/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Copyright by The HDF Group. *
* Copyright by the Board of Trustees of the University of Illinois. *
* All rights reserved. *
* *
* This file is part of HDF5. The full HDF5 copyright notice, including *
* terms governing use, modification, and redistribution, is contained in *
* the COPYING file, which can be found at the root of the source code *
* distribution tree, or in https://www.hdfgroup.org/licenses. *
* If you do not have access to either file, you may request a copy from *
* help@hdfgroup.org. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* This file contains public declarations for the HDF5 module.
*/
#ifndef H5public_H
#define H5public_H
/* Include files for public use... */
/*
* Since H5pubconf.h is a generated header file, it is messy to try
* to put a #ifndef H5pubconf_H ... #endif guard in it.
* HDF5 has set an internal rule that it is being included here.
* Source files should NOT include H5pubconf.h directly but include
* it via H5public.h. The #ifndef H5public_H guard above would
* prevent repeated include.
*/
#include "H5pubconf.h" /* From configure */
/* API Version macro wrapper definitions */
#include "H5version.h"
#ifdef H5_HAVE_FEATURES_H
#include <features.h> /* For setting POSIX, BSD, etc. compatibility */
#endif
/* C library header files for things that appear in HDF5 public headers */
#ifdef __cplusplus
#define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include <limits.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
/* Unlike most sys/ headers, which are POSIX-only, sys/types.h is available
* on Windows, though it doesn't necessarily contain all the POSIX types
* we need for HDF5 (e.g. ssize_t).
*/
#ifdef H5_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef H5_HAVE_PARALLEL
/* Don't link against MPI C++ bindings */
#ifndef MPICH_SKIP_MPICXX
#define MPICH_SKIP_MPICXX 1
#endif
#ifndef OMPI_SKIP_MPICXX
#define OMPI_SKIP_MPICXX 1
#endif
#include <mpi.h>
#ifndef MPI_FILE_NULL /* MPIO may be defined in mpi.h already */
#include <mpio.h>
#endif
#endif
/* Macro to hide a symbol from further preprocessor substitutions */
#define H5_NO_EXPAND(x) (x)
/* Version numbers */
/**
* For major interface/format changes
*/
#define H5_VERS_MAJOR 1
/**
* For minor interface/format changes
*/
#define H5_VERS_MINOR 13
/**
* For tweaks, bug-fixes, or development
*/
#define H5_VERS_RELEASE 1
/**
* For pre-releases like \c snap0. Empty string for official releases.
*/
#define H5_VERS_SUBRELEASE "1"
/**
* Full version string
*/
#define H5_VERS_INFO "HDF5 library version: 1.13.1-1"
#define H5check() H5check_version(H5_VERS_MAJOR, H5_VERS_MINOR, H5_VERS_RELEASE)
/* macros for comparing the version */
/**
* \brief Determines whether the version of the library being used is greater
* than or equal to the specified version
*
* \param[in] Maj Major version number - A non-negative integer value
* \param[in] Min Minor version number - A non-negative integer value
* \param[in] Rel Release version number - A non-negative integer value
* \returns A value of 1 is returned if the library version is greater than
* or equal to the version number specified.\n
* A value of 0 is returned if the library version is less than the
* version number specified.\n
* A library version is greater than the specified version number if
* its major version is larger than the specified major version
* number. If the major version numbers are the same, it is greater
* than the specified version number if its minor version is larger
* than the specified minor version number. If the minor version
* numbers are the same, then a library version would be greater than
* the specified version number if its release number is larger than
* the specified release number.
*
* \details The #H5_VERSION_GE and #H5_VERSION_LE macros are used at compile
* time to conditionally include or exclude code based on the version
* of the HDF5 library against which an application will be linked.
*
* The #H5_VERSION_GE macro compares the version of the HDF5 library
* being used against the version number specified in the parameters.
*
* For more information about release versioning, see \ref_h5lib_relver.
