diff options
Diffstat (limited to 'src/include/access')
| -rw-r--r-- | src/include/access/tupdesc.h | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/src/include/access/tupdesc.h b/src/include/access/tupdesc.h index 670ef5c92e..035a0a85e5 100644 --- a/src/include/access/tupdesc.h +++ b/src/include/access/tupdesc.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/access/tupdesc.h,v 1.49 2006/03/16 00:31:55 tgl Exp $ + * $PostgreSQL: pgsql/src/include/access/tupdesc.h,v 1.50 2006/06/16 18:42:23 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -57,6 +57,14 @@ typedef struct tupleConstr * tdtypeid is RECORDOID, and tdtypmod can be either -1 for a fully anonymous * row type, or a value >= 0 to allow the rowtype to be looked up in the * typcache.c type cache. + * + * Tuple descriptors that live in caches (relcache or typcache, at present) + * are reference-counted: they can be deleted when their reference count goes + * to zero. Tuple descriptors created by the executor need no reference + * counting, however: they are simply created in the appropriate memory + * context and go away when the context is freed. We set the tdrefcount + * field of such a descriptor to -1, while reference-counted descriptors + * always have tdrefcount >= 0. */ typedef struct tupleDesc { @@ -67,6 +75,7 @@ typedef struct tupleDesc Oid tdtypeid; /* composite type ID for tuple type */ int32 tdtypmod; /* typmod for tuple type */ bool tdhasoid; /* tuple has oid attribute in its header */ + int tdrefcount; /* reference count, or -1 if not counting */ } *TupleDesc; @@ -81,6 +90,21 @@ extern TupleDesc CreateTupleDescCopyConstr(TupleDesc tupdesc); extern void FreeTupleDesc(TupleDesc tupdesc); +extern void IncrTupleDescRefCount(TupleDesc tupdesc); +extern void DecrTupleDescRefCount(TupleDesc tupdesc); + +#define PinTupleDesc(tupdesc) \ + do { \ + if ((tupdesc)->tdrefcount >= 0) \ + IncrTupleDescRefCount(tupdesc); \ + } while (0) + +#define ReleaseTupleDesc(tupdesc) \ + do { \ + if ((tupdesc)->tdrefcount >= 0) \ + DecrTupleDescRefCount(tupdesc); \ + } while (0) + extern bool equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2); extern void TupleDescInitEntry(TupleDesc desc, |