[svn-r6708] Purpose:

    Bug fixes/API changes

Description:
    Previously, the Communicator and Info object arguments supplied
    to H5Pset_fapl_mpio() are stored in the property with its handle
    values.  This meant changes to the communicator or the Info object
    after calling H5Pset_fapl_mpio would affect the how the property
    list function.  This was also the case when H5Fopen/create operated.
    They just stored the handle value.  This is not according to the
    MPI-2 defined behavior of how Info objects should be handled. (MPI-2
    defines Info objects must be parsed when called.)
    The old design was trying to avoid numerous duplicates of the same
    information (e.g., every property object holds one version, every
    file opened holds another version, when all of them are referring to
    the same original version.)  Nevertheless it is safer to implement
    it according to MPI-2 definition.
    Futhermore, the library often needs to do message passing using the
    supplied communicator.  Using the same communicator as the application
    version may result in some messages mix up.
Solution:
    H5Pset_fapl_mpio now stores a duplicate of each of the communicator
    and Info object.
    H5Pget_fapl_mpio returns a duplicate of its stored communicator and
    Info object.  It is now the responsibility of the applications to free
    those objects when done.
    H5Fopen/create also stores a duplicate of the communicator and Info
    object supplied by the File Access Property list.
    H5Fclose frees those duplicates.
    There are a few more internal VFL call back functions that they
    follow this "make duplicates" requirement.

Platforms tested:
"h5committested".
What other platforms/configurations were tested?
    Eirene (mpicc), sol(mpicc), copper(parallel)

Misc. update:

1 files changed, 319 insertions, 43 deletions

diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c
index 2f2f8a5..5a378aa 100644
--- a/src/H5FDmpio.c
+++ b/src/H5FDmpio.c
@@ -72,6 +72,8 @@ static herr_t H5FD_mpio_haddr_to_MPIOff(haddr_t addr, MPI_Offset *mpi_off/*out*/
 
 /* Callbacks */
 static void *H5FD_mpio_fapl_get(H5FD_t *_file);
+static void *H5FD_mpio_fapl_copy(const void *_old_fa);
+static herr_t H5FD_mpio_fapl_free(void *_fa);
 static H5FD_t *H5FD_mpio_open(const char *name, unsigned flags, hid_t fapl_id,
 			      haddr_t maxaddr);
 static herr_t H5FD_mpio_close(H5FD_t *_file);
@@ -85,6 +87,9 @@ static herr_t H5FD_mpio_read(H5FD_t *_file, H5FD_mem_t type, hid_t dxpl_id, hadd
 static herr_t H5FD_mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr,
             size_t size, const void *buf);
 static herr_t H5FD_mpio_flush(H5FD_t *_file, hid_t dxpl_id, unsigned closing);
+static herr_t H5FD_mpio_comm_info_dup(MPI_Comm comm, MPI_Info info,
+				MPI_Comm *comm_new, MPI_Info *info_new);
+static herr_t H5FD_mpio_comm_info_free(MPI_Comm *comm, MPI_Info *info);
 
