[svn-r6149] ./hdf5-devel/src/H5Ipublic.h

Purpose:
    Feature; Optimization

Description:
    Clients pass `-1' or make their own #define for HDF5 functions
    that take an optional object ID.

    Blue's GPFS is slow for typical SAF restart dumps.

Solution:
    Added a #define for H5I_INVALID_HID

    Added GPFS-specific code to H5FDmpiposix.c that tells mmfsd to
    forego byte range token prefetching. This code can be compiled
    into the library by defining USE_GPFS_HINTS. The plan is to either
    generalize this so it's detected during configure and turned
    on/off at runtime, or to move it up into DSL/SAF with the new HDF5
    functions to that return the low-level file handle.

Platforms tested:
    SuSE Linux (arborea), gcc and mpich-1.2.4
    SunOS (baldric), gcc

2002-09-05 12:24:28 Robb Matzke  <matzke@arborea.spizella.com>
	*: Added #define for H5I_INVALID_HID. An invalid object handle is
	   actually any integer that isn't currently in use as a
	   handle, and non-positive integers are never used as a
	   handle. The #define is -1, and is mostly so that HDF5
	   users can pass a symbolic name instead of a negative
	   number to functions that take optional object ID
	   arguments.

src/H5Ipublic.h

@@ -47,6 +47,9 @@ typedef enum {
 /* Type of atoms to return to users */
 typedef int hid_t;
 
+/* An invalid object ID. This is also negative for error return. */
+#define H5I_INVALID_HID         (-1)
+
 #ifdef __cplusplus
 extern "C" {
 #endif