8265465: jcmd VM.cds should keep already dumped archive when exception happens #3886

yminqi · 2021-05-05T16:10:21Z

Hi, Please review
When using jcmd to dump shared archive, if the archive name exists, it will be deleted first. If exception happens during dumping process, there is no new archive created. This PR changes to first dump the archive with a temporary file name. With successful dump, the temporary file will be rename to its given name. This way the old archive will not be touched on exception.
The newly added test case skipped testing on Windows since File operation result is not same as on Linux.

Tests: tier1,tier2,tier3,tier4

Thanks
Yumin

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Issue

JDK-8265465: jcmd VM.cds should keep already dumped archive when exception happens

Reviewers

Ioi Lam (@iklam - Reviewer)
Calvin Cheung (@calvinccheung - Reviewer)

Reviewing

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Update a local copy of the PR:
$ git checkout pull/3886
$ git pull https://git.openjdk.java.net/jdk pull/3886/head

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$ git pr checkout 3886

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https://git.openjdk.java.net/jdk/pull/3886.diff

…n happens

bridgekeeper · 2021-05-05T16:11:36Z

👋 Welcome back minqi! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

openjdk · 2021-05-05T16:12:58Z

@yminqi The following labels will be automatically applied to this pull request:

core-libs
hotspot-runtime

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing lists. If you would like to change these labels, use the /label pull request command.

mlbridge · 2021-05-05T16:17:14Z

Webrevs

iklam · 2021-05-05T18:35:13Z

src/java.base/share/classes/jdk/internal/misc/CDS.java

-            fileArchive.delete();
-        }
+        String tempFileName = getArchiveFileName(archiveFileName);
+        File tempArchiveFile = new File(tempFileName);


I think the logic is too complicated. We can always write the archive to a temp file, and then rename it to the actual file. Also, to be consistent with the other variables, it should be tempArchiveFileName

String tempArchiveFileName = archiveFileName + ".tmp";

getArchiveFileName also operates on create/delete temp file, so if that fails, throw exception back to caller. Do you think the logic should be kept?

How about:

File tempArchiveFile = new File(tempArchiveFileName); tempArchiveFile.createNewFile(); // will throw exception if we cannot write to the directory. tempArchiveFile.delete();

src/java.base/share/classes/jdk/internal/misc/CDS.java

iklam · 2021-05-05T18:35:13Z

test/hotspot/jtreg/runtime/cds/appcds/jcmd/JCmdTestFileSecurity.java

+
+    public static void main(String... args) throws Exception {
+        if (Platform.isWindows()) {
+            // ON windows, File operation resulted difference from other OS.


Could you explain what the differences are?

Will add detail explanation.

iklam · 2021-05-05T18:35:13Z

test/hotspot/jtreg/runtime/cds/appcds/jcmd/JCmdTestFileSecurity.java

+ * @build JCmdTestLingeredApp JCmdTestFileSecurity
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm/timeout=480 -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI JCmdTestFileSecurity
+ */


"Security" is usually used for Java language security. I think it's better to call this test JCmdTestFileSafety.

iklam · 2021-05-05T18:35:13Z

test/hotspot/jtreg/runtime/cds/appcds/jcmd/JCmdTestFileSecurity.java

+        String localFileName = "MyStaticDump.jsa";
+        test(localFileName, pid, noBoot,  EXPECT_PASS);
+        File targetFile = CDSTestUtils.getOutputDirAsFile();
+        targetFile.setWritable(false);


getOutputDirAsFile returns the current directory. Other test code may write to this directory. I think it's better to specify:

localFileName = "subdir" + File.separator() + "MyStaticDump.jsa";

and set subdir to be non-writeable.

Also, the local variable should be targetDir instead of targetFile.

Will try this, not sure if the subdir and the file can be created with current code. May be some extra code needed.
Thanks for the review!

iklam

The latest version LGTM

calvinccheung · 2021-05-06T23:59:22Z

test/hotspot/jtreg/runtime/cds/appcds/jcmd/JCmdTestFileSafety.java

+        //  Set target dir not writable, do dynamic dump
+        print2ln(test_count++ + " Set target dir not writable, do dynamic dump");
+        setKeepArchive(true);
+        outputDirFile.setWritable(true);


Should the comment be // Set target dir writable ... ? (since you're setting the dir to writable at line 78)

The comment is for the testing item --- that is consistent with println contents.
The first set 'true' is for get the archive and keep the archive, the real test is after set it to 'false', the test will fail and we check the previous archive still available.

calvinccheung · 2021-05-07T00:01:46Z

test/hotspot/jtreg/runtime/cds/appcds/jcmd/JCmdTestFileSafety.java

+        // cannot dynamically dump twice, restart
+        app = createLingeredApp("-cp", allJars, "-XX:+RecordDynamicDumpInfo");
+        pid = app.getPid();
+        outputDirFile.setWritable(false);
+        test(localFileName, pid, noBoot,  EXPECT_FAIL);
+        outputDirFile.setWritable(true);


Would the test fail without setting the dir not writable at line 87?

