diff options
Diffstat (limited to 'src/H5public.h')
| -rw-r--r-- | src/H5public.h | 658 |
1 files changed, 557 insertions, 101 deletions
diff --git a/src/H5public.h b/src/H5public.h index fa0bfbc..730e3de 100644 --- a/src/H5public.h +++ b/src/H5public.h @@ -39,7 +39,7 @@ #endif #ifdef H5_STDC_HEADERS #include <limits.h> /* For H5T_NATIVE_CHAR defn in H5Tpublic.h */ -#include <stdarg.h> /* For variadic functions in H5VLpublic.h */ +#include <stdarg.h> /* For variadic functions */ #endif #ifndef __cplusplus #ifdef H5_HAVE_STDINT_H @@ -92,50 +92,130 @@ extern "C" { #endif /* Version numbers */ -#define H5_VERS_MAJOR 1 /* For major interface/format changes */ -#define H5_VERS_MINOR 8 /* For minor interface/format changes */ -#define H5_VERS_RELEASE 23 /* For tweaks, bug-fixes, or development */ -#define H5_VERS_SUBRELEASE "1" /* For pre-releases like snap0 */ - /* Empty string for real releases. */ -#define H5_VERS_INFO "HDF5 library version: 1.8.23-1" /* Full version string */ +/** + * For major interface/format changes + */ +#define H5_VERS_MAJOR 1 +/** + * For minor interface/format changes + */ +#define H5_VERS_MINOR 8 +/** + * For tweaks, bug-fixes, or development + */ +#define H5_VERS_RELEASE 23 +/** + * 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: 1.8.23-1" #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)) -/* +/** * 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: - * - * if((dset = H5Dopen2(file, name)) < 0) - * fprintf(stderr, "unable to open the requested dataset\n"); + * \code + * if((dset = H5Dopen2(file, name)) < 0) + * fprintf(stderr, "unable to open the requested dataset\n"); + * \endcode */ typedef int herr_t; -/* +/** * Boolean type. Successful return values are zero (false) or positive * (true). The typical true value is 1 but don't bet on it. Boolean - * functions cannot fail. Functions that return `htri_t' however return zero + * functions cannot fail. 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: - * - * 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"); - * } + * 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 unsigned int hbool_t; typedef int htri_t; @@ -158,17 +238,70 @@ typedef long long ssize_t; #endif #endif +/* int64_t type is used for creation order field for links. It may be + * defined in Posix.1g, otherwise it is defined here. + */ +#if H5_SIZEOF_INT64_T >= 8 +#elif H5_SIZEOF_INT >= 8 +typedef int int64_t; +#undef H5_SIZEOF_INT64_T +#define H5_SIZEOF_INT64_T H5_SIZEOF_INT +#elif H5_SIZEOF_LONG >= 8 +typedef long int64_t; +#undef H5_SIZEOF_INT64_T +#define H5_SIZEOF_INT64_T H5_SIZEOF_LONG +#elif H5_SIZEOF_LONG_LONG >= 8 +typedef long long int64_t; +#undef H5_SIZEOF_INT64_T +#define H5_SIZEOF_INT64_T H5_SIZEOF_LONG_LONG +#else +#error "nothing appropriate for int64_t" +#endif + +/* uint64_t type is used for fields for H5O_info_t. It may be + * defined in Posix.1g, otherwise it is defined here. + */ +#if H5_SIZEOF_UINT64_T >= 8 +#ifndef UINT64_MAX +#define UINT64_MAX ((uint64_t)-1) +#endif +#elif H5_SIZEOF_INT >= 8 +typedef