tor

commit 3931a6f264355d7fe017219f76bd5bec1d8bcbd8
parent 2e8de0de3b5ae10277cd0fd72e782d2f6aa30c81
Author: David Goulet <dgoulet@torproject.org>
Date:   Tue,  3 Oct 2017 14:38:30 -0400

sched: Use SCHED_BUG() macro in scheduler

When a BUG() occurs, this macro will print extra information about the state
of the scheduler and the given channel if any. This will help us greatly to
fix future bugs in the scheduler especially when they occur rarely.

Fixes #23753

Signed-off-by: David Goulet <dgoulet@torproject.org>

Diffstat:
A
changes/bug23753
 | 
4
++++
M
src/or/scheduler.c
 | 
2
+-
M
src/or/scheduler_kist.c
 | 
8
++++----

3 files changed, 9 insertions(+), 5 deletions(-)
diff --git a/changes/bug23753 b/changes/bug23753
@@ -0,0 +1,4 @@
+  o Minor features (logging, scheduler):
+    - Introduce a SCHED_BUG() function to log extra information about the
+      scheduler state if we ever catch a bug in the scheduler. Closes ticket
+      23753.
diff --git a/src/or/scheduler.c b/src/or/scheduler.c
@@ -607,7 +607,7 @@ scheduler_release_channel,(channel_t *chan))
   }
 
   if (chan->scheduler_state == SCHED_CHAN_PENDING) {
-    if (smartlist_pos(channels_pending, chan) == -1) {
+    if (SCHED_BUG(smartlist_pos(channels_pending, chan) == -1, chan)) {
       log_warn(LD_SCHED, "Scheduler asked to release channel %" PRIu64 " "
                          "but it wasn't in channels_pending",
                chan->global_identifier);
diff --git a/src/or/scheduler_kist.c b/src/or/scheduler_kist.c
@@ -116,7 +116,7 @@ channel_outbuf_length(channel_t *chan)
   /* In theory, this can not happen because we can not scheduler a channel
    * without a connection that has its outbuf initialized. Just in case, bug
    * on this so we can understand a bit more why it happened. */
-  if (BUG(BASE_CHAN_TO_TLS(chan)->conn == NULL)) {
+  if (SCHED_BUG(BASE_CHAN_TO_TLS(chan)->conn == NULL, chan)) {
     return 0;
   }
   return buf_datalen(TO_CONN(BASE_CHAN_TO_TLS(chan)->conn)->outbuf);
@@ -370,7 +370,7 @@ socket_can_write(socket_table_t *table, const channel_t *chan)
 {
   socket_table_ent_t *ent = NULL;
   ent = socket_table_search(table, chan);
-  IF_BUG_ONCE(!ent) {
+  if (SCHED_BUG(!ent, chan)) {
     return 1; // Just return true, saying that kist wouldn't limit the socket
   }
 
@@ -390,7 +390,7 @@ update_socket_info(socket_table_t *table, const channel_t *chan)
 {
   socket_table_ent_t *ent = NULL;
   ent = socket_table_search(table, chan);
-  IF_BUG_ONCE(!ent) {
+  if (SCHED_BUG(!ent, chan)) {
     return; // Whelp. Entry didn't exist for some reason so nothing to do.
   }
   update_socket_info_impl(ent);
@@ -402,7 +402,7 @@ update_socket_written(socket_table_t *table, channel_t *chan, size_t bytes)
 {
   socket_table_ent_t *ent = NULL;
   ent = socket_table_search(table, chan);
-  IF_BUG_ONCE(!ent) {
+  if (SCHED_BUG(!ent, chan)) {
     return; // Whelp. Entry didn't exist so nothing to do.
   }