/*
** 2008 Jan 22
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
**
** This file contains code to support the concept of "benign"
** malloc failures (when the xMalloc() or xRealloc() method of the
** sqlite3_mem_methods structure fails to allocate a block of memory
** and returns 0).
**
** Most malloc failures are non-benign. After they occur, SQLite
** abandons the current operation and returns an error code (usually
** SQLITE_NOMEM) to the user. However, sometimes a fault is not necessarily
** fatal. For example, if a malloc fails while resizing a hash table, this
** is completely recoverable simply by not carrying out the resize. The
** hash table will continue to function normally. So a malloc failure
** during a hash table resize is a benign fault.
*/
#include "sqliteInt.h"
#ifndef SQLITE_UNTESTABLE
/*
** Global variables.
*/
typedef struct BenignMallocHooks BenignMallocHooks;
static SQLITE_WSD struct BenignMallocHooks {
void (*xBenignBegin)(void);
void (*xBenignEnd)(void);
} sqlite3Hooks = { 0, 0 };
/* The "wsdHooks" macro will resolve to the appropriate BenignMallocHooks
** structure. If writable static data is unsupported on the target,
** we have to locate the state vector at run-time. In the more common
** case where writable static data is supported, wsdHooks can refer directly
** to the "sqlite3Hooks" state vector declared above.
*/
#ifdef SQLITE_OMIT_WSD
# define wsdHooksInit \
BenignMallocHooks *x = &GLOBAL(BenignMallocHooks,sqlite3Hooks)
# define wsdHooks x[0]
#else
# define wsdHooksInit
# define wsdHooks sqlite3Hooks
#endif
/*
** Register hooks to call when sqlite3BeginBenignMalloc() and
** sqlite3EndBenignMalloc() are called, respectively.
*/
void sqlite3BenignMallocHooks(
void (*xBenignBegin)(void),
void (*xBenignEnd)(void)
){
wsdHooksInit;
wsdHooks.xBenignBegin = xBenignBegin;
wsdHooks.xBenignEnd = xBenignEnd;
}
/*
** This (sqlite3EndBenignMalloc()) is called by SQLite code to indicate that
** subsequent malloc failures are benign. A call to sqlite3EndBenignMalloc()
** indicates that subsequent malloc failures are non-benign.
*/
void sqlite3BeginBenignMalloc(void){
wsdHooksInit;
if( wsdHooks.xBenignBegin ){
wsdHooks.xBenignBegin();
}
}
void sqlite3EndBenignMalloc(void){
wsdHooksInit;
if( wsdHooks.xBenignEnd ){
wsdHooks.xBenignEnd();
}
}
#endif /* #ifndef SQLITE_UNTESTABLE */