*
* \since 1.8.7
*
*/
#define H5_VERSION_GE(Maj, Min, Rel) \
(((H5_VERS_MAJOR == Maj) && (H5_VERS_MINOR == Min) && (H5_VERS_RELEASE >= Rel)) || \
((H5_VERS_MAJOR == Maj) && (H5_VERS_MINOR > Min)) || (H5_VERS_MAJOR > Maj))
/**
* \brief Determines whether the version of the library being used is less
* than or equal to the specified version
*
* \param[in] Maj Major version number - A non-negative integer value
* \param[in] Min Minor version number - A non-negative integer value
* \param[in] Rel Release version number - A non-negative integer value
* \returns A value of 1 is returned if the library version is less than
* or equal to the version number specified.\n
* A value of 0 is returned if the library version is greater than the
* version number specified.\n
* A library version is less than the specified version number if
* its major version is smaller than the specified major version
* number. If the major version numbers are the same, it is smaller
* than the specified version number if its minor version is smaller
* than the specified minor version number. If the minor version
* numbers are the same, then a library version would be smaller than
* the specified version number if its release number is smaller than
* the specified release number.
*
* \details The #H5_VERSION_GE and #H5_VERSION_LE macros are used at compile
* time to conditionally include or exclude code based on the version
* of the HDF5 library against which an application will be linked.
*
* The #H5_VERSION_LE macro compares the version of the HDF5 library
* being used against the version number specified in the parameters.
*
* For more information about release versioning, see \ref_h5lib_relver.
*
* \since 1.8.7
*
*/
#define H5_VERSION_LE(Maj, Min, Rel) \
(((H5_VERS_MAJOR == Maj) && (H5_VERS_MINOR == Min) && (H5_VERS_RELEASE <= Rel)) || \
((H5_VERS_MAJOR == Maj) && (H5_VERS_MINOR < Min)) || (H5_VERS_MAJOR < Maj))
/* Macros for various environment variables that HDF5 interprets */
/**
* Used to specify the name of an HDF5 Virtual File Driver to use as
* the default file driver for file access. Setting this environment
* variable overrides the default file driver for File Access Property
* Lists.
*/
#define HDF5_DRIVER "HDF5_DRIVER"
/**
* Used to specify a configuration string for the HDF5 Virtual File
* Driver being used for file access.
*/
#define HDF5_DRIVER_CONFIG "HDF5_DRIVER_CONFIG"
/**
* Used to specify the name of an HDF5 Virtual Object Layer Connector
* to use as the default VOL connector for file access. Setting this
* environment variable overrides the default VOL connector for File
* Access Property Lists.
*/
#define HDF5_VOL_CONNECTOR "HDF5_VOL_CONNECTOR"
/**
* Used to specify a delimiter-separated (currently, ';' for Windows
* and ':' for other systems) list of paths that HDF5 should search
* when loading plugins.
*/
#define HDF5_PLUGIN_PATH "HDF5_PLUGIN_PATH"
/**
* Used to control the loading of HDF5 plugins at runtime. If this
* environment variable is set to the special string "::" (defined
* in H5PLpublic.h as H5PL_NO_PLUGIN), then dynamic loading of any
* HDF5 plugins will be disabled. No other values are valid for this
* environment variable.
*/
#define HDF5_PLUGIN_PRELOAD "HDF5_PLUGIN_PRELOAD"
/**
* Used to control whether HDF5 uses file locking when creating or
* opening a file. Valid values for this environment variable are
* as follows:
*
* "TRUE" or "1" - Request that file locks should be used
* "FALSE" or "0" - Request that file locks should NOT be used
* "BEST_EFFORT" - Request that file locks should be used and
* that any locking errors caused by file
* locking being disabled on the system
* should be ignored
*/
#define HDF5_USE_FILE_LOCKING "HDF5_USE_FILE_LOCKING"
/**
* Used to instruct HDF5 not to cleanup files created during testing.
*/
#define HDF5_NOCLEANUP "HDF5_NOCLEANUP"
/**
* Status return values. Failed integer functions in HDF5 result almost
* always in a negative value (unsigned failing functions sometimes return
* zero for failure) while successful return is non-negative (often zero).
* The negative failure value is most commonly -1, but don't bet on it.
