Greetings,

This is the implementation of JEP [JDK-8350338 Cooperative JFR Sampling](https://bugs.openjdk.org/browse/JDK-8350338).

Implementations in this change set are provided and have been tested on the following platforms:

- windows-x64 - windows-x64-debug - linux-x64 - linux-x64-debug - macosx-x64 - macosx-x64-debug - linux-aarch64 - linux-aarch64-debug - macosx-aarch64 - macosx-aarch64-debug

Testing: tier1-6, jdk_jfr, stress testing.

Platform porters note: Some platform-specific code needs to be provided, mainly in the interpreter. Take a look at the following files for changes:

- src/hotspot/cpu/x86/frame_x86.cpp - src/hotspot/cpu/x86/interp_masm_x86.cpp - src/hotspot/cpu/x86/interp_masm_x86.hpp - src/hotspot/cpu/x86/javaFrameAnchor_x86.hpp - src/hotspot/cpu/x86/macroAssembler_x86.cpp - src/hotspot/cpu/x86/macroAssembler_x86.hpp - src/hotspot/cpu/x86/templateInterpreterGenerator_x86.cpp - src/hotspot/cpu/x86/templateTable_x86.cpp - src/hotspot/os_cpu/linux_x86/javaThread_linux_x86.hpp

Thanks Markus

Markus Grönlund has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 21 commits: - Merge branch 'master' into 8352251 - 8350338: the minimal arm32 support - Merge branch 'master' into 8352251 - Configuration and test for jdk.SafepointLatency event - include guards - push back pd constants into pd code - Attempt to build Windows-AARCH64 - No invariants for sender_for_interpreter_frame - zero - Merge branch 'master' into 8352251 - ... and 11 more: https://git.openjdk.org/jdk/compare/97d2a379...0a78858d ------------- Changes: https://git.openjdk.org/jdk/pull/24296/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24296&range=17 Stats: 3482 lines in 85 files changed: 2164 ins; 965 del; 353 mod Patch: https://git.openjdk.org/jdk/pull/24296.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/24296/head:pull/24296 PR: https://git.openjdk.org/jdk/pull/24296