8252685: APIs that require JavaThread should take JavaThread arguments #3877

dholmes-ora · 2021-05-05T10:16:29Z

Our code is littered with API's that take, or manifest, a Thread* and then assert/guarantee that it must be a JavaThread, rather than taking/manifesting a JavaThread in the first place. The main reason for this is that the TRAPS macro, used in relation to exception generation and processing, is declared as "Thread* THREAD". In practice only JavaThreads that can execute Java code can generate arbitrary exceptions, because it requires executing Java code. In other places we can get away with other kinds of threads "throwing" exceptions because they are only pre-allocated instances that require no Java code execution (e.g. OOME), or when executed by a non-JavaThread the code actually by-passes the logic would throw an exception. Such code also eventually clears the exception and reports the OOM by some other means. We have been progressively untangling these code paths and modifying TRAPS/CHECK usage so that only JavaThreads will call TRAPS methods and throw exceptions. Having done that pre-work we are now ready to convert TRAPS to be "JavaThread* THREAD" and that is what this change does. The resulting changes are largely mechanical:

declarations of "Thread* THREAD" become "JavaThread* THREAD" (where THREAD is needed for exceptions, otherwise THREAD is renamed to current)
methods that took a Thread* parameter that was always THREAD, now take a JavaThread* param
Manifestations of Thread::current() become JavaThread::current()
THREAD->as_Java_thread() becomes just THREAD
THREAD->is_Java_thread() is reworked so that THREAD is "current"

There are still places where a CompilerThread (which is a JavaThread but may not be able to execute Java code) calls a TRAPS function (primarily where OOME is possible). Fixing that would be a future RFE and may not be possible without reworking a lot of the allocation code paths.

Testing:

tiers 1-8 on Linux-x64
all builds in tiers 1-4
tiers 1-3 on all platforms

Thanks,
David

Progress

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Issue

JDK-8252685: APIs that require JavaThread should take JavaThread arguments

Reviewers

Coleen Phillimore (@coleenp - Reviewer) ⚠️ Review applies to ae1801c
Serguei Spitsyn (@sspitsyn - Reviewer) ⚠️ Review applies to b08c19c
Vladimir Kozlov (@vnkozlov - Reviewer) ⚠️ Review applies to b08c19c
Ioi Lam (@iklam - Reviewer) ⚠️ Review applies to a6d74cc

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk pull/3877/head:pull/3877
$ git checkout pull/3877

Update a local copy of the PR:
$ git checkout pull/3877
$ git pull https://git.openjdk.java.net/jdk pull/3877/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 3877

View PR using the GUI difftool:
$ git pr show -t 3877

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk/pull/3877.diff

bridgekeeper · 2021-05-05T10:17:39Z

👋 Welcome back dholmes! 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 · 2021-05-05T10:19:38Z

@dholmes-ora The following labels will be automatically applied to this pull request:

hotspot
serviceability

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.

coleenp

I started out thinking that this was too big and should be broken up but then the change is pretty simple to review and mostly mechanical. So ignore my comments to break it up. I think it's fine. Hitting "approve" even though it's a draft.

src/hotspot/share/cds/archiveBuilder.cpp

src/hotspot/share/cds/dynamicArchive.cpp

coleenp · 2021-05-08T13:19:21Z

src/hotspot/share/classfile/classLoader.cpp

@@ -1074,7 +1074,7 @@ ClassPathEntry* find_first_module_cpe(ModuleEntry* mod_entry,


 // Search either the patch-module or exploded build entries for class.
-ClassFileStream* ClassLoader::search_module_entries(Thread* current,
+ClassFileStream* ClassLoader::search_module_entries(JavaThread* current,


I wonder if these CDS and classLoader.hpp/cpp changes can be done first? Just change the caller to pass ->as_Java_thread() until TRAPS is changed.

src/hotspot/share/runtime/sharedRuntime.cpp

openjdk · 2021-05-08T13:20:53Z

@dholmes-ora this pull request can not be integrated into master due to one or more merge conflicts. To resolve these merge conflicts and update this pull request you can run the following commands in the local repository for your personal fork:

git checkout 8252685
git fetch https://git.openjdk.java.net/jdk master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push

src/hotspot/share/cds/archiveBuilder.cpp

dholmes-ora · 2021-05-09T22:43:59Z

Thanks for the pre-review comments Coleen! I started responding to your various comments then realized they were the ones about breaking things up that you said I could now ignore :)

openjdk · 2021-05-09T22:47:11Z

@dholmes-ora 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:

8252685: APIs that require JavaThread should take JavaThread arguments

Reviewed-by: coleenp, sspitsyn, kvn, iklam

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 no new commits pushed to the master branch. If another commit should be pushed before you perform the /integrate command, your PR will be automatically rebased. If you prefer to avoid any potential 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.

mlbridge · 2021-05-09T22:54:06Z

Webrevs

src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadState.cpp

sspitsyn

David,
This looks pretty good. At least, I do not see real problems.
It is really nice to make it more consistent.
Thanks,
Serguei

vnkozlov

Compiler related changes seems fine.
@dougxc, note that jvmci is affected. It looks reasonable for me but you may need to check if it is correct from libgraal POV.

dougxc · 2021-05-13T13:17:36Z

Compiler related changes seems fine.
@dougxc, note that jvmci is affected. It looks reasonable for me but you may need to check if it is correct from libgraal POV.

