8332065: Calling readLine(null...) or readPassword(null...) on System.console() hangs jshell

[lahodaj]

JShell supports using System.console() when running snippets in a separate VM (the agent). This works by re-sending requests from the agent to the main process.

For some Console methods, like readLine, this has two phases - first a prompt is sent, and then input is received. But, there's a mistake on the way this is handled: the protocol starts a "transaction", and then goes to process the prompt. And if the prompt processing fails, the "transaction" never ends, and the communication locks.

The proposal here is to do the prompt processing before starting the communication, so if it fails, there are no problems with the communication.

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Issue

• JDK-8332065: Calling readLine(null...) or readPassword(null...) on System.console() hangs jshell (Bug - P3)

Reviewers

• Pavel Rappo (@pavelrappo - Reviewer)

Reviewing

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[openjdk]

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

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

8332065: Calling readLine(null...) or readPassword(null...) on System.console() hangs jshell

Reviewed-by: prappo

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At the time when this comment was updated there had been 5 new commits pushed to the master branch:

• 2edb6d9: 8330386: Replace Opaque4Node of Initialized Assertion Predicate with new OpaqueInitializedAssertionPredicateNode
• 1850914: 8332864: Parallel: Merge ParMarkBitMapClosure into MoveAndUpdateClosure
• 2f2cf38: 8332883: Some simple cleanup in vectornode.cpp
• b5e1615: 8292955: Collections.checkedMap Map.merge does not properly check key and value
• 86eb5d9: 8329958: Windows x86 build fails: downcallLinker.cpp(36) redefinition

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[mlbridge]

Webrevs

• 00: Full (22cd1d51)

[pavelrappo]

Right: IllegalFormatConversionException would cause the same hang.

[lahodaj]

/integrate

[openjdk]

Going to push as commit 57bfd0e.
Since your change was applied there have been 37 commits pushed to the master branch:

• 9a72068: 8332230: jshell throws AssertionError when processing annotations
• 66d9bfc: 8332725: Binding patterns with inferred type have erroneous node in the AST
• 2ea365c: 8333099: Missing check for is_LoadVector in StoreNode::Identity
• 789ac8b: 8333189: Make sure clang on linux uses lld as linker
• c8eea59: 8332919: SA PointerLocation needs to print a newline after dumping java thread info for JNI Local Ref
• bc7d9e3: 8333013: Update vmTestbase/nsk/share/LocalProcess.java to don't use finalization
• 03b7a85: 8332259: JvmtiTrace::safe_get_thread_name fails if current thread is in native state
• 43a2f17: 8333149: ubsan : memset on nullptr target detected in jvmtiEnvBase.cpp get_object_monitor_usage
• fed2b56: 8320999: RISC-V: C2 RotateLeftV
• 6cda4c5: 8321543: Update NSS to version 3.96
• ... and 27 more: https://git.openjdk.org/jdk/compare/be1d374bc54d43aae3b3c1feace22d38fe2156b6...master

Your commit was automatically rebased without conflicts.

[openjdk]

@lahodaj Pushed as commit 57bfd0e.

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