Camera: Collect capture latency histograms
Add capture latency histograms to existing westworld metrics data.
Test: Camera CTS, and observe statsd output
Bug: 154159000
Change-Id: Id0ac5c29f29bdab5ac21f16fe33430f7a7456553
diff --git a/services/camera/libcameraservice/device3/Camera3Device.cpp b/services/camera/libcameraservice/device3/Camera3Device.cpp
index 92c8e30..e80404b 100644
--- a/services/camera/libcameraservice/device3/Camera3Device.cpp
+++ b/services/camera/libcameraservice/device3/Camera3Device.cpp
@@ -2161,6 +2161,14 @@
streamStats[i].mRequestCount = stats->second.mRequestedFrameCount;
streamStats[i].mErrorCount = stats->second.mDroppedFrameCount;
streamStats[i].mStartLatencyMs = stats->second.mStartLatencyMs;
+ streamStats[i].mHistogramType =
+ hardware::CameraStreamStats::HISTOGRAM_TYPE_CAPTURE_LATENCY;
+ streamStats[i].mHistogramBins.assign(
+ stats->second.mCaptureLatencyBins.begin(),
+ stats->second.mCaptureLatencyBins.end());
+ streamStats[i].mHistogramCounts.assign(
+ stats->second.mCaptureLatencyHistogram.begin(),
+ stats->second.mCaptureLatencyHistogram.end());
}
}
listener->notifyIdle(requestCount, resultErrorCount, deviceError, streamStats);
diff --git a/services/camera/libcameraservice/utils/SessionStatsBuilder.cpp b/services/camera/libcameraservice/utils/SessionStatsBuilder.cpp
index 83965c4..7a7707c 100644
--- a/services/camera/libcameraservice/utils/SessionStatsBuilder.cpp
+++ b/services/camera/libcameraservice/utils/SessionStatsBuilder.cpp
@@ -18,12 +18,21 @@
#define ATRACE_TAG ATRACE_TAG_CAMERA
//#define LOG_NDEBUG 0
+#include <numeric>
+
+#include <inttypes.h>
#include <utils/Log.h>
#include "SessionStatsBuilder.h"
namespace android {
+// Bins for capture latency: [0, 100], [100, 200], [200, 300], ...
+// [1300, 2100], [2100, inf].
+// Capture latency is in the unit of millisecond.
+const std::array<int32_t, StreamStats::LATENCY_BIN_COUNT-1> StreamStats::mCaptureLatencyBins {
+ { 100, 200, 300, 400, 500, 700, 900, 1300, 2100 } };
+
status_t SessionStatsBuilder::addStream(int id) {
std::lock_guard<std::mutex> l(mLock);
StreamStats stats;
@@ -52,10 +61,14 @@
mCounterStopped = false;
mDeviceError = false;
for (auto& streamStats : mStatsMap) {
- streamStats.second.mRequestedFrameCount = 0;
- streamStats.second.mDroppedFrameCount = 0;
- streamStats.second.mCounterStopped = false;
- streamStats.second.mStartLatencyMs = 0;
+ StreamStats& streamStat = streamStats.second;
+ streamStat.mRequestedFrameCount = 0;
+ streamStat.mDroppedFrameCount = 0;
+ streamStat.mCounterStopped = false;
+ streamStat.mStartLatencyMs = 0;
+
+ std::fill(streamStat.mCaptureLatencyHistogram.begin(),
+ streamStat.mCaptureLatencyHistogram.end(), 0);
}
}
@@ -66,23 +79,28 @@
void SessionStatsBuilder::stopCounter(int id) {
std::lock_guard<std::mutex> l(mLock);
- mStatsMap[id].mCounterStopped = true;
+ StreamStats& streamStat = mStatsMap[id];
+ streamStat.mCounterStopped = true;
}
void SessionStatsBuilder::incCounter(int id, bool dropped, int32_t captureLatencyMs) {
std::lock_guard<std::mutex> l(mLock);
+
auto it = mStatsMap.find(id);
- if (it != mStatsMap.end()) {
- if (!it->second.mCounterStopped) {
- it->second.mRequestedFrameCount++;
- if (dropped) {
- it->second.mDroppedFrameCount++;
- } else if (it->second.mRequestedFrameCount == 1) {
- // The capture latency for the first request.
- it->second.mStartLatencyMs = captureLatencyMs;
- }
- }
+ if (it == mStatsMap.end()) return;
+
+ StreamStats& streamStat = it->second;
+ if (streamStat.mCounterStopped) return;
+
+ streamStat.mRequestedFrameCount++;
+ if (dropped) {
+ streamStat.mDroppedFrameCount++;
+ } else if (streamStat.mRequestedFrameCount - streamStat.mDroppedFrameCount == 1) {
+ // The capture latency for the first request.
+ streamStat.mStartLatencyMs = captureLatencyMs;
}
+
+ streamStat.updateLatencyHistogram(captureLatencyMs);
}
void SessionStatsBuilder::stopCounter() {
@@ -95,10 +113,10 @@
void SessionStatsBuilder::incResultCounter(bool dropped) {
std::lock_guard<std::mutex> l(mLock);
- if (!mCounterStopped) {
- mRequestCount ++;
- if (dropped) mErrorResultCount++;
- }
+ if (mCounterStopped) return;
+
+ mRequestCount++;
+ if (dropped) mErrorResultCount++;
}
void SessionStatsBuilder::onDeviceError() {
@@ -106,4 +124,18 @@
mDeviceError = true;
}
+void StreamStats::updateLatencyHistogram(int32_t latencyMs) {
+ size_t i;
+ for (i = 0; i < mCaptureLatencyBins.size(); i++) {
+ if (latencyMs < mCaptureLatencyBins[i]) {
+ mCaptureLatencyHistogram[i] ++;
+ break;
+ }
+ }
+
+ if (i == mCaptureLatencyBins.size()) {
+ mCaptureLatencyHistogram[i]++;
+ }
+}
+
}; // namespace android
diff --git a/services/camera/libcameraservice/utils/SessionStatsBuilder.h b/services/camera/libcameraservice/utils/SessionStatsBuilder.h
index 7943637..c23abb6 100644
--- a/services/camera/libcameraservice/utils/SessionStatsBuilder.h
+++ b/services/camera/libcameraservice/utils/SessionStatsBuilder.h
@@ -19,22 +19,38 @@
#include <utils/Errors.h>
-#include <mutex>
+#include <array>
#include <map>
+#include <mutex>
namespace android {
// Helper class to build stream stats
struct StreamStats {
+ // Fields for buffer drop
int64_t mRequestedFrameCount;
int64_t mDroppedFrameCount;
bool mCounterStopped;
+
+ // Fields for stream startup latency
int32_t mStartLatencyMs;
+ // Fields for capture latency measurement
+ const static int LATENCY_BIN_COUNT = 10;
+ // Boundary values separating between adjacent bins, excluding 0 and
+ // infinity.
+ const static std::array<int32_t, LATENCY_BIN_COUNT-1> mCaptureLatencyBins;
+ // Counter values for all histogram bins. One more entry than mCaptureLatencyBins.
+ std::array<int64_t, LATENCY_BIN_COUNT> mCaptureLatencyHistogram;
+
StreamStats() : mRequestedFrameCount(0),
mDroppedFrameCount(0),
mCounterStopped(false),
- mStartLatencyMs(0) {}
+ mStartLatencyMs(0),
+ mCaptureLatencyHistogram{}
+ {}
+
+ void updateLatencyHistogram(int32_t latencyMs);
};
// Helper class to build session stats