Please review this PR which adds a utility API in the test libraries to assert
whether a file is currently open.
Several OpenJDK tests currently rely on approximations to check this,
including deletion (fails only on Windows), or checking `/proc/<pid>/fd` (Works
only on Linux). These approximations are blunt instruments, it would be better
to have an exact cross platform solution for this need to check if a file is
open or closed.
Initial support includes:
* `FileInputStream`, `FileOutputStream` and `RandomAccessFile` from `java.io`
* `FileChannelImpl` from `java.nio`, meaning we can check synchronous NIO APIs
such as `Files.newInputStream`, `Files.newOutputStream`, `Files.newByteChannel`
and `FileChannel.open`
This allows testing of many (most?) JDK APIs such as `ZipFile`, `JarFile`,
`JarURLConnection`, `FileURLConnection` etc.
Tests use the following configuration to enable instrumentation of file access
APIs:
* @library /test/lib
* @run driver jdk.test.lib.util.OpenFilesAgent
* @run junit/othervm -javaagent:OpenFilesAgent.jar OpenFilesTest
Also provided is an assertion API to verify whether files are open or not:
Path file = Files.createFile(Path.of("file.txt"));
assertClosed(file);
try (var is = Files.newInputStream(file)) {
assertOpen(file);
}
assertClosed(file);
```
A failed `assertClosed` shows the stack trace for whatever action opened the
file:
Caused by: java.lang.Throwable: Opening stack trace of
jdk/build/macosx-x86_64-server-release/JTwork/scratch/file.txt
at jdk.test.lib.util.OpenFiles.openFile(OpenFiles.java:59)
at java.base/java.nio.file.Files.newByteChannel(Files.java:357)
at java.base/java.nio.file.Files.newByteChannel(Files.java:399)
at
java.base/java.nio.file.spi.FileSystemProvider.newInputStream(FileSystemProvider.java:371)
at java.base/java.nio.file.Files.newInputStream(Files.java:154)
at OpenFilesTest.sample(OpenFilesTest.java:81)
See the library implementation test `OpenFilesTest` for samples.
Verification:
With `OpenFilesTest` temporarily in tier1, GHA completed successfully across
platforms.
-------------
Commit messages:
- Revert "Temporarily move OpenFilesTest to tier one to trigger run in GHA"
- Temporarily move OpenFilesTest to tier one to trigger run in GHA
- Simplify NIO instrumentation to only instrument FileChannelImpl::open and
FileChannelImpl::implCloseChannel
- Avoid calling OpenFiles.closeFile twice when closing streams created by
Files.newOutputStream
- Add support for Files.newOutputStream
- Add support for FileOutputStream
- Fix some Javadocs in OpenFiles
- Add some missing Javadocs in OpenFiles
- Add support for Files::newByteChannel
- Test infrastructure to assert that a file is open or closed
Changes: https://git.openjdk.org/jdk/pull/22343/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22343&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8344911
Stats: 898 lines in 3 files changed: 898 ins; 0 del; 0 mod
Patch: https://git.openjdk.org/jdk/pull/22343.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/22343/head:pull/22343
PR: https://git.openjdk.org/jdk/pull/22343