*
* The proper way to detect failure is something like:
* \code
* if((dset = H5Dopen2(file, name)) < 0)
* fprintf(stderr, "unable to open the requested dataset\n");
* \endcode
*/
typedef int herr_t;
/**
* C99-style Boolean type. Successful return values are zero (false) or positive
* (true). The typical true value is 1 but don't bet on it.
* \attention Boolean functions cannot fail.
*/
#include <stdbool.h>
typedef bool hbool_t;
/**
* Three-valued Boolean type. Functions that return #htri_t however return zero
* (false), positive (true), or negative (failure).
*
* The proper way to test for truth from a #htri_t function is:
* \code
* if ((retval = H5Tcommitted(type)) > 0) {
* printf("data type is committed\n");
* } else if (!retval) {
* printf("data type is not committed\n");
* } else {
* printf("error determining whether data type is committed\n");
* }
* \endcode
*/
typedef int htri_t;
/* The signed version of size_t
*
* ssize_t is POSIX and not defined in any C standard. It's used in some
* public HDF5 API calls so this work-around will define it if it's not
* present.
*
* Use of ssize_t should be discouraged in new code.
*/
#if H5_SIZEOF_SSIZE_T == 0
/* Undefine this size, we will re-define it in one of the sections below */
#undef H5_SIZEOF_SSIZE_T
#if H5_SIZEOF_SIZE_T == H5_SIZEOF_INT
typedef int ssize_t;
#define H5_SIZEOF_SSIZE_T H5_SIZEOF_INT
#elif H5_SIZEOF_SIZE_T == H5_SIZEOF_LONG
typedef long ssize_t;
#define H5_SIZEOF_SSIZE_T H5_SIZEOF_LONG
#elif H5_SIZEOF_SIZE_T == H5_SIZEOF_LONG_LONG
typedef long long ssize_t;
#define H5_SIZEOF_SSIZE_T H5_SIZEOF_LONG_LONG
#else /* Can't find matching type for ssize_t */
#error "nothing appropriate for ssize_t"
#endif
#endif
/**
* The size of file objects.
*
* \internal Defined as a (minimum) 64-bit integer type.
*/
typedef uint64_t hsize_t;
/**
* The size of file objects. Used when negative values are needed to indicate errors.
*
* \internal Defined as a (minimum) 64-bit integer type. Use of hssize_t
* should be discouraged in new code.
*/
typedef int64_t hssize_t;
#define PRIdHSIZE PRId64
#define PRIiHSIZE PRIi64
#define PRIoHSIZE PRIo64
#define PRIuHSIZE PRIu64
#define PRIxHSIZE PRIx64
#define PRIXHSIZE PRIX64
#define H5_SIZEOF_HSIZE_T 8
#define H5_SIZEOF_HSSIZE_T 8
#define HSIZE_UNDEF UINT64_MAX
/**
* The address of an object in the file.
*
* \internal Defined as a (minimum) 64-bit unsigned integer type.
*/
typedef uint64_t haddr_t;
#define PRIdHADDR PRId64
#define PRIoHADDR PRIo64
#define PRIuHADDR PRIu64
#define PRIxHADDR PRIx64
#define PRIXHADDR PRIX64
#define H5_SIZEOF_HADDR_T 8
#define HADDR_UNDEF UINT64_MAX
#define H5_PRINTF_HADDR_FMT "%" PRIuHADDR
#define HADDR_MAX (HADDR_UNDEF - 1)
#ifdef H5_HAVE_PARALLEL
#define HADDR_AS_MPI_TYPE MPI_LONG_LONG_INT
#endif
//! <!-- [H5_iter_order_t_snip] -->
/**
* Common iteration orders
*/
typedef enum {
H5_ITER_UNKNOWN = -1, /**< Unknown order */
H5_ITER_INC, /**< Increasing order */
H5_ITER_DEC, /**< Decreasing order */
H5_ITER_NATIVE, /**< No particular order, whatever is fastest */
H5_ITER_N /**< Number of iteration orders */
} H5_iter_order_t;
//! <!-- [H5_iter_order_t_snip] -->
/* Iteration callback values */
/* (Actually, any positive value will cause the iterator to stop and pass back
* that positive value to the function that called the iterator)
*/
#define H5_ITER_ERROR (-1) /**< Error, stop iteration */
#define H5_ITER_CONT (0) /**< Continue iteration */
#define H5_ITER_STOP (1) /**< Stop iteration, short-circuit success */
//! <!-- [H5_index_t_snip] -->
/**
* The types of indices on links in groups/attributes on objects.
