Create TestUtils methods to generate unique temp dirs, deprecate the …

…current ones that are decidedly non-unique.

Unique temp dirs may take longer to set up, but not as long as dealing with flaky tests.

PiperOrigin-RevId: 345428489

src/java_tools/junitrunner/javatests/com/google/testing/junit/runner/sharding/ShardingEnvironmentTest.java

@@ -18,6 +18,7 @@
 
 import com.google.devtools.build.lib.testutil.TestUtils;
 import java.io.File;
+import java.io.IOException;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -28,8 +29,8 @@ public class ShardingEnvironmentTest {
 
   @SuppressWarnings({"ResultOfMethodCallIgnored"})
   @Test
-  public void testTouchShardingFile() {
-    File shardFile = new File(TestUtils.tmpDirFile(), "shard_file_123");
+  public void testTouchShardingFile() throws IOException {
+    File shardFile = TestUtils.createUniqueTmpDir(null).getChild("shard_file_123").getPathFile();
     assertThat(shardFile.exists()).isFalse();
     try {
       ShardingEnvironment.touchShardFile(shardFile);

src/test/java/com/google/devtools/build/lib/dynamic/DynamicSpawnStrategyTest.java

@@ -61,6 +61,7 @@
 import com.google.devtools.build.lib.vfs.Root;
 import com.google.devtools.build.lib.vfs.util.FileSystems;
 import com.google.devtools.common.options.OptionsParser;
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collection;
@@ -217,8 +218,7 @@ boolean succeeded() {
 
   @Before
   public void setUp() throws Exception {
-    testRoot = FileSystems.getNativeFileSystem().getPath(TestUtils.tmpDir()).getRelative("test");
-    testRoot.deleteTreesBelow();
+    testRoot = TestUtils.createUniqueTmpDir(FileSystems.getNativeFileSystem());
     outErr = new FileOutErr(testRoot.getRelative("stdout"), testRoot.getRelative("stderr"));
   }
 
@@ -400,6 +400,13 @@ public void tearDown() throws Exception {
     if (executorServiceForCleanup != null) {
       executorServiceForCleanup.shutdownNow();
     }
+    if (testRoot != null) {
+      try {
+        testRoot.deleteTree();
+      } catch (FileNotFoundException e) {
+        // This can happen if one of the dynamic threads are still cleaning up. No big deal.
+      }
+    }
   }
 
   /** Constructs a new spawn with a custom mnemonic and execution info. */

src/test/java/com/google/devtools/build/lib/exec/local/LocalSpawnRunnerTest.java

@@ -640,10 +640,7 @@ public void waitFor() throws InterruptedException {
   public void interruptWaitsForProcessExit() throws Exception {
     assumeTrue(OS.getCurrent() != OS.WINDOWS);
 
-    File tempDirFile = TestUtils.makeTempDir();
-    tempDirFile.deleteOnExit();
-    FileSystem fs = new JavaIoFileSystem(DigestHashFunction.SHA256);
-    Path tempDir = fs.getPath(tempDirFile.getPath());
+    Path tempDir = TestUtils.createUniqueTmpDir(new JavaIoFileSystem(DigestHashFunction.SHA256));
 
     LocalSpawnRunner runner =
         new LocalSpawnRunner(
@@ -852,10 +849,7 @@ private Path copyCpuTimeSpenderIntoExecRoot(Path execRoot) throws IOException {
   }
 
   private Path getTemporaryRoot(FileSystem fs, String name) throws IOException {
-    File tempDirFile = TestUtils.makeTempDir();
-    tempDirFile.deleteOnExit();
-
-    Path tempDirPath = fs.getPath(tempDirFile.getPath());
+    Path tempDirPath = TestUtils.createUniqueTmpDir(fs);
     assertThat(tempDirPath.exists()).isTrue();
 
     Path root = tempDirPath.getRelative(name);

src/test/java/com/google/devtools/build/lib/sandbox/SandboxfsSandboxedSpawnTest.java

@@ -46,8 +46,7 @@ public class SandboxfsSandboxedSpawnTest {
   @Before
   public final void setupTestDirs() throws IOException {
     FileSystem fileSystem = new InMemoryFileSystem(DigestHashFunction.SHA256);
-    testRoot = fileSystem.getPath(TestUtils.tmpDir());
-    testRoot.createDirectoryAndParents();
+    testRoot = TestUtils.createUniqueTmpDir(fileSystem);
 
     workspaceDir = testRoot.getRelative("workspace");
     workspaceDir.createDirectory();

src/test/java/com/google/devtools/build/lib/shell/CommandUsingLinuxSandboxTest.java

@@ -93,7 +93,7 @@ private void checkLinuxSandboxStatistics(Duration userTimeToSpend, Duration syst
             Long.toString(userTimeToSpend.getSeconds()),
             Long.toString(systemTimeToSpend.getSeconds()));
 
-    Path outputDir = testFS.getPath(TestUtils.makeTempDir().getCanonicalPath());
+    Path outputDir = TestUtils.createUniqueTmpDir(testFS);
     Path statisticsFilePath = outputDir.getRelative("stats.out");
 
     List<String> fullCommandLine =

src/test/java/com/google/devtools/build/lib/shell/CommandUsingProcessWrapperTest.java

