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Diffstat (limited to 'src/mem1.c')
| -rw-r--r-- | src/mem1.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/src/mem1.c b/src/mem1.c new file mode 100644 index 0000000..512ab37 --- /dev/null +++ b/src/mem1.c @@ -0,0 +1,291 @@ +/* +** 2007 August 14 +** +** 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 low-level memory allocation drivers for when +** SQLite will use the standard C-library malloc/realloc/free interface +** to obtain the memory it needs. +** +** This file contains implementations of the low-level memory allocation +** routines specified in the sqlite3_mem_methods object. The content of +** this file is only used if SQLITE_SYSTEM_MALLOC is defined. The +** SQLITE_SYSTEM_MALLOC macro is defined automatically if neither the +** SQLITE_MEMDEBUG nor the SQLITE_WIN32_MALLOC macros are defined. The +** default configuration is to use memory allocation routines in this +** file. +** +** C-preprocessor macro summary: +** +** HAVE_MALLOC_USABLE_SIZE The configure script sets this symbol if +** the malloc_usable_size() interface exists +** on the target platform. Or, this symbol +** can be set manually, if desired. +** If an equivalent interface exists by +** a different name, using a separate -D +** option to rename it. +** +** SQLITE_WITHOUT_ZONEMALLOC Some older macs lack support for the zone +** memory allocator. Set this symbol to enable +** building on older macs. +** +** SQLITE_WITHOUT_MSIZE Set this symbol to disable the use of +** _msize() on windows systems. This might +** be necessary when compiling for Delphi, +** for example. +*/ +#include "sqliteInt.h" + +/* +** This version of the memory allocator is the default. It is +** used when no other memory allocator is specified using compile-time +** macros. +*/ +#ifdef SQLITE_SYSTEM_MALLOC +#if defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC) + +/* +** Use the zone allocator available on apple products unless the +** SQLITE_WITHOUT_ZONEMALLOC symbol is defined. +*/ +#include <sys/sysctl.h> +#include <malloc/malloc.h> +#ifdef SQLITE_MIGHT_BE_SINGLE_CORE +#include <libkern/OSAtomic.h> +#endif /* SQLITE_MIGHT_BE_SINGLE_CORE */ +static malloc_zone_t* _sqliteZone_; +#define SQLITE_MALLOC(x) malloc_zone_malloc(_sqliteZone_, (x)) +#define SQLITE_FREE(x) malloc_zone_free(_sqliteZone_, (x)); +#define SQLITE_REALLOC(x,y) malloc_zone_realloc(_sqliteZone_, (x), (y)) +#define SQLITE_MALLOCSIZE(x) \ + (_sqliteZone_ ? _sqliteZone_->size(_sqliteZone_,x) : malloc_size(x)) + +#else /* if not __APPLE__ */ + +/* +** Use standard C library malloc and free on non-Apple systems. +** Also used by Apple systems if SQLITE_WITHOUT_ZONEMALLOC is defined. +*/ +#define SQLITE_MALLOC(x) malloc(x) +#define SQLITE_FREE(x) free(x) +#define SQLITE_REALLOC(x,y) realloc((x),(y)) + +/* +** The malloc.h header file is needed for malloc_usable_size() function +** on some systems (e.g. Linux). +*/ +#if HAVE_MALLOC_H && HAVE_MALLOC_USABLE_SIZE +# define SQLITE_USE_MALLOC_H 1 +# define SQLITE_USE_MALLOC_USABLE_SIZE 1 +/* +** The MSVCRT has malloc_usable_size(), but it is called _msize(). The +** use of _msize() is automatic, but can be disabled by compiling with +** -DSQLITE_WITHOUT_MSIZE. Using the _msize() function also requires +** the malloc.h header file. +*/ +#elif defined(_MSC_VER) && !defined(SQLITE_WITHOUT_MSIZE) +# define SQLITE_USE_MALLOC_H +# define SQLITE_USE_MSIZE +#endif + +/* +** Include the malloc.h header file, if necessary. Also set define macro +** SQLITE_MALLOCSIZE to the appropriate function name, which is _msize() +** for MSVC and malloc_usable_size() for most other systems (e.g. Linux). +** The memory size function can always be overridden manually by defining +** the macro SQLITE_MALLOCSIZE to the desired function name. +*/ +#if defined(SQLITE_USE_MALLOC_H) +# include <malloc.h> +# if defined(SQLITE_USE_MALLOC_USABLE_SIZE) +# if !defined(SQLITE_MALLOCSIZE) +# define SQLITE_MALLOCSIZE(x) malloc_usable_size(x) +# endif +# elif defined(SQLITE_USE_MSIZE) +# if !defined(SQLITE_MALLOCSIZE) +# define SQLITE_MALLOCSIZE _msize +# endif +# endif +#endif /* defined(SQLITE_USE_MALLOC_H) */ + +#endif /* __APPLE__ or not __APPLE__ */ + +/* +** Like malloc(), but remember the size of the allocation +** so that we can find it later using sqlite3MemSize(). +** +** For this low-level routine, we are guaranteed that nByte>0 because +** cases of nByte<=0 will be intercepted and dealt with by higher level +** routines. +*/ +static void *sqlite3MemMalloc(int nByte){ +#ifdef SQLITE_MALLOCSIZE + void *p; + testcase( ROUND8(nByte)==nByte ); + p = SQLITE_MALLOC( nByte ); + if( p==0 ){ + testcase( sqlite3GlobalConfig.xLog!