I tried to test this patch against GraalVM but am blocked due to jdk.internal.vm.compiler no longer being upgradeable.

iklam

LGTM

mlbridge · 2021-05-14T18:29:23Z

Mailing list message from David Holmes on hotspot-dev:

On 11/05/2021 9:14 am, Serguei Spitsyn wrote:

On Wed, 5 May 2021 10:16:29 GMT, David Holmes <dholmes at openjdk.org> wrote:

David,
This looks pretty good. At least, I do not see real problems.
It is really nice to make it more consistent.
Thanks,
Serguei

Thanks for the review Serguei!

David

mlbridge · 2021-05-14T18:29:31Z

Mailing list message from David Holmes on hotspot-dev:

On 11/05/2021 9:14 am, Serguei Spitsyn wrote:

On Wed, 5 May 2021 10:16:29 GMT, David Holmes <dholmes at openjdk.org> wrote:

David,
This looks pretty good. At least, I do not see real problems.
It is really nice to make it more consistent.
Thanks,
Serguei

Thanks for the review Serguei!

David

mlbridge · 2021-05-14T18:29:32Z

Mailing list message from David Holmes on hotspot-dev:

On 11/05/2021 9:00 am, Serguei Spitsyn wrote:

On Wed, 5 May 2021 10:16:29 GMT, David Holmes <dholmes at openjdk.org> wrote:

src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadState.cpp line 108:

106:
107: // caller needs ResourceMark
108: const char* get_java_thread_name(const JavaThread* t) {

Nit: Better to rename it: t => jt

Changed.

mlbridge · 2021-05-14T18:29:40Z

Mailing list message from David Holmes on hotspot-dev:

On 11/05/2021 9:00 am, Serguei Spitsyn wrote:

On Wed, 5 May 2021 10:16:29 GMT, David Holmes <dholmes at openjdk.org> wrote:

src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadState.cpp line 108:

106:
107: // caller needs ResourceMark
108: const char* get_java_thread_name(const JavaThread* t) {

Nit: Better to rename it: t => jt

Changed.

mlbridge · 2021-05-14T18:29:42Z

Mailing list message from David Holmes on hotspot-dev:

On 13/05/2021 1:29 pm, Vladimir Kozlov wrote:

On Tue, 11 May 2021 01:56:21 GMT, David Holmes <dholmes at openjdk.org> wrote:

David Holmes has updated the pull request incrementally with one additional commit since the last revision:

Review feedback from Serguei

Compiler related changes seems fine.
@dougxc, note that jvmci is affected. It looks reasonable for me but you may need to check if it is correct from libgraal POV.

Thanks for the review Vladimir!

cc'ing Doug in case the @-notification doesn't work.

David

mlbridge · 2021-05-14T18:29:44Z

Mailing list message from David Holmes on hotspot-dev:

On 13/05/2021 1:29 pm, Vladimir Kozlov wrote:

On Tue, 11 May 2021 01:56:21 GMT, David Holmes <dholmes at openjdk.org> wrote:

David Holmes has updated the pull request incrementally with one additional commit since the last revision:

Review feedback from Serguei

Compiler related changes seems fine.
@dougxc, note that jvmci is affected. It looks reasonable for me but you may need to check if it is correct from libgraal POV.

Thanks for the review Vladimir!

cc'ing Doug in case the @-notification doesn't work.

David

mlbridge · 2021-05-14T18:29:46Z

Mailing list message from David Holmes on hotspot-dev:

Thanks for the review Ioi!

David

On 14/05/2021 3:03 am, Ioi Lam wrote:

mlbridge · 2021-05-14T18:29:50Z

Mailing list message from David Holmes on hotspot-dev:

Thanks for the review Ioi!

David

On 14/05/2021 3:03 am, Ioi Lam wrote:

dholmes-ora · 2021-05-17T04:03:10Z

/integrate

openjdk · 2021-05-17T04:06:11Z

@dholmes-ora Pushed as commit 02f895c.

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

8252685: APIs that require JavaThread should take JavaThread arguments

ae1801c

openjdk bot added serviceability serviceability-dev@openjdk.org hotspot hotspot-dev@openjdk.org labels May 5, 2021

coleenp approved these changes May 8, 2021

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openjdk bot added the merge-conflict Pull request has merge conflict with target branch label May 8, 2021

dholmes-ora commented May 9, 2021

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src/hotspot/share/cds/archiveBuilder.cpp Show resolved Hide resolved

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dholmes-ora marked this pull request as ready for review May 9, 2021 22:45

openjdk bot added ready Pull request is ready to be integrated rfr Pull request is ready for review and removed merge-conflict Pull request has merge conflict with target branch labels May 9, 2021

sspitsyn reviewed May 10, 2021

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src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadState.cpp Outdated Show resolved Hide resolved

sspitsyn approved these changes May 10, 2021

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Review feedback from Serguei

b08c19c

sspitsyn approved these changes May 11, 2021

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vnkozlov approved these changes May 13, 2021

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dholmes-ora added 2 commits May 13, 2021 00:20

Merge branch 'master' into 8252685-JavaThread

3aca802

Update after merge with master

a6d74cc

iklam approved these changes May 13, 2021

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Merge branch 'master' into 8252685-JavaThread

3f3e840

openjdk bot closed this May 17, 2021

openjdk bot added integrated Pull request has been integrated and removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels May 17, 2021

dholmes-ora deleted the 8252685 branch May 17, 2021 04:06

8252685: APIs that require JavaThread should take JavaThread arguments #3877

8252685: APIs that require JavaThread should take JavaThread arguments #3877

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8252685: APIs that require JavaThread should take JavaThread arguments #3877

8252685: APIs that require JavaThread should take JavaThread arguments #3877

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dholmes-ora commented May 5, 2021 • edited by openjdk bot

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