/*
 * Copyright (C) 2020 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.
 */

#include <stdlib.h>
#include <sys/types.h>

#include <string>

#include "perfetto/base/logging.h"
#include "perfetto/ext/base/android_utils.h"
#include "perfetto/tracing/core/data_source_config.h"
#include "src/base/test/test_task_runner.h"
#include "test/android_test_utils.h"
#include "test/gtest_and_gmock.h"
#include "test/test_helper.h"

#include "protos/perfetto/config/profiling/perf_event_config.gen.h"
#include "protos/perfetto/trace/profiling/profile_common.gen.h"
#include "protos/perfetto/trace/profiling/profile_packet.gen.h"
#include "protos/perfetto/trace/trace_packet.gen.h"

namespace perfetto {
namespace {

// Skip these tests if the device in question doesn't have the necessary kernel
// LSM hooks in perf_event_open. This comes up when a device with an older
// kernel upgrades to R.
bool HasPerfLsmHooks() {
  return base::GetAndroidProp("sys.init.perf_lsm_hooks") == "1";
}

std::string RandomSessionName() {
  std::random_device rd;
  std::default_random_engine generator(rd());
  std::uniform_int_distribution<> distribution('a', 'z');

  constexpr size_t kSessionNameLen = 20;
  std::string result(kSessionNameLen, '\0');
  for (size_t i = 0; i < kSessionNameLen; ++i)
    result[i] = static_cast<char>(distribution(generator));
  return result;
}

std::vector<protos::gen::TracePacket> ProfileSystemWide(std::string app_name) {
  base::TestTaskRunner task_runner;

  // (re)start the target app's main activity
  if (IsAppRunning(app_name)) {
    StopApp(app_name, "old.app.stopped", &task_runner);
    task_runner.RunUntilCheckpoint("old.app.stopped", 10000 /*ms*/);
  }
  StartAppActivity(app_name, "BusyWaitActivity", "target.app.running",
                   &task_runner,
                   /*delay_ms=*/100);
  task_runner.RunUntilCheckpoint("target.app.running", 10000 /*ms*/);

  // set up tracing
  TestHelper helper(&task_runner);
  helper.ConnectConsumer();
  helper.WaitForConsumerConnect();

  TraceConfig trace_config;
  trace_config.add_buffers()->set_size_kb(20 * 1024);
  trace_config.set_duration_ms(3000);
  trace_config.set_data_source_stop_timeout_ms(8000);
  trace_config.set_unique_session_name(RandomSessionName().c_str());

  auto* ds_config = trace_config.add_data_sources()->mutable_config();
  ds_config->set_name("linux.perf");
  ds_config->set_target_buffer(0);

  protos::gen::PerfEventConfig perf_config;

  perf_config.set_all_cpus(true);
  perf_config.set_sampling_frequency(10);  // Hz
  ds_config->set_perf_event_config_raw(perf_config.SerializeAsString());

  // start tracing
  helper.StartTracing(trace_config);
  helper.WaitForTracingDisabled(15000 /*ms*/);
  helper.ReadData();
  helper.WaitForReadData();

  return helper.trace();
}

void AssertHasSampledStacksForPid(std::vector<protos::gen::TracePacket> packets,
                                  int pid) {
  uint32_t target_pid = static_cast<uint32_t>(pid);
  ASSERT_GT(packets.size(), 0u);

  int total_perf_packets = 0;
  int lost_records_packets = 0;
  int full_samples = 0;
  int target_samples = 0;
  int target_skipped_samples = 0;
  for (const auto& packet : packets) {
    if (!packet.has_perf_sample())
      continue;

    total_perf_packets++;
    EXPECT_GT(packet.timestamp(), 0u) << "all packets should have a timestamp";
    const auto& sample = packet.perf_sample();
    if (sample.has_kernel_records_lost()) {
      lost_records_packets++;
      continue;
    }
    if (sample.has_sample_skipped_reason()) {
      if (sample.pid() == target_pid)
        target_skipped_samples++;
      continue;
    }

