From 890a3e72ac0d38f5bc6dde2a120d9bc6260db1af Mon Sep 17 00:00:00 2001
From: Andy Wilkinson <wilkinsona@vmware.com>
Date: Tue, 31 Oct 2023 18:29:08 +0000
Subject: [PATCH] Repair file channel when it's closed by interruption

When an interrupted that calls FileChannel.read, the channel is
closed and the read fails with a ClosedByInterruptException. The
closure of the channel makes it unusable by other threads. To
allow other threads to read from the data block, this commit
recreates the FileChannel when a read fails on an interrupted
thread with a ClosedByInterruptException. The exception is then
rethrown to continue the thread's interruption.

Closes gh-38154
---
 .../boot/loader/zip/FileChannelDataBlock.java | 21 ++++++++++++++--
 .../loader/zip/FileChannelDataBlockTests.java | 24 +++++++++++++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/zip/FileChannelDataBlock.java b/spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/zip/FileChannelDataBlock.java
index 1824281ede3..0346a87d4d0 100644
--- a/spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/zip/FileChannelDataBlock.java
+++ b/spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/zip/FileChannelDataBlock.java
@@ -18,6 +18,7 @@ package org.springframework.boot.loader.zip;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.nio.channels.ClosedByInterruptException;
 import java.nio.channels.ClosedChannelException;
 import java.nio.channels.FileChannel;
 import java.nio.file.Files;
@@ -179,7 +180,13 @@ class FileChannelDataBlock implements CloseableDataBlock {
 			synchronized (this.lock) {
 				if (position < this.bufferPosition || position >= this.bufferPosition + this.bufferSize) {
 					this.buffer.clear();
-					this.bufferSize = this.fileChannel.read(this.buffer, position);
+					try {
+						this.bufferSize = this.fileChannel.read(this.buffer, position);
+					}
+					catch (ClosedByInterruptException ex) {
+						repairFileChannel();
+						throw ex;
+					}
 					this.bufferPosition = position;
 				}
 				if (this.bufferSize <= 0) {
@@ -193,6 +200,16 @@ class FileChannelDataBlock implements CloseableDataBlock {
 			}
 		}
 
+		private void repairFileChannel() throws IOException {
+			if (tracker != null) {
+				tracker.closedFileChannel(this.path, this.fileChannel);
+			}
+			this.fileChannel = FileChannel.open(this.path, StandardOpenOption.READ);
+			if (tracker != null) {
+				tracker.openedFileChannel(this.path, this.fileChannel);
+			}
+		}
+
 		void open() throws IOException {
 			synchronized (this.lock) {
 				if (this.referenceCount == 0) {
@@ -231,7 +248,7 @@ class FileChannelDataBlock implements CloseableDataBlock {
 
 		<E extends Exception> void ensureOpen(Supplier<E> exceptionSupplier) throws E {
 			synchronized (this.lock) {
-				if (this.referenceCount == 0) {
+				if (this.referenceCount == 0 || !this.fileChannel.isOpen()) {
 					throw exceptionSupplier.get();
 				}
 			}
diff --git a/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/zip/FileChannelDataBlockTests.java b/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/zip/FileChannelDataBlockTests.java
index 9beb4aa314d..df015ff68d5 100644
--- a/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/zip/FileChannelDataBlockTests.java
+++ b/spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/zip/FileChannelDataBlockTests.java
@@ -19,9 +19,11 @@ package org.springframework.boot.loader.zip;
 import java.io.File;
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.nio.channels.ClosedByInterruptException;
 import java.nio.channels.FileChannel;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.concurrent.atomic.AtomicReference;
 
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -74,6 +76,28 @@ class FileChannelDataBlockTests {
 		}
 	}
 
+	@Test
+	void readReadsFileWhenAnotherThreadHasBeenInterrupted() throws IOException, InterruptedException {
+		try (FileChannelDataBlock block = createAndOpenBlock()) {
+			ByteBuffer buffer = ByteBuffer.allocate(CONTENT.length);
+			AtomicReference<IOException> failure = new AtomicReference<>();
+			Thread thread = new Thread(() -> {
+				Thread.currentThread().interrupt();
+				try {
+					block.read(ByteBuffer.allocate(CONTENT.length), 0);
+				}
+				catch (IOException ex) {
+					failure.set(ex);
+				}
+			});
+			thread.start();
+			thread.join();
+			assertThat(failure.get()).isInstanceOf(ClosedByInterruptException.class);
+			assertThat(block.read(buffer, 0)).isEqualTo(6);
+			assertThat(buffer.array()).containsExactly(CONTENT);
+		}
+	}
+
 	@Test
 	void readDoesNotReadPastEndOfFile() throws IOException {
 		try (FileChannelDataBlock block = createAndOpenBlock()) {