flutter-bench.yml

name: Flutter benchmark

# Measures ONE application built two ways -- Flutter's own release build and
# the identical Dart source transpiled by Codename One -- and publishes the
# comparison to the pull request and to port status.
#
# Neither application is vendored. `scripts/flutter-bench/app/prepare.sh` takes
# the gallery from the Flutter SDK this workflow installs
# ($FLUTTER_ROOT/dev/integration_tests/new_gallery) and copies the SAME 159
# files into both sides, so the comparison cannot drift: there is no second
# copy for an edit to land on. The Codename One side is generated from the
# SHIPPING archetype, which means a change that breaks the documented Flutter
# wiring breaks this workflow too instead of passing unnoticed.

on:
  pull_request:
    paths:
      - 'maven/flutter-runtime/**'
      - 'maven/dart-transpiler/**'
      - 'maven/dart-runtime/**'
      - 'maven/codenameone-maven-plugin/**'
      # The builders the plugin runs live here since the build engine split out.
      - 'maven/build-engine/**'
      - 'maven/cn1app-archetype/**'
      - 'scripts/flutter-bench/**'
      # The regression gate's rules and CPU detection are the ParparVM gate's own
      # (flutter_baseline.py runs vm/selfhost/perf_baseline.py with its own layout).
      - 'vm/selfhost/perf_baseline.py'
      - 'vm/selfhost/perf-gate.py'
      - '.github/workflows/flutter-bench.yml'
  schedule:
    # Nightly, so port status carries a current number and the PR runs have a
    # trend to sit against rather than a single point.
    - cron: '0 3 * * *'
  workflow_dispatch:
    inputs:
      platforms:
        description: 'Comma separated platform ids, or "all"'
        default: 'all'

concurrency:
  group: flutter-bench-${{ github.ref }}
  cancel-in-progress: true

env:
  # The Flutter release this benchmark measures against, PINNED rather than
  # tracking stable.
  #
  # A benchmark whose reference moves on its own is not one: the gallery, its
  # dependency resolution and Flutter's own code generation all change between
  # releases, so a number from last week and a number from today would differ
  # for reasons that have nothing to do with this repository. Tracking stable
  # also broke outright -- 3.47.5's tree resolved google_fonts to a version
  # without robotoCondensed and three studies stopped compiling.
  #
  # Bumping this is a deliberate act that re-baselines the comparison: expect
  # every start-up and memory ratio to move, and rebaseline them in the same
  # change's own overlay (scripts/flutter-bench/flutter_baseline.py calibrate
  # --pr N --reason "Flutter <version>" over every platform's baseline-*.json).
  FLUTTER_REF: '3.35.4'

permissions:
  contents: read
  pull-requests: write
  # The framework job runs in the pr-ci-container image on ghcr, and pulling it
  # needs this. Without it the job dies in "Initialize containers" with a bare
  # "Error response from daemon: denied", which reads like the image is missing
  # rather than like the token cannot see it.
  packages: read

jobs:
  # The framework is built ONCE, here, and the platform jobs consume the
  # artifacts. Two reasons it cannot be built per platform:
  #
  #   * It needs JDK 8. codenameone-javase imports javafx.*, which no JDK after
  #     8 carries, so a JDK 17 build of the reactor fails compiling the JavaSE
  #     port. An earlier version of this workflow set up JDK 8 and then JDK 17,
  #     and since the last setup-java wins it silently built everything on 17.
  #   * macOS arm64 runners have no Temurin 8 at all -- setup-java reports
  #     "Could not find satisfied version for SemVer 8", the oldest offered
  #     being 11.
  #
  # The container is the same one pr.yml uses, which bakes JDK 8 and a
  # cn1-binaries snapshot.
  framework:
    name: framework
    runs-on: ubuntu-latest
    container: ghcr.io/codenameone/codenameone/pr-ci-container:latest
    timeout-minutes: 90
    steps:
      - uses: actions/checkout@v4

      - name: Link cn1-binaries
        run: ln -s /opt/cn1-binaries ../cn1-binaries

      # The container supplies JAVA_HOME_8 and JAVA_HOME_17; this is how pr.yml
      # selects between them. Not setup-java, which would download a second JDK
      # into an image that already has the right ones, and not a hard-coded
      # path -- an earlier version of this guessed
      # /usr/lib/jvm/java-8-openjdk-amd64 and the build died on "The JAVA_HOME
      # environment variable is not defined correctly", which says nothing
      # about which JDK was wanted or what was there.
      - name: Check the container's JDKs
        run: |
          for var in JAVA_HOME_8 JAVA_HOME_17; do
            eval "path=\${$var:-}"
            if [ -z "$path" ] || [ ! -x "$path/bin/javac" ]; then
              echo "$var is unset or has no javac: '${path:-<unset>}'" >&2
              exit 1
            fi
            echo "$var=$path"
          done

