This reverts commit 6cb6d5abc3.
This reverts commit 1484b786ae.
I think we don't need these assertions anymore. I believe the problem
is solved by abf678a439
We are seeing an error where code that is generated with MJIT contains
references to objects that have been moved. I believe this is due to a
race condition in the compaction function.
`gc_compact` has two steps:
1. Run a full GC to pin objects
2. Compact / update references
Step one is executed with `garbage_collect`. `garbage_collect` calls
`gc_enter` / `gc_exit`, these functions acquire a JIT lock and release a
JIT lock. So a lock is held for the duration of step 1.
Step two is executed by `gc_compact_after_gc`. It also holds a JIT
lock.
I believe the problem is that the JIT is free to execute between step 1
and step 2. It copies call cache values, but doesn't pin them when it
copies them. So the compactor thinks it's OK to move the call cache
even though it is not safe.
We need to hold a lock for the duration of `garbage_collect` *and*
`gc_compact_after_gc`. This patch introduces a lock level which
increments and decrements. The compaction function can increment and
decrement the lock level and prevent MJIT from executing during both
steps.
Accessing a shareable object is prohibitted because it can cause
race condition, but if the shareable object is frozen, there is no
problem to access ivars.
rb_ractor_belonging() returns 0 only if it has sharable flag.
rb_ractor_confirm_belonging() checks rb_ractor_shareable_p()
if the belonging ractor id is different from current ractor id.
20201021T123003Z.log.html.gz
```
/home/chkbuild/chkbuild/tmp/build/20201021T123003Z/ruby/test/json/json_parser_test.rb:227: warning: ambiguous first argument; put parentheses or a space even after `-' operator
/home/chkbuild/chkbuild/tmp/build/20201021T123003Z/ruby/test/json/json_parser_test.rb:228: warning: ambiguous first argument; put parentheses or a space even after `-' operator
```
rb_objspace_reachable_objects_from(obj) is used to traverse all
reachable objects from obj. This function modify objspace but it
is not ractor-safe (thread-safe). This patch fix the problem.
Strategy:
(1) call GC mark process during_gc
(2) call Ractor-local custom mark func when !during_gc
