1 /*

     2 ** 2008 Jan 22

     3 **

     4 ** The author disclaims copyright to this source code.  In place of

     5 ** a legal notice, here is a blessing:

     6 **

     7 **    May you do good and not evil.

     8 **    May you find forgiveness for yourself and forgive others.

     9 **    May you share freely, never taking more than you give.

    10 **

    11 *************************************************************************

    12 **

    13 ** $Id: fault.c,v 1.10 2008/06/22 12:37:58 drh Exp $

    14 */

    15 

    16 /*

    17 ** This file contains code to support the concept of "benign" 

    18 ** malloc failures (when the xMalloc() or xRealloc() method of the

    19 ** sqlite3_mem_methods structure fails to allocate a block of memory

    20 ** and returns 0). 

    21 **

    22 ** Most malloc failures are non-benign. After they occur, SQLite

    23 ** abandons the current operation and returns an error code (usually

    24 ** SQLITE_NOMEM) to the user. However, sometimes a fault is not necessarily

    25 ** fatal. For example, if a malloc fails while resizing a hash table, this 

    26 ** is completely recoverable simply by not carrying out the resize. The 

    27 ** hash table will continue to function normally.  So a malloc failure 

    28 ** during a hash table resize is a benign fault.

    29 */

    30 

    31 #include "sqliteInt.h"

    32 

    33 #ifndef SQLITE_OMIT_BUILTIN_TEST

    34 

    35 /*

    36 ** Global variables.

    37 */

    38 static struct BenignMallocHooks {

    39   void (*xBenignBegin)(void);

    40   void (*xBenignEnd)(void);

    41 } hooks;

    42 

    43 /*

    44 ** Register hooks to call when sqlite3BeginBenignMalloc() and

    45 ** sqlite3EndBenignMalloc() are called, respectively.

    46 */

    47 void sqlite3BenignMallocHooks(

    48   void (*xBenignBegin)(void),

    49   void (*xBenignEnd)(void)

    50 ){

    51   hooks.xBenignBegin = xBenignBegin;

    52   hooks.xBenignEnd = xBenignEnd;

    53 }

    54 

    55 /*

    56 ** This (sqlite3EndBenignMalloc()) is called by SQLite code to indicate that

    57 ** subsequent malloc failures are benign. A call to sqlite3EndBenignMalloc()

    58 ** indicates that subsequent malloc failures are non-benign.

    59 */

    60 void sqlite3BeginBenignMalloc(void){

    61   if( hooks.xBenignBegin ){

    62     hooks.xBenignBegin();

    63   }

    64 }

    65 void sqlite3EndBenignMalloc(void){

    66   if( hooks.xBenignEnd ){

    67     hooks.xBenignEnd();

    68   }

    69 }

    70 

    71 #endif   /* #ifndef SQLITE_OMIT_BUILTIN_TEST */