      # JDK 8 for everything that targets it. The flutter modules are NOT in
      # this reactor: maven/pom.xml puts them behind a profile that activates
      # on JDK 17 and newer, precisely because they cannot compile here.
      - name: Build the framework on JDK 8
        run: |
          cd maven
          # -Plocal-dev-javase is required to build the JavaSE port, which
          # -am pulls in. Without it the build dies in javase's
          # cn1-generate-build-hint-data execution, which is a long way from
          # anything this workflow is about.
          # Through retry.sh, like every other Maven step in this repository: Central
          # throttles runners with 403/429, and a bare mvn failed this job twice in
          # one day at resolving org.junit:junit-bom before compiling anything.
          JAVA_HOME="$JAVA_HOME_8" bash ../scripts/ci/retry.sh mvn -B -q install -DskipTests \
              -Dmaven.javadoc.skip=true -Dmaven.source.skip=true \
              -Plocal-dev-javase \
              -Dmaven.repo.local="$GITHUB_WORKSPACE/m2" \
              -pl core,dart-transpiler,codenameone-maven-plugin,cn1app-archetype -am

      # Without -am: everything these depend on was installed by the pass
      # above, and re-resolving it here would rebuild core on the wrong JDK.
      - name: Build the Flutter runtime on JDK 17
        run: |
          cd maven
          JAVA_HOME="$JAVA_HOME_17" bash ../scripts/ci/retry.sh mvn -B -q install -DskipTests \
              -Dmaven.javadoc.skip=true -Dmaven.source.skip=true \
              -Plocal-dev-javase \
              -Dmaven.repo.local="$GITHUB_WORKSPACE/m2" \
              -pl dart-runtime,flutter-runtime

      - name: Pack the repository
        run: tar -C "$GITHUB_WORKSPACE" -czf framework-m2.tgz m2

      - name: Upload the repository
        uses: actions/upload-artifact@v4
        with:
          name: flutter-bench-framework
          path: framework-m2.tgz
          retention-days: 1

  # The platforms to measure. Every one on a pull request or the nightly run; on a
  # manual dispatch, the ones its `platforms` input names. The input used to be
  # read by nothing, so asking to re-run one platform launched all six -- several
  # of them two-hour native builds.
  plan:
    name: plan
    runs-on: ubuntu-latest
    outputs:
      include: ${{ steps.pick.outputs.include }}
    steps:
      - id: pick
        env:
          REQUESTED: ${{ github.event_name == 'workflow_dispatch' && inputs.platforms || 'all' }}
        shell: python3 {0}
        run: |
          import json, os, sys
          ALL = [
              {"platform": "macos", "runner": "macos-latest"},
              {"platform": "ios", "runner": "macos-latest"},
              {"platform": "android", "runner": "ubuntu-latest"},
              {"platform": "linux", "runner": "ubuntu-latest"},
              # PINNED, like FLUTTER_REF and for the same reason. windows-latest
              # is Server 2025 and its Visual Studio has moved to 2026 (major
              # 18), which Flutter 3.35.4 predates: it detects that install and
              # reports it healthy, then maps it to no generator it knows and
              # emits "Visual Studio 16 2019" instead. Pinning Flutter without
              # pinning the toolchain it has to drive only moved the moving part.
              {"platform": "windows", "runner": "windows-2022"},
              {"platform": "javascript", "runner": "ubuntu-latest"},
          ]
          requested = os.environ.get("REQUESTED", "").strip().lower()
          if requested in ("", "all"):
              chosen = ALL
          else:
              names = [n.strip() for n in requested.split(",") if n.strip()]
              known = {p["platform"] for p in ALL}
              unknown = [n for n in names if n not in known]
              if unknown or not names:
                  # Loud, not an empty matrix: a typo must not "succeed" by measuring nothing.
                  sys.exit("unknown platform(s) %s; choose from %s, or all"
                           % (", ".join(unknown) or "<none>", ", ".join(sorted(known))))
              chosen = [p for p in ALL if p["platform"] in names]
          print("measuring: " + ", ".join(p["platform"] for p in chosen))
          with open(os.environ["GITHUB_OUTPUT"], "a") as out:
              out.write("include=" + json.dumps(chosen) + "\n")

