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, 6 insertions, 5 deletions

diff --git a/thread_sync.c b/thread_sync.c
index 3b8c5364a9..deb3858c31 100644
--- a/thread_sync.c
+++ b/thread_sync.c
@@ -264,13 +264,13 @@ do_mutex_lock(VALUE self, int interruptible_p)
 
 	    th->status = THREAD_STOPPED_FOREVER;
 	    th->locking_mutex = self;
-	    th->vm->sleeper++;
+            rb_ractor_sleeper_threads_inc(th->ractor);
 	    /*
 	     * Carefully! while some contended threads are in native_sleep(),
-	     * vm->sleeper is unstable value. we have to avoid both deadlock
+	     * ractor->sleeper is unstable value. we have to avoid both deadlock
 	     * and busy loop.
 	     */
-	    if ((vm_living_thread_num(th->vm) == th->vm->sleeper) &&
+	    if ((rb_ractor_living_thread_num(th->ractor) == rb_ractor_sleeper_thread_num(th->ractor)) &&
 		!patrol_thread) {
 		timeout = &rel;
 		patrol_thread = th;
@@ -289,17 +289,18 @@ do_mutex_lock(VALUE self, int interruptible_p)
 
 	    th->locking_mutex = Qfalse;
 	    if (mutex->th && timeout && !RUBY_VM_INTERRUPTED(th->ec)) {
-		rb_check_deadlock(th->vm);
+		rb_check_deadlock(th->ractor);
 	    }
 	    if (th->status == THREAD_STOPPED_FOREVER) {
 		th->status = prev_status;
 	    }
-	    th->vm->sleeper--;
+            rb_ractor_sleeper_threads_dec(th->ractor);
 
             if (interruptible_p) {
                 /* release mutex before checking for interrupts...as interrupt checking
                  * code might call rb_raise() */
                 if (mutex->th == th) mutex->th = 0;
+
                 RUBY_VM_CHECK_INTS_BLOCKING(th->ec); /* may release mutex */
                 if (!mutex->th) {
                     mutex->th = th;