[libcamera-devel] [PATCH 2/7] ipa: raspberrypi: AWB: Improve locking.

[David Plowman]

Fix a couple of places where notify_one() was called with the lock
held. Also restartAsync doesn't need the lock for its entire duration.

This change exactly matches commit db552b where we do the same for
ALSC (the asynchronous thread arrangement there is identical).

Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
---
 src/ipa/raspberrypi/controller/rpi/awb.cpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/ipa/raspberrypi/controller/rpi/awb.cpp b/src/ipa/raspberrypi/controller/rpi/awb.cpp
index dabab726..791b5108 100644
--- a/src/ipa/raspberrypi/controller/rpi/awb.cpp
+++ b/src/ipa/raspberrypi/controller/rpi/awb.cpp
@@ -136,8 +136,8 @@ Awb::~Awb()
 	{
 		std::lock_guard<std::mutex> lock(mutex_);
 		async_abort_ = true;
-		async_signal_.notify_one();
 	}
+	async_signal_.notify_one();
 	async_thread_.join();
 }
 
@@ -239,11 +239,14 @@ void Awb::restartAsync(StatisticsPtr &stats, double lux)
 			: (mode_ == nullptr ? config_.default_mode : mode_);
 	lux_ = lux;
 	frame_phase_ = 0;
-	async_start_ = true;
 	async_started_ = true;
 	size_t len = mode_name_.copy(async_results_.mode,
 				     sizeof(async_results_.mode) - 1);
 	async_results_.mode[len] = '\0';
+	{
+		std::lock_guard<std::mutex> lock(mutex_);
+		async_start_ = true;
+	}
 	async_signal_.notify_one();
 }
 
@@ -297,7 +300,6 @@ void Awb::Process(StatisticsPtr &stats, Metadata *image_metadata)
 			LOG(RPiAwb, Debug) << "No lux metadata found";
 		LOG(RPiAwb, Debug) << "Awb lux value is " << lux_status.lux;
 
-		std::unique_lock<std::mutex> lock(mutex_);
 		if (async_started_ == false)
 			restartAsync(stats, lux_status.lux);
 	}
@@ -319,8 +321,8 @@ void Awb::asyncFunc()
 		{
 			std::lock_guard<std::mutex> lock(mutex_);
 			async_finished_ = true;
-			sync_signal_.notify_one();
 		}
+		sync_signal_.notify_one();
 	}
 }
 
-- 
2.20.1