 /* MPIO-specific file access properties */
 typedef struct H5FD_mpio_fapl_t {
@@ -102,8 +107,8 @@ static const H5FD_class_t H5FD_mpio_g = {
     NULL,					/*sb_decode		*/
     sizeof(H5FD_mpio_fapl_t),			/*fapl_size		*/
     H5FD_mpio_fapl_get,				/*fapl_get		*/
-    NULL,					/*fapl_copy		*/
-    NULL, 					/*fapl_free		*/
+    H5FD_mpio_fapl_copy,			/*fapl_copy		*/
+    H5FD_mpio_fapl_free, 			/*fapl_free		*/
     0,		                		/*dxpl_size		*/
     NULL,					/*dxpl_copy		*/
     NULL,					/*dxpl_free		*/
@@ -209,24 +214,25 @@ done:
 /*-------------------------------------------------------------------------
  * Function:	H5Pset_fapl_mpio
  *
- * Purpose:	Store the user supplied MPIO communicator COMM and INFO in
+ * Purpose:	Store the user supplied MPIO communicator comm and info in
  *		the file access property list FAPL_ID which can then be used
  *		to create and/or open the file.  This function is available
  *		only in the parallel HDF5 library and is not collective.
  *
- *		COMM is the MPI communicator to be used for file open as
- *		defined in MPI_FILE_OPEN of MPI-2. This function does not
- *		make a duplicated communicator. Any modification to COMM
- *		after this function call returns may have undetermined effect
- *		on the access property list. Users should not modify the
- *		communicator while it is defined in a property list.
+ *		comm is the MPI communicator to be used for file open as
+ *		defined in MPI_FILE_OPEN of MPI-2. This function makes a
+ *		duplicate of comm. Any modification to comm after this function
+ *		call returns has no effect on the access property list.
  *
- *		INFO is the MPI info object to be used for file open as
- *		defined in MPI_FILE_OPEN of MPI-2. This function does not
- *		make a duplicated info. Any modification to info after this
- *		function call returns may have undetermined effect on the
- *		access property list. Users should not modify the info while
- *		it is defined in a property list.
+ *		info is the MPI Info object to be used for file open as
+ *		defined in MPI_FILE_OPEN of MPI-2. This function makes a
+ *		duplicate of info. Any modification to info after this
+ *		function call returns has no effect on the access property
+ *		list.
+ *
+ *              If fapl_id has previously set comm and info values, they
+ *              will be replaced and the old communicator and Info object
+ *              are freed.
  *
  * Return:	Success:	Non-negative
  *
@@ -252,11 +258,16 @@ done:
  * 		Robb Matzke, 1999-08-06
  *		Modified to work with the virtual file layer.
  *
- *		Raymond Lu 
- * 		Tuesday, Oct 23, 2001
+ *		Raymond Lu, 2001-10-23
  *		Changed the file access list to the new generic property 
  *		list.
  *
+ *		Albert Cheng, 2003-04-17
+ *		Modified the description of the function that it now stores
+ *		a duplicate of the communicator and INFO object.  Free the
+ *		old duplicates if previously set.  (Work is actually done
+ *		by H5P_set_driver.)
+ *
  *-------------------------------------------------------------------------
  */
 herr_t
@@ -275,10 +286,8 @@ H5Pset_fapl_mpio(hid_t fapl_id, MPI_Comm comm, MPI_Info info)
     /* Check arguments */
     if(NULL == (plist = H5P_object_verify(fapl_id,H5P_FILE_ACCESS)))
         HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a file access list");
-
-#ifdef LATER
-#warning "We need to verify that COMM and INFO contain sensible information."
-#endif
+    if (MPI_COMM_NULL == comm)
+	HGOTO_ERROR(H5E_PLIST, H5E_BADTYPE, FAIL, "not a valid communicator");
 
     /* Initialize driver specific properties */
     fa.comm = comm;
@@ -295,15 +304,18 @@ done:
  * Function:	H5Pget_fapl_mpio
  *
  * Purpose:	If the file access property list is set to the H5FD_MPIO
- *		driver then this function returns the MPI communicator and
- *		information through the COMM and INFO pointers.
+ *		driver then this function returns duplicates of the MPI
+ *		communicator and Info object stored through the comm and
+ *		info pointers.  It is the responsibility of the application
+ *		to free the returned communicator and Info object.
  *
  * Return:	Success:	Non-negative with the communicator and
- *				information returned through the COMM and
- *				INFO arguments if non-null. Neither piece of
- *				information is copied and they are therefore
- *				valid only until the file access property
- *				list is modified or closed.
+ *				Info object returned through the comm and
+ *				info arguments if non-null. Since they are
+ *				duplicates of the stored objects, future
+ *				modifications to the access property list do
+ *				not affect them and it is the responsibility
+ *				of the application to free them.
  *
  * 		Failure:	Negative
  *
@@ -317,11 +329,13 @@ done:
  *	        to be controlled by data transfer property list during data
  *	        read/write calls.
  *
- *		Raymond Lu 
- * 		Tuesday, Oct 23, 2001
+ *		Raymond Lu, 2001-10-23
  *		Changed the file access list to the new generic property 
  *		list.
  *
+ *		Albert Cheng, 2003-04-17
+ *		Return duplicates of the stored communicator and Info object.
+ *
  *-------------------------------------------------------------------------
  */
 herr_t
@@ -329,7 +343,9 @@ H5Pget_fapl_mpio(hid_t fapl_id, MPI_Comm *comm/*out*/, MPI_Info *info/*out*/)
 {
     H5FD_mpio_fapl_t	*fa;
     H5P_genplist_t *plist;      /* Property list pointer */
-    herr_t      ret_value=SUCCEED;       /* Return value */
+    MPI_Comm	comm_tmp=MPI_COMM_NULL;
+    int		mpi_code;		/* mpi return code */
+    herr_t      ret_value=SUCCEED;      /* Return value */
     
