MINOR: listener: pause_listener() becomes suspend_listener()
We are simply renaming pause_listener() to suspend_listener() to prevent
confusion around listener pausing.
A suspended listener can be in two differents valid states:
- LI_PAUSED: the listener is effectively paused, it will unpause on
resume_listener()
- LI_ASSIGNED (not bound): the listener does not support the LI_PAUSED
state, so it was unbound to satisfy the suspend request, it will
correcly re-bind on resume_listener()
Besides that, we add the LI_F_SUSPENDED flag to mark suspended listeners in
suspend_listener() and unmark them in resume_listener().
We're also adding li_suspend proxy variable to track the number of currently
suspended listeners:
That is, the number of listeners that were suspended through suspend_listener()
and that are either in LI_PAUSED or LI_ASSIGNED state.
Counter is increased on successful suspend in suspend_listener() and it is
decreased on successful resume in resume_listener()
--
Backport notes:
-> 2.4 only, as "MINOR: proxy/listener: support for additional PAUSED state"
was not backported:
Replace this:
| /* PROXY_LOCK is require
| proxy_cond_resume(px);
By this:
| ha_warning("Resumed %s %s.\n", proxy_cap_str(px->cap), px->id);
| send_log(px, LOG_WARNING, "Resumed %s %s.\n", proxy_cap_str(px->cap), px->id);
-> 2.6 and 2.7 only, as "MINOR: listener: make sure we don't pause/resume" was
custom patched:
Replace this:
|@@ -253,6 +253,7 @@ struct listener {
|
| /* listener flags (16 bits) */
| #define LI_F_FINALIZED 0x0001 /* listener made it to the READY||LIMITED||FULL state at least once, may be suspended/resumed safely */
|+#define LI_F_SUSPENDED 0x0002 /* listener has been suspended using suspend_listener(), it is either is LI_PAUSED or LI_ASSIGNED state */
|
| /* Descriptor for a "bind" keyword. The ->parse() function returns 0 in case of
| * success, or a combination of ERR_* flags if an error is encountered. The
By this:
|@@ -222,6 +222,7 @@ struct li_per_thread {
|
| #define LI_F_QUIC_LISTENER 0x00000001 /* listener uses proto quic */
| #define LI_F_FINALIZED 0x00000002 /* listener made it to the READY||LIMITED||FULL state at least once, may be suspended/resumed safely */
|+#define LI_F_SUSPENDED 0x00000004 /* listener has been suspended using suspend_listener(), it is either is LI_PAUSED or LI_ASSIGNED state */
|
| /* The listener will be directly referenced by the fdtab[] which holds its
| * socket. The listener provides the protocol-specific accept() function to
diff --git a/include/haproxy/listener-t.h b/include/haproxy/listener-t.h
index d9a32e0..58dce2f 100644
--- a/include/haproxy/listener-t.h
+++ b/include/haproxy/listener-t.h
@@ -253,6 +253,7 @@
/* listener flags (16 bits) */
#define LI_F_FINALIZED 0x0001 /* listener made it to the READY||LIMITED||FULL state at least once, may be suspended/resumed safely */
+#define LI_F_SUSPENDED 0x0002 /* listener has been suspended using suspend_listener(), it is either is LI_PAUSED or LI_ASSIGNED state */
/* Descriptor for a "bind" keyword. The ->parse() function returns 0 in case of
* success, or a combination of ERR_* flags if an error is encountered. The
diff --git a/include/haproxy/listener.h b/include/haproxy/listener.h
index 0017372..d7d6bf9 100644
--- a/include/haproxy/listener.h
+++ b/include/haproxy/listener.h
@@ -43,11 +43,13 @@
* involves SHUT_WR && listen && SHUT_RD. In case of success, the FD's polling
* is disabled. It normally returns non-zero, unless an error is reported.
* It will need to operate under the proxy's lock and the listener's lock.
+ * suspend() may totally stop a listener if it doesn't support the PAUSED
+ * state, in which case state will be set to ASSIGNED.
* The caller is responsible for indicating in lpx, lli whether the respective
* locks are already held (non-zero) or not (zero) so that the function pick
* the missing ones, in this order.
*/
-int pause_listener(struct listener *l, int lpx, int lli);
+int suspend_listener(struct listener *l, int lpx, int lli);
/* This function tries to resume a temporarily disabled listener.