  measure:
    name: ${{ matrix.platform }}
    needs: [framework, plan]
    runs-on: ${{ matrix.runner }}
    timeout-minutes: 120
    env:
      # Which pull request's overlay (scripts/flutter-bench/baseline/pr/<N>.json) is
      # this run's own: a stale own overlay is judged around, not refused, and the
      # printed calibrate command names it. A dispatched run asks gh for the branch's.
      CN1_PR_NUMBER: ${{ github.event.pull_request.number }}
      GH_TOKEN: ${{ github.token }}
    strategy:
      # One platform failing must not hide the others: a benchmark that
      # publishes nothing because a single runner broke is worse than one that
      # publishes five platforms and says the sixth did not run.
      fail-fast: false
      matrix:
        include: ${{ fromJson(needs.plan.outputs.include) }}

    steps:
      - uses: actions/checkout@v4

      # JDK 17 only. Nothing here builds the framework, so nothing here needs
      # the JDK 8 that is unavailable on an arm64 macOS runner anyway.
      - name: Set up JDK 17
        uses: actions/setup-java@v4
        with:
          distribution: temurin
          java-version: 17

      - name: Download the framework
        uses: actions/download-artifact@v4
        with:
          name: flutter-bench-framework

      - name: Unpack the framework
        shell: bash
        run: tar -xzf framework-m2.tgz

      # A full SDK CHECKOUT, not a release archive. The benchmark's application
      # is dev/integration_tests/new_gallery inside the SDK, and the published
      # release archives do not carry dev/ at all -- so the usual setup actions,
      # which unpack a release, leave prepare.sh with nothing to copy. Cloning
      # the SDK is also what pins the reference: the revision is recorded in
      # every result, so a number can be traced to the Flutter that produced it.
      - name: Check out the Flutter SDK
        shell: bash
        run: |
          git clone --depth 1 --branch "$FLUTTER_REF" \
              https://github.com/flutter/flutter.git "$RUNNER_TEMP/flutter"
          echo "$RUNNER_TEMP/flutter/bin" >> "$GITHUB_PATH"
          echo "FLUTTER_ROOT=$RUNNER_TEMP/flutter" >> "$GITHUB_ENV"

      - name: Report the toolchain, and prove the gallery is present
        shell: bash
        run: |
          flutter --version
          flutter precache
          test -d "$FLUTTER_ROOT/dev/integration_tests/new_gallery/lib" || {
            echo "this Flutter checkout has no gallery; prepare.sh cannot run" >&2
            exit 1; }
          echo "gallery Dart files: $(find "$FLUTTER_ROOT/dev/integration_tests/new_gallery/lib" -name '*.dart' | wc -l)"
          test -f "$FLUTTER_ROOT/pubspec.lock" || {
            echo "the SDK checkout has no root pubspec.lock; prepare.sh needs it" >&2
            echo "to hold the gallery's unpinned dependencies at tested versions" >&2
            exit 1; }

      # A benchmark records the toolchain it measured with; on Windows it also
      # has to CHECK it. Flutter picks the CMake generator from the Visual
      # Studio it detects and falls back to "Visual Studio 16 2019" when it
      # detects NONE -- so an undetected Visual Studio does not say so. It fails
      # minutes later inside CMake, claiming VS 2019 could not be found, which
      # is true and is not the problem. vswhere's own view is printed beside
      # Flutter's so the two can be compared: a Visual Studio that vswhere lists
      # and Flutter does not is a different fault from one that is simply absent.
      - name: Report the Windows toolchain, and prove Flutter can see it
        if: ${{ runner.os == 'Windows' }}
        shell: bash
        run: |
          VS_VERSION=""
          VSWHERE="/c/Program Files (x86)/Microsoft Visual Studio/Installer/vswhere.exe"
          if [ -x "$VSWHERE" ]; then
            echo "== vswhere sees:"
            VS_VERSION="$("$VSWHERE" -products '*' -prerelease -format value \
                -property installationVersion 2>/dev/null | head -1)"
            echo "${VS_VERSION:-<none>}"
            "$VSWHERE" -products '*' -prerelease -format value \
                -property installationPath || true
          else
            echo "== vswhere is not installed at the usual path"
          fi
          echo "== flutter doctor:"
          flutter doctor -v 2>&1 | tee /tmp/doctor.txt || true
          # Checking that Flutter can MAP the install, not that it can see one.
          # Presence is the wrong question: doctor reported
          # "[OK] Visual Studio - develop Windows apps (Visual Studio Enterprise
          # 2026 18.9.2)" on the very run this replaces, and the build then died
          # in CMake. flutter_tools/lib/src/windows/visual_studio.dart maps major
          # 17 and nothing else; every other major, detected or not, silently
          # becomes the "Visual Studio 16 2019" generator. Update SUPPORTED_VS
          # when FLUTTER_REF moves, and note that it is the CMake generator
          # mapping that decides, not what doctor is willing to tick.
          SUPPORTED_VS=17
          MAJOR="$(printf '%s' "$VS_VERSION" | cut -d. -f1)"
          if [ -z "$MAJOR" ] || [ "$MAJOR" != "$SUPPORTED_VS" ]; then
            echo "This runner's Visual Studio is major '${MAJOR:-none}', and Flutter" >&2
            echo "$FLUTTER_REF only maps major $SUPPORTED_VS to a CMake generator." >&2
            echo "It would fall back to 'Visual Studio 16 2019' and fail inside" >&2
            echo "CMake rather than here -- naming a version nobody asked for." >&2
            echo "Pin the runner image to one carrying Visual Studio" >&2
            echo "$SUPPORTED_VS, or move FLUTTER_REF and re-record baselines." >&2
            exit 1
          fi

