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/*-------------------------------------------------------------------------
*
* ipci.c
* POSTGRES inter-process communication initialization code.
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/ipc/ipci.c,v 1.64 2004/02/10 01:55:25 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "miscadmin.h"
#include "access/clog.h"
#include "access/xlog.h"
#include "storage/bufmgr.h"
#include "storage/freespace.h"
#include "storage/ipc.h"
#include "storage/lmgr.h"
#include "storage/lwlock.h"
#include "storage/pg_sema.h"
#include "storage/pg_shmem.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "storage/sinval.h"
#include "storage/spin.h"
/*
* CreateSharedMemoryAndSemaphores
* Creates and initializes shared memory and semaphores.
*
* This is called by the postmaster or by a standalone backend.
* It is NEVER called by a backend forked from the postmaster;
* for such a backend, the shared memory is already ready-to-go.
*
* If "makePrivate" is true then we only need private memory, not shared
* memory. This is true for a standalone backend, false for a postmaster.
*/
void
CreateSharedMemoryAndSemaphores(bool makePrivate,
int maxBackends,
int port)
{
int size;
int numSemas;
PGShmemHeader *seghdr;
/*
* Size of the Postgres shared-memory block is estimated via
* moderately-accurate estimates for the big hogs, plus 100K for the
* stuff that's too small to bother with estimating.
*/
size = BufferShmemSize();
size += LockShmemSize(maxBackends);
size += XLOGShmemSize();
size += CLOGShmemSize();
size += LWLockShmemSize();
size += SInvalShmemSize(maxBackends);
size += FreeSpaceShmemSize();
#ifdef EXEC_BACKEND
size += ShmemBackendArraySize();
#endif
size += 100000;
/* might as well round it off to a multiple of a typical page size */
size += 8192 - (size % 8192);
elog(DEBUG3, "invoking IpcMemoryCreate(size=%d)", size);
/*
* Create the shmem segment
*/
seghdr = PGSharedMemoryCreate(size, makePrivate, port);
/*
* Create semaphores
*/
numSemas = ProcGlobalSemas(maxBackends);
numSemas += SpinlockSemas();
PGReserveSemaphores(numSemas, port);
/*
* Set up shared memory allocation mechanism
*/
InitShmemAllocation(seghdr, true);
/*
* Now initialize LWLocks, which do shared memory allocation and are
* needed for InitShmemIndex.
*/
CreateLWLocks();
/*
* Set up shmem.c index hashtable
*/
InitShmemIndex();
/*
* Set up xlog, clog, and buffers
*/
XLOGShmemInit();
CLOGShmemInit();
InitBufferPool();
/*
* Set up lock manager
*/
InitLocks();
InitLockTable(maxBackends);
/*
* Set up process table
*/
InitProcGlobal(maxBackends);
/*
* Set up shared-inval messaging
*/
CreateSharedInvalidationState(maxBackends);
/*
* Set up free-space map
*/
InitFreeSpaceMap();
/*
* Set up child-to-postmaster signaling mechanism
*/
PMSignalInit();
#ifdef EXEC_BACKEND
/*
* Alloc the win32 shared backend array
*/
ShmemBackendArrayAllocation();
#endif
}
#ifdef EXEC_BACKEND
/*
* AttachSharedMemoryAndSemaphores
* Attaches to the existing shared resources.
*/
/* FIXME: [fork/exec] This function is starting to look pretty much like
CreateSharedMemoryAndSemaphores. Refactor? */
void
AttachSharedMemoryAndSemaphores(void)
{
PGShmemHeader *seghdr = PGSharedMemoryCreate(-1,false,-1);
InitShmemAllocation(seghdr, false);
InitShmemIndex();
XLOGShmemInit();
CLOGShmemInit();
InitBufferPool();
InitLocks();
InitLockTable(MaxBackends);
InitProcGlobal(MaxBackends);
CreateSharedInvalidationState(MaxBackends);
InitFreeSpaceMap();
PMSignalInit();
}
#endif
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