Merge "ftrace_reader: Automatically start/stop tracing"
diff --git a/include/perfetto/ftrace_reader/ftrace_controller.h b/include/perfetto/ftrace_reader/ftrace_controller.h
index 2829437..848940e 100644
--- a/include/perfetto/ftrace_reader/ftrace_controller.h
+++ b/include/perfetto/ftrace_reader/ftrace_controller.h
@@ -111,9 +111,6 @@
std::unique_ptr<FtraceSink> CreateSink(FtraceConfig, FtraceSink::Delegate*);
- void Start();
- void Stop();
-
protected:
// Protected for testing.
FtraceController(std::unique_ptr<FtraceProcfs>,
@@ -132,6 +129,9 @@
void RegisterForEvent(const std::string& event_name);
void UnregisterForEvent(const std::string& event_name);
+ void StartIfNeeded();
+ void StopIfNeeded();
+
// Called when we know there is data for the raw pipe
// for the given |cpu|. Kicks off the reading/parsing
// of the pipe.
diff --git a/src/ftrace_reader/end_to_end_integrationtest.cc b/src/ftrace_reader/end_to_end_integrationtest.cc
index 7e35ffa..4201796 100644
--- a/src/ftrace_reader/end_to_end_integrationtest.cc
+++ b/src/ftrace_reader/end_to_end_integrationtest.cc
@@ -111,15 +111,9 @@
// Let some events build up.
sleep(1);
- // Start watching pipe fds.
- ftrace->Start();
-
// Start processing the tasks (OnBundleComplete will quit the task runner).
runner()->Run();
- // Stop listening to fds.
- ftrace->Stop();
-
// Disable events.
sink.reset();
diff --git a/src/ftrace_reader/ftrace_controller.cc b/src/ftrace_reader/ftrace_controller.cc
index 81961b2..f68853f 100644
--- a/src/ftrace_reader/ftrace_controller.cc
+++ b/src/ftrace_reader/ftrace_controller.cc
@@ -67,13 +67,17 @@
ftrace_procfs_->DisableEvent(event->group, event->name);
}
}
+ if (listening_for_raw_trace_data_) {
+ sinks_.clear();
+ StopIfNeeded();
+ }
}
-void FtraceController::Start() {
- if (listening_for_raw_trace_data_) {
- PERFETTO_DLOG("FtraceController is already started.");
+void FtraceController::StartIfNeeded() {
+ if (sinks_.size() > 1)
return;
- }
+ PERFETTO_CHECK(sinks_.size() != 0);
+ PERFETTO_CHECK(!listening_for_raw_trace_data_);
listening_for_raw_trace_data_ = true;
ftrace_procfs_->EnableTracing();
for (size_t cpu = 0; cpu < ftrace_procfs_->NumberOfCpus(); cpu++) {
@@ -90,17 +94,18 @@
}
}
-void FtraceController::Stop() {
- if (!listening_for_raw_trace_data_) {
- PERFETTO_DLOG("FtraceController is already stopped.");
+void FtraceController::StopIfNeeded() {
+ if (sinks_.size() != 0)
return;
- }
+ PERFETTO_CHECK(listening_for_raw_trace_data_);
listening_for_raw_trace_data_ = false;
for (size_t cpu = 0; cpu < ftrace_procfs_->NumberOfCpus(); cpu++) {
CpuReader* reader = GetCpuReader(cpu);
int fd = reader->GetFileDescriptor();
task_runner_->RemoveFileDescriptorWatch(fd);
}
+ readers_.clear();
+ ftrace_procfs_->DisableTracing();
}
void FtraceController::OnRawFtraceDataAvailable(size_t cpu) {
@@ -151,6 +156,8 @@
PERFETTO_DCHECK_THREAD(thread_checker_);
auto it_and_inserted = sinks_.insert(sink);
PERFETTO_DCHECK(it_and_inserted.second);
+
+ StartIfNeeded();
for (const std::string& name : sink->enabled_events())
RegisterForEvent(name);
}
@@ -183,8 +190,10 @@
PERFETTO_DCHECK_THREAD(thread_checker_);
size_t removed = sinks_.erase(sink);
PERFETTO_DCHECK(removed == 1);
+
for (const std::string& name : sink->enabled_events())
UnregisterForEvent(name);
+ StopIfNeeded();
}
FtraceSink::FtraceSink(base::WeakPtr<FtraceController> controller_weak,
diff --git a/src/ftrace_reader/ftrace_controller_unittest.cc b/src/ftrace_reader/ftrace_controller_unittest.cc
index 9f58211..e03f0b9 100644
--- a/src/ftrace_reader/ftrace_controller_unittest.cc
+++ b/src/ftrace_reader/ftrace_controller_unittest.cc
@@ -32,6 +32,7 @@
using testing::Return;
using testing::ByMove;
using testing::AnyNumber;
+using testing::NiceMock;
using Table = perfetto::ProtoTranslationTable;
