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Get rid of PID entries in shmem hash table; there is no longer any need

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for them, and making them just wastes time during backend startup/shutdown.
Also, remove compile-time MAXBACKENDS limit per long-ago proposal.
You can now set MaxBackends as high as your kernel can stand without
any reconfiguration/recompilation.
This commit is contained in:
Tom Lane
2001-09-07 00:27:30 +00:00
parent 0059c4216c
commit 863aceb54f
12 changed files with 213 additions and 316 deletions
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26
src/include/storage/proc.h
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@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: proc.h,v 1.45 2001/07/06 21:04:26 tgl Exp $
* $Id: proc.h,v 1.46 2001/09/07 00:27:30 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -104,10 +104,21 @@ do { \
* in each set for identification purposes.)
*
* PROC_SEM_MAP_ENTRIES is the number of semaphore sets we need to allocate
* to keep track of up to MAXBACKENDS backends.
* to keep track of up to maxBackends backends.
*/
#define PROC_NSEMS_PER_SET 16
#define PROC_SEM_MAP_ENTRIES ((MAXBACKENDS-1)/PROC_NSEMS_PER_SET+1)
#define PROC_SEM_MAP_ENTRIES(maxBackends) (((maxBackends)-1)/PROC_NSEMS_PER_SET+1)
typedef struct
{
/* info about a single set of per-process semaphores */
IpcSemaphoreId procSemId;
int32 freeSemMap;
/*
* In freeSemMap, bit i is set if the i'th semaphore of this sema
* set is allocated to a process. (i counts from 0 at the LSB)
*/
} SEM_MAP_ENTRY;
typedef struct procglobal
{
@ -115,13 +126,12 @@ typedef struct procglobal
SHMEM_OFFSET freeProcs;
/* Info about semaphore sets used for per-process semaphores */
IpcSemaphoreId procSemIds[PROC_SEM_MAP_ENTRIES];
int32 freeSemMap[PROC_SEM_MAP_ENTRIES];
int semMapEntries;
/*
* In each freeSemMap entry, bit i is set if the i'th semaphore of the
* set is allocated to a process. (i counts from 0 at the LSB)
* VARIABLE LENGTH ARRAY: actual length is semMapEntries.
* THIS MUST BE LAST IN THE STRUCT DECLARATION.
*/
SEM_MAP_ENTRY procSemMap[1];
} PROC_HDR;
/*