* Primarily used for "<do> <foo> by index" routines and for iterating over
* links in groups/attributes on objects.
*/
typedef enum H5_index_t {
H5_INDEX_UNKNOWN = -1, /**< Unknown index type */
H5_INDEX_NAME, /**< Index on names */
H5_INDEX_CRT_ORDER, /**< Index on creation order */
H5_INDEX_N /**< Number of indices defined */
} H5_index_t;
//! <!-- [H5_index_t_snip] -->
/**
* Storage info struct used by H5O_info_t and H5F_info_t
*/
//! <!-- [H5_ih_info_t_snip] -->
typedef struct H5_ih_info_t {
hsize_t index_size; /**< btree and/or list */
hsize_t heap_size;
} H5_ih_info_t;
//! <!-- [H5_ih_info_t_snip] -->
/**
* The maximum size allowed for tokens
* \details Tokens are unique and permanent identifiers that are
* used to reference HDF5 objects in a container. This allows
* for 128-bit tokens
*/
#define H5O_MAX_TOKEN_SIZE (16)
//! <!-- [H5O_token_t_snip] -->
/**
* Type for object tokens
*
* \internal (Hoisted here, since it's used by both the
* H5Lpublic.h and H5Opublic.h headers)
*/
typedef struct H5O_token_t {
uint8_t __data[H5O_MAX_TOKEN_SIZE];
} H5O_token_t;
//! <!-- [H5O_token_t_snip] -->
/**
* Allocation statistics info struct
*/
typedef struct H5_alloc_stats_t {
unsigned long long total_alloc_bytes; /**< Running count of total # of bytes allocated */
size_t curr_alloc_bytes; /**< Current # of bytes allocated */
size_t peak_alloc_bytes; /**< Peak # of bytes allocated */
size_t max_block_size; /**< Largest block allocated */
size_t total_alloc_blocks_count; /**< Running count of total # of blocks allocated */
size_t curr_alloc_blocks_count; /**< Current # of blocks allocated */
size_t peak_alloc_blocks_count; /**< Peak # of blocks allocated */
} H5_alloc_stats_t;
/**
* Library shutdown callback, used by H5atclose().
*/
typedef void (*H5_atclose_func_t)(void *ctx);
/* API adapter header (defines H5_DLL, etc.) */
#include "H5api_adpt.h"
#ifdef __cplusplus
extern "C" {
#endif
/* Functions in H5.c */
/**
* \ingroup H5
* \brief Initializes the HDF5 library
* \return \herr_t
*
* \details H5open() initializes the HDF5 library.
*
* \details When the HDF5 library is used in a C application, the library is
* automatically initialized when the first HDf5 function call is
* issued. If one finds that an HDF5 library function is failing
* inexplicably, H5open() can be called first. It is safe to call
* H5open() before an application issues any other function calls to
* the HDF5 library as there are no damaging side effects in calling
* it more than once.
*/
H5_DLL herr_t H5open(void);
/**
* \ingroup H5
* \brief Registers a callback for the library to invoke when it's closing.
* \param[in] func The function pointer to invoke
* \param[in] ctx Context to pass to \p func when invoked
* \return \herr_t
*
* \details H5atclose() registers a callback that the HDF5 library will invoke
* when closing. The full capabilities of the HDF5 library are
* available to callbacks invoked through this mechanism, library
* shutdown will only begin in earnest when all callbacks have been
* invoked and have returned.
*
* Registered callbacks are invoked in LIFO order, similar to the
* Standard C 'atexit' routine. For example, if 'func1' is registered,
* then 'func2', when the library is closing 'func2' will
* be invoked first, then 'func1'.