using FtraceEventBundle = perfetto::protos::pbzero::FtraceEventBundle;
@@ -40,6 +41,9 @@
namespace {
+const char kFooEnablePath[] = "/root/events/group/foo/enable";
+const char kBarEnablePath[] = "/root/events/group/bar/enable";
+
class MockTaskRunner : public base::TaskRunner {
public:
MOCK_METHOD1(PostTask, void(std::function<void()>));
@@ -127,9 +131,9 @@
} // namespace
TEST(FtraceControllerTest, NoExistentEventsDontCrash) {
- MockTaskRunner task_runner;
+ NiceMock<MockTaskRunner> task_runner;
auto ftrace_procfs =
- std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
+ std::unique_ptr<MockFtraceProcfs>(new NiceMock<MockFtraceProcfs>());
TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
FakeTable());
@@ -151,12 +155,14 @@
MockDelegate delegate;
FtraceConfig config({"foo"});
- EXPECT_CALL(*raw_ftrace_procfs,
- WriteToFile("/root/events/group/foo/enable", "1"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "1"));
+ EXPECT_CALL(task_runner, AddFileDescriptorWatch(_, _));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "1"));
std::unique_ptr<FtraceSink> sink = controller.CreateSink(config, &delegate);
- EXPECT_CALL(*raw_ftrace_procfs,
- WriteToFile("/root/events/group/foo/enable", "0"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "0"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "0"));
+ EXPECT_CALL(task_runner, RemoveFileDescriptorWatch(_));
sink.reset();
}
@@ -173,20 +179,20 @@
FtraceConfig configA({"foo"});
FtraceConfig configB({"foo", "bar"});
- EXPECT_CALL(*raw_ftrace_procfs,
- WriteToFile("/root/events/group/foo/enable", "1"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "1"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "1"));
+ EXPECT_CALL(task_runner, AddFileDescriptorWatch(_, _));
std::unique_ptr<FtraceSink> sinkA = controller.CreateSink(configA, &delegate);
- EXPECT_CALL(*raw_ftrace_procfs,
- WriteToFile("/root/events/group/bar/enable", "1"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kBarEnablePath, "1"));
std::unique_ptr<FtraceSink> sinkB = controller.CreateSink(configB, &delegate);
sinkA.reset();
- EXPECT_CALL(*raw_ftrace_procfs,
- WriteToFile("/root/events/group/foo/enable", "0"));
- EXPECT_CALL(*raw_ftrace_procfs,
- WriteToFile("/root/events/group/bar/enable", "0"));
+ EXPECT_CALL(task_runner, RemoveFileDescriptorWatch(_));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "0"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kBarEnablePath, "0"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "0"));
sinkB.reset();
}
@@ -201,38 +207,17 @@
MockDelegate delegate;
FtraceConfig config({"foo"});
- EXPECT_CALL(*raw_ftrace_procfs,
- WriteToFile("/root/events/group/foo/enable", "1"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "1"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "1"));
+ EXPECT_CALL(task_runner, AddFileDescriptorWatch(_, _));
std::unique_ptr<FtraceSink> sink = controller->CreateSink(config, &delegate);
- EXPECT_CALL(*raw_ftrace_procfs,
- WriteToFile("/root/events/group/foo/enable", "0"));
+ EXPECT_CALL(task_runner, RemoveFileDescriptorWatch(_));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile(kFooEnablePath, "0"));
+ EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "0"));
controller.reset();
sink.reset();
}
-TEST(FtraceControllerTest, StartStop) {
- MockTaskRunner task_runner;
- auto ftrace_procfs =
- std::unique_ptr<MockFtraceProcfs>(new MockFtraceProcfs());
- auto raw_ftrace_procfs = ftrace_procfs.get();
- TestFtraceController controller(std::move(ftrace_procfs), &task_runner,
- FakeTable());
-
- // Stopping before we start does nothing.
- controller.Stop();
-
- EXPECT_CALL(*raw_ftrace_procfs, WriteToFile("/root/tracing_on", "1"));
- EXPECT_CALL(task_runner, AddFileDescriptorWatch(_, _));
- controller.Start();
- // Double start does nothing.
