From: Carl Hetherington <cth@carlh.net>
Date: Fri, 2 Oct 2015 09:06:48 +0000 (+0100)
Subject: Speculative fix for hangs during Encoder::end().
X-Git-Tag: v2.3.13~4
X-Git-Url: https://main.carlh.net/gitweb/?p=dcpomatic.git;a=commitdiff_plain;h=aac97a7653003ab7032d927eeb236cff4ad726d1

Speculative fix for hangs during Encoder::end().

I think it's possible that, if an exception is thrown by
an Encoder thread during the clear-out loop at the
top of Encoder::end, that loop will hang waiting for
a notify() on _full_condition that never comes.

Fix this by rethrow()ing in this loop and notifying
_full_condition if an encoder thread throws an exception.
---

diff --git a/src/lib/encoder.cc b/src/lib/encoder.cc
index 6fe745dd7..ef58ca09e 100644
--- a/src/lib/encoder.cc
+++ b/src/lib/encoder.cc
@@ -43,6 +43,7 @@
 #include "i18n.h"
 
 #define LOG_GENERAL(...) _film->log()->log (String::compose (__VA_ARGS__), Log::TYPE_GENERAL);
+#define LOG_GENERAL_NC(...) _film->log()->log (__VA_ARGS__, Log::TYPE_GENERAL);
 #define LOG_ERROR(...) _film->log()->log (String::compose (__VA_ARGS__), Log::TYPE_ERROR);
 #define LOG_TIMING(...) _film->log()->microsecond_log (String::compose (__VA_ARGS__), Log::TYPE_TIMING);
 
@@ -95,12 +96,15 @@ Encoder::end ()
 
 	/* Keep waking workers until the queue is empty */
 	while (!_queue.empty ()) {
+		rethrow ();
 		_empty_condition.notify_all ();
 		_full_condition.wait (lock);
 	}
 
 	lock.unlock ();
 
+	LOG_GENERAL_NC (N_("Terminating encoder threads"));
+
 	terminate_threads ();
 
 	LOG_GENERAL (N_("Mopping up %1"), _queue.size());
@@ -373,6 +377,8 @@ try
 catch (...)
 {
 	store_current ();
+	/* Wake anything waiting on _full_condition so it can see the exception */
+	_full_condition.notify_all ();
 }
 
 void