Last modified: 28 February 2014

Name:H5Pget_metadata_read_attempts

Signature:
herr_t H5Pget_metadata_read_attempts( hid_t plist_id, unsigned *attempts )

Purpose:
Retrieves the number of read attempts from a file access property list.

Motivation:
See the description in H5Pset_metadata_read_attempts.

Description:
H5Pget_metadata_read_attempts retrieves the number of read attempts that is set in the file access property list plist_id.

For a default file access property list, the value retrieved will depend on whether the user sets the number of attempts via H5Pset_metadata_read_attempts:

For the file access property list of a specified HDF5 file, the value retrieved will depend on how the file is opened and whether the user sets the number of read attempts via H5Pset_metadata_read_attempts:


Parameters:
hid_t plist_id  IN: Identifier for a file access property list.
unsigned *attempts    OUT: The number of read attempts.

Returns:
Returns a non-negative value if successful; otherwise returns a negative value.

Failure Modes:
When the input property list is not a file access property list.

When the library is unable to retrieve the number of read attempts from the file access property list.


Example Usage:
The first example illustrates the two cases for retrieving the number of read attempts from a default file access property list.
    /* Get a copy of file access property list */
    fapl = H5Pcreate(H5P_FILE_ACCESS);

    /* Retrieve the # of read attempts from the file access property list */
    H5Pget_metadata_read_attempts(fapl, &attempts);

    /*
     *  The value returned in "attempts" will be 1 (default for non-SWMR access).
     */

    /* Set the # of read attempts to 20 */
    H5Pset_metadata_read_attempts(fapl, 20);

    /* Retrieve the # of read attempts from the file access property list */
    H5Pget_metadata_read_attempts(fapl, &attempts);

    /*
     *  The value returned in "attempts" will be 20 as set.
     */

    /* Close the property list */	    
    H5Pclose(fapl);
The second example illustrates the two cases for retrieving the number of read attempts from the file access property list of a file opened with SWMR acccess.
    /* Open the file with SWMR access and default file access property list */
    fid = H5Fopen(FILE, (H5F_ACC_RDONLY | H5F_ACC_SWMR_READ), H5P_DEFAULT);

    /* Get the file's file access roperty list */
    file_fapl = H5Fget_access_plist(fid);

    /* Retrieve the # of read attempts from the file's file access property list */
    H5Pget_metadata_read_attempts(file_fapl, &attempts);

    /*
     *  The value returned in "attempts" will be 100 (default for SWMR access).
     */

    /* Close the property list */	    
    H5Pclose(file_fapl);

    /* Close the file */
    H5Fclose(fid);

    /* Create a copy of file access property list */
    fapl = H5Pcreate(H5P_FILE_ACCESS);

    /* Set the # of read attempts */
    H5Pset_metadata_read_attempts(fapl, 20);

    /* Open the file with SWMR access and the non-default file access property list */
    fid = H5Fopen(FILE, (H5F_ACC_RDONLY | H5F_ACC_SWMR_READ), fapl);

    /* Get the file's file access roperty list */
    file_fapl = H5Fget_access_plist(fid);

    /* Retrieve the # of read attempts from the file's file access property list */
    H5Pget_metadata_read_attempts(file_fapl, &attempts);

    /*
     *  The value returned in "attempts" will be 20.
     */

    /* Close the property lists */	    
    H5Pclose(file_fapl);
    H5Pclose(fapl);

    /* Close the file */
    H5Fclose(fid);
The third example illustrates the two cases for retrieving the number of read attempts from the file access property list of a file opened with non-SWMR acccess.
    /* Open the file with non-SWMR access and default file access property list */
    fid = H5Fopen(FILE, H5F_ACC_RDONLY, H5P_DEFAULT);

    /* Get the file's file access roperty list */
    file_fapl = H5Fget_access_plist(fid);

    /* Retrieve the # of read attempts from the file's file access property list */
    H5Pget_metadata_read_attempts(file_fapl, &attempts);

    /*
     *  The value returned in "attempts" will be 1 (default for non-SWMR access).
     */

    /* Close the property list */	    
    H5Pclose(file_fapl);

    /* Close the file */
    H5Fclose(fid);

    /* Create a copy of file access property list */
    fapl = H5Pcreate(H5P_FILE_ACCESS);

    /* Set the # of read attempts */
    H5Pset_metadata_read_attempts(fapl, 20);

    /* Open the file with non-SWMR access and the non-default file access property list */
    fid = H5Fopen(FILE, H5F_ACC_RDONLY, fapl);

    /* Get the file's file access roperty list */
    file_fapl = H5Fget_access_plist(fid);

    /* Retrieve the # of read attempts from the file's file access property list */
    H5Pget_metadata_read_attempts(file_fapl, &attempts);

    /*
     *  The value returned in "attempts" will be 1 (default for non-SWMR access).
     */

    /* Close the property lists */	    
    H5Pclose(file_fapl);
    H5Pclose(fapl);

    /* Close the file */
    H5Fclose(fid);

Fortran Interface:
None

See Also:
  • H5Pset_metadata_read_attempts
  • H5Fget_metadata_read_retries_info

  • History:
    Release     Change
    1.10.0 C function introduced with this release.