Merge changes Ic85cab22,I97791a80,I521eb50c
* changes:
Add support for concurrent data sources.
Make NetworkTraceHandler thread safe
Refactor Network Tracing into separate data source
diff --git a/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp b/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
index aeadb4a..be4ffe3 100644
--- a/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
+++ b/service-t/native/libs/libnetworkstats/NetworkTraceHandler.cpp
@@ -55,13 +55,12 @@
NetworkTraceHandler::RegisterDataSource();
}
-NetworkTraceHandler::NetworkTraceHandler()
- : NetworkTraceHandler([this](const PacketTrace& pkt) {
- NetworkTraceHandler::Trace(
- [this, pkt](NetworkTraceHandler::TraceContext ctx) {
- Fill(pkt, *ctx.NewTracePacket());
- });
- }) {}
+// static
+NetworkTracePoller NetworkTraceHandler::sPoller([](const PacketTrace& pkt) {
+ NetworkTraceHandler::Trace([pkt](NetworkTraceHandler::TraceContext ctx) {
+ NetworkTraceHandler::Fill(pkt, *ctx.NewTracePacket());
+ });
+});
void NetworkTraceHandler::OnSetup(const SetupArgs& args) {
const std::string& raw = args.config->network_packet_trace_config_raw();
@@ -75,21 +74,27 @@
}
void NetworkTraceHandler::OnStart(const StartArgs&) {
- if (!Start()) return;
- mTaskRunner = perfetto::Platform::GetDefaultPlatform()->CreateTaskRunner({});
- Loop();
+ mStarted = sPoller.Start(mPollMs);
}
void NetworkTraceHandler::OnStop(const StopArgs&) {
- Stop();
- mTaskRunner.reset();
+ if (mStarted) sPoller.Stop();
+ mStarted = false;
}
-void NetworkTraceHandler::Loop() {
- mTaskRunner->PostDelayedTask([this]() { Loop(); }, mPollMs);
- ConsumeAll();
+void NetworkTracePoller::SchedulePolling() {
+ // Schedules another run of ourselves to recursively poll periodically.
+ mTaskRunner->PostDelayedTask(
+ [this]() {
+ mMutex.lock();
+ SchedulePolling();
+ ConsumeAllLocked();
+ mMutex.unlock();
+ },
+ mPollMs);
}
+// static class method
void NetworkTraceHandler::Fill(const PacketTrace& src, TracePacket& dst) {
dst.set_timestamp(src.timestampNs);
auto* event = dst.set_network_packet();
@@ -113,9 +118,23 @@
}
}
-bool NetworkTraceHandler::Start() {
+bool NetworkTracePoller::Start(uint32_t pollMs) {
ALOGD("Starting datasource");
+ std::scoped_lock<std::mutex> lock(mMutex);
+ if (mSessionCount > 0) {
+ if (mPollMs != pollMs) {
+ // Nothing technical prevents mPollMs from changing, it's just unclear
+ // what the right behavior is. Taking the min of active values could poll
+ // too frequently giving some sessions too much data. Taking the max could
+ // be too infrequent. For now, do nothing.
+ ALOGI("poll_ms can't be changed while running, ignoring poll_ms=%d",
+ pollMs);
+ }
+ mSessionCount++;
+ return true;
+ }
+
auto status = mConfigurationMap.init(PACKET_TRACE_ENABLED_MAP_PATH);
if (!status.ok()) {
ALOGW("Failed to bind config map: %s", status.error().message().c_str());
@@ -136,24 +155,41 @@
return false;
}
+ // Start a task runner to run ConsumeAll every mPollMs milliseconds.
+ mTaskRunner = perfetto::Platform::GetDefaultPlatform()->CreateTaskRunner({});
+ mPollMs = pollMs;
+ SchedulePolling();
+
+ mSessionCount++;
return true;
}
-bool NetworkTraceHandler::Stop() {
+bool NetworkTracePoller::Stop() {
ALOGD("Stopping datasource");
+ std::scoped_lock<std::mutex> lock(mMutex);
+ if (mSessionCount == 0) return false; // This should never happen
+
+ // If this isn't the last session, don't clean up yet.
