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https://github.com/postgres/postgres.git
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5cbfce562f
Includes some manual cleanup of places that pgindent messed up,
most of which weren't per project style anyway.
Notably, it seems some people didn't absorb the style rules of
commit c9d297751, because there were a bunch of new occurrences
of function calls with a newline just after the left paren, all
with faulty expectations about how the rest of the call would get
indented.
81 lines
2.8 KiB
C
81 lines
2.8 KiB
C
/*-------------------------------------------------------------------------
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*
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* shmem.h
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* shared memory management structures
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*
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* Historical note:
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* A long time ago, Postgres' shared memory region was allowed to be mapped
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* at a different address in each process, and shared memory "pointers" were
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* passed around as offsets relative to the start of the shared memory region.
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* That is no longer the case: each process must map the shared memory region
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* at the same address. This means shared memory pointers can be passed
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* around directly between different processes.
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*
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* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* src/include/storage/shmem.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef SHMEM_H
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#define SHMEM_H
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#include "utils/hsearch.h"
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/* shmqueue.c */
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typedef struct SHM_QUEUE
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{
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struct SHM_QUEUE *prev;
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struct SHM_QUEUE *next;
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} SHM_QUEUE;
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/* shmem.c */
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extern void InitShmemAccess(void *seghdr);
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extern void InitShmemAllocation(void);
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extern void *ShmemAlloc(Size size);
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extern void *ShmemAllocNoError(Size size);
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extern void *ShmemAllocUnlocked(Size size);
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extern bool ShmemAddrIsValid(const void *addr);
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extern void InitShmemIndex(void);
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extern HTAB *ShmemInitHash(const char *name, long init_size, long max_size,
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HASHCTL *infoP, int hash_flags);
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extern void *ShmemInitStruct(const char *name, Size size, bool *foundPtr);
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extern Size add_size(Size s1, Size s2);
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extern Size mul_size(Size s1, Size s2);
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/* ipci.c */
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extern void RequestAddinShmemSpace(Size size);
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/* size constants for the shmem index table */
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/* max size of data structure string name */
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#define SHMEM_INDEX_KEYSIZE (48)
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/* estimated size of the shmem index table (not a hard limit) */
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#define SHMEM_INDEX_SIZE (64)
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/* this is a hash bucket in the shmem index table */
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typedef struct
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{
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char key[SHMEM_INDEX_KEYSIZE]; /* string name */
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void *location; /* location in shared mem */
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Size size; /* # bytes requested for the structure */
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Size allocated_size; /* # bytes actually allocated */
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} ShmemIndexEnt;
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/*
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* prototypes for functions in shmqueue.c
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*/
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extern void SHMQueueInit(SHM_QUEUE *queue);
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extern void SHMQueueElemInit(SHM_QUEUE *queue);
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extern void SHMQueueDelete(SHM_QUEUE *queue);
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extern void SHMQueueInsertBefore(SHM_QUEUE *queue, SHM_QUEUE *elem);
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extern void SHMQueueInsertAfter(SHM_QUEUE *queue, SHM_QUEUE *elem);
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extern Pointer SHMQueueNext(const SHM_QUEUE *queue, const SHM_QUEUE *curElem,
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Size linkOffset);
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extern Pointer SHMQueuePrev(const SHM_QUEUE *queue, const SHM_QUEUE *curElem,
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Size linkOffset);
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extern bool SHMQueueEmpty(const SHM_QUEUE *queue);
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extern bool SHMQueueIsDetached(const SHM_QUEUE *queue);
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#endif /* SHMEM_H */
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