10:35 a.m.
On entry to all calls we currently set the error context in
thread-local data. This is somewhat non-trivial, and is wasted effort
if set_error is never called. Avoid this if the call guarantees never
to call set_error.
---
generator/generator | 24 +++++++++++++++---------
lib/aio.c | 12 ++++++------
2 files changed, 21 insertions(+), 15 deletions(-)
diff --git a/generator/generator b/generator/generator
index f0de6b0..cdae440 100755
--- a/generator/generator
+++ b/generator/generator
@@ -814,6 +814,11 @@ type call = {
* field and does nothing else with the handle.
*)
is_locked : bool;
+ (* Most functions can call set_error. For functions which are
+ * {b guaranteed} never to do that we can save a bit of time by
+ * setting this to false.
+ *)
+ can_set_error : bool;
}
and arg =
| ArrayAndLen of arg * string (* array + number of entries *)
@@ -847,7 +852,7 @@ and ret =
let default_call = { args = []; ret = RErr;
shortdesc = ""; longdesc = "";
- is_locked = true }
+ is_locked = true; can_set_error = true }
(* Calls.
*
@@ -1679,7 +1684,7 @@ connection is writable.";
"aio_is_created", {
default_call with
- args = []; ret = RBool; is_locked = false;
+ args = []; ret = RBool; is_locked = false; can_set_error = false;
shortdesc = "check if the connection has just been created";
longdesc = "\
Return true if this connection has just been created. This
@@ -1690,7 +1695,7 @@ by calling functions such as C<nbd_aio_connect>.";
"aio_is_connecting", {
default_call with
- args = []; ret = RBool; is_locked = false;
+ args = []; ret = RBool; is_locked = false; can_set_error = false;
shortdesc = "check if the connection is connecting or handshaking";
longdesc = "\
Return true if this connection is connecting to the server
@@ -1701,7 +1706,7 @@ issue commands (see C<nbd_aio_is_ready>).";
"aio_is_ready", {
default_call with
- args = []; ret = RBool; is_locked = false;
+ args = []; ret = RBool; is_locked = false; can_set_error = false;
shortdesc = "check if the connection is in the ready state";
longdesc = "\
Return true if this connection is connected to the NBD server,
@@ -1712,7 +1717,7 @@ issue commands.";
"aio_is_processing", {
default_call with
- args = []; ret = RBool; is_locked = false;
+ args = []; ret = RBool; is_locked = false; can_set_error = false;
shortdesc = "check if the connection is processing a command";
longdesc = "\
Return true if this connection is connected to the NBD server,
@@ -1726,7 +1731,7 @@ is processing them), but libnbd is not processing them.";
"aio_is_dead", {
default_call with
- args = []; ret = RBool; is_locked = false;
+ args = []; ret = RBool; is_locked = false; can_set_error = false;
shortdesc = "check if the connection is dead";
longdesc = "\
Return true if the connection has encountered a fatal
@@ -1736,7 +1741,7 @@ There is no way to recover a handle from the dead state.";
"aio_is_closed", {
default_call with
- args = []; ret = RBool; is_locked = false;
+ args = []; ret = RBool; is_locked = false; can_set_error = false;
shortdesc = "check if the connection is closed";
longdesc = "\
Return true if the connection has closed. There is no way to
@@ -2661,7 +2666,7 @@ let generate_lib_unlocked_h () =
* grab the thread mutex (lock) and do logging.
*)
let generate_lib_api_c () =
- let print_wrapper (name, {args; ret; is_locked}) =
+ let print_wrapper (name, {args; ret; is_locked; can_set_error}) =
(match ret with
| RBool
| RErr
@@ -2687,7 +2692,8 @@ let generate_lib_api_c () =
pr "\n";
if is_locked then
pr " pthread_mutex_lock (&h->lock);\n";
- pr " nbd_internal_reset_error (\"nbd_%s\");\n" name;
+ if can_set_error then
+ pr " nbd_internal_reset_error (\"nbd_%s\");\n" name;
pr " ret = nbd_unlocked_%s (h" name;
let argnames = List.flatten (List.map name_of_arg args) in
List.iter (pr ", %s") argnames;
diff --git a/lib/aio.c b/lib/aio.c
index 65b1ef3..9e0db68 100644
--- a/lib/aio.c
+++ b/lib/aio.c
@@ -48,7 +48,7 @@ nbd_unlocked_aio_notify_write (struct nbd_handle *h)
return nbd_internal_run (h, notify_write);
}
-/* NB: is_locked = false. */
+/* NB: is_locked = false, can_set_error = false. */
int
nbd_unlocked_aio_is_created (struct nbd_handle *h)
{
@@ -73,7 +73,7 @@ is_connecting_group (enum state_group group)
}
}
-/* NB: is_locked = false. */
+/* NB: is_locked = false, can_set_error = false. */
int
nbd_unlocked_aio_is_connecting (struct nbd_handle *h)
{
@@ -82,7 +82,7 @@ nbd_unlocked_aio_is_connecting (struct nbd_handle *h)
return is_connecting_group (group);
}
-/* NB: is_locked = false. */
+/* NB: is_locked = false, can_set_error = false. */
int
nbd_unlocked_aio_is_ready (struct nbd_handle *h)
{
@@ -103,7 +103,7 @@ is_processing_group (enum state_group group)
}
}
-/* NB: is_locked = false. */
+/* NB: is_locked = false, can_set_error = false. */
int
nbd_unlocked_aio_is_processing (struct nbd_handle *h)
{
@@ -112,14 +112,14 @@ nbd_unlocked_aio_is_processing (struct nbd_handle *h)
return is_processing_group (group);
}
-/* NB: is_locked = false. */
+/* NB: is_locked = false, can_set_error = false. */
int
nbd_unlocked_aio_is_dead (struct nbd_handle *h)
{
return h->state == STATE_DEAD;
}
-/* NB: is_locked = false. */
+/* NB: is_locked = false, can_set_error = false. */
int
nbd_unlocked_aio_is_closed (struct nbd_handle *h)
{
--
2.21.0