From c89cfa534ba1d35e35de7d33c57a6c2906a5b11f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= <niklas.soderlund@ragnatech.se>
Date: Fri, 10 Jan 2020 18:41:30 +0100
Subject: cam: Cache buffer memory mapping
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With the buffer allocator in use it's possible to cache the dmabuf
memory mappings when starting the camera instead of mapping and
unmapping them each time.
Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
src/cam/buffer_writer.cpp | 27 ++++++++++++++++++++++-----
src/cam/buffer_writer.h | 5 +++++
src/cam/capture.cpp | 3 +++
3 files changed, 30 insertions(+), 5 deletions(-)
(limited to 'src/cam')
diff --git a/src/cam/buffer_writer.cpp b/src/cam/buffer_writer.cpp
index 1d7366c8..c5a5eb46 100644
--- a/src/cam/buffer_writer.cpp
+++ b/src/cam/buffer_writer.cpp
@@ -22,6 +22,27 @@ BufferWriter::BufferWriter(const std::string &pattern)
{
}
+BufferWriter::~BufferWriter()
+{
+ for (auto &iter : mappedBuffers_) {
+ void *memory = iter.second.first;
+ unsigned int length = iter.second.second;
+ munmap(memory, length);
+ }
+ mappedBuffers_.clear();
+}
+
+void BufferWriter::mapBuffer(FrameBuffer *buffer)
+{
+ for (const FrameBuffer::Plane &plane : buffer->planes()) {
+ void *memory = mmap(NULL, plane.length, PROT_READ, MAP_SHARED,
+ plane.fd.fd(), 0);
+
+ mappedBuffers_[plane.fd.fd()] =
+ std::make_pair(memory, plane.length);
+ }
+}
+
int BufferWriter::write(FrameBuffer *buffer, const std::string &streamName)
{
std::string filename;
@@ -44,9 +65,7 @@ int BufferWriter::write(FrameBuffer *buffer, const std::string &streamName)
return -errno;
for (const FrameBuffer::Plane &plane : buffer->planes()) {
- /* \todo Once the FrameBuffer is done cache mapped memory. */
- void *data = mmap(NULL, plane.length, PROT_READ, MAP_SHARED,
- plane.fd.fd(), 0);
+ void *data = mappedBuffers_[plane.fd.fd()].first;
unsigned int length = plane.length;
ret = ::write(fd, data, length);
@@ -61,8 +80,6 @@ int BufferWriter::write(FrameBuffer *buffer, const std::string &streamName)
<< length << std::endl;
break;
}
-
- munmap(data, length);
}
close(fd);
diff --git a/src/cam/buffer_writer.h b/src/cam/buffer_writer.h
index 5917a7df..8c9b2436 100644
--- a/src/cam/buffer_writer.h
+++ b/src/cam/buffer_writer.h
@@ -7,6 +7,7 @@
#ifndef __LIBCAMERA_BUFFER_WRITER_H__
#define __LIBCAMERA_BUFFER_WRITER_H__
+#include <map>
#include <string>
#include <libcamera/buffer.h>
@@ -15,12 +16,16 @@ class BufferWriter
{
public:
BufferWriter(const std::string &pattern = "frame-#.bin");
+ ~BufferWriter();
+
+ void mapBuffer(libcamera::FrameBuffer *buffer);
int write(libcamera::FrameBuffer *buffer,
const std::string &streamName);
private:
std::string pattern_;
+ std::map<int, std::pair<void *, unsigned int>> mappedBuffers_;
};
#endif /* __LIBCAMERA_BUFFER_WRITER_H__ */
diff --git a/src/cam/capture.cpp b/src/cam/capture.cpp
index dd078eb0..738fa1c2 100644
--- a/src/cam/capture.cpp
+++ b/src/cam/capture.cpp
@@ -116,6 +116,9 @@ int Capture::capture(EventLoop *loop, FrameBufferAllocator *allocator)
<< std::endl;
return ret;
}
+
+ if (writer_)
+ writer_->mapBuffer(buffer.get());
}
requests.push_back(request);
--
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