On Tue, 9 May 2023 01:26:43 GMT, Serguei Spitsyn <sspit...@openjdk.org> wrote:
> The compatible lifecycle `ThreadStart/ThreadEnd` events were added in JDK 19 > to support legacy virtual thread unaware JVMTI agents which do not enable the > can_support_virtual_threads capability. When this capability is enabled then > the `VirtualThreadStart/VirtualThreadEnd` instead of the > `ThreadStart/ThreadEnd` events are generated for virtual threads and can be > managed (enabled/disabled) separately. If the the > `can_support_virtual_threads` capability is disabled then the > `ThreadStart/ThreadEnd` events are generated for virtual threads. > This enhancement is to get rid of the compatible lifecycle > `ThreadStart/ThreadEnd` events. > Motivation: Performance overhead from compatible lifecycle events can be > significant when a lot of virtual threads are created. > > Also, there is an experimental VM flag > `PostVirtualThreadCompatibleLifecycleEvents` (enabled by default). > If it is turned on then the default compatible lifecycle > `ThreadStart/ThreadEnd` events for virtual threads are generated. This VM > flag has to be removed now. > > Testing: > The mach5 tiers 1-6 were submitted and passed. This pull request has now been integrated. Changeset: 2be1f10f Author: Serguei Spitsyn <sspit...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/2be1f10fec37057a4532fbbc3467b41240c4dba9 Stats: 72 lines in 6 files changed: 19 ins; 31 del; 22 mod 8307399: get rid of compatibility ThreadStart/ThreadEnd events for virtual threads Reviewed-by: alanb, pchilanomate, cjplummer ------------- PR: https://git.openjdk.org/jdk/pull/13874