*
* The \p ctx pointer will be passed to \p func when it's invoked.
* NULL is allowed for \p ctx.
*
* If the HDF5 library is initialized and closed more than once, the
* \p func callback must be registered within each open/close cycle.
*
* \since 1.13.0
*/
H5_DLL herr_t H5atclose(H5_atclose_func_t func, void *ctx);
/**
* \ingroup H5
* \brief Flushes all data to disk, closes all open objects, and releases memory
* \return \herr_t
*
* \details H5close() flushes all data to disk, closes all open HDF5 objects,
* and cleans up all memory used by the HDF5 library. This function is
* generally called when the application calls exit(), but may be
* called earlier in the event of an emergency shutdown or out of a
* desire to free all resources used by the HDF5 library.
*/
H5_DLL herr_t H5close(void);
/**
* \ingroup H5
* \brief Instructs library not to install atexit() cleanup routine
* \return \herr_t
*
* \details H5dont_atexit() indicates to the library that an atexit() cleanup
* routine should not be installed. The major purpose for using this
* function is in situations where the library is dynamically linked
* into an application and is un-linked from the application before
* exit() gets called. In those situations, a routine installed with
* atexit() would jump to a routine which was no longer in memory,
* causing errors.
*
* \attention In order to be effective, this routine \Emph{must} be called
* before any other HDF5 function calls, and must be called each
* time the library is loaded/linked into the application (the first
* time and after it's been un-loaded).
*/
H5_DLL herr_t H5dont_atexit(void);
/**
* \ingroup H5
* \brief Garbage collects on all free-lists of all types
* \return \herr_t
*
* \details H5garbage_collect() walks through all garbage collection routines
* of the library, freeing any unused memory.
*
* It is not required that H5garbage_collect() be called at any
* particular time; it is only necessary in certain situations where
* the application has performed actions that cause the library to
* allocate many objects. The application should call
* H5garbage_collect() if it eventually releases those objects and
* wants to reduce the memory used by the library from the peak usage
* required.
*
* \note The library automatically garbage collects all the free lists when the
* application ends.
*/
H5_DLL herr_t H5garbage_collect(void);
/**
* \ingroup H5
* \brief Sets free-list size limits
*
* \param[in] reg_global_lim The cumulative limit, in bytes, on memory used for
* all regular free lists (Default: 1MB)
* \param[in] reg_list_lim The limit, in bytes, on memory used for each regular
* free list (Default: 64KB)
* \param[in] arr_global_lim The cumulative limit, in bytes, on memory used for
* all array free lists (Default: 4MB)
* \param[in] arr_list_lim The limit, in bytes, on memory used for each array
* free list (Default: 256KB)
* \param[in] blk_global_lim The cumulative limit, in bytes, on memory used for
* all block free lists and, separately, for all
* factory free lists (Default: 16MB)
* \param[in] blk_list_lim The limit, in bytes, on memory used for each block
* or factory free list (Default: 1MB)
* \return \herr_t
*
* \details H5set_free_list_limits() sets size limits on all types of free
* lists. The HDF5 library uses free lists internally to manage
* memory. The types of free lists used are as follows:
* \li Regular free lists manage memory for single internal data
* structures.
* \li Array free lists manage memory for arrays of internal
* data structures.
* \li Block free lists manage memory for arbitrarily-sized blocks
* of bytes.
* \li Factory free lists manage memory for fixed-size blocks of
* bytes.
*
* The parameters specify global and per-list limits; for example, \p
* reg_global_limit and \p reg_list_limit limit the accumulated size
* of all regular free lists and the size of each individual regular
* free list, respectively. Therefore, if an application sets a 1Mb
* limit on each of the global lists, up to 4Mb of total storage might
* be allocated, 1Mb for each of the regular, array, block, and
* factory type lists.
*
* The settings specified for block free lists are duplicated for
* factory free lists. Therefore, increasing the global limit on block
* free lists by x bytes will increase the potential free list memory
* usage by 2x bytes.
*
* Using a value of -1 for a limit means that no limit is set for the
* specified type of free list.
*
* \version 1.8.3 Function changed in this release to set factory free list
* memory limits.