     FUNC_ENTER_API(H5Pget_fapl_mpio, FAIL);
     H5TRACE3("e","ixx",fapl_id,comm,info);
@@ -341,12 +357,34 @@ H5Pget_fapl_mpio(hid_t fapl_id, MPI_Comm *comm/*out*/, MPI_Info *info/*out*/)
     if (NULL==(fa=H5P_get_driver_info(plist)))
         HGOTO_ERROR(H5E_PLIST, H5E_BADVALUE, FAIL, "bad VFL driver info");
 
+    /* Store the duplicated communicator in a temporary variable for error */
+    /* recovery in case the INFO duplication fails.  We cannot attempt to */
+    /* the value into *comm yet since if MPI_Comm_dup fails, we will end  */
+    /* up freeing whatever *comm holds and that could be invalid. */
+    if (comm){
+	if (MPI_SUCCESS != (mpi_code=MPI_Comm_dup(fa->comm, &comm_tmp)))
+	    HMPI_GOTO_ERROR(FAIL, "MPI_Comm_dup failed", mpi_code);
+    }
+    
+    if (info){
+	if (MPI_INFO_NULL != fa->info){
+	    if (MPI_SUCCESS != (mpi_code=MPI_Info_dup(fa->info, info)))
+		HMPI_GOTO_ERROR(FAIL, "MPI_Info_dup failed", mpi_code);
+	}else{
+	    /* do not dup it */
+	    *info = MPI_INFO_NULL;
+	}
+    }
+
     if (comm)
-        *comm = fa->comm;
-    if (info)
-        *info = fa->info;
+        *comm = comm_tmp;
 
 done:
+    if (FAIL==ret_value){
+	/* need to free anything created here */
+	if (comm_tmp != MPI_COMM_NULL)
+	    MPI_Comm_free(&comm_tmp);
+    }
     FUNC_LEAVE_API(ret_value);
 }
 