=0 ); + sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes of memory", nByte); + } + return p; +#else + sqlite3_int64 *p; + assert( nByte>0 ); + testcase( ROUND8(nByte)!=nByte ); + p = SQLITE_MALLOC( nByte+8 ); + if( p ){ + p[0] = nByte; + p++; + }else{ + testcase( sqlite3GlobalConfig.xLog!=0 ); + sqlite3_log(SQLITE_NOMEM, "failed to allocate %u bytes of memory", nByte); + } + return (void *)p; +#endif +} + +/* +** Like free() but works for allocations obtained from sqlite3MemMalloc() +** or sqlite3MemRealloc(). +** +** For this low-level routine, we already know that pPrior!=0 since +** cases where pPrior==0 will have been intecepted and dealt with +** by higher-level routines. +*/ +static void sqlite3MemFree(void *pPrior){ +#ifdef SQLITE_MALLOCSIZE + SQLITE_FREE(pPrior); +#else + sqlite3_int64 *p = (sqlite3_int64*)pPrior; + assert( pPrior!=0 ); + p--; + SQLITE_FREE(p); +#endif +} + +/* +** Report the allocated size of a prior return from xMalloc() +** or xRealloc(). +*/ +static int sqlite3MemSize(void *pPrior){ +#ifdef SQLITE_MALLOCSIZE + assert( pPrior!=0 ); + return (int)SQLITE_MALLOCSIZE(pPrior); +#else + sqlite3_int64 *p; + assert( pPrior!=0 ); + p = (sqlite3_int64*)pPrior; + p--; + return (int)p[0]; +#endif +} + +/* +** Like realloc(). Resize an allocation previously obtained from +** sqlite3MemMalloc(). +** +** For this low-level interface, we know that pPrior!=0. Cases where +** pPrior==0 while have been intercepted by higher-level routine and +** redirected to xMalloc. Similarly, we know that nByte>0 because +** cases where nByte<=0 will have been intercepted by higher-level +** routines and redirected to xFree. +*/ +static void *sqlite3MemRealloc(void *pPrior, int nByte){ +#ifdef SQLITE_MALLOCSIZE + void *p = SQLITE_REALLOC(pPrior, nByte); + if( p==0 ){ + testcase( sqlite3GlobalConfig.xLog!=0 ); + sqlite3_log(SQLITE_NOMEM, + "failed memory resize %u to %u bytes", + SQLITE_MALLOCSIZE(pPrior), nByte); + } + return p; +#else + sqlite3_int64 *p = (sqlite3_int64*)pPrior; + assert( pPrior!=0 && nByte>0 ); + assert( nByte==ROUND8(nByte) ); /* EV: R-46199-30249 */ + p--; + p = SQLITE_REALLOC(p, nByte+8 ); + if( p ){ + p[0] = nByte; + p++; + }else{ + testcase( sqlite3GlobalConfig.xLog!=0 ); + sqlite3_log(SQLITE_NOMEM, + "failed memory resize %u to %u bytes", + sqlite3MemSize(pPrior), nByte); + } + return (void*)p; +#endif +} + +/* +** Round up a request size to the next valid allocation size. +*/ +static int sqlite3MemRoundup(int n){ + return ROUND8(n); +} + +/* +** Initialize this module. +*/ +static int sqlite3MemInit(void *NotUsed){ +#if defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC) + int cpuCount; + size_t len; + if( _sqliteZone_ ){ + return SQLITE_OK; + } + len = sizeof(cpuCount); + /* One usually wants to use hw.acctivecpu for MT decisions, but not here */ + sysctlbyname("hw.ncpu", &cpuCount, &len, NULL, 0); + if( cpuCount>1 ){ + /* defer MT decisions to system malloc */ + _sqliteZone_ = malloc_default_zone(); + }else{ + /* only 1 core, use our own zone to contention over global locks, + ** e.g. we have our own dedicated locks */ + _sqliteZone_ = malloc_create_zone(4096, 0); + malloc_set_zone_name(_sqliteZone_, "Sqlite_Heap"); + } +#endif /* defined(__APPLE__) && !defined(SQLITE_WITHOUT_ZONEMALLOC) */ + UNUSED_PARAMETER(NotUsed); + return SQLITE_OK; +} + +/* +** Deinitialize this module. +*/ +static void sqlite3MemShutdown(void *NotUsed){ + UNUSED_PARAMETER(NotUsed); + return; +} + +/* +** This routine is the only routine in this file with external linkage. +** +** Populate the low-level memory allocation function pointers in +** sqlite3GlobalConfig.m with pointers to the routines in this file. +*/ +void sqlite3MemSetDefault(void){ + static const sqlite3_mem_methods defaultMethods = { + sqlite3MemMalloc, + sqlite3MemFree, + sqlite3MemRealloc, + sqlite3MemSize, + sqlite3MemRoundup, + sqlite3MemInit, + sqlite3MemShutdown, + 0 + }; + sqlite3_config(SQLITE_CONFIG_MALLOC, &defaultMethods); +} + +#endif /* SQLITE_SYSTEM_MALLOC */ |