> Data structures that are accessed by both virtual threads and their carriers > require the virtual thread to pin the continuation to avoid potential > deadlock. A deadlock can arise when a virtual thread is preempted, is > selected and scheduled to be the next owner of the lock/resource, but can't > execute because all carriers are blocking on the same lock/resource. There > are a small number of places that need to pin. One that was missed is the the > notification to the thread container when threads are started or terminate. > This is not currently an issue at this time but it is a potential hazard for > ongoing and future work that will add further scheduling points to the code. > Continuation.pin/unpin have intrinsics since JDK-8338745, and Continuation is > initialized early in startup. Finally, the changes have been in the loom repo > for several months with no issues. > > Testing tier1-5, quick statup/footprint, noreg-hard
Alan Bateman has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 10 additional commits since the last revision: - Fix/improve comment - Merge branch 'master' into JDK-8350765 - Merge branch 'master' into JDK-8350765 - No need to used qualified name - Merge branch 'master' into JDK-8350765 - Update - Merge branch 'master' into JDK-8350765 - Add method to ContinuationSupport - Missing / - Initial commit ------------- Changes: - all: https://git.openjdk.org/jdk/pull/23810/files - new: https://git.openjdk.org/jdk/pull/23810/files/2959e070..5ff93aea Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=23810&range=01 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23810&range=00-01 Stats: 2069 lines in 129 files changed: 1811 ins; 61 del; 197 mod Patch: https://git.openjdk.org/jdk/pull/23810.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/23810/head:pull/23810 PR: https://git.openjdk.org/jdk/pull/23810
