From: Robert Haas <rhaas@postgresql.org>
Date: Fri, 13 Jul 2012 23:09:26 +0000 (-0400)
Subject: More initialization code.
X-Git-Url: http://git.postgresql.org/gitweb/static/developers.postgresql.org?a=commitdiff_plain;h=f26dd3586e58e4a9366eec40d532c0b7f4598889;p=users%2Fandresfreund%2Fpostgres.git

More initialization code.
---

diff --git a/src/backend/utils/hash/chash.c b/src/backend/utils/hash/chash.c
index 3d9adca098..50fdafca43 100644
--- a/src/backend/utils/hash/chash.c
+++ b/src/backend/utils/hash/chash.c
@@ -19,7 +19,9 @@
  * while arena offsets can be stored in a 32-bit word.  In fact, we
  * reserve one bit in each such word as a mark bit, so the maximum size
  * of the arena is 2^31 elements, a restriction that does not currently
- * appear to be problematic.
+ * appear to be problematic.  An additional advantage of this representation
+ * is that aligned 32-bit loads and stores are atomic on all architectures
+ * we support, but 64-bit loads and stores are not.
  *
  * When an element is inserted, we copy the data from the backend-private
  * object supplied by the caller into one of these shared-memory entities.
@@ -250,6 +252,7 @@ CHashInitialize(CHashTable table, CHashDescriptor *desc)
 	Size	size;
 	bool	found;
 	void   *shmem;
+	uint32	i;
 
 	/*
 	 * If we're under the postmaster, this must be the EXEC_BACKEND case where
@@ -286,8 +289,32 @@ CHashInitialize(CHashTable table, CHashDescriptor *desc)
 	/* Arena follows the various lists. */
 	table->arena = (void *) (&table->freelist[table->nfreelists]);
 
-	/* XXX. Must initialize spinlocks, set lists to empty, and then put
-	 * all arena nodes on free lists. */
+	/* Initialize all three sets of lists to empty. */
+	for (i = 0; i < table->nbuckets; ++i)
+	{
+		table->bucket[i].head = InvalidCHashPtr;
+		SpinLockInit(&table->bucket[i].head);
+	}
+	for (i = 0; i < table->ngarbage; ++i)
+	{
+		table->garbage[i].head = InvalidCHashPtr;
+		SpinLockInit(&table->garbage[i].head);
+	}
+	for (i = 0; i < table->nfreelists; ++i)
+	{
+		table->freelist[i].head = InvalidCHashPtr;
+		SpinLockInit(&table->freelist[i].head);
+	}
+
+	/* Put all arena elements on the free lists. */
+	for (i = 0; i < table->arena_limit; ++i)
+	{
+		CHashBucket	   *f = &table->freelist[i % table->nfreelists];
+		CHashNode	   *n = CHashTableGetNode(table, i);
+
+		n->next = f->head;
+		f->head = i;
+	}
 
 	/*
 	 * Copy table (with pointers now filled in) to shared memory.  This is