      # Flutter's own Linux build and Codename One's native Linux port both
      # BOTH sides need a native toolchain here, and they need different
      # things. Flutter's desktop build wants clang and a C++ standard library;
      # the Codename One side compiles the native Linux port, whose CMakeLists
      # resolves the whole GTK/GStreamer/WebKit stack through pkg_check_modules
      # and stops at the first one missing. The shared script is that stack --
      # an ad-hoc subset here configured far enough to fail on libcurl, several
      # minutes into a build that had already transpiled and compiled.
      - name: Install the Linux desktop toolchain
        if: ${{ matrix.platform == 'linux' }}
        run: bash scripts/ci/install-linux-native-deps.sh clang libstdc++-12-dev

      # The Codename One build opens an AWT window (its CSS compiler), so a
      # headless runner fails inside `cn1:css` after the transpile has already
      # succeeded. build_apps.sh wraps Maven in xvfb-run on Linux and refuses
      # to run without it rather than failing later and less legibly. The
      # helper short-circuits when the image already ships xvfb, which these
      # usually do.
      - name: Install xvfb
        if: ${{ runner.os == 'Linux' }}
        run: bash scripts/ci/apt-get-install.sh xvfb

      - name: Prepare both applications from one source
        shell: bash
        run: |
          scripts/flutter-bench/app/prepare.sh \
              --work "${RUNNER_TEMP}/fbench" \
              --maven-repo "${GITHUB_WORKSPACE}/m2"

      - name: Build both applications
        id: build
        shell: bash
        run: |
          scripts/flutter-bench/app/build_apps.sh \
              --work "${RUNNER_TEMP}/fbench" \
              --platform "${{ matrix.platform }}" \
              --maven-repo "${GITHUB_WORKSPACE}/m2" | tee "${RUNNER_TEMP}/paths.txt"
          grep '^cn1='     "${RUNNER_TEMP}/paths.txt" >> "$GITHUB_OUTPUT"
          grep '^flutter=' "${RUNNER_TEMP}/paths.txt" >> "$GITHUB_OUTPUT"

      # Every leg runs the same measure.sh; the legs differ only in what wraps it.
      #
      # Linux runs under Xvfb because both applications are GTK programs that
      # need a display. build_apps.sh's xvfb-run does not help here: it lives
      # exactly as long as the Maven build it wraps, so the Measure step started
      # with no display at all and the adapter reported the platform
      # unavailable after both applications had built.
      - name: Measure
        if: ${{ matrix.platform != 'android' }}
        shell: bash
        run: |
          prefix=""
          if [ "$RUNNER_OS" = "Linux" ]; then
            prefix="xvfb-run -a"
          fi
          $prefix scripts/flutter-bench/app/measure.sh "${{ matrix.platform }}" \
              "${{ steps.build.outputs.cn1 }}" "${{ steps.build.outputs.flutter }}" \
              "${RUNNER_TEMP}/bench-out"

      # Android needs a device. A hosted runner has none, so the adapter found no
      # emulator and recorded the whole platform as unavailable after building
      # both APKs. Same emulator, API level and image as the Android port's own
      # instrumentation leg (scripts-android.yml).
      - name: Enable KVM for the Android emulator
        if: ${{ matrix.platform == 'android' }}
        run: |
          echo 'KERNEL=="kvm", GROUP="kvm", MODE="0666", OPTIONS+="static_node=kvm"' | sudo tee /etc/udev/rules.d/99-kvm4all.rules
          sudo udevadm control --reload-rules
          sudo udevadm trigger --name-match=kvm

