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/*-------------------------------------------------------------------------
*
* memutils_internal.h
* This file contains declarations for memory allocation utility
* functions for internal use.
*
*
* Portions Copyright (c) 2022-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/utils/memutils_internal.h
*
*-------------------------------------------------------------------------
*/
#ifndef MEMUTILS_INTERNAL_H
#define MEMUTILS_INTERNAL_H
#include "utils/memutils.h"
/* These functions implement the MemoryContext API for AllocSet context. */
extern void *AllocSetAlloc(MemoryContext context, Size size);
extern void AllocSetFree(void *pointer);
extern void *AllocSetRealloc(void *pointer, Size size);
extern void AllocSetReset(MemoryContext context);
extern void AllocSetDelete(MemoryContext context);
extern MemoryContext AllocSetGetChunkContext(void *pointer);
extern Size AllocSetGetChunkSpace(void *pointer);
extern bool AllocSetIsEmpty(MemoryContext context);
extern void AllocSetStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
MemoryContextCounters *totals,
bool print_to_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
extern void AllocSetCheck(MemoryContext context);
#endif
/* These functions implement the MemoryContext API for Generation context. */
extern void *GenerationAlloc(MemoryContext context, Size size);
extern void GenerationFree(void *pointer);
extern void *GenerationRealloc(void *pointer, Size size);
extern void GenerationReset(MemoryContext context);
extern void GenerationDelete(MemoryContext context);
extern MemoryContext GenerationGetChunkContext(void *pointer);
extern Size GenerationGetChunkSpace(void *pointer);
extern bool GenerationIsEmpty(MemoryContext context);
extern void GenerationStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
MemoryContextCounters *totals,
bool print_to_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
extern void GenerationCheck(MemoryContext context);
#endif
/* These functions implement the MemoryContext API for Slab context. */
extern void *SlabAlloc(MemoryContext context, Size size);
extern void SlabFree(void *pointer);
extern void *SlabRealloc(void *pointer, Size size);
extern void SlabReset(MemoryContext context);
extern void SlabDelete(MemoryContext context);
extern MemoryContext SlabGetChunkContext(void *pointer);
extern Size SlabGetChunkSpace(void *pointer);
extern bool SlabIsEmpty(MemoryContext context);
extern void SlabStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
MemoryContextCounters *totals,
bool print_to_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
extern void SlabCheck(MemoryContext context);
#endif
/*
* These functions support the implementation of palloc_aligned() and are not
* part of a fully-fledged MemoryContext type.
*/
extern void AlignedAllocFree(void *pointer);
extern void *AlignedAllocRealloc(void *pointer, Size size);
extern MemoryContext AlignedAllocGetChunkContext(void *pointer);
extern Size AlignedAllocGetChunkSpace(void *pointer);
/*
* How many extra bytes do we need to request in order to ensure that we can
* align a pointer to 'alignto'. Since palloc'd pointers are already aligned
* to MAXIMUM_ALIGNOF we can subtract that amount. We also need to make sure
* there is enough space for the redirection MemoryChunk.
*/
#define PallocAlignedExtraBytes(alignto) \
((alignto) + (sizeof(MemoryChunk) - MAXIMUM_ALIGNOF))
/*
* MemoryContextMethodID
* A unique identifier for each MemoryContext implementation which
* indicates the index into the mcxt_methods[] array. See mcxt.c.
*
* For robust error detection, ensure that MemoryContextMethodID has a value
* for each possible bit-pattern of MEMORY_CONTEXT_METHODID_MASK, and make
* dummy entries for unused IDs in the mcxt_methods[] array. We also try
* to avoid using bit-patterns as valid IDs if they are likely to occur in
* garbage data, or if they could falsely match on chunks that are really from
* malloc not palloc. (We can't tell that for most malloc implementations,
* but it happens that glibc stores flag bits in the same place where we put
* the MemoryContextMethodID, so the possible values are predictable for it.)
*/
typedef enum MemoryContextMethodID
{
MCTX_UNUSED1_ID, /* 000 occurs in never-used memory */
MCTX_UNUSED2_ID, /* glibc malloc'd chunks usually match 001 */
MCTX_UNUSED3_ID, /* glibc malloc'd chunks > 128kB match 010 */
MCTX_ASET_ID,
MCTX_GENERATION_ID,
MCTX_SLAB_ID,
MCTX_ALIGNED_REDIRECT_ID,
MCTX_UNUSED4_ID /* 111 occurs in wipe_mem'd memory */
} MemoryContextMethodID;
/*
* The number of bits that 8-byte memory chunk headers can use to encode the
* MemoryContextMethodID.
*/
#define MEMORY_CONTEXT_METHODID_BITS 3
#define MEMORY_CONTEXT_METHODID_MASK \
((((uint64) 1) << MEMORY_CONTEXT_METHODID_BITS) - 1)
/*
* 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 void MemoryContextCreate(MemoryContext node,
NodeTag tag,
MemoryContextMethodID method_id,
MemoryContext parent,
const char *name);
#endif /* MEMUTILS_INTERNAL_H */