From 38dab2309b9e4359b56c544991ec1f8e16f21835 Mon Sep 17 00:00:00 2001
From: Con Kolivas <kernel@kolivas.org>
Date: Mon, 22 Feb 2016 18:03:51 +1100
Subject: [PATCH] Cope with ckmsgqs not set up during start up

---
 src/ckpool.c | 18 ++++++++++++++++--
 src/ckpool.h |  1 +
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/ckpool.c b/src/ckpool.c
index f064a067..a5861899 100644
--- a/src/ckpool.c
+++ b/src/ckpool.c
@@ -112,6 +112,7 @@ static void *ckmsg_queue(void *arg)
 
 	pthread_detach(pthread_self());
 	rename_proc(ckmsgq->name);
+	ckmsgq->active = true;
 
 	while (42) {
 		ckmsg_t *msg;
@@ -181,8 +182,18 @@ ckmsgq_t *create_ckmsgqs(ckpool_t *ckp, const char *name, const void *func, cons
  * ckmsgq parsing thread(s) to wake up and process it. */
 void ckmsgq_add(ckmsgq_t *ckmsgq, void *data)
 {
-	ckmsg_t *msg = ckalloc(sizeof(ckmsg_t));
+	ckmsg_t *msg;
 
+	if (unlikely(!ckmsgq)) {
+		/* Discard data if we're unlucky enough to be sending it to
+		 * msg queues not set up during start up */
+		free(data);
+		return;
+	}
+	while (unlikely(!ckmsgq->active))
+		cksleep_ms(10);
+
+	msg = ckalloc(sizeof(ckmsg_t));
 	msg->data = data;
 
 	mutex_lock(ckmsgq->lock);
@@ -197,11 +208,14 @@ bool ckmsgq_empty(ckmsgq_t *ckmsgq)
 {
 	bool ret = true;
 
+	if (unlikely(!ckmsgq || !ckmsgq->active))
+		goto out;
+
 	mutex_lock(ckmsgq->lock);
 	if (ckmsgq->msgs)
 		ret = (ckmsgq->msgs->next == ckmsgq->msgs->prev);
 	mutex_unlock(ckmsgq->lock);
-
+out:
 	return ret;
 }
 
diff --git a/src/ckpool.h b/src/ckpool.h
index e7ebfd29..08de2914 100644
--- a/src/ckpool.h
+++ b/src/ckpool.h
@@ -50,6 +50,7 @@ struct ckmsgq {
 	ckmsg_t *msgs;
 	void (*func)(ckpool_t *, void *);
 	int64_t messages;
+	bool active;
 };
 
 typedef struct ckmsgq ckmsgq_t;