icuSources/common/ucln.h

   1 /*
   2 ******************************************************************************
   3 *                                                                            *
   4 * Copyright (C) 2001-2004, International Business Machines                   *
   5 *                Corporation and others. All Rights Reserved.                *
   6 *                                                                            *
   7 ******************************************************************************
   8 *   file name:  ucln_cmn.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 __UCLN_H__
  18 #define __UCLN_H__
  19
  20 #include "unicode/utypes.h"
  21
  22 /** These are the functions used to register a library's memory cleanup
  23  * functions.  Each library should define a single library register function
  24  * to call this API.  In the i18n library, it is ucln_i18n_registerCleanup().
  25  *
  26  * None of the cleanup functions should use a mutex to clean up an API's
  27  * allocated memory because a cleanup function is not meant to be thread safe,
  28  * and plenty of data cannot be reference counted in order to make sure that
  29  * no one else needs the allocated data.
  30  *
  31  * In order to make a cleanup function get called when u_cleanup is called,
  32  * You should add your function to the library specific cleanup function.
  33  * If the cleanup function is not in the common library, the code that
  34  * allocates the memory should call the library specific cleanup function.
  35  * For instance, in the i18n library, any memory allocated statically must
  36  * call ucln_i18n_registerCleanup() from the ucln_in.h header.  These library
  37  * cleanup functions are needed in order to prevent a circular dependency
  38  * between the common library and any other library.
  39  *
  40  * The order of the cleanup is very important.  In general, an API that
  41  * depends on a second API should be cleaned up before the second API.
  42  * For instance, the default converter in ustring depends upon the converter
  43  * API.  So the default converter should be closed before the converter API
  44  * has its cache flushed.  This will prevent any memory leaks due to
  45  * reference counting.
  46  *
  47  * Please see common/ucln_cmn.{h,c} and i18n/ucln_in.{h,c} for examples.
  48  */
  49
  50 typedef enum ECleanupLibraryType {
  51     UCLN_START = -1,
  52     UCLN_CUSTOM,    /* Custom is for anyone else. */
  53     UCLN_LAYOUTEX,
  54     UCLN_LAYOUT,
  55     UCLN_IO,
  56     UCLN_I18N,
  57     UCLN_COMMON /* This must be the last one to cleanup. */
  58 } ECleanupLibraryType;
  59
  60 U_CDECL_BEGIN
  61 typedef UBool U_CALLCONV cleanupFunc(void);
  62 U_CDECL_END
  63
  64 U_CAPI void U_EXPORT2 ucln_registerCleanup(ECleanupLibraryType type,
  65                                            cleanupFunc *func);
  66
  67 #endif