      - name: Measure on an Android emulator
        if: ${{ matrix.platform == 'android' }}
        uses: reactivecircus/android-emulator-runner@v2
        with:
          api-level: 36
          arch: x86_64
          target: google_apis
          disk-size: 4096M
          # One line: the action runs each line of `script` in its own shell.
          script: scripts/flutter-bench/app/measure.sh android "${{ steps.build.outputs.cn1 }}" "${{ steps.build.outputs.flutter }}" "${{ runner.temp }}/bench-out"

      # The result and the baseline candidate measured from it. The candidate is
      # what `flutter_baseline.py calibrate --pr N` reads to write the pull
      # request's overlay when a row moved, so it travels with the result rather
      # than having to be re-derived.
      - name: Upload the result
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: flutter-bench-${{ matrix.platform }}
          path: |
            ${{ runner.temp }}/bench-out/result-${{ matrix.platform }}.json
            ${{ runner.temp }}/bench-out/baseline-${{ matrix.platform }}.json
          if-no-files-found: warn

  publish:
    name: Publish
    needs: measure
    # always(), so a platform that regressed still gets its numbers in front of
    # a reviewer. The `measure` jobs already carry the red status; hiding the
    # comment as well would leave the failure with no explanation attached.
    if: always()
    runs-on: ubuntu-latest
    # Read-only contents: on a pull request this job runs the pull request's own
    # files (run_bench.py, publish-quality-comment.js with an authenticated
    # client), so it must never hold a token that can write the repository. The
    # master-only publication that needs contents: write is its own job,
    # publish-status, which a pull_request event never reaches. Job permissions
    # replace the workflow's, so the comment's permission is restated.
    permissions:
      contents: read
      pull-requests: write
    steps:
      - uses: actions/checkout@v4

      - name: Collect every platform's result
        uses: actions/download-artifact@v4
        with:
          pattern: flutter-bench-*
          path: results
          merge-multiple: true

      - name: Render the comment
        run: |
          python3 scripts/flutter-bench/run_bench.py \
              --render 'results/result-*.json' \
              --markdown flutter-benchmark.md
          cat flutter-benchmark.md

      - name: Publish the benchmark comment
        if: ${{ github.event_name == 'pull_request' && hashFiles('flutter-benchmark.md') != '' }}
        uses: actions/github-script@v9
        with:
          retries: 3
          script: |
            const { publishQualityComment } = require('./.github/scripts/publish-quality-comment.js');
            await publishQualityComment({
              github, context, core,
              marker: '<!-- flutter-benchmark -->',
              reportPath: 'flutter-benchmark.md',
            });

      - name: Upload the rendered report
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: flutter-benchmark-report
          path: flutter-benchmark.md

  # The only job holding contents: write. It runs for a scheduled or dispatched
  # run of master alone -- never for a pull_request event -- so the code it
  # executes is master's, not a contributor's.
  publish-status:
    name: Publish port status
    needs: measure
    # Only a run of every platform: port status shows all of them, and a dispatch
    # for a subset would publish a table missing the rest.
    if: >-
      always() &&
      github.event_name != 'pull_request' &&
      github.ref == 'refs/heads/master' &&
      (github.event_name == 'schedule' ||
       (github.event_name == 'workflow_dispatch' && (inputs.platforms == 'all' || inputs.platforms == '')))
    runs-on: ubuntu-latest
    permissions:
      contents: write
    steps:
      - uses: actions/checkout@v4

      - name: Collect every platform's result
        uses: actions/download-artifact@v4
        with:
          pattern: flutter-bench-*
          path: results
          merge-multiple: true

      # Published to the data branch the website build reads, the way every
      # port's own status is. Writing it into docs/website in this job's
      # checkout, as this step used to, put it where nothing would ever see it:
      # the checkout is discarded when the job ends and nothing committed it.
      # Master-only, like the port reports, so a branch's numbers never reach
      # the public page.
      - name: Publish the benchmark to the port status data
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          python3 scripts/flutter-bench/port_status.py \
              --results 'results/result-*.json' \
              --out "${RUNNER_TEMP}/port-status"
          python3 scripts/flutter-bench/publish_benchmark.py \
              "${RUNNER_TEMP}/port-status/flutter_benchmark.json" "${{ github.repository }}"