+ if (--mSessionCount > 0) return true;
+
auto res = mConfigurationMap.writeValue(0, false, BPF_ANY);
if (!res.ok()) {
ALOGW("Failed to disable tracing: %s", res.error().message().c_str());
- return false;
}
+ mTaskRunner.reset();
mRingBuffer.reset();
- return true;
+ return res.ok();
}
-bool NetworkTraceHandler::ConsumeAll() {
+bool NetworkTracePoller::ConsumeAll() {
+ std::scoped_lock<std::mutex> lock(mMutex);
+ return ConsumeAllLocked();
+}
+
+bool NetworkTracePoller::ConsumeAllLocked() {
if (mRingBuffer == nullptr) {
ALOGW("Tracing is not active");
return false;
diff --git a/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp b/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp
index 560194f..543be21 100644
--- a/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp
+++ b/service-t/native/libs/libnetworkstats/NetworkTraceHandlerTest.cpp
@@ -39,6 +39,9 @@
namespace android {
namespace bpf {
+// Use uint32 max to cause the handler to never Loop. Instead, the tests will
+// manually drive things by calling ConsumeAll explicitly.
+constexpr uint32_t kNeverPoll = std::numeric_limits<uint32_t>::max();
__be16 bindAndListen(int s) {
sockaddr_in sin = {.sin_family = AF_INET};
@@ -83,7 +86,7 @@
}
};
-class NetworkTraceHandlerTest : public testing::Test {
+class NetworkTracePollerTest : public testing::Test {
protected:
void SetUp() {
if (access(PACKET_TRACE_RINGBUF_PATH, R_OK)) {
@@ -95,31 +98,49 @@
}
};
-TEST_F(NetworkTraceHandlerTest, PollWhileInactive) {
- NetworkTraceHandler handler([&](const PacketTrace& pkt) {});
+TEST_F(NetworkTracePollerTest, PollWhileInactive) {
+ NetworkTracePoller handler([&](const PacketTrace& pkt) {});
// One succeed after start and before stop.
EXPECT_FALSE(handler.ConsumeAll());
- ASSERT_TRUE(handler.Start());
+ ASSERT_TRUE(handler.Start(kNeverPoll));
EXPECT_TRUE(handler.ConsumeAll());
ASSERT_TRUE(handler.Stop());
EXPECT_FALSE(handler.ConsumeAll());
}
-TEST_F(NetworkTraceHandlerTest, TraceTcpSession) {
+TEST_F(NetworkTracePollerTest, ConcurrentSessions) {
+ // Simulate two concurrent sessions (two starts followed by two stops). Check
+ // that tracing is stopped only after both sessions finish.
+ NetworkTracePoller handler([&](const PacketTrace& pkt) {});
+
+ ASSERT_TRUE(handler.Start(kNeverPoll));
+ EXPECT_TRUE(handler.ConsumeAll());
+
+ ASSERT_TRUE(handler.Start(kNeverPoll));
+ EXPECT_TRUE(handler.ConsumeAll());
+
+ ASSERT_TRUE(handler.Stop());
+ EXPECT_TRUE(handler.ConsumeAll());
+
+ ASSERT_TRUE(handler.Stop());
+ EXPECT_FALSE(handler.ConsumeAll());
+}
+
+TEST_F(NetworkTracePollerTest, TraceTcpSession) {
__be16 server_port = 0;
std::vector<PacketTrace> packets;
// Record all packets with the bound address and current uid. This callback is
// involked only within ConsumeAll, at which point the port should have
// already been filled in and all packets have been processed.
- NetworkTraceHandler handler([&](const PacketTrace& pkt) {
+ NetworkTracePoller handler([&](const PacketTrace& pkt) {
if (pkt.sport != server_port && pkt.dport != server_port) return;
if (pkt.uid != getuid()) return;
packets.push_back(pkt);
});
- ASSERT_TRUE(handler.Start());
+ ASSERT_TRUE(handler.Start(kNeverPoll));
const uint32_t kClientTag = 2468;
const uint32_t kServerTag = 1357;
diff --git a/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h b/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h
index c257aa0..3f244b3 100644
--- a/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h
+++ b/service-t/native/libs/libnetworkstats/include/netdbpf/NetworkTraceHandler.h
@@ -22,6 +22,7 @@
#include <string>
#include <unordered_map>
+#include "android-base/thread_annotations.h"
#include "bpf/BpfMap.h"
#include "bpf/BpfRingbuf.h"
@@ -31,6 +32,56 @@
namespace android {
namespace bpf {
+// NetworkTracePoller is responsible for interactions with the BPF ring buffer
+// including polling. This class is an internal helper for NetworkTraceHandler,
+// it is not meant to be used elsewhere.