@@ -772,7 +810,9 @@ done:
  *              Friday, August 13, 1999
  *
  * Modifications:
- *
+ * 		Albert Cheng, 2003-04-17
+ * 		Duplicate the communicator and Info object so that the new
+ * 		property list is insulated from the old one.
  *-------------------------------------------------------------------------
  */
 static void *
@@ -803,6 +843,108 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5FD_mpio_fapl_copy
+ *
+ * Purpose:	Copies the mpio-specific file access properties.
+ *
+ * Return:	Success:	Ptr to a new property list
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	Albert Cheng
+ *              Jan  8, 2003
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5FD_mpio_fapl_copy(const void *_old_fa)
+{
+    void		*ret_value = NULL;
+    const H5FD_mpio_fapl_t *old_fa = (const H5FD_mpio_fapl_t*)_old_fa;
+    H5FD_mpio_fapl_t	*new_fa = NULL;
+    
+    FUNC_ENTER_NOAPI(H5FD_mpio_fapl_copy, NULL);
+#ifdef H5FDmpio_DEBUG
+if (H5FD_mpio_Debug[(int)'t'])
+fprintf(stderr, "enter H5FD_mpio_fapl_copy\n");
+#endif
+
+    if (NULL==(new_fa=H5MM_malloc(sizeof(H5FD_mpio_fapl_t))))
+        HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
+
+    /* Copy the general information */
+    HDmemcpy(new_fa, old_fa, sizeof(H5FD_mpio_fapl_t));
+
+    /* Duplicate communicator and Info object. */
+    if (FAIL==H5FD_mpio_comm_info_dup(old_fa->comm, old_fa->info,
+					&new_fa->comm, &new_fa->info))
+	HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL,
+		"Communicator/Info duplicate failed");
+    ret_value = new_fa;
+
+done:
+    if (NULL == ret_value){
+	/* cleanup */
+	if (new_fa)
+	    H5MM_xfree(new_fa);
+    }
+
+#ifdef H5FDmpio_DEBUG
+if (H5FD_mpio_Debug[(int)'t'])
+fprintf(stderr, "leaving H5FD_mpio_fapl_copy\n");
+#endif
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5FD_mpio_fapl_copy() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5FD_mpio_fapl_free
+ *
+ * Purpose:	Frees the mpio-specific file access properties.
+ *
+ * Return:	Success:	0
+ *
+ *		Failure:	-1
+ *
+ * Programmer:	Albert Cheng
+ *              Jan  8, 2003
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_mpio_fapl_free(void *_fa)
+{
+    herr_t		ret_value = SUCCEED;
+    H5FD_mpio_fapl_t	*fa = (H5FD_mpio_fapl_t*)_fa;
+
+    FUNC_ENTER_NOAPI(H5FD_mpio_fapl_free, FAIL);
+#ifdef H5FDmpio_DEBUG
+if (H5FD_mpio_Debug[(int)'t'])
+fprintf(stderr, "in H5FD_mpio_fapl_free\n");
+#endif
+    assert(fa);
+
+    /* Free the internal communicator and INFO object */
+    assert(MPI_COMM_NULL!=fa->comm);
+    MPI_Comm_free(&fa->comm);
+    if (MPI_INFO_NULL != fa->info)
+	MPI_Info_free(&fa->info);
+    H5MM_xfree(fa);
+
+done:
+#ifdef H5FDmpio_DEBUG
+if (H5FD_mpio_Debug[(int)'t'])
+fprintf(stderr, "leaving H5FD_mpio_fapl_free\n");
+#endif
+    FUNC_LEAVE_NOAPI(SUCCEED);
+} /* end H5FD_mpio_fapl_free() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5FD_mpio_open
  *
  * Purpose:     Opens a file with name NAME.  The FLAGS are a bit field with
@@ -859,6 +1001,9 @@ H5FD_mpio_open(const char *name, unsigned flags, hid_t fapl_id,
     H5FD_mpio_fapl_t		_fa;
     H5P_genplist_t *plist;      /* Property list pointer */
     H5FD_t			*ret_value;     /* Return value */
+    MPI_Comm                    comm_dup=MPI_COMM_NULL;
+    MPI_Info                    info_dup=MPI_INFO_NULL;
+
 
     FUNC_ENTER_NOAPI(H5FD_mpio_open, NULL);
 
@@ -881,6 +1026,11 @@ H5FD_mpio_open(const char *name, unsigned flags, hid_t fapl_id,
 	assert(fa);
     }
 
+    /* Duplicate communicator and Info object for use by this file. */
+    if (FAIL==H5FD_mpio_comm_info_dup(fa->comm, fa->info, &comm_dup, &info_dup))
+	HGOTO_ERROR(H5E_INTERNAL, H5E_CANTCOPY, NULL,
+		"Communicator/Info duplicate failed");
+
     /* convert HDF5 flags to MPI-IO flags */
     /* some combinations are illegal; let MPI-IO figure it out */
     mpi_amode  = (flags&H5F_ACC_RDWR) ? MPI_MODE_RDWR : MPI_MODE_RDONLY;
@@ -924,15 +1074,15 @@ H5FD_mpio_open(const char *name, unsigned flags, hid_t fapl_id,
 #endif
 
     /*OKAY: CAST DISCARDS CONST*/
-    if (MPI_SUCCESS != (mpi_code=MPI_File_open(fa->comm, (char*)name,
-            mpi_amode, fa->info, &fh)))
+    mpi_code=MPI_File_open(comm_dup, (char*)name, mpi_amode, info_dup, &fh);
+    if (MPI_SUCCESS != mpi_code)
         HMPI_GOTO_ERROR(NULL, "MPI_File_open failed", mpi_code);
     file_opened=1;
 
