From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Tue, 4 Feb 2020 20:46:41 +0000 (-0500)
Subject: Fix: event notifier: adapt read iterator state to poll expectations
X-Git-Tag: v2.13.0-rc1~137
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=31c02fb796462c07482101ab2845827f98df30d0;p=lttng-modules.git

Fix: event notifier: adapt read iterator state to poll expectations

When completing to read a subbuffer, ensure that the state of the
iterator is moved forward so the "put_subbuf" is performed before
returning to the user, so poll() will not return POLLIN when there
is actually no data available to read.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ia94b5dcb0c72d8548325b1004f214044f50fd191
---

diff --git a/src/lttng-abi.c b/src/lttng-abi.c
index 09e43788..c62e295e 100644
--- a/src/lttng-abi.c
+++ b/src/lttng-abi.c
@@ -909,11 +909,14 @@ skip_get_next:
 		}
 		read_count += copy_len;
 	}
-	return read_count;
+	goto put_record;
 
 nodata:
 	*ppos = 0;
 	chan->iter.len_left = 0;
+
+put_record:
+	lib_ring_buffer_put_current_record(buf);
 	return read_count;
 }