Replace the per-btree handle spinlock with an array of 256 spinlocks in

the connection structure.   When a page is first modified, the
sequentially next spinlock is assigned to the page, and then the page
uses that spinlock to serialize its modifications.

Reference #721.

1 files changed, 11 insertions, 0 deletions

diff --git a/src/conn/conn_handle.c b/src/conn/conn_handle.c
index 3cef3f3ddd7..fda8d0a7fcf 100644
--- a/src/conn/conn_handle.c
+++ b/src/conn/conn_handle.c
@@ -15,6 +15,7 @@ int
 __wt_connection_init(WT_CONNECTION_IMPL *conn)
 {
 	WT_SESSION_IMPL *session;
+	u_int i;
 
 	session = conn->default_session;
 
@@ -40,6 +41,11 @@ __wt_connection_init(WT_CONNECTION_IMPL *conn)
 	WT_RET(__wt_spin_init(session, &conn->fh_lock, "file list"));
 	WT_RET(__wt_spin_init(session, &conn->hot_backup_lock, "hot backup"));
 	WT_RET(__wt_spin_init(session, &conn->schema_lock, "schema"));
+	for (i = 0; i < WT_PAGE_LOCKS(conn); ++i) {
+		WT_RET(__wt_calloc_def(session, 1, &conn->page_lock[i]));
+		WT_RET(
+		    __wt_spin_init(session, conn->page_lock[i], "btree page"));
+	}
 
 	/*
 	 * Block manager.
@@ -62,6 +68,7 @@ __wt_connection_destroy(WT_CONNECTION_IMPL *conn)
 {
 	WT_DECL_RET;
 	WT_SESSION_IMPL *session;
+	u_int i;
 
 	/* Check there's something to destroy. */
 	if (conn == NULL)
@@ -94,6 +101,10 @@ __wt_connection_destroy(WT_CONNECTION_IMPL *conn)
 	__wt_spin_destroy(session, &conn->fh_lock);
 	__wt_spin_destroy(session, &conn->hot_backup_lock);
 	__wt_spin_destroy(session, &conn->schema_lock);
+	for (i = 0; i < WT_PAGE_LOCKS(conn); ++i) {
+		__wt_spin_destroy(session, conn->page_lock[i]);
+		__wt_free(session, conn->page_lock[i]);
+	}
 
 	/* Free allocated memory. */
 	__wt_free(session, conn->home);