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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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90
src/backend/storage/ipc/shmem.c
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@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/ipc/shmem.c,v 1.57 2001/03/22 03:59:45 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/ipc/shmem.c,v 1.58 2001/09/07 00:27:29 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -259,92 +259,6 @@ ShmemInitHash(char *name, /* table string name for shmem index */
return hash_create(init_size, infoP, hash_flags);
}
/*
* ShmemPIDLookup -- lookup process data structure using process id
*
* Returns: TRUE if no error. locationPtr is initialized if PID is
* found in the shmem index.
*
* NOTES:
* only information about success or failure is the value of
* locationPtr.
*/
bool
ShmemPIDLookup(int pid, SHMEM_OFFSET *locationPtr)
{
ShmemIndexEnt *result,
item;
bool found;
Assert(ShmemIndex);
MemSet(item.key, 0, SHMEM_INDEX_KEYSIZE);
sprintf(item.key, "PID %d", pid);
SpinAcquire(ShmemIndexLock);
result = (ShmemIndexEnt *)
hash_search(ShmemIndex, (char *) &item, HASH_ENTER, &found);
if (!result)
{
SpinRelease(ShmemIndexLock);
elog(ERROR, "ShmemInitPID: ShmemIndex corrupted");
return FALSE;
}
if (found)
*locationPtr = result->location;
else
result->location = *locationPtr;
SpinRelease(ShmemIndexLock);
return TRUE;
}
/*
* ShmemPIDDestroy -- destroy shmem index entry for process
* using process id
*
* Returns: offset of the process struct in shared memory or
* INVALID_OFFSET if not found.
*
* Side Effect: removes the entry from the shmem index
*/
SHMEM_OFFSET
ShmemPIDDestroy(int pid)
{
ShmemIndexEnt *result,
item;
bool found;
SHMEM_OFFSET location = 0;
Assert(ShmemIndex);
MemSet(item.key, 0, SHMEM_INDEX_KEYSIZE);
sprintf(item.key, "PID %d", pid);
SpinAcquire(ShmemIndexLock);
result = (ShmemIndexEnt *)
hash_search(ShmemIndex, (char *) &item, HASH_REMOVE, &found);
if (found)
location = result->location;
SpinRelease(ShmemIndexLock);
if (!result)
{
elog(ERROR, "ShmemPIDDestroy: PID table corrupted");
return INVALID_OFFSET;
}
if (found)
return location;
else
return INVALID_OFFSET;
}
/*
* ShmemInitStruct -- Create/attach to a structure in shared
* memory.
@@ -373,7 +287,6 @@ ShmemInitStruct(char *name, Size size, bool *foundPtr)
if (!ShmemIndex)
{
/*
* If the shmem index doesn't exist, we are bootstrapping: we must
* be trying to init the shmem index itself.
@@ -400,7 +313,6 @@ ShmemInitStruct(char *name, Size size, bool *foundPtr)
if (*foundPtr)
{
/*
* Structure is in the shmem index so someone else has allocated
* it already. The size better be the same as the size we are