SF: Simplify layer tracing
As preparation to support transaction tracing, do the
following:
1. refactor the ring buffer code so it can be reused
2. remove layer async tracing since we will use
transaction tracing for always on tracing
Test: presubmit
Test: capture sf trace via bugreport
Bug: 200284593
Change-Id: I28388c6db27a420c078e1cc33b0b378c55c6c5d6
diff --git a/services/surfaceflinger/Tracing/RingBuffer.h b/services/surfaceflinger/Tracing/RingBuffer.h
new file mode 100644
index 0000000..d0fb3f2
--- /dev/null
+++ b/services/surfaceflinger/Tracing/RingBuffer.h
@@ -0,0 +1,112 @@
+/*
+ * Copyright 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <android-base/file.h>
+#include <android-base/stringprintf.h>
+
+#include <log/log.h>
+#include <utils/Errors.h>
+#include <utils/SystemClock.h>
+#include <utils/Trace.h>
+#include <queue>
+
+namespace android {
+
+class SurfaceFlinger;
+
+template <typename FileProto, typename EntryProto>
+class RingBuffer {
+public:
+ size_t size() const { return mSizeInBytes; }
+ size_t used() const { return mUsedInBytes; }
+ size_t frameCount() const { return mStorage.size(); }
+ void setSize(size_t newSize) { mSizeInBytes = newSize; }
+ EntryProto& front() { return mStorage.front(); }
+ const EntryProto& front() const { return mStorage.front(); }
+
+ void reset(size_t newSize) {
+ // use the swap trick to make sure memory is released
+ std::queue<EntryProto>().swap(mStorage);
+ mSizeInBytes = newSize;
+ mUsedInBytes = 0U;
+ }
+ void flush(FileProto& fileProto) {
+ fileProto.mutable_entry()->Reserve(static_cast<int>(mStorage.size()));
+ while (!mStorage.empty()) {
+ auto entry = fileProto.add_entry();
+ entry->Swap(&mStorage.front());
+ mStorage.pop();
+ }
+ }
+
+ status_t writeToFile(FileProto& fileProto, std::string filename) {
+ ATRACE_CALL();
+ std::string output;
+ flush(fileProto);
+ reset(mSizeInBytes);
+ if (!fileProto.SerializeToString(&output)) {
+ ALOGE("Could not serialize proto.");
+ return UNKNOWN_ERROR;
+ }
+
+ // -rw-r--r--
+ const mode_t mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
+ if (!android::base::WriteStringToFile(output, filename, mode, getuid(), getgid(), true)) {
+ ALOGE("Could not save the proto file.");
+ return PERMISSION_DENIED;
+ }
+ return NO_ERROR;
+ }
+
+ std::vector<EntryProto> emplace(EntryProto&& proto) {
+ std::vector<EntryProto> replacedEntries;
+ size_t protoSize = static_cast<size_t>(proto.ByteSize());
+ while (mUsedInBytes + protoSize > mSizeInBytes) {
+ if (mStorage.empty()) {
+ return {};
+ }
+ mUsedInBytes -= static_cast<size_t>(mStorage.front().ByteSize());
+ replacedEntries.emplace_back(mStorage.front());
+ mStorage.pop();
+ }
+ mUsedInBytes += protoSize;
+ mStorage.emplace();
+ mStorage.back().Swap(&proto);
+ return replacedEntries;
+ }
+
+ void dump(std::string& result) const {
+ std::chrono::milliseconds duration(0);
+ if (frameCount() > 0) {
+ duration = std::chrono::duration_cast<std::chrono::milliseconds>(
+ std::chrono::nanoseconds(systemTime() - front().elapsed_realtime_nanos()));
+ }
+ const int64_t durationCount = duration.count();
+ base::StringAppendF(&result,
+ " number of entries: %zu (%.2fMB / %.2fMB) duration: %" PRIi64 "ms\n",
+ frameCount(), float(used()) / 1024.f * 1024.f,
+ float(size()) / 1024.f * 1024.f, durationCount);
+ }
+
+private:
+ size_t mUsedInBytes = 0U;
+ size_t mSizeInBytes = 0U;
+ std::queue<EntryProto> mStorage;
+};
+
+} // namespace android