icuSources/common/unicode/uclean.h

   1 /*
   2 ******************************************************************************
   3 *                                                                            *
   4 * Copyright (C) 2001-2009, International Business Machines                   *
   5 *                Corporation and others. All Rights Reserved.                *
   6 *                                                                            *
   7 ******************************************************************************
   8 *   file name:  uclean.h
   9 *   encoding:   US-ASCII
  10 *   tab size:   8 (not used)
  11 *   indentation:4
  12 *
  13 *   created on: 2001July05
  14 *   created by: George Rhoten
  15 */
  16
  17 #ifndef __UCLEAN_H__
  18 #define __UCLEAN_H__
  19
  20 #include "unicode/utypes.h"
  21 /**
  22  * \file
  23  * \brief C API: Initialize and clean up ICU
  24  */
  25
  26 /**
  27  *  Initialize ICU.
  28  *
  29  *  Use of this function is optional.  It is OK to simply use ICU
  30  *  services and functions without first having initialized
  31  *  ICU by calling u_init().
  32  *
  33  *  u_init() will attempt to load some part of ICU's data, and is
  34  *  useful as a test for configuration or installation problems that
  35  *  leave the ICU data inaccessible.  A successful invocation of u_init()
  36  *  does not, however, guarantee that all ICU data is accessible.
  37  *
  38  *  Multiple calls to u_init() cause no harm, aside from the small amount
  39  *  of time required.
  40  *
  41  *  In old versions of ICU, u_init() was required in multi-threaded applications
  42  *  to ensure the thread safety of ICU.  u_init() is no longer needed for this purpose.
  43  *
  44  * @param status An ICU UErrorCode parameter. It must not be <code>NULL</code>.
  45  *    An Error will be returned if some required part of ICU data can not
  46  *    be loaded or initialized.
  47  *    The function returns immediately if the input error code indicates a
  48  *    failure, as usual.
  49  *
  50  * @stable ICU 2.6
  51  */
  52 U_STABLE void U_EXPORT2
  53 u_init(UErrorCode *status);
  54
  55 /**
  56  * Clean up the system resources, such as allocated memory or open files,
  57  * used in all ICU libraries. This will free/delete all memory owned by the
  58  * ICU libraries, and return them to their original load state. All open ICU
  59  * items (collators, resource bundles, converters, etc.) must be closed before
  60  * calling this function, otherwise ICU may not free its allocated memory
  61  * (e.g. close your converters and resource bundles before calling this
  62  * function). Generally, this function should be called once just before
  63  * an application exits. For applications that dynamically load and unload
  64  * the ICU libraries (relatively uncommon), u_cleanup() should be called
  65  * just before the library unload.
  66  * <p>
  67  * u_cleanup() also clears any ICU heap functions, mutex functions or
  68  * trace functions that may have been set for the process.
  69  * This has the effect of restoring ICU to its initial condition, before
  70  * any of these override functions were installed.  Refer to
  71  * u_setMemoryFunctions(), u_setMutexFunctions and
  72  * utrace_setFunctions().  If ICU is to be reinitialized after after
  73  * calling u_cleanup(), these runtime override functions will need to
  74  * be set up again if they are still required.
  75  * <p>
  76  * u_cleanup() is not thread safe.  All other threads should stop using ICU
  77  * before calling this function.
  78  * <p>
  79  * Any open ICU items will be left in an undefined state by u_cleanup(),
  80  * and any subsequent attempt to use such an item will give unpredictable
  81  * results.
  82  * <p>
  83  * After calling u_cleanup(), an application may continue to use ICU by
  84  * calling u_init().  An application must invoke u_init() first from one single
  85  * thread before allowing other threads call u_init().  All threads existing
  86  * at the time of the first thread's call to u_init() must also call
  87  * u_init() themselves before continuing with other ICU operations.
  88  * <p>
  89  * The use of u_cleanup() just before an application terminates is optional,
  90  * but it should be called only once for performance reasons. The primary
  91  * benefit is to eliminate reports of memory or resource leaks originating
  92  * in ICU code from the results generated by heap analysis tools.
  93  * <p>
  94  * <strong>Use this function with great care!</strong>
  95  * </p>
  96  *
  97  * @stable ICU 2.0
  98  * @system
  99  */
 100 U_STABLE void U_EXPORT2
 101 u_cleanup(void);
 102
 103
 104
 105
 106 /**
 107   * An opaque pointer type that represents an ICU mutex.
 108   * For user-implemented mutexes, the value will typically point to a
 109   *  struct or object that implements the mutex.
 110   * @stable ICU 2.8
 111   * @system
 112   */
 113 typedef void *UMTX;
 114
 115 /**
 116   *  Function Pointer type for a user supplied mutex initialization function.
 117   *  The user-supplied function will be called by ICU whenever ICU needs to create a
 118   *  new mutex.  The function implementation should create a mutex, and store a pointer
 119   *  to something that uniquely identifies the mutex into the UMTX that is supplied
 120   *  as a paramter.
 121   *  @param context user supplied value, obtained from from u_setMutexFunctions().
 122   *  @param mutex   Receives a pointer that identifies the new mutex.
 123   *                 The mutex init function must set the UMTX to a non-null value.
 124   *                 Subsequent calls by ICU to lock, unlock, or destroy a mutex will
 125   *                 identify the mutex by the UMTX value.
 126   *  @param status  Error status.  Report errors back to ICU by setting this variable
 127   *                 with an error code.
 128   *  @stable ICU 2.8
 129   *  @system
 130   */
 131 typedef void U_CALLCONV UMtxInitFn (const void *context, UMTX  *mutex, UErrorCode* status);
 132
 133
 134 /**
 135   *  Function Pointer type for a user supplied mutex functions.