*
* \since 1.6.0
*/
H5_DLL herr_t H5set_free_list_limits(int reg_global_lim, int reg_list_lim, int arr_global_lim,
int arr_list_lim, int blk_global_lim, int blk_list_lim);
/**
* \ingroup H5
* \brief Gets the current size of the free lists used to manage memory
*
* \param[out] reg_size The current size of all "regular" free list memory used
* \param[out] arr_size The current size of all "array" free list memory used
* \param[out] blk_size The current size of all "block" free list memory used
* \param[out] fac_size The current size of all "factory" free list memory used
* \return \herr_t
*
* \details H5get_free_list_sizes() obtains the current size of the different
* kinds of free lists that the library uses to manage memory. The
* free list sizes can be set with H5set_free_list_limits() and
* garbage collected with H5garbage_collect(). These lists are global
* for the entire library.
*
* \since 1.12.1
*/
H5_DLL herr_t H5get_free_list_sizes(size_t *reg_size, size_t *arr_size, size_t *blk_size, size_t *fac_size);
/**
* \ingroup H5
* \brief Gets the memory allocation statistics for the library
*
* \param[out] stats Memory allocation statistics
* \return \herr_t
*
* \details H5get_alloc_stats() gets the memory allocation statistics for the
* library, if the \c --enable-memory-alloc-sanity-check option was
* given when building the library. Applications can check whether
* this option was enabled detecting if the
* \c H5_MEMORY_ALLOC_SANITY_CHECK macro is defined. This option is
* enabled by default for debug builds of the library and disabled by
* default for non-debug builds. If the option is not enabled, all the
* values returned with be 0. These statistics are global for the
* entire library, but do not include allocations from chunked dataset
* I/O filters or non-native VOL connectors.
*
* \since 1.12.1
*/
H5_DLL herr_t H5get_alloc_stats(H5_alloc_stats_t *stats);
/**
* \ingroup H5
* \brief Returns the HDF library release number
*
* \param[out] majnum The major version number of the library
* \param[out] minnum The minor version number of the library
* \param[out] relnum The release version number of the library
* \return \herr_t
*
* \details H5get_libversion() retrieves the major, minor, and release numbers
* of the version of the HDF5 library which is linked to the
* application.
*
*/
H5_DLL herr_t H5get_libversion(unsigned *majnum, unsigned *minnum, unsigned *relnum);
/**
* \ingroup H5
* \brief Verifies that HDF5 library versions are consistent
*
* \param[in] majnum HDF5 library major version number
* \param[in] minnum HDF5 library minor version number
* \param[in] relnum HDF5 library release number
* \return \herr_t
*
* \details H5check_version() verifies that the version of the HDF5 library
* with which an application was compiled, as indicated by the passed
* parameters, matches the version of the HDF5 library against which
* the application is currently linked.
*
* \p majnum is the major version number of the HDF library with which
* the application was compiled, \p minnum is the minor version
* number, and \p relnum is the release number. Consider the following
* example:
*
* An official HDF5 release is labelled as follows:
* HDF5 Release \Code{\<majnum\>.\<minnum\>.\<relnum\>}\n
* For example, in HDF5 Release 1.8.5:
* \li 1 is the major version number, \p majnum.
* \li 8 is the minor version number, \p minnum.
* \li 5 is the release number, \p relnum.
*
* As stated above, H5check_version() first verifies that the version
* of the HDF5 library with which an application was compiled matches
* the version of the HDF5 library against which the application is
* currently linked. If this check fails, H5check_version() causes the
* application to abort (by means of a standard C abort() call) and
* prints information that is usually useful for debugging. This
* precaution is is taken to avoid the risks of data corruption or
* segmentation faults.
*
* The most common cause of this failure is that an application was
* compiled with one version of HDF5 and is dynamically linked with a
* different version different version.
*
* If the above test passes, H5check_version() proceeds to verify the
* consistency of additional library version information. This is
* designed to catch source code inconsistencies that do not normally
* cause failures; if this check reveals an inconsistency, an
* informational warning is printed but the application is allowed to
* run.
