/* -*- 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"

#if defined(HAVE_STRERROR_R) && defined(NEEDS_STRERROR_R_DECL)

#if defined(STRERROR_R_CHAR_P)

char *strerror_r(int errnum, char *strerrbuf, size_t buflen);

#else

int strerror_r(int errnum, char *strerrbuf, size_t buflen);

#endif

#endif

/* ideally, provides a thread-safe version of strerror */

const char *MPIR_Strerror(int errnum)

{

#if defined(HAVE_STRERROR_R)

    char *buf;

    MPIR_Per_thread_t *per_thread = NULL;

    int err = 0;

    MPID_THREADPRIV_KEY_GET_ADDR(MPIR_ThreadInfo.isThreaded, MPIR_Per_thread_key,

                                 MPIR_Per_thread, per_thread, &err;;

    MPIR_Assert(err == 0);

    buf = per_thread->strerrbuf;

#if defined(STRERROR_R_CHAR_P)

    /* strerror_r returns char ptr (old GNU-flavor).  Static strings for known

     * errnums are in returned buf, unknown errnums put a message in buf and

     * return buf */

    buf = strerror_r(errnum, buf, MPIR_STRERROR_BUF_SIZE);

#else

    /* strerror_r returns an int */

    strerror_r(errnum, buf, MPIR_STRERROR_BUF_SIZE);

#endif

    return buf;

#elif defined(HAVE_STRERROR)

    /* MT - not guaranteed to be thread-safe, but on may platforms it will be

     * anyway for the most common cases (looking up an error string in a table

     * of constants).

     *

     * Using a mutex here would be an option, but then you need a version

     * without the mutex to call when interpreting errors from mutex functions

     * themselves. */

    return strerror(errnum);

#else

    /* nowadays this case is most likely to happen because of a configure or

     * internal header file inclusion bug rather than an actually missing

     * strerror routine */

    return "(strerror() unavailable on this platform)"

#endif

}