- controller.Start();
-
- EXPECT_CALL(task_runner, RemoveFileDescriptorWatch(_));
- controller.Stop();
- // Double stop does nothing.
- controller.Stop();
-}
-
} // namespace perfetto
diff --git a/src/ftrace_reader/ftrace_procfs.cc b/src/ftrace_reader/ftrace_procfs.cc
index 225aa62..c838df3 100644
--- a/src/ftrace_reader/ftrace_procfs.cc
+++ b/src/ftrace_reader/ftrace_procfs.cc
@@ -83,6 +83,11 @@
return WriteToFile(path, "0");
}
+bool FtraceProcfs::DisableAllEvents() {
+ std::string path = root_ + "events/enable";
+ return WriteToFile(path, "0");
+}
+
std::string FtraceProcfs::ReadEventFormat(const std::string& group,
const std::string& name) const {
std::string path = root_ + "events/" + group + "/" + name + "/format";
diff --git a/src/ftrace_reader/ftrace_procfs.h b/src/ftrace_reader/ftrace_procfs.h
index abd0412..8169816 100644
--- a/src/ftrace_reader/ftrace_procfs.h
+++ b/src/ftrace_reader/ftrace_procfs.h
@@ -34,6 +34,9 @@
// Disable the event under with the given |group| and |name|.
bool DisableEvent(const std::string& group, const std::string& name);
+ // Disable all events by writing to the global enable file.
+ bool DisableAllEvents();
+
// Read the format for event with the given |group| and |name|.
std::string ReadEventFormat(const std::string& group,
const std::string& name) const;
diff --git a/src/ftrace_reader/ftrace_procfs_integrationtest.cc b/src/ftrace_reader/ftrace_procfs_integrationtest.cc
index fa7b3dd..ccf2154 100644
--- a/src/ftrace_reader/ftrace_procfs_integrationtest.cc
+++ b/src/ftrace_reader/ftrace_procfs_integrationtest.cc
@@ -30,6 +30,12 @@
const char kTracingPath[] = "/sys/kernel/debug/tracing/";
const char kTracePath[] = "/sys/kernel/debug/tracing/trace";
+void ResetFtrace(FtraceProcfs* ftrace) {
+ ftrace->DisableAllEvents();
+ ftrace->ClearTrace();
+ ftrace->EnableTracing();
+}
+
std::string GetTraceOutput() {
std::ifstream fin(kTracePath, std::ios::in);
if (!fin) {
@@ -46,6 +52,7 @@
TEST(FtraceProcfsIntegrationTest, ClearTrace) {
FtraceProcfs ftrace(kTracingPath);
+ ResetFtrace(&ftrace);
ftrace.WriteTraceMarker("Hello, World!");
ftrace.ClearTrace();
EXPECT_THAT(GetTraceOutput(), Not(HasSubstr("Hello, World!")));
@@ -53,12 +60,14 @@
TEST(FtraceProcfsIntegrationTest, TraceMarker) {
FtraceProcfs ftrace(kTracingPath);
+ ResetFtrace(&ftrace);
ftrace.WriteTraceMarker("Hello, World!");
EXPECT_THAT(GetTraceOutput(), HasSubstr("Hello, World!"));
}
TEST(FtraceProcfsIntegrationTest, EnableDisableEvent) {
FtraceProcfs ftrace(kTracingPath);
+ ResetFtrace(&ftrace);
ftrace.EnableEvent("sched", "sched_switch");
sleep(1);
EXPECT_THAT(GetTraceOutput(), HasSubstr("sched_switch"));
@@ -71,7 +80,7 @@
TEST(FtraceProcfsIntegrationTest, EnableDisableTracing) {
FtraceProcfs ftrace(kTracingPath);
- ftrace.ClearTrace();
+ ResetFtrace(&ftrace);
EXPECT_TRUE(ftrace.IsTracingEnabled());
ftrace.WriteTraceMarker("Before");
ftrace.DisableTracing();
@@ -92,6 +101,12 @@
EXPECT_THAT(format, HasSubstr("field:char buf"));
}
+TEST(FtraceProcfsIntegrationTest, ReadAvailableEvents) {
+ FtraceProcfs ftrace(kTracingPath);
+ std::string format = ftrace.ReadAvailableEvents();
+ EXPECT_THAT(format, HasSubstr("sched:sched_switch"));
+}
+
TEST(FtraceProcfsIntegrationTest, CanOpenTracePipeRaw) {
FtraceProcfs ftrace(kTracingPath);
EXPECT_TRUE(ftrace.OpenPipeForCpu(0));