[libcamera-devel] [PATCH v5 17/33] ipa: libipa: Pass FCQueue size as template argument

[Laurent Pinchart]

The frame context queue size is meant to be a compile-time constant, not
a variable that can change between runs. Pass it to the class as a
template argument.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 src/ipa/ipu3/ipa_context.h   |  5 ++++-
 src/ipa/ipu3/ipu3.cpp        |  5 +----
 src/ipa/libipa/fc_queue.cpp  |  6 +++---
 src/ipa/libipa/fc_queue.h    | 17 ++++++++---------
 src/ipa/rkisp1/ipa_context.h |  4 +++-
 src/ipa/rkisp1/rkisp1.cpp    |  4 +---
 6 files changed, 20 insertions(+), 21 deletions(-)

diff --git a/src/ipa/ipu3/ipa_context.h b/src/ipa/ipu3/ipa_context.h
index 36099353e9f2..bdba3d07d13a 100644
--- a/src/ipa/ipu3/ipa_context.h
+++ b/src/ipa/ipu3/ipa_context.h
@@ -79,11 +79,14 @@ struct IPAFrameContext : public FrameContext {
 	} sensor;
 };
 
+/* Maximum number of frame contexts to be held */
+static constexpr uint32_t kMaxFrameContexts = 16;
+
 struct IPAContext {
 	IPASessionConfiguration configuration;
 	IPAActiveState activeState;
 
-	FCQueue<IPAFrameContext> frameContexts;
+	FCQueue<IPAFrameContext, kMaxFrameContexts> frameContexts;
 };
 
 } /* namespace ipa::ipu3 */
diff --git a/src/ipa/ipu3/ipu3.cpp b/src/ipa/ipu3/ipu3.cpp
index d1ea081d595d..f5292a77e4d3 100644
--- a/src/ipa/ipu3/ipu3.cpp
+++ b/src/ipa/ipu3/ipu3.cpp
@@ -55,9 +55,6 @@ static constexpr uint32_t kMinCellSizeLog2 = 3;
 /* log2 of the maximum grid cell width and height, in pixels */
 static constexpr uint32_t kMaxCellSizeLog2 = 6;
 
-/* Maximum number of frame contexts to be held */
-static constexpr uint32_t kMaxFrameContexts = 16;
-
 namespace libcamera {
 
 LOG_DEFINE_CATEGORY(IPAIPU3)
@@ -191,7 +188,7 @@ private:
 };
 
 IPAIPU3::IPAIPU3()
-	: context_({ {}, {}, { kMaxFrameContexts } })
+	: context_({ {}, {}, {} })
 {
 }
 
diff --git a/src/ipa/libipa/fc_queue.cpp b/src/ipa/libipa/fc_queue.cpp
index e812faa505a5..9b5702ec5eb0 100644
--- a/src/ipa/libipa/fc_queue.cpp
+++ b/src/ipa/libipa/fc_queue.cpp
@@ -42,6 +42,7 @@ namespace ipa {
  * \class FCQueue
  * \brief A support class for managing FrameContext instances in IPA modules
  * \tparam FrameContext The IPA module-specific FrameContext derived class type
+ * \tparam Size The number of contexts in the queue
  *
  * Along with the Module and Algorithm classes, the frame context queue is a
  * core component of the libipa infrastructure. It stores per-frame contexts
@@ -90,9 +91,8 @@ namespace ipa {
  */
 
 /**
- * \fn FCQueue::FCQueue(unsigned int size)
- * \brief Construct a frame contexts queue of a specified size
- * \param[in] size The number of contexts in the queue
+ * \fn FCQueue::FCQueue()
+ * \brief Construct a frame contexts queue
  */
 
 /**
diff --git a/src/ipa/libipa/fc_queue.h b/src/ipa/libipa/fc_queue.h
index a589e7e1031b..b9c8c6fe5a62 100644
--- a/src/ipa/libipa/fc_queue.h
+++ b/src/ipa/libipa/fc_queue.h
@@ -7,8 +7,8 @@
 
 #pragma once
 
+#include <array>
 #include <stdint.h>
-#include <vector>
 
 #include <libcamera/base/log.h>
 
@@ -18,21 +18,20 @@ LOG_DECLARE_CATEGORY(FCQueue)
 
 namespace ipa {
 
-template<typename FrameContext>
+template<typename FrameContext, std::size_t Size>
 class FCQueue;
 
 struct FrameContext {
 private:
-	template<typename T> friend class FCQueue;
+	template<typename T, std::size_t> friend class FCQueue;
 	uint32_t frame;
 };
 
-template<typename FrameContext>
+template<typename FrameContext, std::size_t Size>
 class FCQueue
 {
 public:
-	FCQueue(unsigned int size)
-		: contexts_(size)
+	FCQueue()
 	{
 	}
 
@@ -44,7 +43,7 @@ public:
 
 	FrameContext &alloc(const uint32_t frame)
 	{
-		FrameContext &frameContext = contexts_[frame % contexts_.size()];
+		FrameContext &frameContext = contexts_[frame % Size];
 
 		/*
 		 * Do not re-initialise if a get() call has already fetched this
@@ -68,7 +67,7 @@ public:
 
 	FrameContext &get(uint32_t frame)
 	{
-		FrameContext &frameContext = contexts_[frame % contexts_.size()];
+		FrameContext &frameContext = contexts_[frame % Size];
 
 		/*
 		 * If the IPA algorithms try to access a frame context slot which
@@ -110,7 +109,7 @@ private:
 		frameContext.frame = frame;
 	}
 
-	std::vector<FrameContext> contexts_;
+	std::array<FrameContext, Size> contexts_;
 };
 
 } /* namespace ipa */
diff --git a/src/ipa/rkisp1/ipa_context.h b/src/ipa/rkisp1/ipa_context.h
index f6aaefffed52..4481bd2acde6 100644
--- a/src/ipa/rkisp1/ipa_context.h
+++ b/src/ipa/rkisp1/ipa_context.h
@@ -94,11 +94,13 @@ struct IPAActiveState {
 struct IPAFrameContext : public FrameContext {
 };
 
+static constexpr uint32_t kMaxFrameContexts = 16;
+
 struct IPAContext {
 	IPASessionConfiguration configuration;
 	IPAActiveState activeState;
 
-	FCQueue<IPAFrameContext> frameContexts;
+	FCQueue<IPAFrameContext, kMaxFrameContexts> frameContexts;
 };
 
 } /* namespace ipa::rkisp1 */
diff --git a/src/ipa/rkisp1/rkisp1.cpp b/src/ipa/rkisp1/rkisp1.cpp
index eb3481949897..b7c1ecfee4c8 100644
--- a/src/ipa/rkisp1/rkisp1.cpp
+++ b/src/ipa/rkisp1/rkisp1.cpp
@@ -41,8 +41,6 @@ using namespace std::literals::chrono_literals;
 namespace ipa::rkisp1 {
 
 /* Maximum number of frame contexts to be held */
-static constexpr uint32_t kMaxFrameContexts = 16;
-
 class IPARkISP1 : public IPARkISP1Interface, public Module
 {
 public:
@@ -106,7 +104,7 @@ const ControlInfoMap::Map rkisp1Controls{
 } /* namespace */
 
 IPARkISP1::IPARkISP1()
-	: context_({ {}, {}, { kMaxFrameContexts } })
+	: context_({ {}, {}, {} })
 {
 }
 
-- 
Regards,

Laurent Pinchart