icuSources/common/unicode/uclean.h

   1 /*
   2 ******************************************************************************
   3 *                                                                            *
   4 * Copyright (C) 2001-2004, 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 /**
  23  *  Initialize ICU.  This function loads and initializes data items
  24  *  that are required internally by various ICU functions.  Use of this explicit
  25  *  initialization is required in multi-threaded applications; in
  26  *  single threaded apps, use is optional, but incurs little additional
  27  *  cost, and is thus recommended.
  28  *  <p>
  29  *  In multi-threaded applications, u_init() should be called  in the
  30  *  main thread before starting additional threads, or, alternatively
  31  *  it can be called in each individual thread once, before other ICU
  32  *  functions are called in that thread.  In this second scenario, the
  33  *  application must guarantee that the first call to u_init() happen
  34  *  without contention, in a single thread only.
  35  *  <p>
  36  *  If <code>u_setMemoryFunctions()</code> or
  37  *  <code>u_setMutexFunctions</code> are needed (uncommon), they must be
  38  *  called _before_ <code>u_init()</code>.
  39  *  <p>
  40  *  Extra, repeated, or otherwise unneeded calls to u_init() do no harm,
  41  *  other than taking a small amount of time.
  42  *
  43  * @param status An ICU UErrorCode parameter. It must not be <code>NULL</code>.
  44  *    An Error will be returned if some required part of ICU data can not
  45  *    be loaded or initialized.
  46  *    The function returns immediately if the input error code indicates a
  47  *    failure, as usual.
  48  *
  49  * @stable ICU 2.6
  50  */
  51 U_STABLE void U_EXPORT2
  52 u_init(UErrorCode *status);
  53
  54 /**
  55  * Clean up the system resources, such as allocated memory or open files,
  56  * used in all ICU libraries. This will free/delete all memory owned by the
  57  * ICU libraries, and return them to their original load state. All open ICU
  58  * items (collators, resource bundles, converters, etc.) must be closed before
  59  * calling this function, otherwise ICU may not free its allocated memory
  60  * (e.g. close your converters and resource bundles before calling this
  61  * function). Generally, this function should be called once just before
  62  * an application exits. For applications that dynamically load and unload
  63  * the ICU libraries (relatively uncommon), u_cleanup() should be called
  64  * just before the library unload.
  65  * <p>
  66  * u_cleanup() also clears any ICU heap functions, mutex functions or
  67  * trace functions that may have been set for the process.
  68  * This has the effect of restoring ICU to its initial condition, before
  69  * any of these override functions were installed.  Refer to
  70  * u_setMemoryFunctions(), u_setMutexFunctions and
  71  * utrace_setFunctions().  If ICU is to be reinitialized after after
  72  * calling u_cleanup(), these runtime override functions will need to
  73  * be set up again if they are still required.
  74  * <p>
  75  * u_cleanup() is not thread safe.  All other threads should stop using ICU
  76  * before calling this function.
  77  * <p>
  78  * Any open ICU items will be left in an undefined state by u_cleanup(),
  79  * and any subsequent attempt to use such an item will give unpredictable
  80  * results.
  81  * <p>
  82  * After calling u_cleanup(), an application may continue to use ICU by
  83  * calling u_init().  An application must invoke u_init() first from one single
  84  * thread before allowing other threads call u_init().  All threads existing
  85  * at the time of the first thread's call to u_init() must also call
  86  * u_init() themselves before continuing with other ICU operations.
  87  * <p>
  88  * The use of u_cleanup() just before an application terminates is optional,
  89  * but it should be called only once for performance reasons. The primary
  90  * benefit is to eliminate reports of memory or resource leaks originating
  91  * in ICU code from the results generated by heap analysis tools.
  92  * <p>
  93  * <strong>Use this function with great care!</strong>
  94  * </p>
  95  *
  96  * @stable ICU 2.0
  97  * @system
  98  */
  99 U_STABLE void U_EXPORT2
 100 u_cleanup(void);
 101
 102
 103
 104
 105 /**
 106   * An opaque pointer type that represents an ICU mutex.
 107   * For user-implemented mutexes, the value will typically point to a
 108   *  struct or object that implements the mutex.
 109   * @draft ICU 2.8
 110   * @system
 111   */
 112 typedef void *UMTX;
 113
 114 /**
 115   *  Function Pointer type for a user supplied mutex initialization function.
 116   *  The user-supplied function will be called by ICU whenever ICU needs to create a
 117   *  new mutex.  The function implementation should create a mutex, and store a pointer
 118   *  to something that uniquely identifies the mutex into the UMTX that is supplied
 119   *  as a paramter.
 120   *  @param context user supplied value, obtained from from u_setMutexFunctions().
 121   *  @param mutex   Receives a pointer that identifies the new mutex.
 122   *                 The mutex init function must set the UMTX to a non-null value.
 123   *                 Subsequent calls by ICU to lock, unlock, or destroy a mutex will
 124   *                 identify the mutex by the UMTX value.
 125   *  @param status  Error status.  Report errors back to ICU by setting this variable
 126   *                 with an error code.
 127   *  @draft ICU 2.8
 128   *  @system
 129   */
 130 typedef void U_CALLCONV UMtxInitFn (const void *context, UMTX  *mutex, UErrorCode* status);
 131
 132
 133 /**
 134   *  Function Pointer type for a user supplied mutex functions.
 135   *  One of the  user-supplied functions with this signature will be called by ICU
 136   *  whenever ICU needs to lock, unlock, or destroy a mutex.
 137   *  @param context user supplied value, obtained from from u_setMutexFunctions().