@@ -88,7 +88,7 @@ private void checkProcessWrapperStatistics(Duration userTimeToSpend, Duration sy
             Long.toString(userTimeToSpend.getSeconds()),
             Long.toString(systemTimeToSpend.getSeconds()));
 
-    Path outputDir = testFS.getPath(TestUtils.makeTempDir().getCanonicalPath());
+    Path outputDir = TestUtils.createUniqueTmpDir(testFS);
     Path statisticsFilePath = outputDir.getRelative("stats.out");
 
     List<String> fullCommandLine =

src/test/java/com/google/devtools/build/lib/shell/ExecutionStatisticsTest.java

@@ -38,8 +38,7 @@ public final class ExecutionStatisticsTest {
   @Before
   public final void createFileSystem() throws Exception {
     FileSystem testFS = new InMemoryFileSystem(DigestHashFunction.SHA256);
-    workingDir = testFS.getPath(TestUtils.makeTempDir().getCanonicalPath());
-    workingDir.createDirectoryAndParents();
+    workingDir = TestUtils.createUniqueTmpDir(testFS);
   }
 
   private Path createExecutionStatisticsProtoFile(

src/test/java/com/google/devtools/build/lib/testutil/BUILD

@@ -113,6 +113,9 @@ java_library(
 java_library(
     name = "TestUtils",
     srcs = ["TestUtils.java"],
+    deps = [
+        "//src/main/java/com/google/devtools/build/lib/vfs",
+    ],
 )
 
 java_library(

src/test/java/com/google/devtools/build/lib/testutil/TestUtils.java

@@ -14,6 +14,10 @@
 
 package com.google.devtools.build.lib.testutil;
 
+import com.google.devtools.build.lib.vfs.DigestHashFunction;
+import com.google.devtools.build.lib.vfs.FileSystem;
+import com.google.devtools.build.lib.vfs.JavaIoFileSystem;
+import com.google.devtools.build.lib.vfs.Path;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
@@ -49,8 +53,14 @@ public static ThreadPoolExecutor getPool() {
     return POOL;
   }
 
+  /**
+   * Returns the path to a fixed temporary directory, with back-slashes turned into slashes. The
+   * directory is guaranteed to exist and be unique for the test <em>target</em>. Since test
+   * <em>cases</em> may run in parallel, prefer using {@link #createUniqueTmpDir} instead, which
+   * also guarantees that the directory is empty.
+   */
   public static String tmpDir() {
-    return tmpDirFile().getAbsolutePath().replaceAll("\\\\", "/");
+    return tmpDirFile().getAbsolutePath().replace('\\', '/');
   }
 
   static String getUserValue(String key) {
@@ -61,10 +71,48 @@ static String getUserValue(String key) {
     return value;
   }
 
+  /**
+   * Returns a fixed temporary directory, guaranteed to exist and be unique for the test
+   * <em>target</em>. Since test <em>cases</em> may run in parallel, prefer using {@link
+   * #createUniqueTmpDir} instead, which also guarantees that the directory is empty.
+   */
   public static File tmpDirFile() {
-    File tmpDir;
+    File tmpDir = tmpDirRoot();
+
+    // Ensure tmpDir exists
+    if (!tmpDir.isDirectory()) {
+      tmpDir.mkdirs();
+    }
+    return tmpDir;
+  }
+
+  /**
+   * Creates a unique and empty temporary directory.
+   *
+   * @param fileSystem The file system the directory should be created on. If null, uses the Java
+   *     file system.
+   * @return A newly created directory, extremely likely to be unique.
+   */
+  public static Path createUniqueTmpDir(FileSystem fileSystem) throws IOException {
+    if (fileSystem == null) {
+      fileSystem = new JavaIoFileSystem(DigestHashFunction.SHA256);
+    }
+    File tmpDirRoot = tmpDirRoot();
+    Path path = fileSystem.getPath(tmpDirRoot.getPath()).getRelative(UUID.randomUUID().toString());
+    path.createDirectoryAndParents();
+    return path;
+  }
 
-    // Flag value specified in environment?
+  /**
+   * Creates a unique and empty temporary directory and returns the path, with backslashes turned
+   * into slashes.
+   */
+  public static String createUniqueTmpDirString() throws IOException {
+    return createUniqueTmpDir(null).getPathString().replace('\\', '/');
+  }
+
+  private static File tmpDirRoot() {
+    File tmpDir; // Flag value specified in environment?
     String tmpDirStr = getUserValue("TEST_TMPDIR");
 
     if (tmpDirStr != null && tmpDirStr.length() > 0) {
@@ -82,15 +130,10 @@ public static File tmpDirFile() {
       tmpDir = new File(tmpDir, username);
       tmpDir = new File(tmpDir, "tmp");
     }
-
-    // Ensure tmpDir exists
-    if (!tmpDir.isDirectory()) {
-      tmpDir.mkdirs();
-    }
     return tmpDir;
   }
 
-  public static File makeTempDir() throws IOException {
+  public static File makeTmpDir() throws IOException {
     File dir = File.createTempFile(TestUtils.class.getName(), ".temp", tmpDirFile());
     if (!dir.delete()) {
       throw new IOException("Cannot remove a temporary file " + dir);