Greetings,
Here's the new webrev URLs after CR0:
Full:
http://cr.openjdk.java.net/~dcubed/8227117-webrev/1_for_jdk14.full/
Inc:
http://cr.openjdk.java.net/~dcubed/8227117-webrev/1_for_jdk14.inc/
Only src/hotspot/share/prims/jvmtiEventController.cpp changed in this
round. The only code change was this:
VM_ChangeSingleStep::VM_ChangeSingleStep(bool on)
- : _on(on != 0)
+ : _on(on)
{
}
The other change is a header comment block rewrite...
Thanks, in advance, for questions, comments or suggestions.
Dan
On 7/3/19 10:04 PM, Daniel D. Daugherty wrote:
Greetings,
Robbin recently discovered this issue with Thread Local Handshakes. Since
he's not available at the moment, I'm handling the issue:
JDK-8227117 normal interpreter table is not restored after single
stepping with TLH
https://bugs.openjdk.java.net/browse/JDK-8227117
When using Thread Local Handshakes, the normal interpreter table is
not restored after single stepping. This issue is caused by the
VM_ChangeSingleStep VM-op relying on SafepointSynchronize::end() to
restore the normal interpreter table for the "off" case.
Prior to Thread Local Handshakes, this was a valid assumption to make.
SafepointSynchronize::end() has been refactored into
disarm_safepoint() and it only calls Interpreter::ignore_safepoints()
on the global safepoint branch. That matches up with the call to
Interpreter::notice_safepoints() that is also on the global safepoint
branch.
The solution is for the VM_ChangeSingleStep VM-op for the "off" case
to call Interpreter::ignore_safepoints() directly.
Here's the webrev URL:
http://cr.openjdk.java.net/~dcubed/8227117-webrev/0_for_jdk14/
The fix is just a small addition to VM_ChangeSingleStep::doit():
if (_on) {
Interpreter::notice_safepoints();
+ } else {
+ Interpreter::ignore_safepoints();
}
Everything else is just new logging support for future debugging of
interpreter table management and single stepping.
Tested this fix with Mach5 Tier[1-3] on the standard Oracle platforms.
Mach5 Tier[4-6] on standard Oracle platforms is running now.
Thanks, in advance, for questions, comments or suggestions.
Dan
