xenstored now supports multiple concurrent transactions per

connection, plus interleaving of transactional and
non-transactional accesses. A transaction identifier is added
to the xsd_sockmsg header structure (0 means 'not in context
of a transaction'). The user and kernel xs interfaces accept
a pointer to a transaction handle where appropriate --
currently this is directly cast to an integer identifier in
the client library / kernel driver, but will allow for keeping
extra dynamic client-side state in future if we need to.

The transaction mutex has now gone. It's replaced with a
read-write mutex, but this is only acquired for exclusive
access during suspend/resume, to ensure there are no in-progress
transactions.

Signed-off-by: Keir Fraser <keir@xensource.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/tools/xenstore/xenstored_transaction.h b/tools/xenstore/xenstored_transaction.h
index 2617339940..992791f7a9 100644
--- a/tools/xenstore/xenstored_transaction.h
+++ b/tools/xenstore/xenstored_transaction.h
@@ -25,10 +25,11 @@ struct transaction;
 void do_transaction_start(struct connection *conn, struct buffered_data *node);
 void do_transaction_end(struct connection *conn, const char *arg);
 
-bool transaction_block(struct connection *conn);
+struct transaction *transaction_lookup(struct connection *conn, u32 id);
 
 /* This node was changed: can fail and longjmp. */
-void add_change_node(struct transaction *trans, const char *node, bool recurse);
+void add_change_node(struct transaction *trans, const char *node,
+                     bool recurse);
 
 /* Return tdb context to use for this connection. */
 TDB_CONTEXT *tdb_transaction_context(struct transaction *trans);