src/trace_processor/ftrace_utils.cc

/*
 * Copyright (C) 2019 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 "src/trace_processor/ftrace_utils.h"

#include <algorithm>

#include "perfetto/base/logging.h"

namespace perfetto {
namespace trace_processor {
namespace ftrace_utils {

TaskState::TaskStateStr TaskState::ToString() const {
  PERFETTO_CHECK(is_valid());

  char buffer[32];
  size_t pos = 0;

  // This mapping is given by the file
  // https://android.googlesource.com/kernel/msm.git/+/android-msm-wahoo-4.4-pie-qpr1/include/trace/events/sched.h#155
  if (is_runnable()) {
    buffer[pos++] = 'R';
  } else {
    if (state_ & Atom::kInterruptibleSleep)
      buffer[pos++] = 'S';
    if (state_ & Atom::kUninterruptibleSleep)
      buffer[pos++] = 'D';  // D for (D)isk sleep
    if (state_ & Atom::kStopped)
      buffer[pos++] = 'T';
    if (state_ & Atom::kTraced)
      buffer[pos++] = 't';
    if (state_ & Atom::kExitDead)
      buffer[pos++] = 'X';
    if (state_ & Atom::kExitZombie)
      buffer[pos++] = 'Z';
    if (state_ & Atom::kTaskDead)
      buffer[pos++] = 'x';
    if (state_ & Atom::kWakeKill)
      buffer[pos++] = 'K';
    if (state_ & Atom::kWaking)
      buffer[pos++] = 'W';
    if (state_ & Atom::kParked)
      buffer[pos++] = 'P';
    if (state_ & Atom::kNoLoad)
      buffer[pos++] = 'N';
  }

  if (is_kernel_preempt())
    buffer[pos++] = '+';

  // It is very unlikely that we have used more than the size of the string
  // array. Double check that belief on debug builds.
  PERFETTO_DCHECK(pos < std::tuple_size<TaskStateStr>() - 1);

  TaskStateStr output{};
  memcpy(output.data(), buffer, std::min(pos, output.size() - 1));
  return output;
}

}  // namespace ftrace_utils
}  // namespace trace_processor
}  // namespace perfetto