    full_samples++;
    EXPECT_GT(sample.tid(), 0u);
    EXPECT_GT(sample.callstack_iid(), 0u);

    if (sample.pid() == target_pid)
      target_samples++;
  }

  EXPECT_GT(target_samples, 0)
      << "target_pid: " << target_pid << ", packets.size(): " << packets.size()
      << ", total_perf_packets: " << total_perf_packets
      << ", full_samples: " << full_samples
      << ", lost_records_packets: " << lost_records_packets
      << ", target_skipped_samples: " << target_skipped_samples << "\n";
}

void AssertNoStacksForPid(std::vector<protos::gen::TracePacket> packets,
                          int pid) {
  uint32_t target_pid = static_cast<uint32_t>(pid);
  // The process can still be sampled, but the stacks should be discarded
  // without unwinding.
  for (const auto& packet : packets) {
    if (packet.perf_sample().pid() == target_pid) {
      EXPECT_EQ(packet.perf_sample().callstack_iid(), 0u);
      EXPECT_TRUE(packet.perf_sample().has_sample_skipped_reason());
    }
  }
}

TEST(TracedPerfCtsTest, SystemWideDebuggableApp) {
  if (!HasPerfLsmHooks())
    GTEST_SKIP() << "skipped due to lack of perf_event_open LSM hooks";

  std::string app_name = "android.perfetto.cts.app.debuggable";
  const auto& packets = ProfileSystemWide(app_name);
  int app_pid = PidForProcessName(app_name);
  ASSERT_GT(app_pid, 0) << "failed to find pid for target process";

  AssertHasSampledStacksForPid(packets, app_pid);
  PERFETTO_CHECK(IsAppRunning(app_name));
  StopApp(app_name);
}

TEST(TracedPerfCtsTest, SystemWideProfileableApp) {
  if (!HasPerfLsmHooks())
    GTEST_SKIP() << "skipped due to lack of perf_event_open LSM hooks";

  std::string app_name = "android.perfetto.cts.app.profileable";
  const auto& packets = ProfileSystemWide(app_name);
  int app_pid = PidForProcessName(app_name);
  ASSERT_GT(app_pid, 0) << "failed to find pid for target process";

  AssertHasSampledStacksForPid(packets, app_pid);
  PERFETTO_CHECK(IsAppRunning(app_name));
  StopApp(app_name);
}

TEST(TracedPerfCtsTest, SystemWideNonProfileableApp) {
  if (!HasPerfLsmHooks())
    GTEST_SKIP() << "skipped due to lack of perf_event_open LSM hooks";

  std::string app_name = "android.perfetto.cts.app.nonprofileable";
  const auto& packets = ProfileSystemWide(app_name);
  int app_pid = PidForProcessName(app_name);
  ASSERT_GT(app_pid, 0) << "failed to find pid for target process";

  if (!IsUserBuild())
    AssertHasSampledStacksForPid(packets, app_pid);
  else
    AssertNoStacksForPid(packets, app_pid);
  PERFETTO_CHECK(IsAppRunning(app_name));
  StopApp(app_name);
}

TEST(TracedPerfCtsTest, SystemWideReleaseApp) {
  if (!HasPerfLsmHooks())
    GTEST_SKIP() << "skipped due to lack of perf_event_open LSM hooks";

  std::string app_name = "android.perfetto.cts.app.release";
  const auto& packets = ProfileSystemWide(app_name);
  int app_pid = PidForProcessName(app_name);
  ASSERT_GT(app_pid, 0) << "failed to find pid for target process";

  if (!IsUserBuild())
    AssertHasSampledStacksForPid(packets, app_pid);
  else
    AssertNoStacksForPid(packets, app_pid);

  PERFETTO_CHECK(IsAppRunning(app_name));
  StopApp(app_name);
}

}  // namespace
}  // namespace perfetto