ui/src/tracks/cpu_slices/controller.ts

// Copyright (C) 2018 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.

import {fromNs, toNs} from '../../common/time';

import {
  TrackController,
  trackControllerRegistry
} from '../../controller/track_controller';

import {Config, CPU_SLICE_TRACK_KIND, Data, SliceData} from './common';

class CpuSliceTrackController extends TrackController<Config, Data> {
  static readonly kind = CPU_SLICE_TRACK_KIND;
  private maxDurNs = 0;

  async onBoundsChange(start: number, end: number, resolution: number):
      Promise<Data> {
    const startNs = toNs(start);
    const endNs = toNs(end);

    const pxSize = this.pxSize();

    // ns per quantization bucket (i.e. ns per pixel). /2 * 2 is to force it to
    // be an even number, so we can snap in the middle.
    const bucketNs = Math.round(resolution * 1e9 * pxSize / 2) * 2;

    if (this.maxDurNs === 0) {
      const query = `SELECT max(dur) FROM sched WHERE cpu = ${this.config.cpu}`;
      const rawResult = await this.query(query);
      if (rawResult.numRecords === 1) {
        this.maxDurNs = rawResult.columns[0].longValues![0];
      }
    }

    const query = `
      SELECT
        (ts + ${bucketNs / 2}) / ${bucketNs} * ${bucketNs} as tsq,
        ts,
        max(dur),
        utid,
        id
      FROM sched
      WHERE cpu = ${this.config.cpu} AND 
        ts >= (${startNs - this.maxDurNs}) AND
        ts <= ${endNs} AND
        utid != 0
      GROUP BY tsq`;
    const rawResult = await this.query(query);

    const numRows = +rawResult.numRecords;
    const slices: SliceData = {
      kind: 'slice',
      start,
      end,
      resolution,
      length: numRows,
      ids: new Float64Array(numRows),
      starts: new Float64Array(numRows),
      ends: new Float64Array(numRows),
      utids: new Uint32Array(numRows),
    };

    const cols = rawResult.columns;
    for (let row = 0; row < numRows; row++) {
      const startNsQ = +cols[0].longValues![row];
      const startNs = +cols[1].longValues![row];
      const durNs = +cols[2].longValues![row];
      const endNs = startNs + durNs;

      let endNsQ = Math.floor((endNs + bucketNs / 2 - 1) / bucketNs) * bucketNs;
      endNsQ = Math.max(endNsQ, startNsQ + bucketNs);

      if (startNsQ === endNsQ) {
        throw new Error('Should never happen');
      }

      slices.starts[row] = fromNs(startNsQ);
      slices.ends[row] = fromNs(endNsQ);
      slices.utids[row] = +cols[3].longValues![row];
      slices.ids[row] = +cols[4].longValues![row];
    }

    return slices;
  }
}

trackControllerRegistry.register(CpuSliceTrackController);