ensure the gRPC LoggingInterceptor does not throw exceptions where they cannot be handled

This fixes a hang that I've struggled with for ages: when using `--build_event_json_file` to write a BEP file, enabling `--experimental_remote_grpc_log` causes the build to hang indefinitely after completion with a message of "Waiting for build events upload: JsonFormatFileTransport".

The default `--build_event_json_file_path_conversion` ends up doing an RPC call when closing the BEP file. Unfortunately, this call happens after the gRPC log file has already been closed. That exception in the LoggingInterceptor is uncatchable -- it [causes the RPC call to hang indefinitely](https://github.com/grpc/grpc-java/pull/6107). Therefore, Bazel needs to handle and consume the exception so `onClose` always succeeds.

Closes #12416.

PiperOrigin-RevId: 340796218

src/main/java/com/google/devtools/build/lib/remote/logging/BUILD

diff --git a/src/main/java/com/google/devtools/build/lib/remote/logging/BUILD b/src/main/java/com/google/devtools/build/lib/remote/logging/BUILD
index 8cb4b04..46a9b5f 100644
--- a/src/main/java/com/google/devtools/build/lib/remote/logging/BUILD
+++ b/src/main/java/com/google/devtools/build/lib/remote/logging/BUILD
@@ -18,6 +18,7 @@
         "//src/main/java/com/google/devtools/build/lib/remote/util",
         "//src/main/java/com/google/devtools/build/lib/util/io",
         "//src/main/protobuf:remote_execution_log_java_proto",
+        "//third_party:flogger",
         "//third_party:jsr305",
         "//third_party/grpc:grpc-jar",
         "//third_party/protobuf:protobuf_java",

src/main/java/com/google/devtools/build/lib/remote/logging/LoggingInterceptor.java

diff --git a/src/main/java/com/google/devtools/build/lib/remote/logging/LoggingInterceptor.java b/src/main/java/com/google/devtools/build/lib/remote/logging/LoggingInterceptor.java
index ee4771f..c673894 100644
--- a/src/main/java/com/google/devtools/build/lib/remote/logging/LoggingInterceptor.java
+++ b/src/main/java/com/google/devtools/build/lib/remote/logging/LoggingInterceptor.java
@@ -20,6 +20,7 @@
 import build.bazel.remote.execution.v2.ExecutionGrpc;
 import build.bazel.remote.execution.v2.RequestMetadata;
 import com.google.bytestream.ByteStreamGrpc;
+import com.google.common.flogger.GoogleLogger;
 import com.google.devtools.build.lib.clock.Clock;
 import com.google.devtools.build.lib.remote.logging.RemoteExecutionLog.LogEntry;
 import com.google.devtools.build.lib.remote.util.TracingMetadataUtils;
@@ -39,6 +40,8 @@
 
 /** Client interceptor for logging details of certain gRPC calls. */
 public class LoggingInterceptor implements ClientInterceptor {
+  private static final GoogleLogger logger = GoogleLogger.forEnclosingClass();
+
   private final AsynchronousFileOutputStream rpcLogFile;
   private final Clock clock;
 
@@ -133,12 +136,22 @@
               super.onMessage(message);
             }
 
+            /**
+             * This method must not throw any exceptions! Doing so will cause the wrapped call to
+             * silently hang indefinitely: https://github.com/grpc/grpc-java/pull/6107
+             */
             @Override
             public void onClose(Status status, Metadata trailers) {
               entryBuilder.setEndTime(getCurrentTimestamp());
               entryBuilder.setStatus(makeStatusProto(status));
               entryBuilder.setDetails(handler.getDetails());
-              rpcLogFile.write(entryBuilder.build());
+              try {
+                rpcLogFile.write(entryBuilder.build());
+              } catch (RuntimeException e) {
+                // e.g. the log file is already closed.
+                logger.atWarning().withCause(e).log(
+                    "Unable to write RPC log entry for %s", entryBuilder.build());
+              }
               super.onClose(status, trailers);
             }
           },