Make writing and reading flag file arguments interruptible.

Looking into this also pointed out that input prefetching should be interruptible, but that's a larger piece of work.

PiperOrigin-RevId: 523984388
Change-Id: I82d96593a85e92beb37497230738bf6b223ddd22

src/main/java/com/google/devtools/build/lib/sandbox/SandboxHelpers.java

@@ -452,7 +452,7 @@ public SandboxInputs processInputFiles(
       Path withinSandboxExecRootPath,
       ImmutableList<Root> packageRoots,
       Path sandboxSourceRoots)
-      throws IOException {
+      throws IOException, InterruptedException {
     Root withinSandboxExecRoot = Root.fromPath(withinSandboxExecRootPath);
     Root execRoot =
         withinSandboxExecRootPath.equals(execRootPath)
@@ -465,6 +465,9 @@ public SandboxInputs processInputFiles(
     Map<Root, Root> sourceRootToSandboxSourceRoot = new TreeMap<>();
 
     for (Map.Entry<PathFragment, ActionInput> e : inputMap.entrySet()) {
+      if (Thread.interrupted()) {
+        throw new InterruptedException();
+      }
       PathFragment pathFragment = e.getKey();
       ActionInput actionInput = e.getValue();
       if (actionInput instanceof VirtualActionInput) {

src/main/java/com/google/devtools/build/lib/worker/WorkerSpawnRunner.java

@@ -243,7 +243,7 @@ private WorkRequest createWorkRequest(
       Map<VirtualActionInput, byte[]> virtualInputDigests,
       InputMetadataProvider inputFileCache,
       WorkerKey key)
-      throws IOException {
+      throws IOException, InterruptedException {
     WorkRequest.Builder requestBuilder = WorkRequest.newBuilder();
     for (String flagfile : flagfiles) {
       expandArgument(execRoot, flagfile, requestBuilder);
@@ -298,8 +298,11 @@ private WorkRequest createWorkRequest(
    * @throws java.io.IOException if one of the files containing options cannot be read.
    */
   static void expandArgument(Path execRoot, String arg, WorkRequest.Builder requestBuilder)
-      throws IOException {
+      throws IOException, InterruptedException {
     if (arg.startsWith("@") && !arg.startsWith("@@") && !isExternalRepositoryLabel(arg)) {
+      if (Thread.interrupted()) {
+        throw new InterruptedException();
+      }
       String argValue = arg.substring(1);
       Path path = execRoot.getRelative(argValue);
       try {

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

@@ -171,7 +171,7 @@ protected void setExecutable(PathFragment path, boolean executable) throws IOExc
                     sandboxHelpers.processInputFiles(
                         inputMap(input), customExecRoot, customExecRoot, ImmutableList.of(), null);
                 finishProcessingSemaphore.release();
-              } catch (IOException e) {
+              } catch (IOException | InterruptedException e) {
                 throw new IllegalArgumentException(e);
               }
             });

src/test/java/com/google/devtools/build/lib/worker/WorkerSpawnRunnerTest.java

@@ -511,7 +511,8 @@ public void testExecInWorker_throwsWithEmptyResponse() throws Exception {
   }
 
   @Test
-  public void testExpandArgument_expandsArgumentsRecursively() throws IOException {
+  public void testExpandArgument_expandsArgumentsRecursively()
+      throws IOException, InterruptedException {
     WorkRequest.Builder requestBuilder = WorkRequest.newBuilder();
     FileSystemUtils.writeIsoLatin1(fs.getPath("/file"), "arg1\n@file2\nmulti arg\n");
     FileSystemUtils.writeIsoLatin1(fs.getPath("/file2"), "arg2\narg3");
@@ -521,7 +522,8 @@ public void testExpandArgument_expandsArgumentsRecursively() throws IOException
   }
 
   @Test
-  public void testExpandArgument_expandsOnlyProperArguments() throws IOException {
+  public void testExpandArgument_expandsOnlyProperArguments()
+      throws IOException, InterruptedException {
     WorkRequest.Builder requestBuilder = WorkRequest.newBuilder();
     FileSystemUtils.writeIsoLatin1(fs.getPath("/file"), "arg1\n@@nonfile\n@foo//bar\narg2");
     WorkerSpawnRunner.expandArgument(fs.getPath("/"), "@file", requestBuilder);