     /* Get the MPI rank of this process and the total number of processes */
-    if (MPI_SUCCESS != (mpi_code=MPI_Comm_rank (fa->comm, &mpi_rank)))
+    if (MPI_SUCCESS != (mpi_code=MPI_Comm_rank (comm_dup, &mpi_rank)))
         HMPI_GOTO_ERROR(NULL, "MPI_Comm_rank failed", mpi_code);
-    if (MPI_SUCCESS != (mpi_code=MPI_Comm_size (fa->comm, &mpi_size)))
+    if (MPI_SUCCESS != (mpi_code=MPI_Comm_size (comm_dup, &mpi_size)))
         HMPI_GOTO_ERROR(NULL, "MPI_Comm_size failed", mpi_code);
 
 /*  Following changes in handling file-truncation made be rkyates and ppweidhaas, sep 99  */
@@ -945,7 +1095,7 @@ H5FD_mpio_open(const char *name, unsigned flags, hid_t fapl_id,
     }
 
     /* Broadcast file-size */
-    if (MPI_SUCCESS != (mpi_code=MPI_Bcast(&size, sizeof(MPI_Offset), MPI_BYTE, 0, fa->comm)))
+    if (MPI_SUCCESS != (mpi_code=MPI_Bcast(&size, sizeof(MPI_Offset), MPI_BYTE, 0, comm_dup)))
         HMPI_GOTO_ERROR(NULL, "MPI_Bcast failed", mpi_code);
 
     /* Only if size > 0, truncate the file - if requested */
@@ -954,7 +1104,7 @@ H5FD_mpio_open(const char *name, unsigned flags, hid_t fapl_id,
             HMPI_GOTO_ERROR(NULL, "MPI_File_set_size failed", mpi_code);
 
 	/* Don't let any proc return until all have truncated the file. */
-        if (MPI_SUCCESS!= (mpi_code=MPI_Barrier(fa->comm)))
+        if (MPI_SUCCESS!= (mpi_code=MPI_Barrier(comm_dup)))
             HMPI_GOTO_ERROR(NULL, "MPI_Barrier failed", mpi_code);
         size = 0;
     }
@@ -964,8 +1114,8 @@ H5FD_mpio_open(const char *name, unsigned flags, hid_t fapl_id,
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed");
 
     file->f = fh;
-    file->comm = fa->comm;
-    file->info = fa->info;
+    file->comm = comm_dup;
+    file->info = info_dup;
     file->mpi_rank = mpi_rank;
     file->mpi_size = mpi_size;
     file->eof = H5FD_mpio_MPIOff_to_haddr(size);
@@ -977,6 +1127,12 @@ done:
     if(ret_value==NULL) {
         if(file_opened)
             MPI_File_close(&fh);
+	if (MPI_COMM_NULL != comm_dup)
+	    MPI_Comm_free(&comm_dup);
+	if (MPI_INFO_NULL != info_dup)
+	    MPI_Info_free(&info_dup);
+	if (file)
+	    H5MM_xfree(file);
     } /* end if */
 
 #ifdef H5FDmpio_DEBUG
@@ -1028,6 +1184,7 @@ H5FD_mpio_close(H5FD_t *_file)
         HMPI_GOTO_ERROR(FAIL, "MPI_File_close failed", mpi_code);
 
     /* Clean up other stuff */
+    H5FD_mpio_comm_info_free(&file->comm, &file->info);
     H5MM_xfree(file);
 
 done:
@@ -2011,4 +2168,123 @@ H5FD_mpio_haddr_to_MPIOff(haddr_t addr, MPI_Offset *mpi_off/*out*/)
 