+class NetworkTracePoller {
+ public:
+ // Testonly: initialize with a callback capable of intercepting data.
+ NetworkTracePoller(std::function<void(const PacketTrace&)> callback)
+ : mCallback(std::move(callback)) {}
+
+ // Starts tracing with the given poll interval.
+ bool Start(uint32_t pollMs) EXCLUDES(mMutex);
+
+ // Stops tracing and release any held state.
+ bool Stop() EXCLUDES(mMutex);
+
+ // Consumes all available events from the ringbuffer.
+ bool ConsumeAll() EXCLUDES(mMutex);
+
+ private:
+ void SchedulePolling() REQUIRES(mMutex);
+ bool ConsumeAllLocked() REQUIRES(mMutex);
+
+ std::mutex mMutex;
+
+ // Records the number of successfully started active sessions so that only the
+ // first active session attempts setup and only the last cleans up. Note that
+ // the session count will remain zero if Start fails. It is expected that Stop
+ // will not be called for any trace session where Start fails.
+ int mSessionCount GUARDED_BY(mMutex);
+
+ // How often to poll the ring buffer, defined by the trace config.
+ uint32_t mPollMs GUARDED_BY(mMutex);
+
+ // The function to process PacketTrace, typically a Perfetto sink.
+ std::function<void(const PacketTrace&)> mCallback GUARDED_BY(mMutex);
+
+ // The BPF ring buffer handle.
+ std::unique_ptr<BpfRingbuf<PacketTrace>> mRingBuffer GUARDED_BY(mMutex);
+
+ // The packet tracing config map (really a 1-element array).
+ BpfMap<uint32_t, bool> mConfigurationMap GUARDED_BY(mMutex);
+
+ // This must be the last member, causing it to be the first deleted. If it is
+ // not, members required for callbacks can be deleted before it's stopped.
+ std::unique_ptr<perfetto::base::TaskRunner> mTaskRunner GUARDED_BY(mMutex);
+};
+
+// NetworkTraceHandler implements the android.network_packets data source. This
+// class is registered with Perfetto and is instantiated when tracing starts and
+// destroyed when tracing ends. There is one instance per trace session.
class NetworkTraceHandler : public perfetto::DataSource<NetworkTraceHandler> {
public:
// Registers this DataSource.
@@ -39,45 +90,19 @@
// Connects to the system Perfetto daemon and registers the trace handler.
static void InitPerfettoTracing();
- // Initialize with the default Perfetto callback.
- NetworkTraceHandler();
-
- // Testonly: initialize with a callback capable of intercepting data.
- NetworkTraceHandler(std::function<void(const PacketTrace&)> callback)
- : mCallback(std::move(callback)) {}
-
- // Testonly: standalone functions without perfetto dependency.
- bool Start();
- bool Stop();
- bool ConsumeAll();
-
// perfetto::DataSource overrides:
- void OnSetup(const SetupArgs&) override;
+ void OnSetup(const SetupArgs& args) override;
void OnStart(const StartArgs&) override;
void OnStop(const StopArgs&) override;
- // Convert a PacketTrace into a Perfetto trace packet.
- void Fill(const PacketTrace& src,
- ::perfetto::protos::pbzero::TracePacket& dst);
-
private:
- void Loop();
+ // Convert a PacketTrace into a Perfetto trace packet.
+ static void Fill(const PacketTrace& src,
+ ::perfetto::protos::pbzero::TracePacket& dst);
- // How often to poll the ring buffer, defined by the trace config.
+ static NetworkTracePoller sPoller;
uint32_t mPollMs;
-
- // The function to process PacketTrace, typically a Perfetto sink.
- std::function<void(const PacketTrace&)> mCallback;
-
- // The BPF ring buffer handle.
- std::unique_ptr<BpfRingbuf<PacketTrace>> mRingBuffer;
-
- // The packet tracing config map (really a 1-element array).
- BpfMap<uint32_t, bool> mConfigurationMap;
-
- // This must be the last member, causing it to be the first deleted. If it is
- // not, members required for callbacks can be deleted before it's stopped.
- std::unique_ptr<perfetto::base::TaskRunner> mTaskRunner;
+ bool mStarted;
};
} // namespace bpf