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/*-------------------------------------------------------------------------
*
* shmem.h--
* shared memory management structures
*
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: shmem.h,v 1.13 1998/06/27 15:47:48 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef SHMEM_H
#define SHMEM_H
#include <utils/hsearch.h>
#include <storage/spin.h>
/* The shared memory region can start at a different address
* in every process. Shared memory "pointers" are actually
* offsets relative to the start of the shared memory region(s).
*/
typedef unsigned long SHMEM_OFFSET;
#define INVALID_OFFSET (-1)
#define BAD_LOCATION (-1)
/* start of the lowest shared memory region. For now, assume that
* there is only one shared memory region
*/
extern SHMEM_OFFSET ShmemBase;
/* coerce an offset into a pointer in this process's address space */
#define MAKE_PTR(xx_offs)\
(ShmemBase+((unsigned long)(xx_offs)))
/* coerce a pointer into a shmem offset */
#define MAKE_OFFSET(xx_ptr)\
(SHMEM_OFFSET) (((unsigned long)(xx_ptr))-ShmemBase)
#define SHM_PTR_VALID(xx_ptr)\
(((unsigned long)xx_ptr) > ShmemBase)
/* cannot have an offset to ShmemFreeStart (offset 0) */
#define SHM_OFFSET_VALID(xx_offs)\
((xx_offs != 0) && (xx_offs != INVALID_OFFSET))
extern SPINLOCK ShmemLock;
extern SPINLOCK ShmemIndexLock;
/* shmemqueue.c */
typedef struct SHM_QUEUE
{
SHMEM_OFFSET prev;
SHMEM_OFFSET next;
} SHM_QUEUE;
/* shmem.c */
extern void ShmemIndexReset(void);
extern void ShmemCreate(unsigned int key, unsigned int size);
extern int InitShmem(unsigned int key, unsigned int size);
extern long *ShmemAlloc(unsigned long size);
extern int ShmemIsValid(unsigned long addr);
extern HTAB *
ShmemInitHash(char *name, long init_size, long max_size,
HASHCTL *infoP, int hash_flags);
extern bool ShmemPIDLookup(int pid, SHMEM_OFFSET *locationPtr);
extern SHMEM_OFFSET ShmemPIDDestroy(int pid);
extern long *
ShmemInitStruct(char *name, unsigned long size,
bool *foundPtr);
extern bool TransactionIdIsInProgress(TransactionId xid);
typedef int TableID;
/* size constants for the shmem index table */
/* max size of data structure string name */
#define SHMEM_INDEX_KEYSIZE (50)
/* data in shmem index table hash bucket */
#define SHMEM_INDEX_DATASIZE (sizeof(ShmemIndexEnt) - SHMEM_INDEX_KEYSIZE)
/* maximum size of the shmem index table */
#define SHMEM_INDEX_SIZE (100)
/* this is a hash bucket in the shmem index table */
typedef struct
{
char key[SHMEM_INDEX_KEYSIZE]; /* string name */
unsigned long location; /* location in shared mem */
unsigned long size; /* numbytes allocated for the structure */
} ShmemIndexEnt;
/*
* prototypes for functions in shmqueue.c
*/
extern void SHMQueueInit(SHM_QUEUE *queue);
extern void SHMQueueElemInit(SHM_QUEUE *queue);
extern void SHMQueueDelete(SHM_QUEUE *queue);
extern void SHMQueueInsertTL(SHM_QUEUE *queue, SHM_QUEUE *elem);
extern void
SHMQueueFirst(SHM_QUEUE *queue, Pointer *nextPtrPtr,
SHM_QUEUE *nextQueue);
extern bool SHMQueueEmpty(SHM_QUEUE *queue);
#endif /* SHMEM_H */
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