Add NOWAIT option to SELECT FOR UPDATE/SHARE.

Original patch by Hans-Juergen Schoenig, revisions by Karel Zak
and Tom Lane.

8 files changed, 39 insertions, 17 deletions

diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index dde6fe8ecd8..9c040b0dfd4 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/heapam.h,v 1.102 2005/06/20 18:37:01 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/access/heapam.h,v 1.103 2005/08/01 20:31:13 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -163,7 +163,8 @@ extern HTSU_Result heap_delete(Relation relation, ItemPointer tid, ItemPointer c
 extern HTSU_Result heap_update(Relation relation, ItemPointer otid, HeapTuple tup,
 		ItemPointer ctid, CommandId cid, Snapshot crosscheck, bool wait);
 extern HTSU_Result heap_lock_tuple(Relation relation, HeapTuple tup,
-				 Buffer *userbuf, CommandId cid, LockTupleMode mode);
+				 Buffer *userbuf, CommandId cid,
+				 LockTupleMode mode, bool nowait);
 
 extern Oid	simple_heap_insert(Relation relation, HeapTuple tup);
 extern void simple_heap_delete(Relation relation, ItemPointer tid);
diff --git a/src/include/access/multixact.h b/src/include/access/multixact.h
index 2199b05f2c5..8a4d2101e75 100644
--- a/src/include/access/multixact.h
+++ b/src/include/access/multixact.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/access/multixact.h,v 1.3 2005/06/08 15:50:28 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/access/multixact.h,v 1.4 2005/08/01 20:31:13 tgl Exp $
  */
 #ifndef MULTIXACT_H
 #define MULTIXACT_H
@@ -42,6 +42,7 @@ extern MultiXactId MultiXactIdCreate(TransactionId xid1, TransactionId xid2);
 extern MultiXactId MultiXactIdExpand(MultiXactId multi, TransactionId xid);
 extern bool MultiXactIdIsRunning(MultiXactId multi);
 extern void MultiXactIdWait(MultiXactId multi);
+extern bool ConditionalMultiXactIdWait(MultiXactId multi);
 extern void MultiXactIdSetOldestMember(void);
 
 extern void AtEOXact_MultiXact(void);
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index c7584968a36..2ce578b3f41 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.294 2005/07/31 17:19:20 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.295 2005/08/01 20:31:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200507301
+#define CATALOG_VERSION_NO	200508011
 
 #endif
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 46d27a56f53..73648f93ade 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.136 2005/06/26 22:05:41 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.137 2005/08/01 20:31:15 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -319,8 +319,9 @@ typedef struct EState
 
 	uint32		es_processed;	/* # of tuples processed */
 	Oid			es_lastoid;		/* last oid processed (by INSERT) */
-	List	   *es_rowMark;		/* not good place, but there is no other */
-	bool		es_forUpdate;	/* was it FOR UPDATE or FOR SHARE */
+	List	   *es_rowMarks;	/* not good place, but there is no other */
+	bool		es_forUpdate;	/* true = FOR UPDATE, false = FOR SHARE */
+	bool		es_rowNoWait;	/* FOR UPDATE/SHARE NOWAIT option */
 
 	bool		es_instrument;	/* true requests runtime instrumentation */
 	bool		es_select_into; /* true if doing SELECT INTO */
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 24480f1281a..bc980757121 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.174 2005/08/01 04:03:58 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.175 2005/08/01 20:31:15 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -315,6 +315,7 @@ typedef enum NodeTag
 	T_CompositeTypeStmt,
 	T_InhRelation,
 	T_FunctionParameter,
+	T_LockingClause,
 
 	/*
 	 * TAGS FOR RANDOM OTHER STUFF
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index fc88dec5351..90a282e1632 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.288 2005/08/01 04:03:58 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.289 2005/08/01 20:31:15 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -95,6 +95,7 @@ typedef struct Query
 
 	bool		forUpdate;		/* true if rowMarks are FOR UPDATE,
 								 * false if they are FOR SHARE */
+	bool		rowNoWait;		/* FOR UPDATE/SHARE NOWAIT option */
 