     FUNC_LEAVE_NOAPI(ret_value);
 }
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_mpio_comm_info_dup
+ *
+ * Purpose:     Make duplicates of communicator and Info object.
+ * 		If the Info object is in fact MPI_INFO_NULL, no duplicate
+ * 		is made but the same value assigned to the new Info object
+ * 		handle.
+ *
+ * Return:      Success:	Non-negative.  The new communicator and Info
+ * 				object handles are returned via comm_new and
+ * 				info_new pointers.
+ *
+ * 		Failure:	Negative.
+ *
+ * Programmer:  Albert Cheng
+ *              Jan  8, 2003
+ *
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_mpio_comm_info_dup(MPI_Comm comm, MPI_Info info, MPI_Comm *comm_new, MPI_Info *info_new)
+{
+    herr_t	ret_value=SUCCEED;
+    MPI_Comm	comm_dup=MPI_COMM_NULL;
+    MPI_Info	info_dup=MPI_INFO_NULL;
+    int		mpi_code;
+    
+    FUNC_ENTER_NOAPI(H5FD_mpio_comm_info_dup, FAIL);
+
+#ifdef H5FDmpio_DEBUG
+if (H5FD_mpio_Debug[(int)'t'])
+fprintf(stderr, "In H5FD_mpio_comm_info_dup: argument comm/info = %d/%ld\n", comm, (long)info);
+#endif
+    /* Check arguments */
+    if (MPI_COMM_NULL == comm)
+	HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "not a valid argument");
+    if (!comm_new || !info_new)
+	HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "bad pointers");
+
+    /* Dup them.  Using temporary variables for error recovery cleanup. */
+    if (MPI_SUCCESS != (mpi_code=MPI_Comm_dup(comm, &comm_dup)))
+	HMPI_GOTO_ERROR(FAIL, "MPI_Comm_dup failed", mpi_code);
+    if (MPI_INFO_NULL != info){
+	if (MPI_SUCCESS != (mpi_code=MPI_Info_dup(info, &info_dup)))
+	    HMPI_GOTO_ERROR(FAIL, "MPI_Info_dup failed", mpi_code);
+    }else{
+	/* No dup, just copy it. */
+	info_dup = info;
+    }
+
+    /* copy them to the return arguments */
+    *comm_new = comm_dup;
+    *info_new = info_dup;
+
+done:
+    if (FAIL == ret_value){
+	/* need to free anything created here */
+	if (MPI_COMM_NULL != comm_dup)
+	    MPI_Comm_free(&comm_dup);
+	if (MPI_INFO_NULL != info_dup)
+	    MPI_Info_free(&info_dup);
+    }
+
+#ifdef H5FDmpio_DEBUG
+if (H5FD_mpio_Debug[(int)'t'])
+fprintf(stderr, "Leaving H5FD_mpio_comm_info_dup\n");
+#endif
+    FUNC_LEAVE_NOAPI(ret_value);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FD_mpio_comm_info_free
+ *
+ * Purpose:     Free the communicator and Info object.
+ * 		If comm or info is in fact MPI_COMM_NULL or MPI_INFO_NULL
+ * 		respectively, no action occurs to it. 
+ *
+ * Return:      Success:	Non-negative.  The values the pointers refer
+ * 				to will be set to the corresponding NULL
+ * 				handles.
+ *
+ * 		Failure:	Negative.
+ *
+ * Programmer:  Albert Cheng
+ *              Jan  8, 2003
+ *
+ * Modifications:
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5FD_mpio_comm_info_free(MPI_Comm *comm, MPI_Info *info)
+{
+    herr_t      ret_value=SUCCEED;
+    FUNC_ENTER_NOAPI(H5FD_mpio_comm_info_free, FAIL);
+
+#ifdef H5FDmpio_DEBUG
+if (H5FD_mpio_Debug[(int)'t'])
+fprintf(stderr, "in H5FD_mpio_comm_info_free\n");
+#endif
+    /* Check arguments */
+    if (!comm || !info)
+	HGOTO_ERROR(H5E_INTERNAL, H5E_BADVALUE, FAIL, "not a valid argument");
+
+    if (MPI_COMM_NULL != *comm)
+	MPI_Comm_free(comm);
+    if (MPI_INFO_NULL != *info)
+	MPI_Info_free(info);
+
+done:
+#ifdef H5FDmpio_DEBUG
+if (H5FD_mpio_Debug[(int)'t'])
+fprintf(stderr, "Leaving H5FD_mpio_comm_info_free\n");
+#endif
+    FUNC_LEAVE_NOAPI(SUCCEED);
+}
 #endif /* H5_HAVE_PARALLEL */