From 04066dd70256e511f3715b67cdafc9e0bdbd1e52 Mon Sep 17 00:00:00 2001
From: Saint Wesonga <saint.wesonga@microsoft.com>
Date: Mon, 6 May 2024 19:11:00 -0600
Subject: [PATCH] Read output of GetAvailableProcessors from a temporary file

---
 .../os/windows/GetAvailableProcessors.java        | 15 +++++++++++++--
 .../os/windows/TestAvailableProcessors.java       | 15 ++++++++++++++-
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/test/hotspot/jtreg/runtime/os/windows/GetAvailableProcessors.java b/test/hotspot/jtreg/runtime/os/windows/GetAvailableProcessors.java
index ee7d7c2f42fea..2631521b8d19f 100644
--- a/test/hotspot/jtreg/runtime/os/windows/GetAvailableProcessors.java
+++ b/test/hotspot/jtreg/runtime/os/windows/GetAvailableProcessors.java
@@ -22,8 +22,19 @@
  *
  */
 
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
 public class GetAvailableProcessors {
-  public static void main(String[] args) {
-    System.out.println("Runtime.availableProcessors: " + Runtime.getRuntime().availableProcessors());
+  public static void main(String[] args) throws IOException {
+    String message = "Runtime.availableProcessors: " + Runtime.getRuntime().availableProcessors();
+    System.out.println(message);
+
+    if (args.length > 0) {
+      Path filePath = Path.of(args[0]);
+      Files.writeString(filePath, message, StandardCharsets.UTF_8);
+    }
   }
 }
diff --git a/test/hotspot/jtreg/runtime/os/windows/TestAvailableProcessors.java b/test/hotspot/jtreg/runtime/os/windows/TestAvailableProcessors.java
index 963f286455afa..9797e73704c18 100644
--- a/test/hotspot/jtreg/runtime/os/windows/TestAvailableProcessors.java
+++ b/test/hotspot/jtreg/runtime/os/windows/TestAvailableProcessors.java
@@ -38,6 +38,8 @@
  */
 
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayList;
@@ -178,8 +180,12 @@ private static void verifyAvailableProcessorsFromStartAffinity(boolean productFl
 
         String productFlag = productFlagEnabled ? "-XX:+UseAllWindowsProcessorGroups" : "-XX:-UseAllWindowsProcessorGroups";
 
+        // Write output of GetAvailableProcessors to a temporary file
+        Path outputFile = Files.createTempFile(Paths.get("."), TestAvailableProcessors.class.getSimpleName(), ".tmp");
+        String outputFilePath = outputFile.toString();
+
         ProcessBuilder processBuilder = ProcessTools.createLimitedTestJavaProcessBuilder(
-            new String[] {productFlag, "GetAvailableProcessors"}
+            new String[] {productFlag, "GetAvailableProcessors", outputFilePath}
         );
 
         String javaCommandLine = ProcessTools.getCommandLine(processBuilder);
@@ -192,6 +198,13 @@ private static void verifyAvailableProcessorsFromStartAffinity(boolean productFl
 
         var outputAnalyzer = new OutputAnalyzer(processBuilder.start());
         outputAnalyzer.shouldHaveExitValue(0);
+
+        // Read the output of GetAvailableProcessors from the temporary file
+        byte[] bytesFromFile = Files.readAllBytes(outputFile);
+        String fileContent = new String(bytesFromFile, StandardCharsets.UTF_8);
+        System.out.println("GetAvailableProcessors output: " + fileContent);
+
+        outputAnalyzer = new OutputAnalyzer(fileContent);
         outputAnalyzer.shouldContain(runtimeAvailableProcessorsMessage);
 
         int runtimeAvailableProcs = getAvailableProcessors(outputAnalyzer);