unsigned uint64_t; +#define UINT64_MAX UINT_MAX +#undef H5_SIZEOF_UINT64_T +#define H5_SIZEOF_UINT64_T H5_SIZEOF_INT +#elif H5_SIZEOF_LONG >= 8 +typedef unsigned long uint64_t; +#define UINT64_MAX ULONG_MAX +#undef H5_SIZEOF_UINT64_T +#define H5_SIZEOF_UINT64_T H5_SIZEOF_LONG +#elif H5_SIZEOF_LONG_LONG >= 8 +typedef unsigned long long uint64_t; +#define UINT64_MAX ULLONG_MAX +#undef H5_SIZEOF_UINT64_T +#define H5_SIZEOF_UINT64_T H5_SIZEOF_LONG_LONG +#else +#error "nothing appropriate for uint64_t" +#endif + /* - * The sizes of file objects have their own types defined here, use a 64-bit - * type. + * The sizes of file objects have their own types defined here, use a minimum + * 64-bit type. */ #if H5_SIZEOF_LONG_LONG >= 8 H5_GCC_DIAG_OFF("long-long") typedef unsigned long long hsize_t; typedef signed long long hssize_t; H5_GCC_DIAG_ON("long-long") +#define PRIdHSIZE H5_PRINTF_LL_WIDTH "d" +#define PRIiHSIZE H5_PRINTF_LL_WIDTH "i" +#define PRIoHSIZE H5_PRINTF_LL_WIDTH "o" +#define PRIuHSIZE H5_PRINTF_LL_WIDTH "u" +#define PRIxHSIZE H5_PRINTF_LL_WIDTH "x" +#define PRIXHSIZE H5_PRINTF_LL_WIDTH "X" #define H5_SIZEOF_HSIZE_T H5_SIZEOF_LONG_LONG #define H5_SIZEOF_HSSIZE_T H5_SIZEOF_LONG_LONG +#define HSIZE_UNDEF ULLONG_MAX #else #error "nothing appropriate for hsize_t" #endif @@ -176,58 +309,58 @@ H5_GCC_DIAG_ON("long-long") /* * File addresses have their own types. */ -#if H5_SIZEOF_INT64_T >= 8 -typedef uint64_t haddr_t; -#define HADDR_UNDEF ((haddr_t)(int64_t)(-1)) -#define H5_SIZEOF_HADDR_T H5_SIZEOF_INT64_T -#ifdef H5_HAVE_PARALLEL -#define HADDR_AS_MPI_TYPE MPI_LONG_LONG_INT -#endif /* H5_HAVE_PARALLEL */ -#elif H5_SIZEOF_INT >= 8 +#if H5_SIZEOF_INT >= 8 typedef unsigned haddr_t; -#define HADDR_UNDEF ((haddr_t)(-1)) +#define HADDR_UNDEF UINT_MAX #define H5_SIZEOF_HADDR_T H5_SIZEOF_INT #ifdef H5_HAVE_PARALLEL #define HADDR_AS_MPI_TYPE MPI_UNSIGNED #endif /* H5_HAVE_PARALLEL */ +#define PRIdHADDR "d" +#define PRIoHADDR "o" +#define PRIuHADDR "u" +#define PRIxHADDR "x" +#define PRIXHADDR "X" #elif H5_SIZEOF_LONG >= 8 typedef unsigned long haddr_t; -#define HADDR_UNDEF ((haddr_t)(long)(-1)) +#define HADDR_UNDEF ULONG_MAX #define H5_SIZEOF_HADDR_T H5_SIZEOF_LONG #ifdef H5_HAVE_PARALLEL #define HADDR_AS_MPI_TYPE MPI_UNSIGNED_LONG #endif /* H5_HAVE_PARALLEL */ +#define PRIdHADDR "ld" +#define PRIoHADDR "lo" +#define PRIuHADDR "lu" +#define PRIxHADDR "lx" +#define PRIXHADDR "lX" #elif H5_SIZEOF_LONG_LONG >= 8 typedef unsigned long long haddr_t; -#define HADDR_UNDEF ((haddr_t)(long long)(-1)) +#define HADDR_UNDEF ULLONG_MAX #define H5_SIZEOF_HADDR_T H5_SIZEOF_LONG_LONG #ifdef H5_HAVE_PARALLEL #define HADDR_AS_MPI_TYPE MPI_LONG_LONG_INT #endif /* H5_HAVE_PARALLEL */ +#define PRIdHADDR H5_PRINTF_LL_WIDTH "d" +#define PRIoHADDR H5_PRINTF_LL_WIDTH "o" +#define PRIuHADDR H5_PRINTF_LL_WIDTH "u" +#define PRIxHADDR H5_PRINTF_LL_WIDTH "x" +#define PRIXHADDR H5_PRINTF_LL_WIDTH "X" #else #error "nothing appropriate for haddr_t" #endif -#if H5_SIZEOF_HADDR_T == H5_SIZEOF_INT -#define H5_PRINTF_HADDR_FMT "%u" -#elif