Simplify ftrace architecture and integration with traced_probes
Historically the ftrace reader code has been strongly decoupled
from the rest of the codebase. The use case that was justifying
it (fall back into a library for other perf tools) is no more,
and we are left with extra layers that are unneeded and hurt
code readability. This CL removes the glue layers between
ftrace and probes_producer, in preparation of upcoming behavioral
changes (Flush). The main changes introduced by this CL are:
- Introduce a base class with hand-rolled RTTI for probes_producer.
This simplifies the bookkeeping logic within the traced_probes
binary.
- Collapse Ftrace's Sink and SinkDelegate into a FtraceDataSource
class. FDS keeps track of all the state of ftrace for a given
tracing session.
- Remove ftrace/end_to_end_integrationtest.cc, it had just two
tests and they were disabled.
- Minor cleanups: introduce PERFETTO_WARN_UNUSED_RESULT; move
stats to a dedicated header.
Change-Id: I7047fc07bbaf9f9bf862cdb81c87e567ffbc6779
diff --git a/src/traced/probes/ftrace/ftrace_controller.h b/src/traced/probes/ftrace/ftrace_controller.h
index 3a73771..d3f9e3d 100644
--- a/src/traced/probes/ftrace/ftrace_controller.h
+++ b/src/traced/probes/ftrace/ftrace_controller.h
@@ -21,99 +21,76 @@
#include <bitset>
#include <condition_variable>
+#include <functional>
#include <map>
#include <memory>
#include <mutex>
#include <set>
#include <string>
-#include <vector>
#include "gtest/gtest_prod.h"
-#include "perfetto/base/scoped_file.h"
#include "perfetto/base/task_runner.h"
+#include "perfetto/base/utils.h"
#include "perfetto/base/weak_ptr.h"
-#include "perfetto/protozero/message_handle.h"
-#include "perfetto/traced/data_source_types.h"
-#include "src/traced/probes/ftrace/ftrace_sink.h"
+#include "src/traced/probes/ftrace/ftrace_config.h"
namespace perfetto {
-namespace protos {
-namespace pbzero {
-class FtraceEventBundle;
-class FtraceStats;
-class FtraceCpuStats;
-} // namespace pbzero
-} // namespace protos
-
-struct FtraceCpuStats {
- uint64_t cpu;
- uint64_t entries;
- uint64_t overrun;
- uint64_t commit_overrun;
- uint64_t bytes_read;
- double oldest_event_ts;
- double now_ts;
- uint64_t dropped_events;
- uint64_t read_events;
-
- void Write(protos::pbzero::FtraceCpuStats*) const;
-};
-
-struct FtraceStats {
- std::vector<FtraceCpuStats> cpu_stats;
-
- void Write(protos::pbzero::FtraceStats*) const;
-};
-
-constexpr size_t kMaxSinks = 32;
-constexpr size_t kMaxCpus = 64;
+class CpuReader;
+class FtraceConfigMuxer;
+class FtraceDataSource;
+class FtraceProcfs;
+class ProtoTranslationTable;
+struct FtraceStats;
// Method of last resort to reset ftrace state.
void HardResetFtraceState();
-class CpuReader;
-class EventFilter;
-class FtraceConfig;
-class FtraceController;
-class FtraceConfigMuxer;
-class FtraceProcfs;
-class ProtoTranslationTable;
-
// Utility class for controlling ftrace.
class FtraceController {
public:
- static std::unique_ptr<FtraceController> Create(base::TaskRunner*);
- virtual ~FtraceController();
+ class Observer {
+ public:
+ virtual ~Observer();
+ virtual void OnFtraceDataWrittenIntoDataSourceBuffers() = 0;
+ };
- std::unique_ptr<FtraceSink> CreateSink(FtraceConfig, FtraceSink::Delegate*);
+ // The passed Observer must outlive the returned FtraceController instance.
+ static std::unique_ptr<FtraceController> Create(base::TaskRunner*, Observer*);
+ virtual ~FtraceController();
void DisableAllEvents();
void WriteTraceMarker(const std::string& s);
void ClearTrace();
+ bool AddDataSource(FtraceDataSource*) PERFETTO_WARN_UNUSED_RESULT;
+ void RemoveDataSource(FtraceDataSource*);
+
+ void DumpFtraceStats(FtraceStats*);
+
+ base::WeakPtr<FtraceController> GetWeakPtr() {
+ return weak_factory_.GetWeakPtr();
+ }
+
protected:
// Protected for testing.
FtraceController(std::unique_ptr<FtraceProcfs>,
std::unique_ptr<ProtoTranslationTable>,
std::unique_ptr<FtraceConfigMuxer>,
- base::TaskRunner*);
+ base::TaskRunner*,
+ Observer*);
- // Write
- void DumpFtraceStats(FtraceStats*);
-
- // Called to read data from the staging pipe for the given |cpu| and parse it
- // into the sinks. Protected and virtual for testing.
- virtual void OnRawFtraceDataAvailable(size_t cpu);
+ virtual void OnDrainCpuForTesting(size_t /*cpu*/) {}
// Protected and virtual for testing.
virtual uint64_t NowMs() const;
private:
- friend FtraceSink;
friend class TestFtraceController;
FRIEND_TEST(FtraceControllerIntegrationTest, EnableDisableEvent);
+ static constexpr size_t kMaxCpus = 64;
+
FtraceController(const FtraceController&) = delete;
FtraceController& operator=(const FtraceController&) = delete;
@@ -129,9 +106,6 @@
uint32_t GetDrainPeriodMs();
- void Register(FtraceSink*);
- void Unregister(FtraceSink*);
-
void StartIfNeeded();
void StopIfNeeded();
@@ -142,15 +116,16 @@
bool listening_for_raw_trace_data_ = false;
// End lock-protected members.
+ base::TaskRunner* const task_runner_;
+ Observer* const observer_;
std::unique_ptr<FtraceProcfs> ftrace_procfs_;
std::unique_ptr<ProtoTranslationTable> table_;
std::unique_ptr<FtraceConfigMuxer> ftrace_config_muxer_;
size_t generation_ = 0;
bool atrace_running_ = false;
- base::TaskRunner* task_runner_ = nullptr;
std::map<size_t, std::unique_ptr<CpuReader>> cpu_readers_;
- std::set<FtraceSink*> sinks_;
- base::WeakPtrFactory<FtraceController> weak_factory_;
+ std::set<FtraceDataSource*> data_sources_;
+ base::WeakPtrFactory<FtraceController> weak_factory_; // Keep last.
PERFETTO_THREAD_CHECKER(thread_checker_)
};