*
*/
H5_DLL herr_t H5check_version(unsigned majnum, unsigned minnum, unsigned relnum);
/**
* \ingroup H5
* \brief Checks whether the HDF5 library is closing.
* \param[out] is_terminating Flag indicating whether library is shutting down
* \return \herr_t
*
* \details H5is_library_terminating() queries whether the HDF5 library is in
* the process of shutting down. The \p is_terminating flag will only
* be set to TRUE after shutdown starts, it will be FALSE before the
* library has been initialized, while the library is initialized, and
* after it has been closed. The value of \p is_terminating is
* undefined if this routine fails.
*
* \since 1.13.0
*/
H5_DLL herr_t H5is_library_terminating(hbool_t *is_terminating);
/**
* \ingroup H5
* \brief Determines whether the HDF5 library was built with the thread-safety
* feature enabled
*
* \param[out] is_ts Boolean value indicating whether the library was built
* with thread-safety enabled
* \return \herr_t
*
* \details The HDF5 library, although not internally multi-threaded, can be
* built with a thread-safety feature enabled that protects internal
* data structures with a mutex. In certain circumstances, it may be
* useful to determine, at run-time, whether the linked HDF5 library
* was built with the thread-safety feature enabled.
*/
H5_DLL herr_t H5is_library_threadsafe(hbool_t *is_ts);
/**
* \ingroup H5
* \brief Frees memory allocated by the HDF5 library
*
* \param[in] mem Buffer to be freed. Can be NULL
* \return \herr_t
*
* \details H5free_memory() frees memory that has been allocated by the caller
* with H5allocate_memory() or by the HDF5 library on behalf of the
* caller.
*
* H5Tget_member_name() provides an example of memory allocation on
* behalf of the caller: The function returns a buffer containing the
* name of a compound datatype member. It is the caller’s
* responsibility to eventually free that buffer with H5free_memory().
*
* \attention It is especially important to use this function to free memory
* allocated by the library on Windows. The C standard library is
* implemented in dynamic link libraries (DLLs) known as the C
* run-time (CRT). Each version of Visual Studio comes with two CRT
* DLLs (debug and release) and allocating and freeing across DLL
* boundaries can cause resource leaks and subtle bugs due to heap
* corruption.\n
* Only use this function to free memory allocated by the HDF5
* Library. It will generally not be safe to use this function to
* free memory allocated by any other means.\n
* Even when using this function, it is still best to ensure that
* all components of a C application are built with the same version
* of Visual Studio and build (debug or release) and thus linked
* against the same CRT.
*
* \see H5allocate_memory(), H5resize_memory()
*
* \since 1.8.13
*
*/
H5_DLL herr_t H5free_memory(void *mem);
/**
* \ingroup H5
* \brief Frees memory allocated by the HDF5 library
*
* \param[in] size The size in bytes of the buffer to be allocated
* \param[in] clear Flag whether the new buffer is to be initialized with 0
*
* \return On success, returns pointer to newly allocated buffer or returns
* NULL if size is 0 (zero).\n
* Returns NULL on failure.
*
* \details H5allocate_memory() allocates a memory buffer of size bytes that
* will later be freed internally by the HDF5 library.
*
* The boolean \p clear parameter specifies whether the buffer should
* be initialized. If clear is \c TRUE, all bits in the buffer are to be
* set to 0 (zero); if clear is \c FALSE, the buffer will not be
* initialized.
*
* This function is intended to have the semantics of malloc() and
* calloc(). However, unlike malloc() and calloc() which allow for a
* "special" pointer to be returned instead of NULL, this function
* always returns NULL on failure or when size is set to 0 (zero).
*
* \note At this time, the only intended use for this function is to allocate
* memory that will be returned to the library as a data buffer from a
* third-party filter.
