From: Matthew Smith <mgsmith@netgate.com>
Date: Fri, 24 May 2024 19:53:55 +0000 (+0000)
Subject: vapi: only wait if queue is empty
X-Git-Tag: v25.06-rc0~129
X-Git-Url: https://gerrit.fd.io/r/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F83%2F40983%2F2;p=vpp.git

vapi: only wait if queue is empty

Type: fix
Fixes: 4b9935cd54

In vapi_wait(), check that the queue is empty before waiting. The
condvar is only signaled on addition of the first message.
pthread_cond_wait() will block approximately forever if there are
already messages in the queue.

Change-Id: Ic52befe443509f3c53aa9a872ba62bb05aaac25e
Signed-off-by: Matthew Smith <mgsmith@netgate.com>
---

diff --git a/src/vpp-api/vapi/vapi.c b/src/vpp-api/vapi/vapi.c
index 61801fc3726..c818ab0bbec 100644
--- a/src/vpp-api/vapi/vapi.c
+++ b/src/vpp-api/vapi/vapi.c
@@ -1627,7 +1627,8 @@ vapi_wait (vapi_ctx_t ctx)
     return VAPI_ENOTSUP;
 
   svm_queue_lock (ctx->vl_input_queue);
-  svm_queue_wait (ctx->vl_input_queue);
+  if (ctx->vl_input_queue->cursize == 0)
+    svm_queue_wait (ctx->vl_input_queue);
   svm_queue_unlock (ctx->vl_input_queue);
 
   return VAPI_OK;