H5_SIZEOF_HADDR_T == H5_SIZEOF_LONG -#define H5_PRINTF_HADDR_FMT "%lu" -#elif H5_SIZEOF_HADDR_T == H5_SIZEOF_LONG_LONG -#define H5_PRINTF_HADDR_FMT "%" H5_PRINTF_LL_WIDTH "u" -#else -#error "nothing appropriate for H5_PRINTF_HADDR_FMT" -#endif -#define HADDR_MAX (HADDR_UNDEF - 1) +#define H5_PRINTF_HADDR_FMT "%" PRIuHADDR +#define HADDR_MAX (HADDR_UNDEF - 1) /* uint32_t type is used for creation order field for messages. It may be * defined in Posix.1g, otherwise it is defined here. */ #if H5_SIZEOF_UINT32_T >= 4 #elif H5_SIZEOF_SHORT >= 4 -typedef short uint32_t; +typedef short uint32_t; #undef H5_SIZEOF_UINT32_T #define H5_SIZEOF_UINT32_T H5_SIZEOF_SHORT #elif H5_SIZEOF_INT >= 4 -typedef unsigned int uint32_t; +typedef unsigned int uint32_t; #undef H5_SIZEOF_UINT32_T #define H5_SIZEOF_UINT32_T H5_SIZEOF_INT #elif H5_SIZEOF_LONG >= 4 @@ -238,54 +371,18 @@ typedef unsigned long uint32_t; #error "nothing appropriate for uint32_t" #endif -/* int64_t type is used for creation order field for links. It may be - * defined in Posix.1g, otherwise it is defined here. - */ -#if H5_SIZEOF_INT64_T >= 8 -#elif H5_SIZEOF_INT >= 8 -typedef int int64_t; -#undef H5_SIZEOF_INT64_T -#define H5_SIZEOF_INT64_T H5_SIZEOF_INT -#elif H5_SIZEOF_LONG >= 8 -typedef long int64_t; -#undef H5_SIZEOF_INT64_T -#define H5_SIZEOF_INT64_T H5_SIZEOF_LONG -#elif H5_SIZEOF_LONG_LONG >= 8 -typedef long long int64_t; -#undef H5_SIZEOF_INT64_T -#define H5_SIZEOF_INT64_T H5_SIZEOF_LONG_LONG -#else -#error "nothing appropriate for int64_t" -#endif - -/* uint64_t type is used for fields for H5O_info_t. It may be - * defined in Posix.1g, otherwise it is defined here. +//! <!-- [H5_iter_order_t_snip] --> +/** + * Common iteration orders */ -#if H5_SIZEOF_UINT64_T >= 8 -#elif H5_SIZEOF_INT >= 8 -typedef unsigned uint64_t; -#undef H5_SIZEOF_UINT64_T -#define H5_SIZEOF_UINT64_T H5_SIZEOF_INT -#elif H5_SIZEOF_LONG >= 8 -typedef unsigned long uint64_t; -#undef H5_SIZEOF_UINT64_T -#define H5_SIZEOF_UINT64_T H5_SIZEOF_LONG -#elif H5_SIZEOF_LONG_LONG >= 8 -typedef unsigned long long uint64_t; -#undef H5_SIZEOF_UINT64_T -#define H5_SIZEOF_UINT64_T H5_SIZEOF_LONG_LONG -#else -#error "nothing appropriate for uint64_t" -#endif - -/* 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_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 @@ -295,39 +392,398 @@ typedef enum { #define H5_ITER_CONT (0) #define H5_ITER_STOP (1) -/* +//! <!-- [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_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 index_size; /**< btree and/or list */ hsize_t heap_size; } H5_ih_info_t; +//! <!-- [H5_ih_info_t_snip] --> /* 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 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 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 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); -H5_DLL void * H5allocate_memory(size_t size, hbool_t clear); -H5_DLL void * H5resize_memory(void *mem, size_t size); +/** + * \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 } |