MEDIUM: check: implement check deletion for dynamic servers
Implement a mechanism to free a started check on runtime for dynamic
servers. A new function check_purge is created for this. The check task
will be marked for deletion and scheduled to properly close connection
elements and free the task/tasklet/buf_wait elements.
This function will be useful to delete a dynamic server wich checks.
diff --git a/include/haproxy/check-t.h b/include/haproxy/check-t.h
index b78a9f9..084b15e 100644
--- a/include/haproxy/check-t.h
+++ b/include/haproxy/check-t.h
@@ -53,6 +53,7 @@
#define CHK_ST_IN_ALLOC 0x0040 /* check blocked waiting for input buffer allocation */
#define CHK_ST_OUT_ALLOC 0x0080 /* check blocked waiting for output buffer allocation */
#define CHK_ST_CLOSE_CONN 0x0100 /* check is waiting that the connection gets closed */
+#define CHK_ST_PURGE 0x0200 /* check must be freed */
/* check status */
enum healthcheck_status {
diff --git a/include/haproxy/check.h b/include/haproxy/check.h
index 228f9d6..fdc4471 100644
--- a/include/haproxy/check.h
+++ b/include/haproxy/check.h
@@ -79,6 +79,7 @@
void check_release_buf(struct check *check, struct buffer *bptr);
const char *init_check(struct check *check, int type);
void free_check(struct check *check);
+void check_purge(struct check *check);
int init_srv_check(struct server *srv);
int init_srv_agent_check(struct server *srv);
diff --git a/src/check.c b/src/check.c
index c2ab8e8..c40a47d 100644
--- a/src/check.c
+++ b/src/check.c
@@ -1102,7 +1102,10 @@
if (check->server)
HA_SPIN_LOCK(SERVER_LOCK, &check->server->lock);
- if (!(check->state & CHK_ST_INPROGRESS)) {
+ if (unlikely(check->state & CHK_ST_PURGE)) {
+ TRACE_STATE("health-check state to purge", CHK_EV_TASK_WAKE, check);
+ }
+ else if (!(check->state & (CHK_ST_INPROGRESS))) {
/* no check currently running */
if (!expired) /* woke up too early */ {
TRACE_STATE("health-check wake up too early", CHK_EV_TASK_WAKE, check);
@@ -1139,7 +1142,7 @@
* First, let's check whether there was an uncaught error,
* which can happen on connect timeout or error.
*/
- if (check->result == CHK_RES_UNKNOWN) {
+ if (check->result == CHK_RES_UNKNOWN && likely(!(check->state & CHK_ST_PURGE))) {
/* Here the connection must be defined. Otherwise the
* error would have already been detected
*/
@@ -1197,7 +1200,7 @@
check->sess = NULL;
}
- if (check->server) {
+ if (check->server && likely(!(check->state & CHK_ST_PURGE))) {
if (check->result == CHK_RES_FAILED) {
/* a failure or timeout detected */
TRACE_DEVEL("report failure", CHK_EV_TASK_WAKE|CHK_EV_HCHK_END|CHK_EV_HCHK_ERR, check);
@@ -1236,6 +1239,23 @@
HA_SPIN_UNLOCK(SERVER_LOCK, &check->server->lock);
TRACE_LEAVE(CHK_EV_TASK_WAKE, check);
+
+ /* Free the check if set to PURGE. After this, the check instance may be
+ * freed via the free_server invocation, so it must not be accessed
+ * after this point.
+ */
+ if (unlikely(check->state & CHK_ST_PURGE)) {
+ /* buf_wait */
+ LIST_DELETE(&check->buf_wait.list);
+ /* tasklet */
+ pool_free(pool_head_tasklet, check->wait_list.tasklet);
+ /* task */
+ task_destroy(check->task);
+ t = NULL;
+
+ free_server(check->server);
+ }
+
return t;
}
@@ -1314,6 +1334,11 @@
return NULL;
}
+/* Liberates the resources allocated for a check.
+ *
+ * This function must only be used at startup when it is known that the check
+ * has never been executed.
+ */
void free_check(struct check *check)
{
task_destroy(check->task);
@@ -1329,6 +1354,18 @@
}
}
+/* This function must be used in order to free a started check. The check will
+ * be scheduled for a next execution in order to properly close and free all
+ * check elements.
+ *
+ * Non thread-safe.
+ */
+void check_purge(struct check *check)
+{
+ check->state = CHK_ST_PURGE;
+ task_wakeup(check->task, TASK_WOKEN_OTHER);
+}
+
/* manages a server health-check. Returns the time the task accepts to wait, or
* TIME_ETERNITY for infinity.
*/