* The resulting state will either be LI_READY or LI_FULL. 0 is returned
diff --git a/include/haproxy/proxy-t.h b/include/haproxy/proxy-t.h
index 3db2d3e..50c8488 100644
--- a/include/haproxy/proxy-t.h
+++ b/include/haproxy/proxy-t.h
@@ -403,6 +403,7 @@
unsigned int li_paused; /* total number of listeners paused (LI_PAUSED) */
unsigned int li_bound; /* total number of listeners ready (LI_LISTEN) */
unsigned int li_ready; /* total number of listeners ready (>=LI_READY) */
+ unsigned int li_suspended; /* total number of listeners suspended (could be paused or unbound) */
/* warning: these structs are huge, keep them at the bottom */
struct sockaddr_storage dispatch_addr; /* the default address to connect to */
diff --git a/src/listener.c b/src/listener.c
index dfd1fd9..ca13a71 100644
--- a/src/listener.c
+++ b/src/listener.c
@@ -480,14 +480,14 @@
* closes upon SHUT_WR and refuses to rebind. So a common validation path
* involves SHUT_WR && listen && SHUT_RD. In case of success, the FD's polling
* is disabled. It normally returns non-zero, unless an error is reported.
- * pause() may totally stop a listener if it doesn't support the PAUSED state,
- * in which case state will be set to ASSIGNED.
+ * suspend() may totally stop a listener if it doesn't support the PAUSED
+ * state, in which case state will be set to ASSIGNED.
* It will need to operate under the proxy's lock and the listener's lock.
* The caller is responsible for indicating in lpx, lli whether the respective
* locks are already held (non-zero) or not (zero) so that the function pick
* the missing ones, in this order.
*/
-int pause_listener(struct listener *l, int lpx, int lli)
+int suspend_listener(struct listener *l, int lpx, int lli)
{
struct proxy *px = l->bind_conf->frontend;
int ret = 1;
@@ -518,6 +518,10 @@
*/
listener_set_state(l, ((ret) ? LI_PAUSED : LI_ASSIGNED));
+ if (px && !(l->flags & LI_F_SUSPENDED))
+ px->li_suspended++;
+ l->flags |= LI_F_SUSPENDED;
+
/* at this point, everything is under control, no error should be
* returned to calling function
*/
@@ -545,7 +549,7 @@
* or LI_FULL. 0 is returned in case of failure to resume (eg: dead socket).
* Listeners bound to a different process are not woken up unless we're in
* foreground mode, and are ignored. If the listener was only in the assigned
- * state, it's totally rebound. This can happen if a pause() has completely
+ * state, it's totally rebound. This can happen if a suspend() has completely
* stopped it. If the resume fails, 0 is returned and an error might be
* displayed.
* It will need to operate under the proxy's lock and the listener's lock.
@@ -590,6 +594,10 @@
listener_set_state(l, LI_READY);
done:
+ if (px && (l->flags & LI_F_SUSPENDED))
+ px->li_suspended--;
+ l->flags &= ~LI_F_SUSPENDED;
+
if (was_paused && !px->li_paused) {
/* PROXY_LOCK is required */
proxy_cond_resume(px);
@@ -1275,7 +1283,7 @@
* Let's put it to pause in this case.
*/
if (l->rx.proto && l->rx.proto->rx_listening(&l->rx) == 0) {
- pause_listener(l, 0, 0);
+ suspend_listener(l, 0, 0);
goto end;
}
diff --git a/src/protocol.c b/src/protocol.c
index 71bfa83..c627d5c 100644
--- a/src/protocol.c
+++ b/src/protocol.c
@@ -174,10 +174,10 @@
HA_SPIN_UNLOCK(PROTO_LOCK, &proto_lock);
}
-/* pauses all listeners of all registered protocols. This is typically
+/* suspends all listeners of all registered protocols. This is typically
* used on SIG_TTOU to release all listening sockets for the time needed to
- * try to bind a new process. The listeners enter LI_PAUSED. It returns
- * ERR_NONE, with ERR_FATAL on failure.
+ * try to bind a new process. The listeners enter LI_PAUSED or LI_ASSIGNED.
+ * It returns ERR_NONE, with ERR_FATAL on failure.
*/
int protocol_pause_all(void)
{
@@ -189,7 +189,7 @@
HA_SPIN_LOCK(PROTO_LOCK, &proto_lock);
list_for_each_entry(proto, &protocols, list) {
list_for_each_entry(listener, &proto->receivers, rx.proto_list)
- if (!pause_listener(listener, 0, 0))
+ if (!suspend_listener(listener, 0, 0))
err |= ERR_FATAL;
}
HA_SPIN_UNLOCK(PROTO_LOCK, &proto_lock);
diff --git a/src/proxy.c b/src/proxy.c
index fd5c49e..93c7620 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -2286,7 +2286,7 @@
goto end;
list_for_each_entry(l, &p->conf.listeners, by_fe)
- pause_listener(l, 1, 0);
+ suspend_listener(l, 1, 0);
if (p->li_ready) {
ha_warning("%s %s failed to enter pause mode.\n", proxy_cap_str(p->cap), p->id);