On Tue, 28 Nov 2023 06:15:54 GMT, Alan Bateman <al...@openjdk.org> wrote:
>> Note that there is no answer for the "syscall" case mentioned as it depends
>> on the code that makes the syscall: if from a native method then yes; if
>> from the VM then no.
>
>> Note that there is no answer for the "syscall" case mentioned as it depends
>> on the code that makes the syscall: if from a native method then yes; if
>> from the VM then no.
>
> Right, if the thread invokes a Java native method then it may or may not
> invoke a system call, it doesn't matter, the ThreadInfo::isInNative method is
> just reporting a bit of thread state to say that it is in a native method.
> Same thing when calling a native function with the FFM API, the native
> function may be a syscall, or the native code may invoke a syscall, it
> doesn't matter to ThreadInfo::isInNative as it just returns a bit of thread
> state.
btw for the following (system/native/runtime/embryotic) Reader thread tseems to
be no java method marked "native" on the stack, what case is that?
"JDWP Event Helper Thread" #22 daemon prio=10 os_prio=0 cpu=0.00ms
elapsed=65.02s tid=0x000001fc4f7e9970 nid=0x32e0 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"JDWP Command Reader" #23 daemon prio=10 os_prio=0 cpu=0.00ms elapsed=65.02s
tid=0x000001fc4f7ea480 nid=0x69c4 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
"Notification Thread" #24 daemon prio=9 os_prio=0 cpu=0.00ms elapsed=64.99s
tid=0x000001fc4f7f12a0 nid=0x75f0 runnable [0x0000000000000000]
java.lang.Thread.State: RUNNABLE
jshell> mx.getThreadInfo(23)
$17 ==> "JDWP Command Reader" daemon prio=10 Id=23 RUNNABLE (in native)
funfact: its not in the list:
jshell> mx.getAllThreadIds()
$11 ==> long[8] { 1, 2, 3, 4, 5, 24, 25, 26 }
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PR Review Comment: https://git.openjdk.org/jdk/pull/16791#discussion_r1407852578
