From 40c9e627d6002718293e0cb53823a3764a51b7e1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=94=B0=E6=98=95?= <tianxin7@xiaomi.com>
Date: Tue, 10 Jan 2023 20:32:25 +0800
Subject: [PATCH] net/local:set POLLIN/POLLOUT threshold for local fifo
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: 田昕 <tianxin7@xiaomi.com>
---
 net/local/local_fifo.c | 75 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/net/local/local_fifo.c b/net/local/local_fifo.c
index 22e72958ec..d361e1f259 100644
--- a/net/local/local_fifo.c
+++ b/net/local/local_fifo.c
@@ -324,6 +324,60 @@ static int local_set_policy(FAR struct file *filep, unsigned long policy)
   return ret;
 }
 
+/****************************************************************************
+ * Name: local_set_pollinthreshold
+ *
+ * Description:
+ *   Set the local pollin threshold:
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NET_LOCAL_DGRAM
+static int local_set_pollinthreshold(FAR struct file *filep,
+                                     unsigned long threshold)
+{
+  int ret;
+
+  /* Set the buffer poll threshold */
+
+  ret = file_ioctl(filep, PIPEIOC_POLLINTHRD, threshold);
+  if (ret < 0)
+    {
+      nerr("ERROR: Failed to set FIFO pollin threshold: %lu\n",
+           threshold);
+    }
+
+  return ret;
+}
+#endif /* CONFIG_NET_LOCAL_DGRAM */
+
+/****************************************************************************
+ * Name: local_set_polloutthreshold
+ *
+ * Description:
+ *   Set the local pollout threshold:
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NET_LOCAL_DGRAM
+static int local_set_polloutthreshold(FAR struct file *filep,
+                                      unsigned long threshold)
+{
+  int ret;
+
+  /* Set the buffer poll threshold */
+
+  ret = file_ioctl(filep, PIPEIOC_POLLOUTTHRD, threshold);
+  if (ret < 0)
+    {
+      nerr("ERROR: Failed to set FIFO pollout threshold: %lu\n",
+           threshold);
+    }
+
+  return ret;
+}
+#endif /* CONFIG_NET_LOCAL_DGRAM */
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -603,6 +657,17 @@ int local_open_receiver(FAR struct local_conn_s *conn, bool nonblock)
       /* Policy: Free FIFO resources when the buffer is empty. */
 
       ret = local_set_policy(&conn->lc_infile, 1);
+
+      if (ret == 0)
+        {
+          /* Set POLLOUT threshold bigger than preamble len.
+           * This is to avoid non-blocking read failed with -EAGAIN when
+           * only preamble len is sent and read by reader.
+           */
+
+          ret = local_set_polloutthreshold(&conn->lc_infile,
+                                           sizeof(uint16_t));
+        }
     }
 
   return ret;
@@ -636,6 +701,16 @@ int local_open_sender(FAR struct local_conn_s *conn, FAR const char *path,
       /* Policy: Free FIFO resources when the buffer is empty. */
 
       ret = local_set_policy(&conn->lc_outfile, 1);
+      if (ret == 0)
+        {
+          /* Set POLLIN threshold bigger than preamble len.
+           * This is to avoid non-blocking read failed with -EAGAIN when
+           * only preamble len is sent and read by reader.
+           */
+
+          ret = local_set_pollinthreshold(&conn->lc_outfile,
+                                          sizeof(uint16_t));
+        }
     }
 
   return ret;