[crac] RFR: Extract crac functionality into OS-agnostic files [v8]

[Anton Kozlov]

On Mon, 3 Jul 2023 15:34:49 GMT, Roman Marchenko <rmarchenko at openjdk.org> wrote:

>> CRaC-related functionality is moved to `crac*.hpp/cpp` files, and now it is in `crac` class instead of `os`.
>
> Roman Marchenko has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 10 commits:
> 
>  - Merge branch 'master' into crac-extract
>  - Merge branch 'openjdk:crac' into crac-extract
>  - Merge pull request #1 from jankratochvil/crac-extract-jan
>    
>    Fix compilation errors:
>  - Fix compilation errors:
>    
>    commit 5d2fe3461534d56b0408788c8d7c1b94f85530c0
>    ../../src/hotspot/share/runtime/arguments.cpp: In static member function 'static jint Arguments::finalize_vm_init_args(bool)':
>    ../../src/hotspot/share/runtime/arguments.cpp:3235:28: error: 'crac' has not been declared
>     3235 |   if (CRaCCheckpointTo && !crac::prepare_checkpoint()) {
>          |                            ^~~~
>    
>    ../../src/hotspot/share/prims/jvm.cpp: In function '_jobjectArray* JVM_Checkpoint(JNIEnv*, jarray, jobjectArray, jboolean, jlong)':
>    ../../src/hotspot/share/prims/jvm.cpp:3853:16: error: 'crac' has not been declared
>     3853 |   Handle ret = crac::checkpoint(fd_arr, obj_arr, dry_run, jcmd_stream, CHECK_NULL);
>          |                ^~~~
>    ../../src/hotspot/share/services/management.cpp: In function 'jlong get_long_attribute(jmmLongAttribute)':
>    ../../src/hotspot/share/services/management.cpp:957:12: error: 'crac' has not been declared
>      957 |     return crac::restore_start_time();
>          |            ^~~~
>    ../../src/hotspot/share/services/management.cpp:961:21: error: 'crac' has not been declared
>      961 |       jlong ticks = crac::uptime_since_restore();
>          |                     ^~~~
>    
>    Remove a no longer used declaration of os::Linux::checkpoint_restore().
>  - Merge branch 'crac' into crac-extract
>  - Merge branch 'crac' into crac-extract
>  - Merge branch 'crac' into crac-extract
>  - Getting rid of crac::Linux
>  - Removing trailing spaces
>  - Refactoring - extracted crac* files

Thank you! LGTM

-------------

PR Comment: https://git.openjdk.org/crac/pull/84#issuecomment-1618915100