From 37fc5df25417b632fab33d81e376b0c59ec2c976 Mon Sep 17 00:00:00 2001
From: Georg Reinke <georg.reinke@rwth-aachen.de>
Date: Fri, 28 Jul 2017 12:15:56 +0200
Subject: [PATCH] add polling loop inside shmem_read

---
 lib/nodes/shmem.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/lib/nodes/shmem.c b/lib/nodes/shmem.c
index f98649bfd..1fcbc6054 100644
--- a/lib/nodes/shmem.c
+++ b/lib/nodes/shmem.c
@@ -110,14 +110,15 @@ int shmem_read(struct node *n, struct sample *smps[], unsigned cnt)
 	int recv;
 	struct sample *shared_smps[cnt];
 
-	recv = shmem_int_read(&shm->intf, shared_smps, cnt);
-	if (recv < 0)
+	do {
+		recv = shmem_int_read(&shm->intf, shared_smps, cnt);
+	} while (recv == 0);
+	if (recv < 0) {
 		/* This can only really mean that the other process has exited, so close
 		 * the interface to make sure the shared memory object is unlinked */
 		shmem_int_close(&shm->intf);
-
-	if (recv <= 0)
 		return recv;
+	}
 
 	sample_copy_many(smps, shared_smps, recv);
 	sample_put_many(shared_smps, recv);