We shouldn't block on no work situations directly from the getwork scheduler itself.

sgminer.c

@@ -5713,13 +5713,18 @@ static void pool_resus(struct pool *pool)
 		applog(LOG_INFO, "%s alive", pool->poolname);
 }
 
-static struct work *hash_pop(void)
+/* If this is called non_blocking, it will return NULL for work so that must
+ * be handled. */
+static struct work *hash_pop(bool blocking)
 {
 	struct work *work = NULL, *tmp;
 	int hc;
 
 	mutex_lock(stgd_lock);
-	while (!HASH_COUNT(staged_work)) {
+	if (!HASH_COUNT(staged_work)) {
+		if (!blocking)
+			goto out_unlock;
+		do {
 			struct timespec then;
 			struct timeval now;
 			int rc;
@@ -5736,6 +5741,7 @@ static struct work *hash_pop(void)
 				no_work = true;
 				applog(LOG_WARNING, "Waiting for work to be available from pools.");
 			}
+		} while (!HASH_COUNT(staged_work));
 	}
 
 	if (no_work) {
@@ -5764,6 +5770,7 @@ static struct work *hash_pop(void)
 
 	/* Keep track of last getwork grabbed */
 	last_getwork = time(NULL);
+out_unlock:
 	mutex_unlock(stgd_lock);
 
 	return work;
@@ -5918,7 +5925,7 @@ struct work *get_work(struct thr_info *thr, const int thr_id)
 	applog(LOG_DEBUG, "Popping work from get queue to get work");
 	diff_t = time(NULL);
 	while (!work) {
-		work = hash_pop();
+		work = hash_pop(true);
 		if (stale_work(work, false)) {
 			discard_work(work);
 			work = NULL;
@@ -8178,7 +8185,8 @@ begin_bench:
 			/* Keeps slowly generating work even if it's not being
 			 * used to keep last_getwork incrementing and to see
 			 * if pools are still alive. */
-			work = hash_pop();
+			work = hash_pop(false);
+			if (work)
 				discard_work(work);
 			continue;
 		}