Move remote backoff sleep to before we pop a frame from the queue.

Otherwise in the case of failure it can take a while for the frame to
become available again for a functioning thread to encode.

4 files changed, 20 insertions, 8 deletions

diff --git a/src/lib/j2k_sync_encoder_thread.cc b/src/lib/j2k_sync_encoder_thread.cc
index ef6834f60..158c12b11 100644
--- a/src/lib/j2k_sync_encoder_thread.cc
+++ b/src/lib/j2k_sync_encoder_thread.cc
@@ -25,6 +25,8 @@
 #include "j2k_sync_encoder_thread.h"
 #include <dcp/scope_guard.h>
 
+#include "i18n.h"
+
 
 J2KSyncEncoderThread::J2KSyncEncoderThread(J2KEncoder& encoder)
 	: J2KEncoderThread(encoder)
@@ -40,6 +42,11 @@ try
 	log_thread_start();
 
 	while (true) {
+		if (auto wait = backoff()) {
+			LOG_ERROR(N_("Encoder thread sleeping (due to backoff) for %1s"), wait);
+			boost::this_thread::sleep(boost::posix_time::seconds(wait));
+		}
+
 		LOG_TIMING("encoder-sleep thread=%1", thread_id());
 		auto frame = _encoder.pop();
 
diff --git a/src/lib/j2k_sync_encoder_thread.h b/src/lib/j2k_sync_encoder_thread.h
index 45222279e..06bb1fcef 100644
--- a/src/lib/j2k_sync_encoder_thread.h
+++ b/src/lib/j2k_sync_encoder_thread.h
@@ -26,6 +26,11 @@ public:
 
 	virtual void log_thread_start() const = 0;
 	virtual std::shared_ptr<dcp::ArrayData> encode(DCPVideo const& frame) = 0;
+	/** @return number of seconds we should wait between attempts to use this thread
+	 *  for encoding. Used to avoid flooding non-responsive network servers with
+	 *  requests.
+	 */
+	virtual int backoff() const { return 0; }
 };
 
 
diff --git a/src/lib/remote_j2k_encoder_thread.cc b/src/lib/remote_j2k_encoder_thread.cc
index 49d80953d..2abaf94ba 100644
--- a/src/lib/remote_j2k_encoder_thread.cc
+++ b/src/lib/remote_j2k_encoder_thread.cc
@@ -61,22 +61,18 @@ RemoteJ2KEncoderThread::encode(DCPVideo const& frame)
 		}
 	} catch (std::exception& e) {
 		LOG_ERROR(
-			N_("Remote encode of %1 on %2 failed (%3); thread sleeping for %4s"),
+			N_("Remote encode of %1 on %2 failed (%3)"),
 			frame.index(), _server.host_name(), e.what(), _remote_backoff
 		);
 	} catch (...) {
 		LOG_ERROR(
-			N_("Remote encode of %1 on %2 failed; thread sleeping for %4s"),
+			N_("Remote encode of %1 on %2 failed"),
 			frame.index(), _server.host_name(), _remote_backoff
 		);
 	}
 
-	if (!encoded) {
-		if (_remote_backoff < 60) {
-			/* back off more */
-			_remote_backoff += 10;
-		}
-		boost::this_thread::sleep(boost::posix_time::seconds(_remote_backoff));
+	if (!encoded && _remote_backoff < 60) {
+		_remote_backoff += 10;
 	}
 
 	return encoded;
diff --git a/src/lib/remote_j2k_encoder_thread.h b/src/lib/remote_j2k_encoder_thread.h
index f3fe7f94a..5b203946c 100644
--- a/src/lib/remote_j2k_encoder_thread.h
+++ b/src/lib/remote_j2k_encoder_thread.h
@@ -14,6 +14,10 @@ public:
 		return _server;
 	}
 
+	int backoff() const override {
+		return _remote_backoff;
+	}
+
 private:
 	EncodeServerDescription _server;
 	/** Number of seconds that we currently wait between attempts to connect to the server */