From 670f117bcb34a3c3ab9b8e759a4d3b7d97570d8e Mon Sep 17 00:00:00 2001
From: Richard Fuchs <rfuchs@sipwise.com>
Date: Tue, 13 Jun 2023 12:11:10 -0400
Subject: [PATCH] MT#55283 honour edge-triggered epoll

We need to loop over the read(fd) as we're calling epoll using
edge-triggered semantics.

Reported in #1676

Change-Id: I8f36b76c1ab32cf5c97b3dff1acf4e3e081ea33e
---
 recording-daemon/stream.c | 69 +++++++++++++++++++--------------------
 1 file changed, 33 insertions(+), 36 deletions(-)

diff --git a/recording-daemon/stream.c b/recording-daemon/stream.c
index 548396403..e427395d1 100644
--- a/recording-daemon/stream.c
+++ b/recording-daemon/stream.c
@@ -47,45 +47,42 @@ static void stream_handler(handler_t *handler) {
 
 	//dbg("poll event for %s", stream->name);
 
-	pthread_mutex_lock(&stream->lock);
-
-	if (stream->fd == -1)
-		goto out;
-
-	buf = malloc(ALLOCLEN);
-	int ret = read(stream->fd, buf, MAXBUFLEN);
-	if (ret == 0) {
-		ilog(LOG_INFO, "EOF on stream %s", stream->name);
-		stream_close(stream);
-		goto out;
-	}
-	else if (ret < 0) {
-		if (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)
-			goto out;
-		ilog(LOG_INFO, "Read error on stream %s: %s", stream->name, strerror(errno));
-		stream_close(stream);
-		goto out;
-	}
-
-	// got a packet
-	pthread_mutex_unlock(&stream->lock);
-
-	if (forward_to){
-		if (forward_packet(stream->metafile,buf,ret)) // leaves buf intact
-			g_atomic_int_inc(&stream->metafile->forward_failed);
+	while (true) {
+		pthread_mutex_lock(&stream->lock);
+
+		if (stream->fd == -1)
+			break;
+
+		buf = malloc(ALLOCLEN);
+		int ret = read(stream->fd, buf, MAXBUFLEN);
+		if (ret == 0) {
+			ilog(LOG_INFO, "EOF on stream %s", stream->name);
+			stream_close(stream);
+			break;
+		}
+		else if (ret < 0) {
+			if (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)
+				break;
+			ilog(LOG_INFO, "Read error on stream %s: %s", stream->name, strerror(errno));
+			stream_close(stream);
+			break;
+		}
+
+		// got a packet
+		pthread_mutex_unlock(&stream->lock);
+
+		if (forward_to){
+			if (forward_packet(stream->metafile,buf,ret)) // leaves buf intact
+				g_atomic_int_inc(&stream->metafile->forward_failed);
+			else
+				g_atomic_int_inc(&stream->metafile->forward_count);
+		}
+		if (decoding_enabled)
+			packet_process(stream, buf, ret); // consumes buf
 		else
-			g_atomic_int_inc(&stream->metafile->forward_count);
+			free(buf);
 	}
-	if (decoding_enabled)
-		packet_process(stream, buf, ret); // consumes buf
-	else
-		free(buf);
 
-	log_info_call = NULL;
-	log_info_stream = NULL;
-	return;
-
-out:
 	pthread_mutex_unlock(&stream->lock);
 	free(buf);
 	log_info_call = NULL;