 138   *  @param mutex   specify the mutex on which to operate.
 139   *  @draft ICU 2.8
 140   *  @system
 141   */
 142 typedef void U_CALLCONV UMtxFn   (const void *context, UMTX  *mutex);
 143
 144
 145 /**
 146   *  Set the functions that ICU will use for mutex operations
 147   *  Use of this function is optional; by default (without this function), ICU will
 148   *  directly access system functions for mutex operations
 149   *  This function can only be used when ICU is in an initial, unused state, before
 150   *  u_init() has been called.
 151   *  This function may be used even when ICU has been built without multi-threaded
 152   *  support  (see ICU_USE_THREADS pre-processor variable, umutex.h)
 153   *  @param context This pointer value will be saved, and then (later) passed as
 154   *                 a parameter to the user-supplied mutex functions each time they
 155   *                 are called.
 156   *  @param init    Pointer to a mutex initialization function.  Must be non-null.
 157   *  @param destroy Pointer to the mutex destroy function.  Must be non-null.
 158   *  @param lock    pointer to the mutex lock function.  Must be non-null.
 159   *  @param unlock  Pointer to the mutex unlock function.  Must be non-null.
 160   *  @param status  Receives error values.
 161   *  @draft ICU 2.8
 162   *  @system
 163   */
 164 U_DRAFT void U_EXPORT2
 165 u_setMutexFunctions(const void *context, UMtxInitFn *init, UMtxFn *destroy, UMtxFn *lock, UMtxFn *unlock,
 166                     UErrorCode *status);
 167
 168
 169 /**
 170   *  Pointer type for a user supplied atomic increment or decrement function.
 171   *  @param context user supplied value, obtained from from u_setAtomicIncDecFunctions().
 172   *  @param p   Pointer to a 32 bit int to be incremented or decremented
 173   *  @return    The value of the variable after the inc or dec operation.
 174   *  @draft ICU 2.8
 175   *  @system
 176   */
 177 typedef int32_t U_CALLCONV UMtxAtomicFn(const void *context, int32_t *p);
 178
 179 /**
 180  *  Set the functions that ICU will use for atomic increment and decrement of int32_t values.
 181  *  Use of this function is optional; by default (without this function), ICU will
 182  *  use its own internal implementation of atomic increment/decrement.
 183  *  This function can only be used when ICU is in an initial, unused state, before
 184  *  u_init() has been called.
 185  *  @param context This pointer value will be saved, and then (later) passed as
 186  *                 a parameter to the increment and decrement functions each time they
 187  *                 are called.  This function can only be called
 188  *  @param inc     Pointer to a function to do an atomic increment operation.  Must be non-null.
 189  *  @param dec     Pointer to a function to do an atomic decrement operation.  Must be non-null.
 190  *  @param status  Receives error values.
 191  *  @draft ICU 2.8
 192  *  @system
 193  */
 194 U_DRAFT void U_EXPORT2
 195 u_setAtomicIncDecFunctions(const void *context, UMtxAtomicFn *inc, UMtxAtomicFn *dec,
 196                     UErrorCode *status);
 197
 198
 199
 200 /**
 201   *  Pointer type for a user supplied memory allocation function.
 202   *  @param context user supplied value, obtained from from u_setMemoryFunctions().
 203   *  @param size    The number of bytes to be allocated
 204   *  @return        Pointer to the newly allocated memory, or NULL if the allocation failed.
 205   *  @draft ICU 2.8
 206   *  @system
 207   */
 208 typedef void *U_CALLCONV UMemAllocFn(const void *context, size_t size);
 209 /**
 210   *  Pointer type for a user supplied memory re-allocation function.
 211   *  @param context user supplied value, obtained from from u_setMemoryFunctions().
 212   *  @param size    The number of bytes to be allocated
 213   *  @return        Pointer to the newly allocated memory, or NULL if the allocation failed.
 214   *  @draft ICU 2.8
 215   *  @system
 216   */
 217 typedef void *U_CALLCONV UMemReallocFn(const void *context, void *mem, size_t size);
 218 /**
 219   *  Pointer type for a user supplied memory free  function.  Behavior should be
 220   *  similar the standard C library free().
 221   *  @param context user supplied value, obtained from from u_setMemoryFunctions().
 222   *  @param mem     Pointer to the memory block to be resized
 223   *  @param size    The new size for the block
 224   *  @return        Pointer to the resized memory block, or NULL if the resizing failed.
 225   *  @draft ICU 2.8
 226   *  @system
 227   */
 228 typedef void  U_CALLCONV UMemFreeFn (const void *context, void *mem);
 229
 230 /**
 231  *  Set the functions that ICU will use for memory allocation.
 232  *  Use of this function is optional; by default (without this function), ICU will
 233  *  use the standard C library malloc() and free() functions.
 234  *  This function can only be used when ICU is in an initial, unused state, before
 235  *  u_init() has been called.
 236  *  @param context This pointer value will be saved, and then (later) passed as
 237  *                 a parameter to the memory functions each time they
 238  *                 are called.
 239  *  @param a       Pointer to a user-supplied malloc function.
 240  *  @param r       Pointer to a user-supplied realloc function.
 241  *  @param f       Pointer to a user-supplied free function.
 242  *  @param status  Receives error values.
 243  *  @draft ICU 2.8
 244  *  @system
 245  */
 246 U_DRAFT void U_EXPORT2
 247 u_setMemoryFunctions(const void *context, UMemAllocFn *a, UMemReallocFn *r, UMemFreeFn *f,
 248                     UErrorCode *status);
 249
 250 #endif