Thanks for the review Serguei! David
On 2/07/2021 2:30 am, Serguei Spitsyn wrote:
On Thu, 1 Jul 2021 04:18:28 GMT, David Holmes <[email protected]> wrote:Please see the JBS issue for more details, but basically we have 8 different kinds of internal VM JavaThreads (grouping the three types of CompilerThread together) that all basically duplicated the logic for initializing (preparing is the term we use for user-defined JavaThreads) and starting the new thread. This common code can be factored out into static helpers in JavaThread. This change does not look at the way the java.lang.Thread instance is created - that will be handled by a separate RFE. The semantics of the changes are not identical, but I don't believe there is any observable change in behaviour. The scope of holding the Threads_lock has been reduced, and we now create the JavaThread instances ("new XXXThread(...)") outside of the lock. As far as I can see nothing in the construction process needs to happen under the Threads_lock. A few of the threads use a static `_instance` field to hold a reference to the create JavaThread. This proved very difficult to handle, as logically the field would need to be updated in the middle of the new factored-out method: after setting all the fields but before releasing the newly started thread. I eventually realized that in all but one case those `_instance` fields are never used and so could be deleted. The one case remaining does not need to be set as I just described, but can be set after the thread has started, as the new thread does not examine it (arguably its existence is unnecessary). The trickiest changes related to the CompilerThreads, so they need particular scrutiny. Testing: tiers 1-3 Thanks, DavidDavid Holmes has updated the pull request incrementally with three additional commits since the last revision: - Rename vm_exit_on_thread_allocation_failure to vm_exit_on_osthread_failure - Adjust comment - Comments from PR review: - remove unnecessary new_thread NULL checks - adjust some comments - fix whitespaceMarked as reviewed by sspitsyn (Reviewer). ------------- PR: https://git.openjdk.java.net/jdk/pull/4629
