Introduce Ractor mechanism for parallel execution

This commit introduces Ractor mechanism to run Ruby program in
parallel. See doc/ractor.md for more details about Ractor.
See ticket [Feature #17100] to see the implementation details
and discussions.

[Feature #17100]

This commit does not complete the implementation. You can find
many bugs on using Ractor. Also the specification will be changed
so that this feature is experimental. You will see a warning when
you make the first Ractor with `Ractor.new`.

I hope this feature can help programmers from thread-safety issues.

1 files changed, 2 insertions, 2 deletions

diff --git a/signal.c b/signal.c
index 615ceb7c6e..08de1bccdb 100644
--- a/signal.c
+++ b/signal.c
@@ -448,7 +448,7 @@ rb_f_kill(int argc, const VALUE *argv)
 	}
     }
     else {
-	const rb_pid_t self = (GET_THREAD() == GET_VM()->main_thread) ? getpid() : -1;
+	const rb_pid_t self = (GET_THREAD() == GET_VM()->ractor.main_thread) ? getpid() : -1;
 	int wakeup = 0;
 
 	for (i=1; i<argc; i++) {
@@ -495,7 +495,7 @@ rb_f_kill(int argc, const VALUE *argv)
 	    }
 	}
 	if (wakeup) {
-	    rb_threadptr_check_signal(GET_VM()->main_thread);
+	    rb_threadptr_check_signal(GET_VM()->ractor.main_thread);
 	}
     }
     rb_thread_execute_interrupts(rb_thread_current());