summaryrefslogtreecommitdiffstats
path: root/src/mem1.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--src/mem1.c291
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 */