mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-08-26 16:07:19 +02:00
120 lines
3.9 KiB
C
120 lines
3.9 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* memutils.h
|
|
* This file contains declarations for memory allocation utility
|
|
* functions. These are functions that are not quite widely used
|
|
* enough to justify going in utils/palloc.h, but are still part
|
|
* of the API of the memory management subsystem.
|
|
*
|
|
*
|
|
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
|
|
* Portions Copyright (c) 1994, Regents of the University of California
|
|
*
|
|
* $Id: memutils.h,v 1.40 2001/01/22 00:18:13 tgl Exp $
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
#ifndef MEMUTILS_H
|
|
#define MEMUTILS_H
|
|
|
|
#include "nodes/memnodes.h"
|
|
|
|
|
|
/*
|
|
* MaxAllocSize
|
|
* Arbitrary limit on size of allocations.
|
|
*
|
|
* Note:
|
|
* There is no guarantee that allocations smaller than MaxAllocSize
|
|
* will succeed. Allocation requests larger than MaxAllocSize will
|
|
* be summarily denied.
|
|
*
|
|
* XXX This should be defined in a file of tunable constants.
|
|
*/
|
|
#define MaxAllocSize ((Size) 0xfffffff) /* 16G - 1 */
|
|
|
|
#define AllocSizeIsValid(size) (0 < (size) && (size) <= MaxAllocSize)
|
|
|
|
/*
|
|
* All chunks allocated by any memory context manager are required to be
|
|
* preceded by a StandardChunkHeader at a spacing of STANDARDCHUNKHEADERSIZE.
|
|
* A currently-allocated chunk must contain a backpointer to its owning
|
|
* context as well as the allocated size of the chunk. The backpointer is
|
|
* used by pfree() and repalloc() to find the context to call. The allocated
|
|
* size is not absolutely essential, but it's expected to be needed by any
|
|
* reasonable implementation.
|
|
*/
|
|
typedef struct StandardChunkHeader
|
|
{
|
|
MemoryContext context; /* owning context */
|
|
Size size; /* size of data space allocated in chunk */
|
|
#ifdef MEMORY_CONTEXT_CHECKING
|
|
/* when debugging memory usage, also store actual requested size */
|
|
Size requested_size;
|
|
#endif
|
|
} StandardChunkHeader;
|
|
|
|
#define STANDARDCHUNKHEADERSIZE MAXALIGN(sizeof(StandardChunkHeader))
|
|
|
|
|
|
/*
|
|
* Standard top-level memory contexts.
|
|
*
|
|
* Only TopMemoryContext and ErrorContext are initialized by
|
|
* MemoryContextInit() itself.
|
|
*/
|
|
extern DLLIMPORT MemoryContext TopMemoryContext;
|
|
extern DLLIMPORT MemoryContext ErrorContext;
|
|
extern DLLIMPORT MemoryContext PostmasterContext;
|
|
extern DLLIMPORT MemoryContext CacheMemoryContext;
|
|
extern DLLIMPORT MemoryContext QueryContext;
|
|
extern DLLIMPORT MemoryContext TopTransactionContext;
|
|
extern DLLIMPORT MemoryContext TransactionCommandContext;
|
|
|
|
|
|
/*
|
|
* Memory-context-type-independent functions in mcxt.c
|
|
*/
|
|
extern void MemoryContextInit(void);
|
|
extern void MemoryContextReset(MemoryContext context);
|
|
extern void MemoryContextDelete(MemoryContext context);
|
|
extern void MemoryContextResetChildren(MemoryContext context);
|
|
extern void MemoryContextDeleteChildren(MemoryContext context);
|
|
extern void MemoryContextResetAndDeleteChildren(MemoryContext context);
|
|
extern void MemoryContextStats(MemoryContext context);
|
|
extern void MemoryContextCheck(MemoryContext context);
|
|
extern bool MemoryContextContains(MemoryContext context, void *pointer);
|
|
|
|
/*
|
|
* This routine handles the context-type-independent part of memory
|
|
* context creation. It's intended to be called from context-type-
|
|
* specific creation routines, and noplace else.
|
|
*/
|
|
extern MemoryContext MemoryContextCreate(NodeTag tag, Size size,
|
|
MemoryContextMethods *methods,
|
|
MemoryContext parent,
|
|
const char *name);
|
|
|
|
|
|
/*
|
|
* Memory-context-type-specific functions
|
|
*/
|
|
|
|
/* aset.c */
|
|
extern MemoryContext AllocSetContextCreate(MemoryContext parent,
|
|
const char *name,
|
|
Size minContextSize,
|
|
Size initBlockSize,
|
|
Size maxBlockSize);
|
|
|
|
/*
|
|
* Recommended default alloc parameters, suitable for "ordinary" contexts
|
|
* that might hold quite a lot of data.
|
|
*/
|
|
#define ALLOCSET_DEFAULT_MINSIZE (8 * 1024)
|
|
#define ALLOCSET_DEFAULT_INITSIZE (8 * 1024)
|
|
#define ALLOCSET_DEFAULT_MAXSIZE (8 * 1024 * 1024)
|
|
|
|
|
|
#endif /* MEMUTILS_H */
|