Manage java.io.tmpdir better to make multi-process test pass reliably, move ProcessRunner into tests where it belongs

Author: nicktindall

affinity/src/test/java/net/openhft/affinity/FileLockLockCheckTest.java

@@ -18,10 +18,7 @@
 package net.openhft.affinity;
 
 import net.openhft.affinity.testimpl.TestFileLockBasedLockChecker;
-import org.junit.Assert;
-import org.junit.Assume;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.*;
 
 import java.io.File;
 import java.io.IOException;
@@ -54,6 +51,11 @@ public void before() {
         System.setProperty("java.io.tmpdir", TARGET + "/" + System.nanoTime());
     }
 
+    @After
+    public void after() {
+        System.setProperty("java.io.tmpdir", TMP);
+    }
+
     @Test
     public void test() throws IOException {
         Assert.assertTrue(LockCheck.isCpuFree(cpu));

affinity/src/test/java/net/openhft/affinity/LockCheckTest.java

@@ -18,10 +18,7 @@
 package net.openhft.affinity;
 
 import net.openhft.affinity.testimpl.TestFileBasedLockChecker;
-import org.junit.Assert;
-import org.junit.Assume;
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.*;
 
 import java.io.File;
 import java.io.FileWriter;
@@ -55,6 +52,11 @@ public void before() {
         System.setProperty("java.io.tmpdir", TARGET + "/" + System.nanoTime());
     }
 
+    @After
+    public void after() {
+        System.setProperty("java.io.tmpdir", TMP);
+    }
+
     @Test
     public void test() throws IOException {
         Assert.assertTrue(LockCheck.isCpuFree(cpu));

affinity/src/test/java/net/openhft/affinity/MultiProcessAffinityTest.java

@@ -2,8 +2,8 @@
 
 import net.openhft.affinity.common.ProcessRunner;
 import net.openhft.affinity.lockchecker.FileLockBasedLockChecker;
-import org.junit.Assume;
-import org.junit.Test;
+import org.junit.*;
+import org.junit.rules.TemporaryFolder;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -16,11 +16,28 @@
 
 public class MultiProcessAffinityTest {
 
+    @Rule
+    public TemporaryFolder folder = new TemporaryFolder();
+    private String originalTmpDir;
+
+    @Before
+    public void setUp() {
+        originalTmpDir = System.getProperty("java.io.tmpdir");
+        System.setProperty("java.io.tmpdir", folder.getRoot().getAbsolutePath());
+    }
+
+    @After
+    public void tearDown() {
+        System.setProperty("java.io.tmpdir", originalTmpDir);
+    }
+
     @Test
     public void shouldNotAcquireLockOnCoresLockedByOtherProcesses() throws IOException, InterruptedException {
         Assume.assumeTrue(IS_LINUX);
         // run the separate affinity locker
-        final Process affinityLockerProcess = ProcessRunner.runClass(AffinityLockerProcess.class, "last");
+        final Process affinityLockerProcess = ProcessRunner.runClass(AffinityLockerProcess.class,
+                new String[]{"-Djava.io.tmpdir=" + folder.getRoot().getAbsolutePath()},
+                new String[]{"last"});
         try {
             int lastCpuId = AffinityLock.PROCESSORS - 1;
 

…enhft/affinity/common/ProcessRunner.java …enhft/affinity/common/ProcessRunner.javaaffinity/src/main/java/net/openhft/affinity/common/ProcessRunner.java renamed to affinity/src/test/java/net/openhft/affinity/common/ProcessRunner.java affinity/src/main/java/net/openhft/affinity/common/ProcessRunner.java renamed to affinity/src/test/java/net/openhft/affinity/common/ProcessRunner.java

@@ -29,6 +29,19 @@ public class ProcessRunner {
      * @throws IOException if there is an error starting the process
      */
     public static Process runClass(Class<?> clazz, String... args) throws IOException {
+        return runClass(clazz, new String[]{}, args);
+    }
+
+    /**
+     * Spawn a process running the main method of a specified class
+     *
+     * @param clazz       The class to execute
+     * @param jvmArgs     Any arguments to pass to the process
+     * @param programArgs Any arguments to pass to the process
+     * @return the Process spawned
+     * @throws IOException if there is an error starting the process
+     */
+    public static Process runClass(Class<?> clazz, String[] jvmArgs, String[] programArgs) throws IOException {
         // Because Java17 must be run using various module flags, these must be propagated
         // to the child processes
         // https://stackoverflow.com/questions/1490869/how-to-get-vm-arguments-from-inside-of-java-application
@@ -46,10 +59,11 @@ public static Process runClass(Class<?> clazz, String... args) throws IOExceptio
         List<String> allArgs = new ArrayList<>();
         allArgs.add(javaBin);
         allArgs.addAll(jvmArgsWithoutJavaAgents);
+        allArgs.addAll(Arrays.asList(jvmArgs));
         allArgs.add("-cp");
         allArgs.add(classPath);
         allArgs.add(className);
-        allArgs.addAll(Arrays.asList(args));
+        allArgs.addAll(Arrays.asList(programArgs));
         ProcessBuilder processBuilder = new ProcessBuilder(allArgs.toArray(new String[]{}));
 //        processBuilder.inheritIO(); // this doesn't place nice with surefire
         return processBuilder.start();