Merge pull request #318 from graalvm/ni-demos-refactoring-14

[GR-60094] Refactor and move native-list-dir demo under native-image category.

Author: olyagpl

.github/workflows/native-image-list-files.yml

@@ -0,0 +1,35 @@
+name: native-image/list-files
+on:
+  push:
+    paths:
+      - 'native-image/list-files/**'
+      - '.github/workflows/native-image-list-files.yml'
+  pull_request:
+    paths:
+      - 'native-image/list-files/**'
+      - '.github/workflows/native-image-list-files.yml'
+  schedule:
+    - cron: "0 0 1 * *" # run every month
+  workflow_dispatch:
+permissions:
+  contents: read
+jobs:
+  run:
+    name: Run 'native-image/list-files'
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    strategy:
+      matrix:
+        java-version: ['21', '24-ea']
+    steps:
+      - uses: actions/checkout@v4
+      - uses: graalvm/setup-graalvm@v1
+        with:
+          java-version: ${{ matrix.java-version }}
+          distribution: 'graalvm'
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          native-image-job-reports: 'true'
+      - name: Run 'native-image/list-files'
+        run: |
+          cd native-image/list-files
+          ./run.sh

.github/workflows/native-list-dir.yml

@@ -40,7 +40,7 @@ cd graalvm-demos
       <td align="left" width="70%">Demonstrates how to build a modular Java application into a native executable<br><strong>Technologies: </strong>Native Image, Maven<br><strong>Reference: </strong><a href="https://www.graalvm.org/dev/reference-manual/native-image/guides/build-java-modules-into-native-executable/">Build Java Modules into a Native Executable</a></td>
     </tr>
     <tr>
-      <td align="left" width="30%"><a href="/native-list-dir/">native-list-dir</a><br><a href="https://github.com/graalvm/graalvm-demos/actions/workflows/native-list-dir.yml"><img alt="native-list-dir" src="https://github.com/graalvm/graalvm-demos/actions/workflows/native-list-dir.yml/badge.svg" /></a></td>
+      <td align="left" width="30%"><a href="/native-image/list-files/">native-image/list-files</a><br><a href="https://github.com/graalvm/graalvm-demos/actions/workflows/native-image-list-files.yml"><img alt="native-image/list-files" src="https://github.com/graalvm/graalvm-demos/actions/workflows/native-image-list-files.yml/badge.svg"/></a></td>
       <td align="left" width="70%">Demonstrates how to compile a CLI application into a native executable and then apply Profile-Guided Optimizations (PGO) for more performance gains<br><strong>Technologies: </strong>Native Image, PGO
     </tr>
     <tr>

README.md

@@ -0,0 +1,5 @@
+.class
+.iprof
+listdir
+listdir-instrumented
+listdir-optimized

native-image/list-files/.gitignore

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * The Universal Permissive License (UPL), Version 1.0
@@ -67,4 +67,4 @@ public static void main(String[] args) throws java.io.IOException {
 
 		System.out.println("Total: " + count[0] + " files, total size = " + size[0] + " bytes");
 	}
-}
+}

native-list-dir/ListDir.java renamed to native-image/list-files/ListDir.java

@@ -0,0 +1,56 @@
+# Create a Native Executable and Apply Profile-Guided Optimization
+
+This demo shows how to create a native executable with GraalVM Native Image and apply Profile-Guided Optimization (PGO) for more performance gains.
+It uses the Java application that counts files and their sizes in a specified directory.
+
+## Run the Demo
+
+1. Compile the application:
+    ```bash
+    javac ListDir.java
+    ```
+
+2. Generate a native executable from the class file: 
+    ```bash
+    native-image ListDir
+    ```
+    The executable file _listdir_ is created in the directory.
+
+3. Run the application by passing it a directory that actually contains some files, for example `..` (to count files in the parent of the current directory, containing all the demos in this repository). Check the time spent with the `time` utility.
+    - On HotSpot:
+        ```bash
+        time java ListDir ..
+        ```
+    - From a native executable:
+        ```bash
+        time ./listdir ..
+        ```
+
+## Enable PGO
+
+For more performance gains, you can can apply [Profile-Guided Optimization (PGO)](https://www.graalvm.org/latest/reference-manual/native-image/optimizations-and-performance/PGO/). (Not available with GraalVM Community Edition.)
+With PGO you can collect the profiling data, and then feed it to the `native-image` tool, which will use this information to further optimize the performance of the resulting executable.
+
+1. Build an instrumented image from the _ListDir_ class and run it to collect profiles, specifying a different name for the native executable, for example _listdir-instrumented_:
+
+    ```shell
+    native-image --pgo-instrument ListDir -o listdir-instrumented
+    ```
+    ```bash
+    ./listdir-instrumented ..
+    ```
+    Profiles collected from this run are now stored in the `default.iprof` file. 
+
+2. Use the profiles to build an optimized native executable, giving it a different name than in the previous runs:
+    ```shell
+    native-image --pgo ListDir -o listdir-optimized
+    ```
+
+3. Run that optimized executable:
+    ```shell
+    time ./listdir-optimized ..
+    ```
+
+Find more examples at the website:
+- [Optimize a Native Executable with Profile-Guided Optimizations](https://www.graalvm.org/latest/reference-manual/native-image/guides/optimize-native-executable-with-pgo/).
+- [Basic Usage of Profile-Guided Optimization](https://www.graalvm.org/latest/reference-manual/native-image/optimizations-and-performance/PGO/basic-usage/)

native-image/list-files/README.md

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+set -ex
+
+javac ListDir.java
+native-image ListDir
+./listdir ..
+
+native-image -Ob --pgo-instrument ListDir -o listdir-instrumented
+./listdir-instrumented ..
+native-image -Ob --pgo ListDir -o listdir-optimized
+./listdir-optimized ..