From 3ff46369b93cdd734668d36945cbdda8876d50d2 Mon Sep 17 00:00:00 2001
From: Ashar Fuadi <fushar@gmail.com>
Date: Tue, 28 May 2024 18:58:55 +0700
Subject: [PATCH] grader: try to clean up Isolate box if already exists when
 init-ed (#633)

---
 .../sandboxes/isolate/IsolateSandbox.java     | 42 ++++++++++++-------
 1 file changed, 27 insertions(+), 15 deletions(-)

diff --git a/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/sandboxes/isolate/IsolateSandbox.java b/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/sandboxes/isolate/IsolateSandbox.java
index d020777cf..f9abfe756 100644
--- a/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/sandboxes/isolate/IsolateSandbox.java
+++ b/judgels-backends/judgels-grader-engines/src/main/java/judgels/gabriel/sandboxes/isolate/IsolateSandbox.java
@@ -277,22 +277,34 @@ public SandboxExecutionResult getResult(int exitCode) {
     }
 
     private void initIsolate() {
-        ImmutableList.Builder<String> command = ImmutableList.builder();
-        command.add(isolatePath, "-b" + boxId);
-        command.add("--cg");
-        command.add("--init");
-
-        ProcessBuilder pb = new ProcessBuilder(command.build()).redirectErrorStream(true);
-
-        try {
-            ProcessExecutionResult result = SandboxExecutor.executeProcessBuilder(pb);
-            if (result.getExitCode() != 0) {
+        for (int tries = 0;; tries++) {
+            ImmutableList.Builder<String> command = ImmutableList.builder();
+            command.add(isolatePath, "-b" + boxId);
+            command.add("--cg");
+            command.add("--init");
+
+            ProcessBuilder pb = new ProcessBuilder(command.build()).redirectErrorStream(true);
+
+            try {
+                ProcessExecutionResult result = SandboxExecutor.executeProcessBuilder(pb);
+                if (result.getExitCode() == 0) {
+                    boxDir = new File(result.getOutputLines().get(0), "box");
+                    return;
+                }
+                if (tries < 1) {
+                    String errorMessage = result.getOutputLines().isEmpty() ? "" : result.getOutputLines().get(0);
+                    if (errorMessage.startsWith("Box already exists")) {
+                        // Clean up the box,
+                        cleanUpIsolate();
+
+                        // and try initializing it again.
+                        continue;
+                    }
+                }
                 throw new SandboxException("Cannot initialize Isolate!");
+            } catch (IOException | InterruptedException e) {
+                throw new SandboxException(e);
             }
-
-            boxDir = new File(result.getOutputLines().get(0), "box");
-        } catch (IOException | InterruptedException e) {
-            throw new SandboxException(e);
         }
     }
 
@@ -304,7 +316,7 @@ private void cleanUpIsolate() {
             if (result.getExitCode() != 0) {
                 throw new SandboxException("Cannot clean up Isolate!");
             }
-            if (boxDir.exists()) {
+            if (boxDir != null && boxDir.exists()) {
                 FileUtils.forceDelete(boxDir);
             }
         } catch (IOException | InterruptedException e) {