 136   *  One of the  user-supplied functions with this signature will be called by ICU
 137   *  whenever ICU needs to lock, unlock, or destroy a mutex.
 138   *  @param context user supplied value, obtained from from u_setMutexFunctions().
 139   *  @param mutex   specify the mutex on which to operate.
 140   *  @stable ICU 2.8
 141   *  @system
 142   */
 143 typedef void U_CALLCONV UMtxFn   (const void *context, UMTX  *mutex);
 144
 145
 146 /**
 147   *  Set the functions that ICU will use for mutex operations
 148   *  Use of this function is optional; by default (without this function), ICU will
 149   *  directly access system functions for mutex operations
 150   *  This function can only be used when ICU is in an initial, unused state, before
 151   *  u_init() has been called.
 152   *  This function may be used even when ICU has been built without multi-threaded
 153   *  support  (see ICU_USE_THREADS pre-processor variable, umutex.h)
 154   *  @param context This pointer value will be saved, and then (later) passed as
 155   *                 a parameter to the user-supplied mutex functions each time they
 156   *                 are called.
 157   *  @param init    Pointer to a mutex initialization function.  Must be non-null.
 158   *  @param destroy Pointer to the mutex destroy function.  Must be non-null.
 159   *  @param lock    pointer to the mutex lock function.  Must be non-null.
 160   *  @param unlock  Pointer to the mutex unlock function.  Must be non-null.
 161   *  @param status  Receives error values.
 162   *  @stable ICU 2.8
 163   *  @system
 164   */
 165 U_STABLE void U_EXPORT2
 166 u_setMutexFunctions(const void *context, UMtxInitFn *init, UMtxFn *destroy, UMtxFn *lock, UMtxFn *unlock,
 167                     UErrorCode *status);
 168
 169
 170 /**
 171   *  Pointer type for a user supplied atomic increment or decrement function.
 172   *  @param context user supplied value, obtained from from u_setAtomicIncDecFunctions().
 173   *  @param p   Pointer to a 32 bit int to be incremented or decremented
 174   *  @return    The value of the variable after the inc or dec operation.
 175   *  @stable ICU 2.8
 176   *  @system
 177   */
 178 typedef int32_t U_CALLCONV UMtxAtomicFn(const void *context, int32_t *p);
 179
 180 /**
 181  *  Set the functions that ICU will use for atomic increment and decrement of int32_t values.
 182  *  Use of this function is optional; by default (without this function), ICU will
 183  *  use its own internal implementation of atomic increment/decrement.
 184  *  This function can only be used when ICU is in an initial, unused state, before
 185  *  u_init() has been called.
 186  *  @param context This pointer value will be saved, and then (later) passed as
 187  *                 a parameter to the increment and decrement functions each time they
 188  *                 are called.  This function can only be called
 189  *  @param inc     Pointer to a function to do an atomic increment operation.  Must be non-null.
 190  *  @param dec     Pointer to a function to do an atomic decrement operation.  Must be non-null.
 191  *  @param status  Receives error values.
 192  *  @stable ICU 2.8
 193  *  @system
 194  */
 195 U_STABLE void U_EXPORT2
 196 u_setAtomicIncDecFunctions(const void *context, UMtxAtomicFn *inc, UMtxAtomicFn *dec,
 197                     UErrorCode *status);
 198
 199
 200
 201 /**
 202   *  Pointer type for a user supplied memory allocation function.
 203   *  @param context user supplied value, obtained from from u_setMemoryFunctions().
 204   *  @param size    The number of bytes to be allocated
 205   *  @return        Pointer to the newly allocated memory, or NULL if the allocation failed.
 206   *  @stable ICU 2.8
 207   *  @system
 208   */
 209 typedef void *U_CALLCONV UMemAllocFn(const void *context, size_t size);
 210 /**
 211   *  Pointer type for a user supplied memory re-allocation function.
 212   *  @param context user supplied value, obtained from from u_setMemoryFunctions().
 213   *  @param size    The number of bytes to be allocated
 214   *  @return        Pointer to the newly allocated memory, or NULL if the allocation failed.
 215   *  @stable ICU 2.8
 216   *  @system
 217   */
 218 typedef void *U_CALLCONV UMemReallocFn(const void *context, void *mem, size_t size);
 219 /**
 220   *  Pointer type for a user supplied memory free  function.  Behavior should be
 221   *  similar the standard C library free().
 222   *  @param context user supplied value, obtained from from u_setMemoryFunctions().
 223   *  @param mem     Pointer to the memory block to be resized
 224   *  @param size    The new size for the block
 225   *  @return        Pointer to the resized memory block, or NULL if the resizing failed.
 226   *  @stable ICU 2.8
 227   *  @system
 228   */
 229 typedef void  U_CALLCONV UMemFreeFn (const void *context, void *mem);
 230
 231 /**
 232  *  Set the functions that ICU will use for memory allocation.
 233  *  Use of this function is optional; by default (without this function), ICU will
 234  *  use the standard C library malloc() and free() functions.
 235  *  This function can only be used when ICU is in an initial, unused state, before
 236  *  u_init() has been called.
 237  *  @param context This pointer value will be saved, and then (later) passed as
 238  *                 a parameter to the memory functions each time they
 239  *                 are called.
 240  *  @param a       Pointer to a user-supplied malloc function.
 241  *  @param r       Pointer to a user-supplied realloc function.
 242  *  @param f       Pointer to a user-supplied free function.
 243  *  @param status  Receives error values.
 244  *  @stable ICU 2.8
 245  *  @system
 246  */
 247 U_STABLE void U_EXPORT2
 248 u_setMemoryFunctions(const void *context, UMemAllocFn *a, UMemReallocFn *r, UMemFreeFn *f,
 249                     UErrorCode *status);
 250
 251 #endif