 	List	   *targetList;		/* target list (of TargetEntry) */
 
@@ -415,6 +416,20 @@ typedef struct DefElem
 	Node	   *arg;			/* a (Value *) or a (TypeName *) */
 } DefElem;
 
+/*
+ * LockingClause - raw representation of FOR UPDATE/SHARE options
+ *
+ * Note: lockedRels == NIL means "all relations in query".  Otherwise it
+ * is a list of String nodes giving relation eref names.
+ */
+typedef struct LockingClause
+{
+	NodeTag		type;
+	List	   *lockedRels;		/* FOR UPDATE or FOR SHARE relations */
+	bool		forUpdate;		/* true = FOR UPDATE, false = FOR SHARE */
+	bool		nowait;			/* NOWAIT option */
+} LockingClause;
+
 
 /****************************************************************************
  *	Nodes for a Query tree
@@ -686,8 +701,7 @@ typedef struct SelectStmt
 	List	   *sortClause;		/* sort clause (a list of SortBy's) */
 	Node	   *limitOffset;	/* # of result tuples to skip */
 	Node	   *limitCount;		/* # of result tuples to return */
-	List	   *lockedRels;		/* FOR UPDATE or FOR SHARE relations */
-	bool		forUpdate;		/* true = FOR UPDATE, false = FOR SHARE */
+	LockingClause *lockingClause;	/* FOR UPDATE/FOR SHARE */
 
 	/*
 	 * These fields are used only in upper-level SelectStmts.
@@ -699,6 +713,7 @@ typedef struct SelectStmt
 	/* Eventually add fields for CORRESPONDING spec here */
 } SelectStmt;
 
+
 /* ----------------------
  *		Set Operation node for post-analysis query trees
  *
diff --git a/src/include/parser/parse_node.h b/src/include/parser/parse_node.h
index 291282e0920..c864f5714f8 100644
--- a/src/include/parser/parse_node.h
+++ b/src/include/parser/parse_node.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/parser/parse_node.h,v 1.44 2005/06/05 00:38:11 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/parser/parse_node.h,v 1.45 2005/08/01 20:31:16 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -61,9 +61,9 @@ typedef struct ParseState
 	Oid		   *p_paramtypes;	/* OIDs of types for $n parameter symbols */
 	int			p_numparams;	/* allocated size of p_paramtypes[] */
 	int			p_next_resno;	/* next targetlist resno to assign */
-	List	   *p_lockedRels;	/* FOR UPDATE/SHARE, if any (see gram.y) */
-	Node	   *p_value_substitute;		/* what to replace VALUE with, if
-										 * any */
+	LockingClause *p_locking_clause;	/* FOR UPDATE/FOR SHARE info */
+	Node	   *p_value_substitute;		/* what to replace VALUE with,
+										 * if any */
 	bool		p_variableparams;
 	bool		p_hasAggs;
 	bool		p_hasSubLinks;
diff --git a/src/include/storage/lmgr.h b/src/include/storage/lmgr.h
index 3a83c26c7df..72504ee2ab5 100644
--- a/src/include/storage/lmgr.h
+++ b/src/include/storage/lmgr.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/storage/lmgr.h,v 1.50 2005/06/17 22:32:50 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/storage/lmgr.h,v 1.51 2005/08/01 20:31:16 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -64,12 +64,15 @@ extern void UnlockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
 
 /* Lock a tuple (see heap_lock_tuple before assuming you understand this) */
 extern void LockTuple(Relation relation, ItemPointer tid, LOCKMODE lockmode);
+extern bool ConditionalLockTuple(Relation relation, ItemPointer tid,
+								 LOCKMODE lockmode);
 extern void UnlockTuple(Relation relation, ItemPointer tid, LOCKMODE lockmode);
 
 /* Lock an XID (used to wait for a transaction to finish) */
 extern void XactLockTableInsert(TransactionId xid);
 extern void XactLockTableDelete(TransactionId xid);
 extern void XactLockTableWait(TransactionId xid);
+extern bool ConditionalXactLockTableWait(TransactionId xid);
 
 /* Lock a general object (other than a relation) of the current database */
 extern void LockDatabaseObject(Oid classid, Oid objid, uint16 objsubid,