Record correct exit code for uncaught exceptions in async threads.

Async threads are divorced from the server's error-reporting mechanism. In the event
of a server shutdown originating in an async-thread, write the exit code to a file that
can be read by the client.

--
PiperOrigin-RevId: 141920284
MOS_MIGRATED_REVID=141920284

1 files changed, 45 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/util/CustomExitCodePublisher.java b/src/main/java/com/google/devtools/build/lib/util/CustomExitCodePublisher.java
new file mode 100644
index 0000000000..c281f5a1fa
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/util/CustomExitCodePublisher.java
@@ -0,0 +1,45 @@
+// Copyright 2016 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package com.google.devtools.build.lib.util;
+
+import com.google.devtools.build.lib.vfs.FileSystemUtils;
+import com.google.devtools.build.lib.vfs.Path;
+import java.io.IOException;
+import javax.annotation.Nullable;
+
+/**
+ * Provides an external way for the Bazel server to communicate its exit code to the client, when
+ * the main gRPC channel is unavailable because the exit is too abrupt or originated in an async
+ * thread.
+ */
+public class CustomExitCodePublisher {
+  private static final String EXIT_CODE_FILENAME = "exit_code_to_use_on_abrupt_exit";
+  @Nullable private static Path abruptExitCodeFilePath = null;
+
+  public static void setAbruptExitStatusFileDir(Path path) {
+    abruptExitCodeFilePath = path.getChild(EXIT_CODE_FILENAME);
+  }
+
+  public static void maybeWriteExitStatusFile(int exitCode) {
+    if (abruptExitCodeFilePath != null) {
+      try {
+        FileSystemUtils.writeContentAsLatin1(abruptExitCodeFilePath, String.valueOf(exitCode));
+      } catch (IOException ioe) {
+        System.err.printf(
+            "io error writing %d to abrupt exit status file %s: %s\n",
+            exitCode, abruptExitCodeFilePath, ioe.getMessage());
+      }
+    }
+  }
+}