On Mon, 19 Jan 2026 21:47:26 GMT, Ioi Lam <[email protected]> wrote:
>> The bug is here on line 121:
>>
>> https://github.com/openjdk/jdk/blob/586846b84a38d285c5905437e903cfc57f609410/src/java.base/windows/classes/java/lang/ProcessImpl.java#L118-L121
>>
>> If `System.out` has been closed, `fdAccess.getHandle()` will return -1. This
>> causes `stdHandles[1]` to have the same value as if the child process's
>> stdout was redirected with `Redirect.PIPE`. This will cause a Pipe to be
>> created here for the child process's STDOUT on line 168:
>>
>> https://github.com/openjdk/jdk/blob/586846b84a38d285c5905437e903cfc57f609410/src/java.base/windows/native/libjava/ProcessImpl_md.c#L158-L184
>>
>> However, the caller of the `ProcessBuilder` is not aware of this and will
>> not drain this pipe. This causes the child process to get stuck when writing
>> to its stdout when the pipe 's buffer is filled up.
>>
>> The fix is to treat the redirection as `Redirect.DISCARD` when `System.out`
>> and/or `System.err` have been closed.
>
> Ioi Lam has updated the pull request incrementally with one additional commit
> since the last revision:
>
> Fixed typo
The APINote will trigger need for a CSR.
src/java.base/share/classes/java/lang/ProcessBuilder.java line 936:
> 934: * If {#code System.out} and/or {#code System.err} have been
> 935: * closed in the current process, the corresponding output
> 936: * in the subprocess will be discarded.
Suggestion:
* When the process is {@link #start started},
* if {#code System.out} and/or {#code System.err} have been
* closed in the current process, the corresponding output
* in the subprocess will be discarded.
Qualified to apply at the time the process is started, not when
ProcessBuilder.inheritIO is called.
-------------
PR Review: https://git.openjdk.org/jdk/pull/29198#pullrequestreview-3708036042
PR Review Comment: https://git.openjdk.org/jdk/pull/29198#discussion_r2729282389
