of routine ... */

  fn_exit:
    MPIR_FUNC_TERSE_EXIT(MPID_STATE_MPI_COMM_GET_ATTR);
    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_comm_get_attr", "**mpi_comm_get_attr %C %d %p %p", comm,
                                 comm_keyval, attribute_val, flag);
    }
#endif
    goto fn_exit;
    /* --END ERROR HANDLING-- */
}
