summaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/libcamera/include/v4l2_videodevice.h7
-rw-r--r--src/libcamera/v4l2_videodevice.cpp23
2 files changed, 20 insertions, 10 deletions
diff --git a/src/libcamera/include/v4l2_videodevice.h b/src/libcamera/include/v4l2_videodevice.h
index 359b3664..04802012 100644
--- a/src/libcamera/include/v4l2_videodevice.h
+++ b/src/libcamera/include/v4l2_videodevice.h
@@ -7,11 +7,12 @@
#ifndef __LIBCAMERA_V4L2_VIDEODEVICE_H__
#define __LIBCAMERA_V4L2_VIDEODEVICE_H__
+#include <atomic>
+#include <memory>
#include <string>
#include <vector>
#include <linux/videodev2.h>
-#include <memory>
#include <libcamera/buffer.h>
#include <libcamera/geometry.h>
@@ -120,11 +121,12 @@ private:
{
public:
Entry();
- Entry(bool free, const FrameBuffer &buffer);
+ Entry(bool free, uint64_t lastUsed, const FrameBuffer &buffer);
bool operator==(const FrameBuffer &buffer) const;
bool free;
+ uint64_t lastUsed;
private:
struct Plane {
@@ -140,6 +142,7 @@ private:
std::vector<Plane> planes_;
};
+ std::atomic_uint64_t lastUsedCounter_;
std::vector<Entry> cache_;
/* \todo Expose the miss counter through an instrumentation API. */
unsigned int missCounter_;
diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
index c495de85..ca0d147f 100644
--- a/src/libcamera/v4l2_videodevice.cpp
+++ b/src/libcamera/v4l2_videodevice.cpp
@@ -162,7 +162,7 @@ LOG_DECLARE_CATEGORY(V4L2)
* buffer import, with buffers added to the cache as they are queued.
*/
V4L2BufferCache::V4L2BufferCache(unsigned int numEntries)
- : missCounter_(0)
+ : lastUsedCounter_(1), missCounter_(0)
{
cache_.resize(numEntries);
}
@@ -176,10 +176,12 @@ V4L2BufferCache::V4L2BufferCache(unsigned int numEntries)
* allocated.
*/
V4L2BufferCache::V4L2BufferCache(const std::vector<std::unique_ptr<FrameBuffer>> &buffers)
- : missCounter_(0)
+ : lastUsedCounter_(1), missCounter_(0)
{
for (const std::unique_ptr<FrameBuffer> &buffer : buffers)
- cache_.emplace_back(true, buffer->planes());
+ cache_.emplace_back(true,
+ lastUsedCounter_.fetch_add(1, std::memory_order_acq_rel),
+ buffer->planes());
}
V4L2BufferCache::~V4L2BufferCache()
@@ -205,6 +207,7 @@ int V4L2BufferCache::get(const FrameBuffer &buffer)
{
bool hit = false;
int use = -1;
+ uint64_t oldest = UINT64_MAX;
for (unsigned int index = 0; index < cache_.size(); index++) {
const Entry &entry = cache_[index];
@@ -219,8 +222,10 @@ int V4L2BufferCache::get(const FrameBuffer &buffer)
break;
}
- if (use < 0)
+ if (entry.lastUsed < oldest) {
use = index;
+ oldest = entry.lastUsed;
+ }
}
if (!hit)
@@ -229,7 +234,9 @@ int V4L2BufferCache::get(const FrameBuffer &buffer)
if (use < 0)
return -ENOENT;
- cache_[use] = Entry(false, buffer);
+ cache_[use] = Entry(false,
+ lastUsedCounter_.fetch_add(1, std::memory_order_acq_rel),
+ buffer);
return use;
}
@@ -245,12 +252,12 @@ void V4L2BufferCache::put(unsigned int index)
}
V4L2BufferCache::Entry::Entry()
- : free(true)
+ : free(true), lastUsed(0)
{
}
-V4L2BufferCache::Entry::Entry(bool free, const FrameBuffer &buffer)
- : free(free)
+V4L2BufferCache::Entry::Entry(bool free, uint64_t lastUsed, const FrameBuffer &buffer)
+ : free(free), lastUsed(lastUsed)
{
for (const FrameBuffer::Plane &plane : buffer.planes())
planes_.emplace_back(plane);