*
* \attention To avoid heap corruption, allocated memory should be freed using
* the same library that initially allocated it. In most cases, the
* HDF5 API uses resources that are allocated and freed either
* entirely by the user or entirely by the library, so this is not a
* problem. In rare cases, however, HDF5 API calls will free memory
* that the user allocated. This function allows the user to safely
* allocate this memory.\n
* It is particularly important to use this function to allocate
* memory in Microsoft Windows environments. In Windows, the C
* standard library is implemented in dynamic link libraries (DLLs)
* known as the C run-time (CRT). Each version of Visual Studio
* comes with multiple versions of the CRT DLLs (debug, release, et
* cetera) and allocating and freeing memory across DLL boundaries
* can cause resource leaks and subtle bugs due to heap corruption.\n
* Even when using this function, it is best where possible to
* ensure that all components of a C application are built with the
* same version of Visual Studio and configuration (Debug or
* Release), and thus linked against the same CRT.\n
* Use this function only to allocate memory inside third-party HDF5
* filters. It will generally not be safe to use this function to
* allocate memory for any other purpose.
*
* \see H5free_memory(), H5resize_memory()
*
* \since 1.8.15
*
*/
H5_DLL void *H5allocate_memory(size_t size, hbool_t clear);
/**
* \ingroup H5
* \brief Resizes and, if required, re-allocates memory that will later be
* freed internally by the HDF5 library
*
* \param[in] mem Pointer to a buffer to be resized. May be NULL
* \param[in] size New size of the buffer, in bytes
*
* \return On success, returns pointer to resized or reallocated buffer
* or returns NULL if size is 0 (zero).\n
* Returns NULL on failure.
*
* \details H5resize_memory() takes a pointer to an existing buffer and resizes
* the buffer to match the value in \p size. If necessary, the buffer
* is reallocated. If \p size is 0, the buffer is released.
*
* The input buffer must either be NULL or have been allocated by
* H5allocate_memory() since the input buffer may be freed by the
* library.
*
* For certain behaviors, the pointer \p mem may be passed in as NULL.
*
* This function is intended to have the semantics of realloc():
*
* <table>
* <tr><td>\Code{H5resize_memory(buffer, size)}</td>
* <td>Resizes buffer. Returns pointer to resized buffer.</td></tr>
* <tr><td>\Code{H5resize_memory(NULL, size)}</td>
* <td>Allocates memory using HDF5 Library allocator.
* Returns pointer to new buffer</td></tr>
* <tr><td>\Code{H5resize_memory(buffer, 0)}</td>
* <td>Frees memory using HDF5 Library allocator.
* Returns NULL.</td></tr>
* <tr><td>\Code{H5resize_memory(NULL, 0)}</td>
* <td>Returns NULL (undefined in C standard).</td></tr>
* </table>
*
* Unlike realloc(), which allows for a "special pointer to be
* returned instead of NULL, this function always returns NULL on
* failure or when size is 0 (zero).
*
* \note At this time, the only intended use for this function is to resize or
* reallocate memory that will be returned to the library (and eventually
* to the user) as a data buffer from a third-party HDF5 filter.
*
* \attention To avoid heap corruption, allocated memory should be freed using
* the same library that initially allocated it. In most cases, the
* HDF5 API uses resources that are allocated and freed either
* entirely by the user or entirely by the library, so this is not a
* problem. In rare cases, however, HDF5 API calls will free memory
* that the user allocated. This function allows the user to safely
* allocate this memory.\n
* It is particularly important to use this function to resize
* memory on Microsoft Windows systems. In Windows, the C standard
* library is implemented in dynamic link libraries (DLLs) known as
* the C run-time (CRT). Each version of Visual Studio comes with
* multiple versions of the CRT DLLs (debug, release, et cetera) and
* allocating and freeing memory across DLL boundaries can cause
* resource leaks and subtle bugs due to heap corruption.\n
* Even when using this function, it is still best to ensure that
* all components of a C application are built with the same version
* of Visual Studio and the same configuration (Debug or Release),
* and thus linked against the same CRT.\n
* Only use this function to resize memory inside third-party HDF5
* filters. It will generally not be safe to use this function to
* resize memory for any other purpose.
*
* \see H5allocate_memory(), H5free_memory()
*
* \since 1.8.15
*
*/
H5_DLL void *H5resize_memory(void *mem, size_t size);
#ifdef __cplusplus
}
#endif
#endif /* H5public_H */