diff options
Diffstat (limited to 'src/backend/utils/cache/inval.c')
| -rw-r--r-- | src/backend/utils/cache/inval.c | 48 |
1 files changed, 26 insertions, 22 deletions
diff --git a/src/backend/utils/cache/inval.c b/src/backend/utils/cache/inval.c index cd01bc9adc2..9ebf5f3bf2f 100644 --- a/src/backend/utils/cache/inval.c +++ b/src/backend/utils/cache/inval.c @@ -22,14 +22,14 @@ * second lives till end of transaction. Finally, we need a third list of * all tuples outdated in the current transaction; if we commit, we send * those invalidation events to all other backends (via the SI message queue) - * so that they can flush obsolete entries from their caches. This list + * so that they can flush obsolete entries from their caches. This list * definitely can't be processed until after we commit, otherwise the other * backends won't see our updated tuples as good. * * We do not need to register EVERY tuple operation in this way, just those - * on tuples in relations that have associated catcaches. We do, however, + * on tuples in relations that have associated catcaches. We do, however, * have to register every operation on every tuple that *could* be in a - * catcache, whether or not it currently is in our cache. Also, if the + * catcache, whether or not it currently is in our cache. Also, if the * tuple is in a relation that has multiple catcaches, we need to register * an invalidation message for each such catcache. catcache.c's * PrepareToInvalidateCacheTuple() routine provides the knowledge of which @@ -56,7 +56,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/cache/inval.c,v 1.45 2001/06/19 19:42:16 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/cache/inval.c,v 1.46 2001/10/25 05:49:46 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -74,15 +74,15 @@ /* * To minimize palloc traffic, we keep pending requests in successively- * larger chunks (a slightly more sophisticated version of an expansible - * array). All request types can be stored as SharedInvalidationMessage + * array). All request types can be stored as SharedInvalidationMessage * records. */ typedef struct InvalidationChunk { - struct InvalidationChunk *next; /* list link */ + struct InvalidationChunk *next; /* list link */ int nitems; /* # items currently stored in chunk */ int maxitems; /* size of allocated array in this chunk */ - SharedInvalidationMessage msgs[1]; /* VARIABLE LENGTH ARRAY */ + SharedInvalidationMessage msgs[1]; /* VARIABLE LENGTH ARRAY */ } InvalidationChunk; /* VARIABLE LENGTH STRUCTURE */ typedef struct InvalidationListHeader @@ -148,7 +148,7 @@ AddInvalidationMessage(InvalidationChunk **listHdr, chunk = (InvalidationChunk *) MemoryContextAlloc(TopTransactionContext, sizeof(InvalidationChunk) + - (FIRSTCHUNKSIZE-1) * sizeof(SharedInvalidationMessage)); + (FIRSTCHUNKSIZE - 1) *sizeof(SharedInvalidationMessage)); chunk->nitems = 0; chunk->maxitems = FIRSTCHUNKSIZE; chunk->next = *listHdr; @@ -157,12 +157,12 @@ AddInvalidationMessage(InvalidationChunk **listHdr, else if (chunk->nitems >= chunk->maxitems) { /* Need another chunk; double size of last chunk */ - int chunksize = 2 * chunk->maxitems; + int chunksize = 2 * chunk->maxitems; chunk = (InvalidationChunk *) MemoryContextAlloc(TopTransactionContext, sizeof(InvalidationChunk) + - (chunksize-1) * sizeof(SharedInvalidationMessage)); + (chunksize - 1) *sizeof(SharedInvalidationMessage)); chunk->nitems = 0; chunk->maxitems = chunksize; chunk->next = *listHdr; @@ -279,7 +279,10 @@ DiscardInvalidationMessages(InvalidationListHeader *hdr, bool physicalFree) } else { - /* Assume the storage will go away at xact end, just reset pointers */ + /* + * Assume the storage will go away at xact end, just reset + * pointers + */ hdr->cclist = NULL; hdr->rclist = NULL; } @@ -421,7 +424,7 @@ InvalidateSystemCaches(void) static void PrepareForTupleInvalidation(Relation relation, HeapTuple tuple, void (*CacheIdRegisterFunc) (int, Index, - ItemPointer, Oid), + ItemPointer, Oid), void (*RelationIdRegisterFunc) (Oid, Oid)) { Oid tupleRelId; @@ -460,12 +463,12 @@ PrepareForTupleInvalidation(Relation relation, HeapTuple tuple, * Yes. We need to register a relcache invalidation event for the * relation identified by relationId. * - * KLUGE ALERT: we always send the relcache event with MyDatabaseId, - * even if the rel in question is shared. This essentially means that - * only backends in this same database will react to the relcache flush - * request. This is in fact appropriate, since only those backends could - * see our pg_class or pg_attribute change anyway. It looks a bit ugly - * though. + * KLUGE ALERT: we always send the relcache event with MyDatabaseId, even + * if the rel in question is shared. This essentially means that only + * backends in this same database will react to the relcache flush + * request. This is in fact appropriate, since only those backends + * could see our pg_class or pg_attribute change anyway. It looks a + * bit ugly though. */ (*RelationIdRegisterFunc) (MyDatabaseId, relationId); } @@ -498,7 +501,7 @@ AcceptInvalidationMessages(void) * If isCommit, we must send out the messages in our GlobalInvalidMsgs list * to the shared invalidation message queue. Note that these will be read * not only by other backends, but also by our own backend at the next - * transaction start (via AcceptInvalidationMessages). Therefore, it's okay + * transaction start (via AcceptInvalidationMessages). Therefore, it's okay * to discard any pending LocalInvalidMsgs, since these will be redundant * with the global list. * @@ -538,7 +541,7 @@ AtEOXactInvalidationMessages(bool isCommit) * in a transaction. * * Here, we send no messages to the shared queue, since we don't know yet if - * we will commit. But we do need to locally process the LocalInvalidMsgs + * we will commit. But we do need to locally process the LocalInvalidMsgs * list, so as to flush our caches of any tuples we have outdated in the * current command. * @@ -563,9 +566,10 @@ CommandEndInvalidationMessages(bool isCommit) ProcessInvalidationMessages(&RollbackMsgs, LocalExecuteInvalidationMessage); } + /* - * LocalInvalidMsgs list is not interesting anymore, so flush it - * (for real). Do *not* clear GlobalInvalidMsgs or RollbackMsgs. + * LocalInvalidMsgs list is not interesting anymore, so flush it (for + * real). Do *not* clear GlobalInvalidMsgs or RollbackMsgs. */ DiscardInvalidationMessages(&LocalInvalidMsgs, true); } |