database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-11 10:01:57 +03:00
Code Activity

Add support to dynahash.c for partitioning shared hashtables according

Browse Source 
to the low-order bits of the entry hash value.  Also make some incidental
cleanups in the dynahash API, such as not exporting the hash header
structs to the world.
This commit is contained in:
Tom Lane
2006-07-22 23:04:39 +00:00
parent c0e9b3139f
commit 51ee9fa157
4 changed files with 387 additions and 180 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
src/backend/storage/ipc/shmem.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/ipc/shmem.c,v 1.93 2006/07/14 14:52:22 momjian Exp $
* $PostgreSQL: pgsql/src/backend/storage/ipc/shmem.c,v 1.94 2006/07/22 23:04:39 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -211,9 +211,6 @@ InitShmemIndex(void)
{
HASHCTL info;
int hash_flags;
ShmemIndexEnt *result,
item;
bool found;
/*
* Since ShmemInitHash calls ShmemInitStruct, which expects the ShmemIndex
@ -227,32 +224,11 @@ InitShmemIndex(void)
info.entrysize = sizeof(ShmemIndexEnt);
hash_flags = HASH_ELEM;
/* This will acquire the shmem index lock, but not release it. */
ShmemIndex = ShmemInitHash("ShmemIndex",
SHMEM_INDEX_SIZE, SHMEM_INDEX_SIZE,
&info, hash_flags);
if (!ShmemIndex)
elog(FATAL, "could not initialize Shmem Index");
/*
* Now, create an entry in the hashtable for the index itself.
*/
if (!IsUnderPostmaster)
{
MemSet(item.key, 0, SHMEM_INDEX_KEYSIZE);
strncpy(item.key, "ShmemIndex", SHMEM_INDEX_KEYSIZE);
result = (ShmemIndexEnt *)
hash_search(ShmemIndex, (void *) &item, HASH_ENTER, &found);
Assert(!found);
result->location = MAKE_OFFSET(ShmemIndex->hctl);
result->size = SHMEM_INDEX_SIZE;
}
/* now release the lock acquired in ShmemInitStruct */
LWLockRelease(ShmemIndexLock);
}
/*
@ -295,7 +271,7 @@ ShmemInitHash(const char *name, /* table string name for shmem index */
/* look it up in the shmem index */
location = ShmemInitStruct(name,
sizeof(HASHHDR) + infoP->dsize * sizeof(HASHSEGMENT),
hash_get_shared_size(infoP, hash_flags),
&found);
/*
@ -312,9 +288,8 @@ ShmemInitHash(const char *name, /* table string name for shmem index */
if (found)
hash_flags |= HASH_ATTACH;
/* Now provide the header and directory pointers */
/* Pass location of hashtable header to hash_create */
infoP->hctl = (HASHHDR *) location;
infoP->dir = (HASHSEGMENT *) (((char *) location) + sizeof(HASHHDR));
return hash_create(name, init_size, infoP, hash_flags);
}
@ -363,14 +338,16 @@ ShmemInitStruct(const char *name, Size size, bool *foundPtr)
* If the shmem index doesn't exist, we are bootstrapping: we must
* be trying to init the shmem index itself.
*
* Notice that the ShmemIndexLock is held until the shmem index
* has been completely initialized.
* Notice that the ShmemIndexLock is released before the shmem
* index has been initialized. This should be OK because no
* other process can be accessing shared memory yet.
*/
Assert(shmemseghdr->indexoffset == 0);
structPtr = ShmemAlloc(size);
shmemseghdr->indexoffset = MAKE_OFFSET(structPtr);
*foundPtr = FALSE;
}
LWLockRelease(ShmemIndexLock);
return structPtr;
}

4
src/backend/storage/lmgr/lock.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.166 2006/07/14 14:52:23 momjian Exp $
* $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.167 2006/07/22 23:04:39 tgl Exp $
*
* NOTES
* A lock table is a shared memory hash table. When
@ -1958,7 +1958,7 @@ GetLockStatusData(void)
{
LWLockAcquire(FirstLockMgrLock + i, LW_SHARED);
proclockTable = LockMethodProcLockHash[i];
els += proclockTable->hctl->nentries;
els += hash_get_num_entries(proclockTable);
}
data->nelements = els;