See reply above.

calvinccheung

I have 2 questions on the test.

yminqi · 2021-05-07T00:11:40Z

/integrate

yminqi · 2021-05-07T00:12:01Z

@iklam @calvinccheung Thanks for review!

openjdk · 2021-05-07T00:12:13Z

@yminqi This PR has not yet been marked as ready for integration.

yminqi · 2021-05-07T02:47:00Z

/label remove core-libs

openjdk · 2021-05-07T02:47:34Z

@yminqi
The core-libs label was successfully removed.

openjdk · 2021-05-07T02:59:06Z

@yminqi This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8265465: jcmd VM.cds should keep already dumped archive when exception happens

Reviewed-by: iklam, ccheung

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 24 new commits pushed to the master branch:

66191ff: 8266193: BasicJMapTest does not include testHistoParallel methods
36e5ad6: 8263236: runtime/os/TestTracePageSizes.java fails on old kernels
0ca86da: 8266002: vmTestbase/nsk/jvmti/ClassPrepare/classprep001 should skip events for unexpected classes
52f1db6: 8262002: java/lang/instrument/VerifyLocalVariableTableOnRetransformTest.sh failed with "TestCaseScaffoldException: DummyClassWithLVT did not match .class file"
04f7112: 8266293: Key protection using PBEWithMD5AndDES fails with "java.security.InvalidAlgorithmParameterException: Salt must be 8 bytes long"
a90b33a: 8266573: Make sure blackholes are tagged for all JVMCI paths
2dcbedf: 8266044: Nested class summary should show kind of class or interface
e840597: 8266460: java.io tests fail on null stream with upgraded jtreg/TestNG
fcedfc8: 8266579: Update test/jdk/java/lang/ProcessHandle/PermissionTest.java & test/jdk/java/sql/testng/util/TestPolicy.java
c665dba: 8266561: Remove Compile::_save_argument_registers
... and 14 more: https://git.openjdk.java.net/jdk/compare/6018336fc5e93675482b92df76594712c238adda...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

yminqi · 2021-05-07T03:00:21Z

/integrate

openjdk · 2021-05-07T03:02:02Z

@yminqi Since your change was applied there have been 24 commits pushed to the master branch:

66191ff: 8266193: BasicJMapTest does not include testHistoParallel methods
36e5ad6: 8263236: runtime/os/TestTracePageSizes.java fails on old kernels
0ca86da: 8266002: vmTestbase/nsk/jvmti/ClassPrepare/classprep001 should skip events for unexpected classes
52f1db6: 8262002: java/lang/instrument/VerifyLocalVariableTableOnRetransformTest.sh failed with "TestCaseScaffoldException: DummyClassWithLVT did not match .class file"
04f7112: 8266293: Key protection using PBEWithMD5AndDES fails with "java.security.InvalidAlgorithmParameterException: Salt must be 8 bytes long"
a90b33a: 8266573: Make sure blackholes are tagged for all JVMCI paths
2dcbedf: 8266044: Nested class summary should show kind of class or interface
e840597: 8266460: java.io tests fail on null stream with upgraded jtreg/TestNG
fcedfc8: 8266579: Update test/jdk/java/lang/ProcessHandle/PermissionTest.java & test/jdk/java/sql/testng/util/TestPolicy.java
c665dba: 8266561: Remove Compile::_save_argument_registers
... and 14 more: https://git.openjdk.java.net/jdk/compare/6018336fc5e93675482b92df76594712c238adda...master

Your commit was automatically rebased without conflicts.

Pushed as commit 43ad24f.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

Yumin Qi added 2 commits May 5, 2021

8265465: jcmd VM.cds should keep already dumped archive when exceptio…

9ba9911

…n happens

JCmdTestFileSecurity.java should be excluded from dynamic test group

b420da7

openjdk bot added the rfr label May 5, 2021

openjdk bot added hotspot-runtime core-libs labels May 5, 2021

iklam suggested changes May 5, 2021

View changes

Fixed temp file operation, archive and temp file name consistency

83478dd

openjdk bot removed the rfr label May 6, 2021

Yumin Qi added 2 commits May 6, 2021

Removed using temporary file in test case

e336391

Remove tab space

ab43e47

openjdk bot added the rfr label May 6, 2021

iklam approved these changes May 6, 2021

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calvinccheung reviewed May 6, 2021

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calvinccheung reviewed May 7, 2021

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calvinccheung approved these changes May 7, 2021

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openjdk bot removed the core-libs label May 7, 2021

yminqi changed the title ~~8265465: jcmd VM.cds should keep already dumped archive when exceptions happens~~ 8265465: jcmd VM.cds should keep already dumped archive when exception happens May 7, 2021

openjdk bot added the ready label May 7, 2021

openjdk bot closed this May 7, 2021

openjdk bot added integrated and removed ready rfr labels May 7, 2021

yminqi deleted the jdk-8265465 branch May 7, 2021

8265465: jcmd VM.cds should keep already dumped archive when exception happens #3886

8265465: jcmd VM.cds should keep already dumped archive when exception happens #3886

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8265465: jcmd VM.cds should keep already dumped archive when exception happens #3886

8265465: jcmd VM.cds should keep already dumped archive when exception happens #3886

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yminqi commented May 5, 2021 • edited by openjdk[bot] bot

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