3 files changed, 24 insertions, 16 deletions

diff --git a/bgpd/bgp_io.c b/bgpd/bgp_io.c
index 548167b3a3..cc9c1bda56 100644
--- a/bgpd/bgp_io.c
+++ b/bgpd/bgp_io.c
@@ -109,13 +109,15 @@ int bgp_io_stop(void **result, struct frr_pthread *fpt)
 }
 
 /* Extern API -------------------------------------------------------------- */
+void bgp_io_running(void)
+{
+	while (!atomic_load_explicit(&bgp_io_thread_started,
+				     memory_order_seq_cst))
+		frr_pthread_yield();
+}
 
 void bgp_writes_on(struct peer *peer)
 {
-	while (
-	    !atomic_load_explicit(&bgp_io_thread_started, memory_order_seq_cst))
-		;
-
 	assert(peer->status != Deleted);
 	assert(peer->obuf);
 	assert(peer->ibuf);
@@ -133,10 +135,6 @@ void bgp_writes_on(struct peer *peer)
 
 void bgp_writes_off(struct peer *peer)
 {
-	while (
-	    !atomic_load_explicit(&bgp_io_thread_started, memory_order_seq_cst))
-		;
-
 	struct frr_pthread *fpt = frr_pthread_get(PTHREAD_IO);
 
 	thread_cancel_async(fpt->master, &peer->t_write, NULL);
@@ -147,10 +145,6 @@ void bgp_writes_off(struct peer *peer)
 
 void bgp_reads_on(struct peer *peer)
 {
-	while (
-	    !atomic_load_explicit(&bgp_io_thread_started, memory_order_seq_cst))
-		;
-
 	assert(peer->status != Deleted);
 	assert(peer->ibuf);
 	assert(peer->fd);
@@ -170,10 +164,6 @@ void bgp_reads_on(struct peer *peer)
 
 void bgp_reads_off(struct peer *peer)
 {
-	while (
-	    !atomic_load_explicit(&bgp_io_thread_started, memory_order_seq_cst))
-		;
-
 	struct frr_pthread *fpt = frr_pthread_get(PTHREAD_IO);
 
 	thread_cancel_async(fpt->master, &peer->t_read, NULL);
diff --git a/bgpd/bgp_io.h b/bgpd/bgp_io.h
index c4bd3c2dd9..73587366d7 100644
--- a/bgpd/bgp_io.h
+++ b/bgpd/bgp_io.h
@@ -37,6 +37,16 @@
 extern void bgp_io_init(void);
 
 /**
+ * Ensure that the BGP IO thread is actually up and running
+ *
+ * This function must be called immediately after the thread
+ * has been created for running.  This is because we want
+ * to make sure that the io thread is ready before other
+ * threads start attempting to use it.
+ */
+extern void bgp_io_running(void);
+
+/**
  * Start function for write thread.
  *
  * @param arg - unused
diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index 6dcb603cb6..4d8e4ffe37 100644
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -7437,7 +7437,15 @@ void bgp_pthreads_run()
 	pthread_attr_init(&attr);
 	pthread_attr_setschedpolicy(&attr, SCHED_FIFO);
 
+	/*
+	 * Please ensure that the io thread is running
+	 * by calling bgp_io_running.  The BGP threads
+	 * depend on it being running when we start
+	 * looking for it.
+	 */
 	frr_pthread_run(PTHREAD_IO, &attr, NULL);
+	bgp_io_running();
+
 	frr_pthread_run(PTHREAD_KEEPALIVES, &attr, NULL);
 }